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Acura RL

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Comments

  • chillenhondachillenhonda Member Posts: 105
    Before we write off the RL's engine and transmissions as lackluster, lets a) remember that the 2.4 in the Accord/TSX has an amazingly broad torque curve and its 5-speed auto is one of the best around and b) lets drive it and then discuss our opinions of its performance.
  • legendmanlegendman Member Posts: 362
    >What, may I ask, is your source?<

    Shotgun:

    I read a lot of coverage on the car last night from a great many sites. As I recall, the info on the powertrain warrantly was included in a long list of the cars features and specs. It appeared to come straight from an Acura source, but frankly, because I looked at so many sites, I don't remember which.

    If I have time I will try to research that and if I find it again I will cut and paste the info along with the name and URL of the source.
  • saugataksaugatak Member Posts: 488
    Does it really matter whether the initial torque split is 10-90 (FWD:RWD) or 50-50?

    With SH-AWD, it can be changed up to 40-60 (FWD to RWD) as conditions require. The 40-60 is based off of rumors and speculations listed on various sites, the links to which I can't find right now.

    Also, the latest rumors on the RL's 3.5L engine posted on another site which I can't link to due to Edmunds rules (but the site's name is based off of Honda's VTEC technology) has the following stats on the RL's engine:

    The (speculated) dimensions and specs listed are as follows*:
    Length: 196.5 in. (193.5 in.)
    Width: 72.8 in. (72.6 in.)
    Height: 57.0 in. (57.1 in.)
    Wheelbase: 114.3 in. (110.2 in.)
    Weight: 3,748
    Engine (mentioned above): J35A S-VTEC
    Displacement: 3.5L
    Horsepower: 280 @6200 rpm, 300 (for North America)
    Torque: 260lb-ft @ 5000 rpm

    Max HP and torque are at quite high rpms, not really usable.
  • ranaldranald Member Posts: 147
    Acura's own SH-AWD video says that torque can be varied from 30-70 to 70-30 F-R, with the additional noteworthy feature that the rear axle torque can be split up to 0-100 from right to left depending on conditions.
  • pellucidpellucid Member Posts: 5
    Perfervid Knights of the Road feverishly waiting for Acura's first kiss; like a teen trip to "first base!' Yea, size does matter! How we do speculate without the barest, authenticated shred of evidence. How we tease ourselves with visions of lb.-feet, weight distribution and 0-60 numbers, fearful of that tenth of a second indictment should the RL shamble through at 6.1!!
    Is my body temperature more normal at 98.6 than at 98.7? Do we toss our cars around with greater aplomb UNDER 6 seconds in arriving breathlessly at 60mph? In fact, how many of us, and how often have we sedulously timed our takeoffs after a week or two of ownership? Show of hands, please...
    As I type this, what do I want more: the new RL, or the brochure?? The brochure just skipped in at 5.5!! We articulate our impatience with such power, such importuning, hoping for saintly intercession. Why is Mother Acura smothering us with her unabated silence? Our beaks are open wide, awaiting the barest crumb to give us the strength to journey to the showrooms.Are our lives so barren that we have shed our pride and self respect waiting for that First Drive like expectant grooms?
    Do not elevate yourselves to anger; I mock myself as well as thee!! Let's continue our speculating, CON BRIO!!
  • shotgunshotgun Member Posts: 184
    Pellucid - After reading your post, I've concluded, that I have less than a firm grip on reality! The fever of "RL" anticipation has totally consumed me! Therefore, I am, sir, a very sick man...have mercy!
  • cericceric Member Posts: 1,092
    This would be an interesting development. No sure how the reporter got the information from. Hopefully, not from internet.

    To me, saving gas is just icing on the cake. The electric motor would act like a supercharger. This would surely compensate the lack of torque from 3.5L (around 265ft-lb) and add extra hp to the 300hp engine.

    http://www.floridatoday.com/!NEWSROOM/moneystoryB0620HYBRIDS0.htm

    excerpt:>>
    Expected out this year are hybrid versions of the Chevrolet Silverado, Dodge Ram, Ford Escape, GMC Sierra and Toyota Highlander. Next year come the Acura RL, Honda Odyssey, Honda Pilot and Nissan Altima.
  • lexusguylexusguy Member Posts: 6,419
    GM's system in its full size trucks where it will debut is thus far very unimpressive. They are saying something like a 10% improvement, which is most likely best case scenario. When you get 13mpg, now you'll get possibly as much as 15mpg! Big deal. Toyota stands to make the most gain. Ford bought theirs from Toyota, as did Nissan, so they've got that, not to mention their own hybrids.
  • markcincinnatimarkcincinnati Member Posts: 5,343
    The suspected split is (f/r) 90/10. The ability to shift torque where it is needed most and presumably "instantaneously" would seem to mitigate the naysayers [arguments] who claim that any split other than a rear wheel drive bias makes the offending vehicle merely a "poser."

    But it doesn't. The "best" of "all" worlds AWD is apparently (or would be) in the RL (for example) if it came to market with nearly neutral or neutral weight distribution and rear biased SH AWD. The arguments (most of them "having merit") can be found all over the Internet (some of them here in other town hall communities).

    Moreover, in the "perception" is reality sweepstakes in which we all are always entered, even if the differences lacked the requisite technical verisimilitude to "prove" the superiority of RWD biased AWD, it would hardly matter.

    You see, the public, the better informed public -- growing in size as every second ticks off -- is coming to believe [accurately] that AWD is superior generally to all other forms of putting power to the road (and, moreover, is part of the expectation for one to be playing in the Premium [and growingly, Performance] Class automotive market.)

    Additionally and simultaneously, for the minority (currently) percentage of those educated/informed/smart consumers in this category who further differentiate between front and rear-biased AWD, the perception is that rear-biased AWD is the "superior" or preferred version of AWD.

    Even, to repeat, if this perception was unreliable (and there is no evidence, that I can find that it is not) the fact that "perception is [usually] reality" is sufficient argument to justify the move from FWD to RWD to AWD to Rear-biased AWD starting first (as it already has) in the Premium (or Luxury or Performance, choose your poison) Class and then as things always go percolating DOWN through the lesser automotive classes.

    Just watch what happens the next 18 - 36 months. If I'm wrong, it will most likely be a timing issue rather than an "in the spirit" issue. SH AWD, IMHO, has "bought" Acura some time to move the bias of their interpretation of AWD rearward, just as 300HP in a 6 cylinder engine has mitigated the "gotta have a V8" crowd -- at least for a little while.

    My feelings, not facts, are "who cares?" how the power is made just so long as it IS made. I could be wrong, however; and, frequently I am. And, my feelings pertaining to torque split are that the weight balance is perhaps the most relevant of the two (torque split vs balance) "laws of physics" issues. But when so much critical ink will be expended on the subject of "f" vs "r" awd bias, well "prudence" dicates it is easier and more profitable to switch than fight (if history is any clue whatsoever.)
  • saugataksaugatak Member Posts: 488
    The various half cylinder shutoff systems (such as GM's DoD, Honda's VCM and Chrysler's MDS) work better with larger displacement, more powerful engines.

    The secret to fuel savings is simple: get into half-cylinder shutoff mode as frequently as possible. A weak engine is not going to go into half-cylinder shutoff mode very often. A powerful engine, OTOH, will go into half-cylinder shutoff mode more frequently.

    There are reports that Chrysler's 300C, despite being around 4,000 pounds, gets 35mpg on the highway with the MDS. GM is reporting 20% highway mileage improvements with its DoD systems.

    In stop-and-go city driving, DoD systems are not going to help much since you need all of an engine's power to get a car rolling from a dead stop.

    The nice thing about DoD is that it doesn't compromise power to achieve improved mileage. The power is there when you need it and turned off if you don't. Also, there's no reason why DoD can't work in conjunction with IMA or supercharging or other means of boosting power/improving mileage.

    It's a very flexible solution. If as GM claims DoD enables one to have v8 power with v6 gas mileage, what's to complain about?
  • robertsmxrobertsmx Member Posts: 5,525
    SOHC versus DOHC is a matter of choice. DOHC offers more flexibility in terms of variable valve timing due to an additional pair of cams (a DOHC &#147;V&#148; uses four cams, compared to two in SOHC &#147;V&#148;). However, that also makes SOHC a smaller and lighter engine package.

    A typical SOHC layout is associated with either 2-valve per cylinder (BMW&#146;s V12 in last generation 7-series, and from Honda, the Civic Hybrid&#146;s 1.3-liter I-4), or 3-valve per cylinder (Mercedes). Honda has always used 4-valve/cylinder with SOHC layout for the V6, just like DOHC engines. The only six-cylinder engine from Honda that has 2-valve/cylinder is the 1.8-liter Flat-6 used in Honda Gold Wing/Valkyrie.

    In terms of output, the advantage of DOHC layout over SOHC is debatable. Honda could move to a 3.5-liter DOHC V6 for the RL, but given the way the &#147;J-series&#148; SOHC V6 engines perform with red line limited to 7000 rpm or less, it may not be necessary (Acura TL's 270 HP 3.2/V6 is a good example, as are the other variations). In the past, Honda has developed SOHC and DOHC versions of otherwise virtually identical engines, going with DOHC in high rpm applications.

    Regarding Dick Colliver&#146;s statement: "new and our most powerful engine yet", I see two things here. One, with 300 HP, the 3.5/V6 will exceed the highest (rated) power output offered in any production Honda/Acura (i.e. the 290 HP 3.2/V6 in NSX). And &#147;new&#148; could imply use of J-series V6 (could still be DOHC though) instead of C-series V6 that the current RL uses.
  • robertsmxrobertsmx Member Posts: 5,525
    Having seen the numbers from you that match my guesstimate, I assume your concern regarding RL&#146;s torque numbers being a pie in the sky (or not) has been addressed. My guesstimate is based on assumption that RL will use 3.5-liter version of the V6 used in TL.

    Going beyond the peak numbers, let us analyze the 3.5/V6 used in MDX using the official dynograph.

    In Japan, the engine is rated at 260 PS @ 5800 rpm / 345 Nm (about 255 lb.-ft) @ 3500 to 5000 rpm. North American version got a boost in peak power output to 265 HP for 2004 (but the Japanese version has stayed put to 2003 level).

    At about 1200 rpm, the engine is producing 300 Nm (87% of the peak torque). Between 2000 rpm and 5800 rpm, the engine&#146;s torque output varies about 5-8% with near flat (peak) torque output from 3500 rpm to 5000 rpm. This is a classic example of a Flat AND Broad torque curve, and out to prove it doesn&#146;t matter where the engine produces peak torque, because it is more about &#147;a range&#148;.

    At 10.0:1, the 3.5/V6 in MDX is far from being a &#147;very high compression&#148; engine. In fact, the compression ratio is identical to the 3.5/V6 used in Odyssey & Pilot. For RL, I suspect, the compression will be as high, if not higher, than in the TL (about 11.0:1). This will help boost the output beyond the MDX-levels.

    There are three stages in the output from MDX&#146;s 3.5/V6. The first is the usual tuning, to maximize low-end torque output, the second stage gets a boost from the variable intake manifold, and finally, the third stage gets a boost from VTEC. This is not unlike the 260 HP/3.2-liter V6 we saw in last generation Acura TL (and CL) Type-S. The TL-S engine was rated at 260 HP at 6100 rpm, and 232 lb.-ft at 3500 rpm to 5500 rpm.

    In the end, I suspect Acura RL&#146;s 3.5/V6 to deliver 235-240 lb.-ft at an engine speed, as low as 2000 rpm, and continue to develop within 5-8% of the peak torque between 2000 and 6500 rpm.
  • markcincinnatimarkcincinnati Member Posts: 5,343
    If you are correct, and I hope you are, the need for a V8 will be even further reduced, IMHO.
  • robertsmxrobertsmx Member Posts: 5,525
    To improve its acceleration, assuming my guess that the torque ratings will be "OK" or "good" but not "oh wow, impressive," Acura may have elected to lower the final drive ratio and made 5th gear a bit taller "overdrive" (in an effort to raise its combined MPG). A six speed transmission with both 5th and 6th being overdriven, but 5th only mildly so, would somewhat counter and "mask" the hunting that could have been engineered in if such an approach is actually taken.

    Acura went 5-speed auto with 2000 TL (1999 TL had 4-speed, which was the norm back then), and something I noticed didn&#146;t sit well with me and that had to do with the added weight. The new TL gained about 50 lb.

    I can still see some improvement of going up from 4 to 5 speeds, especially given that the gear ratio spread (between first and final gear ratios) is virtually unchanged meaning the addition gear actually helped close down the spacing. But if every cog ends up adding 50 lb. with diminishing returns, I don&#146;t know if I would like the idea of going to six or seven speeds. Why not just go CVT instead and for those who care, use a preset 7-speed ratios from it?

    In Acura/Honda 5-sp auto, the transition from cruising in the tall overdrive mode to acceleration mode forces an upshift from fifth to third. If it were a six speed auto, &#147;sixth&#148; could replace &#147;fifth&#148; and &#147;fourth&#148; could replace &#147;third&#148;. But since the gearing is going to be closer, there will be times when an additional shift will occur during acceleration.

    So, pros and cons of 5-sp versus 6-sp versus 7-sp is very debatable. It is probably more about academics than practicality.

    As far as RL is concerned, Acura will probably stick with the existing 5-speed gear ratios. In the first, RL will likely carry an overall drive ratio of 11.35-11.55:1 (like it does in TL and MDX). The net thrust at the wheels will likely stay the same because although the car gains in torque by about 10% (compared to TL) it will also gain weight by about 10% (compared to TL). The maximum thrust in RL in first gear is likely to be about 0.60-0.62g, which is quite good. So, it is not going to feel like a muscle car off the line.

    Somewhere I have read (a long time ago) that in a front driver, 0.60g can be considered a limit for traction purposes (both, Accord V6 6-speed Manual and TL 6-speed manual exceed that). With AWD, in RL, &#147;launch traction&#148; is unlikely to be an issue. And then, AWD will be engaged everytime the throttle is depressed the way it works in MDX&#146;s VTM-4 system (somewhere between 30-70% of the torque may be routed to the rear wheels).
  • robertsmxrobertsmx Member Posts: 5,525
    I think the &#147;need a V8&#148; argument will be handled by Honda in its own way, and using a hybrid. If observations are true, with V8 available as an option, the eight banger woos few buyers compared to its six-cylinder counterpart. This gives little incentive to develop a V8 unless it is to be shared with some other vehicles in the lineup.

    This is purely a guess, but a V8 option typically adds a premium of about $4-5K. That&#146;s enough for reasonably powerful and advanced hybrid system. So, with a base engine that can share bits and pieces with others, and a hybrid system that can be shared as well, it makes sense to go the hybrid way.

    The 3.5/V6 in the new RL could simply be the J35A tweaked for 300 HP (tweaks similar to those in TL&#146;s 3.2/V6 will help accomplish that). Or, it could be an all-new 3.5-liter DOHC I-VTEC V6, something Honda showcased three years ago (2001 Honda Dual Note). The Dual Note&#146;s 3.5/V6 was also rated at 300 HP.

    Both engines are compatible with Honda&#146;s IMA (knowing that Honda Accord&#146;s J30A is being mated to IMA for launch this Fall, unless it happens to be an &#147;all-new&#148; engine as well which I doubt given the development efforts on J30A in Japanese market).

    A &#147;twice as powerful&#148; version of the ultra-thin brushless DC motor used in Civic Hybrid could add 70-80 lb.-ft at low-low engine speeds, more than compensating for the low end torque that would come from a 4.0-4.5 liter V8 when compared to a 3.5- liter V6. Even if there is no gain in the top end, if the peak torque hovers around 310-325 lb.-ft @ 2000 rpm, it is sure to make a &#147;must have V8&#148; argument moot (this is not to say that it won&#146;t be brought up).
  • markcincinnatimarkcincinnati Member Posts: 5,343
    The 6 speed tiptronic, steptronic, positronic, or whatever the big three German manufacturers call it, weighed in at 44 pounds less than the outgoing 5 speed tiptronic. The supposed benefit to the 6speed was to keep the engine in the torque sweet spot mostly during gears 1 - 5 with 6th being more overdriven.

    BMW's 7 speed and Audis Multitronic both offer some interesting aruments to the "how many speeds are enough" debate.

    I am not as concerned, now, about the 3.5L in the new RL based on the recent posts pertaining to torque. 5spds will be fine, 6spds will be eventually required for marketing purposes (not that six speeds will be limited to marketing purposes, however).
  • robertsmxrobertsmx Member Posts: 5,525
    It is possible that the old trannies were quite heavy compared to the new to start with. So, weight gain or loss is still debatable compared to perceived (or real) benefits.

    I have participated in some debates that pertain to counts, albeit not just when it comes to cylinders (and in this case, cogs), but also number of valves...

    5-valve per cylinder layout that Audi/VW (and Ferrari) seem to prefer over the usual 4-valve per cylinder.

    Advantage to having 5 versus 4 has been very debatable.
  • steveaccordsteveaccord Member Posts: 108
    As always an excellent contribution. I look at all the numbers and try to interpret them and yet right now I long to drive this car more than anything else.

    Perhaps it is because yesterday I drove back and forth to Indianapolis to see the US GP race and I enjoyed enormously my Accord EX-L. It was the first 'long haul' trip I took in it (~185 miles) along with a couple of friends.
    Not only keeping it at avertage of 75-80 mph was a breeze (and kept us below 3 hrs, including stops, to reach destination) but it was delightfully responsive when I had to overtake at 90-100 mph.
    Indeed the car behaviour was such that my passenger in the back (owner of a >200 HP FWD american vehicle equipped with a V6) kept commenting that the car behaved as it was powered by a V6 (and this even after I told him that indeed it was a lowly I-4 engine that was carrying us around).

    So I guess my point is that for as much we love to see 'nice numbers' I still believe that nothing can 'do justice' to how a vevhicle really drives. I guess is another facet of the same recurring topic of 'how great' european RWD cars feel when you are behind their steering wheel.

    Anyway to add to the pleasant experience the car consumed far less than the stated 28 mpg (~31 mpg) and with few exceptions road noise was limited such that we could enjoy my CD mixes with volume set at 13 (those who have the new digital panels know this is in the level kept for city driving).

    Now if I can get so much from the Accord I do not see how the RL is going to fail to be a pleaser. I can understand that there are lots of very good cars out there but I feel that at the proposed price (and the present day knowledge of tech spec) this Car is going to 'kick butts'.

    Just my thougths, kudos to whoever will think differently and buy something else!!
  • steveaccordsteveaccord Member Posts: 108
    By the way as soon as I will download pictures from yesterda I'll see if I can post some here. It was a great present for father's day to have a podium with 2 Ferrrari and Honda on it. I plan to go there again next year so let me hear from you if you are interested!
  • lexusguylexusguy Member Posts: 6,419
    I have heard that Mercedes is retiring its 3 valve SOHC design. Is this true?
  • robertsmxrobertsmx Member Posts: 5,525
    Seeing that 2005 C-Class will have the C55 AMG in its lineup, I doubt the 3-valve SOHC layout is being retired anytime soon. The C55 will use 5.5 liter 24-valve SOHC V8.
  • markcincinnatimarkcincinnati Member Posts: 5,343
    The "new" Hemi from Chryco has 2 valves per cylinder, Mercedes uses two spark plugs with three valves, the new FSI engines from Audi/VW are back to 4 valves, GM's northstar prefers the 4 valve layout, etc.

    I completely agree, the "proof" will be in the driving. I applaud the 300HP bragging rights w/aV6 approach, if for no other reason, for the potential for better fuel economy.

    As I said before, the "I shoulda had a V8" crowd will be mostly silent if whatever is under the bonnet performs at or above expectations and/or class standards.

    The new A6 has both a V6 and a V8 offered. The net dif is 1 second in the dash to 60 mph. The cost, attempting to equate like for like is over $5K more for the V8 plus a loss of miles per gallon.

    Here in this "big town" of Cincinnati, the ability to regularly and frequently use the extra grunt isn't "worth" the premium in price and longer term fuel upcharge.

    Now, this is not to say that if the price differential were much closer, that I wouldn't at least consider the V8.

    Unless Acrua really "blows it" with the performance (that the automags will harp on) figures with the 3.5, I think, to repeat, they have chosen wisely.
  • shotgunshotgun Member Posts: 184
    Yes, Honda will handle the V8 argument in it's own way by not offering one until it goes in the "real truck" business! For what it's worth, and listening to Dick Colliver, I got the impression, and don't ask me why, other than the emphasis he put on the word "new", it somehow implied to me that he was alluding to a "new" not "recycled" 3.5-liter DOHC I-VTEC V6.
  • ksomanksoman Member Posts: 683
    hmmm, which brings us to why in hell is CVT bad then?
  • steveaccordsteveaccord Member Posts: 108
    In my 2 item list of desirable features to be suggested to Acura's president I listed the "integration' of iPod in the RL stereo system.
    I had the queue from an article suggesting collaboration between Apple Computers Inc. and undisclosed car manufacturers. Well it turns out that BMW will be the first to score in that departement. The glove box installed 'craddle' will be operated via the sterring wheel commands! It will also be made available for Mini (& Roll Royce?) models.

    I still wish Acura will follow!!
  • markcincinnatimarkcincinnati Member Posts: 5,343
    I, for one, don't think CVT is a bad thing. Audi has been unable to offer if for sale in its quattro cars (although they promise it "soon") and it apparently isn't ready for the higher torque of the V8 engine either.

    Other than that, I found the CVT that I have driven as a loaner to be almost eerily smooth and able to accelerate briskly.
  • saugataksaugatak Member Posts: 488
    Having seen the numbers from you that match my guesstimate, I assume your concern regarding RL&#146;s torque numbers being a pie in the sky (or not) has been addressed. My guesstimate is based on assumption that RL will use 3.5-liter version of the V6 used in TL.

    They weren't MY numbers. I was posting numbers from another site, which is also pure speculation.

    We'll see which 3.5L version they use but I don't think they can use the TL's 3.2L v6 and bore it out even more. The TL's 3.2L v6 is itself a bored out version of the Accord 3.0L v6. Getting an extra .3L of displacement out of an already bored out block sounds unrealistic to me.

    My guess is that the RL engine will be based off the MDX's 3.5L v6. Despite your statement that you think the RL's engine will be based off the TL's engine, you draw your numbers from the MDX's 3.5L v6, so I'm not sure what you think.

    North American version got a boost in peak power output to 265 HP for 2004 (but the Japanese version has stayed put to 2003 level).

    I don't think the North American version of the engine changed from 2003 to 2004. I had read that Acura placed a dual exhaust system in the 2004 MDX (2003 MDX had single exhaust system) to get the extra 5HP. Maybe you know more about this.

    At 10.0:1, the 3.5/V6 in MDX is far from being a &#147;very high compression&#148; engine. In fact, the compression ratio is identical to the 3.5/V6 used in Odyssey & Pilot. For RL, I suspect, the compression will be as high, if not higher, than in the TL (about 11.0:1). This will help boost the output beyond the MDX-levels.

    The 2003 TL type-S 3.2L SOHC v6 produced 260HP with a compression ratio of 10.5:1. By raising the compression ratio by 0.5 to 11:1, Honda squeezed out an extra 10 HP for the 2004 TL so that it got 270HP.

    To get the MDX 3.5L engine from 265HP to 300HP by raising the compression ratio, Honda would have to get a compression rato of 13.5:1 (assuming about 10HP per each 0.5 increase in compression ratio).

    I just don't see how Honda could do that. The 3.2L I6 in the BMW M3 has a compression ratio of 11.5:1 and that is VERY high, so high in fact that the M3 engine has had reliability issues because that kind of pressure puts a lot of stress on the internals of an engine.

    I'm curious to see the final details on this engine. Frankly, I don't see an easy way for Honda to get to 300HP out of either the 3.2L v6 in the TL or the 3.5L v6 in the MDX. Honda will have to do more than just raise the compression ratio or bore out the blocks.
  • merc1merc1 Member Posts: 6,081
    Actually the SOHC 3-valve Mercedes engines are on their way out. The new generation DOHC 32v V8 doesn't arrive until the next generation C-Class, due out in 2007. The CLS, E, SL, next S/CL and CLK will all get new DOHC 32v V8s for either 2006 or 2007.

    M
  • saugataksaugatak Member Posts: 488
    Robertsmx, post #1416 was excellent.

    Merc, you got details on the new DOHC 4 valves per cylinder MB engines?

    I always admired MB's creativity for going against the flow and coming up with SOHC 3 valve per cylinder dual spark plug v6's and v8's. I'd love to see if MB has come up with another twist or if they're just going to play the same DOHC game as everyone else.
  • merc1merc1 Member Posts: 6,081
    Well I'm afraid they're going to play basically the same DOHC game as everyone else. You can checkout germancarfans.com under the Mercedes news archive for the details. There are few new tricks like direct-injection (for a gas V6), but they're playing it safe with these engines by incorporating things they've done before (pre-1998) and some newer things others have done since.

    M
  • lexusguylexusguy Member Posts: 6,419
    There's no reason Honda couldn't further enlarge their 3.2L V6. Nissan has pushed its 3.5L VQ to 4.0L for the upcoming North American built Pathfinder (in order for it to deliver 280+ lb.ft of torque). I dont see why Honda couldnt throw on another .3L.
  • saugataksaugatak Member Posts: 488
    We'll have to see. At some point you can't bore out the block any more. You have to build a new and bigger block. I don't know whether Honda has reached that point yet with the 3.2L v6 block.

    I'm eager to see how Honda does it b/c as long as the engine isn't too peaky, 300HP out of a 3.5L v6 is pretty impressive.
  • sirdarbysirdarby Member Posts: 20
    I too am considering a 99 RL. This one is listed for $15,995 from a private owner. It has heated seats and nav. White with grey leather in pretty good condition. The transmission fluid was clear but a little low. Otherwise it drove fine.

    The owner lost his job and wants a quick sale.

    It was a certified car when he bought it and has the remaining warranty on the Powertrain and engine till 100K miles. It currently has 75K miles. Is this a good deal?

    I noticed some rust around the silver back windshield trim; under the hood, some of the bolts had a little rust or corrosion. Looked as if someone up north or near the ocean had it before he got it. Other than a good cleaning, I don't see many problems. We live in the South so winters or water is not a problem.

    What do you guys advise other than the obvious -- getting it checked out etc. Is the price good. I know they will be falling with new body style coming out soon.
  • markcincinnatimarkcincinnati Member Posts: 5,343
    . . .present were 97 cars with VW/Audi 1.8T engines, several were "tuned" to 350HP and very high torque at relatively low rpm.

    These mods to a basic 225HP engine all seemed to be concentrated on breathing modifications (and, remember, they were all turbo charged.)

    Getting a 3.5L V6 to 300HP should NOT involve herculean efforts or Einstein's intellect. Not that this much HP is not impressive (it is).

    And if torque is as the posters are honing in on, well, that bodes well too. There are several, perhaps "many" engineering solutions to the "how did they get 300HP from the 3.5L engine?" riddle.

    I have not, yet, bothered to search the web for possible Acura/Honda approaches, but perhaps someone here has.

    So, how are they doing the HP without forced induction (which would be about the easiest method)? Anyone? Anyone?

    I assume it is not "the Acura way," but imagine what two very small, very light turbos could do for this engine?
  • robertsmxrobertsmx Member Posts: 5,525
    With the exception of NSX and current RL, Honda is using a single family of V6 engines (J-series), and the basic version is the 3.0/V6 in Accord (the J30A).

    The J30A is a square engine (bore: 86 mm, stroke: 86 mm). To develop J32A (3.2/V6 in TL), the bore was increased to 89 mm while the stroke stayed at 86 mm. So, J32A is an undersquare engine. To develop J35A, the bore was increased to 89 mm (same as J32A) and the stroke was increased to 93 mm, making it an oversquare engine.

    The J-series engines are technically similar except in terms of tuning and displacement. There was a fourth displacement for the Japanese market until last year (the J25A) that had replaced the old 2.5-liter Inline-5 in 1999.

    Regarding the 5 HP bump in MDX, the point wasn&#146;t important, only to reduce confusion that might arise from looking at the dyno (from Japanese website) which still has 260 HP version compared to 265 HP in the MDX. I&#146;ve not looked into how the output was increased.

    J35A is also the perfect example to illustrate that output isn&#146;t necessarily dependent only on compression. There are more ways to getting it done. Odyssey & Pilot have the 3.5/V6 rated at 240 HP, and while using same compression (10.0:1), the version in MDX is rated at 265 HP. That&#146;s using simple tweaks to the intake and the valve heads.

    Honda has done this quite often, offering several outputs from tweaking the same engine block in a variety of ways. Another is the J30A. There are two variations of the 3.0/V6 in Japan, both running 11.0:1 compression. In this case, the peak power rating is identical (250 HP @ 6000 rpm), but one of the two engines develops peak torque of 228 lb.-ft (Elysion) compared to 218 lb.-ft (Inspire) in the other.

    I'm eager to see how Honda does it b/c as long as the engine isn't too peaky, 300HP out of a 3.5L v6 is pretty impressive.

    Aah, the benefits of variable valve timing & lift, and multi-stage intake! I&#146;ve observed Honda engines enough to bet that it will deliver more than 90% of its peak torque from about 2000 rpm.
  • robertsmxrobertsmx Member Posts: 5,525
    A 5 psi supercharger could push the peak output to 400 HP/350 lb.-ft.

    Honda does use turbo-charging in production engines (couple of &#147;minis&#148; in Japanese market), and one of its watercrafts. Rumor/news item from a European magazine (who apparently drove the HSC) suggested that the car had a variable-vane turbo set up. Of course, the diesel engine uses a turbo charger.
  • varmintvarmint Member Posts: 6,326
    Geez, I go away for one weekend and come back to 113 unread posts! =)

    I'm more familiar with Honda's smaller engines (like the K24 and K20), but the speculation posted by Robertsmx isn't what I'd call far-fetched. 300 hp without going north of 7,000 rpms is very "doable". So does a reasonable amount of torque in the low end. It won't match the V8s of the class, but it shouldn't be required to if priced below $50K. At that price point, the competition is saddled with V6s offering fewer ponies and about the same torque.

    Just to add to the already voluminous conversation... The original 240 hp MDX engine was rated for something like 95% of peak torque from 2,000 through 5,500 rpms. When they tweaked the engine for higher hp output, the peak went up, but the curve changed very little. Technically, the curve did change and they could no longer make the same percentage claims. However, you need to have an extremely well-calibrated bum dynometer to feel the difference in thrust.

    Another example... There are three versions of the K24 sold in the US. The first was used in the CR-V, the second in the Accord and Element, and the third is in the Acura TSX. The same 4 cyl mill is used in each. They are just tuned differently using VTEC and compression variations.

    The Accord makes 161 lb-ft at 4,500 rpms, but only 160 hp. Conventional wisdom would suggest that making 200 hp using the same engine would require the torque peak to shift up higher on the rev band. It doesn't. The TSX makes 166 lb-ft at the same 4,500 rpms.

    The CR-V produces 162 lb-ft at a lower 3,600 rpms. Many people see the difference in rpms and assume that the CR-V has a stronger bottom end even though the peak output is slighter lower. That's not true, either. When you compare the dyno plots, the TSX's I4 is generating more thrust at 3,600 rpms. Of course the difference is negligible. If your bum-dyno is that sensitive, you must constantly be in danger of falling over as the Earth turns. =)

    Anyway, it would not surprise me to read that the RL's V6 produces 265 or 270 lb-ft of thrust at 4,500 rpms, or even 5,000 rpms. At the same time, it would not surprise me to read that 90% of that power is available by 2,000 rpms.
  • lexusguylexusguy Member Posts: 6,419
    BMW gets even more horsepower than the RL from a smaller displacement inline in their M3. Then of course there is the Porsche GT3 3.6L flat six, that makes 380 normally aspirated horsepower. It can definitely be done.
  • varmintvarmint Member Posts: 6,326
    There's a factory spec NSX in Japan that is offered exclusively for racing. IIRC, it puts out 350 hp in NA form.
  • habitat1habitat1 Member Posts: 4,282
    A 3.5 liter equivalent of the Honda S2000 engine (original 2.0 literversion) would produce 420 horsepower and about 275 ft lbs of torque. Not to mention a 9,000 rpm redline. Match that up with a short throw 6-speed and even I might turn in my TL 6-speed for an RL. It wouldn't be the quietest luxury sedan on the road, but it might be the most fun to drive.

    By the way, I'm not sure a 300 hp V6 is going to be all that fuel efficient. I am somewhat surprised that in 1,400 miles of moderately spirited driving, I've only averaged about 18 mpg in mixed driving with a 6-speed TL. That compares to about 23 with my Nissan Maxima and 22 with the S2000. My one long highway drive averaged about 28, but the mixed City / beltway driving isn't very impressive, at least not yet.
  • jeff88jeff88 Member Posts: 94
    Has been difficult to keep up...

    was reading about 300 posts ago about the octane discussion and maybe missed this but this is one thing I've noticed.

    When running premium gas, the shifts were smoother than running 87. It appeared to me that the retarding of the spark prior to shifting wasn't as well timed with 87 as it was with 93. Upon occasion, my wife would accidentally fill the rl with 87 when driving it since that is the grade for her ride. It was noticeable to me afterward.
    -----------------
    other comments were about the looks of the pre-'05 rl; I have always thought it to be a very pleasing look inside and out but then again, I'm biased.
    -----------------
    someone wrote that their I-4 in their accord felt to a passenger like a 6; my impala company car has a v6 that feels like a 4...

    ...or as a friend once said, it ain't the size of the boat, it's the motion of the ocean.

    Think he may have been describing something else.
  • saugataksaugatak Member Posts: 488
    J35A is also the perfect example to illustrate that output isn&#146;t necessarily dependent only on compression. There are more ways to getting it done. Odyssey & Pilot have the 3.5/V6 rated at 240 HP, and while using same compression (10.0:1), the version in MDX is rated at 265 HP. That&#146;s using simple tweaks to the intake and the valve heads.

    Are you sure this is the case? I've run my MDX on regular fuel and I can feel the loss of HP, might even be 20HP or so which would bring it down to the level of the Ody or Pilot.

    Is it possible that Honda used the EXACT same engine for the Ody, Pilot and MDX and just tweaked the software in the Ody and Pilot so that it could not take advantage of premium fuel? That would seem to be easier and cheaper than tweaking intake and valve heads.

    Aah, the benefits of variable valve timing & lift, and multi-stage intake! I&#146;ve observed Honda engines enough to bet that it will deliver more than 90% of its peak torque from about 2000 rpm.

    Honda's engines are impressive, but not in regards to developing low end torque.

    IMO, Nissan's engines alwasy felt way more torquey than Honda's engines.

    GM's LS1 develops abut 295 ft.lb. of torque (or about 80% of max torque) at about 800 rpm and hits 90% of peak torque below 2,000 rpm.

    http://www.gm.com/automotive/gmpowertrain/engines/gmpow/images/ls- - 1curve.jpg

    The Hemi produces 80% of peak output at around 1,200rpm and 90% of peak output at 2,000rpm. Here's a small and barely readable torque curve chart of the Hemi.

    http://www.popularhotrodding.com/tech/0403phr_hemi/

    GM's upcoming 3.9L OHV v6 (which also has VVT) produces peak 245 ft.lb. of torque at 2,800 rpm, so it's a safe bet that it'll produce more than 90% more torque at 2,000 rpm.
  • lexusguylexusguy Member Posts: 6,419
    Nobody is going to argue that OHVs dont make serious torque down low. They do. The problem with OHV (aside from its general low techness) is the sheer size it has to get to make competitive power to a SOHC or DOHC engine. The LS6 is pushing 6.0L. A 3.9L six that only makes 245ft.lb of torque is hardly what Id call efficient. I bet its hp figures cant match modern DOHC either. I seriously think the OHV 6 is on its death bed. How large would an OHV 6 have to be to match the horsepower of Acura or Nissan's 300hp 3.5L engines? 4.5L? 5.0L?
  • saugataksaugatak Member Posts: 488
    The point is that OHV engines are actually SMALLER than comparable OHC engines. Whereas OHC engines have cams sitting on top, the OHV engines have a "cam in block" architecture and so have one cam sitting within the valley of the V, which would otherwise be wasted space.

    DOHC V engines in particular are very large. Compare the size of 4 cams on top vs. 1 cam nestled in the V.

    While a 3.9L v6 sounds like a HUGE v6 engine, it's not. It fits in comfortably in the upcoming Pontiac G6 which is a FWD car.

    You're focused on specific output (HP/L of displacement) as a measure of efficiency. Another way to determine efficiency is HP/volume of engine size, and by that measure, OHV engines are just as, often more efficient than, comparable OHC engines.

    Another example is the 5.7L Hemi, which is a pushrod. It fits not only in trucks, but also in cars, because it's not a big engine for the amount of displacement it gets.
  • saugataksaugatak Member Posts: 488
    BMW gets even more horsepower than the RL from a smaller displacement inline in their M3.

    I've love to see a torque curve chart of BMW's inline 6's b/c when driving them, I always felt they had more low end power than any OHC v6's I've driven.

    Theoretically, a good inline 6 should have more HP and torque than a v6 b/c the I6 doesn't have a balancer shaft robbing it of power, whereas a v6 does.

    There are also reliability issues. While the M3 straight 6 produces gobs of torque and power, it's had some reliability issues.
  • lexusguylexusguy Member Posts: 6,419
    Well, to a certain extent that has to be expected, considering how hard BMW has pushed that engine in order to not have to resort to forced induction. Hat es einen Turbo? NEIN! sind wir BMW!
  • saugataksaugatak Member Posts: 488
    Aah, the benefits of variable valve timing & lift, and multi-stage intake! I&#146;ve observed Honda engines enough to bet that it will deliver more than 90% of its peak torque from about 2000 rpm.

    You mention VVT and multi-stage intake as 2 factors enhancing low end torque.

    I'm wondering how much VVT actually helps low-end torque? I always thought the extra valve lift was beneficial at higher rpms so that the engine could suck more air. I'm not sure how extra valve lift will help at lower rpms.

    For example, the Hemi and LS engines don't have VVT, but they do have multi-stage intake manifolds (pretty high tech for those low tech pushrods), and they're getting 90% peak torque at 2,000 rpm.

    GM's upcoming 3.9L OHV v6 adds VVT to a dual stage intake manifold and gets 90% of peak torque at 1,800 rpm. GM's engineers indicate that it's the dual stage manifold that is responsible for a broader torque curve.

    http://www.auto-report.net/index.html?gmpt05.html

    The variable intake manifold is a significant low-speed torque 'enhancer' for the 3900. It gives the 3900 a broader torque curve that retains higher specific torque output across the engine speed range.

    As far as I can see, multi-stage manifolds are mainly responsible for enabling engines, whether OHC or OHV, to hit 90% of peak torque at around 2,000 rpms.
  • saugataksaugatak Member Posts: 488
    Excellent post, as always.

    I read through your post carefully again and 3 things struck me right off the bat:

    1. How creative Honda engineers are in tweaking their I4 engines to achieve the desired HP and torque/powerband.

    2. No matter what the Honda engineers did to boost power, they're still limited to a max. torque of around 160 ft.lb.

    The 2.4L I4 Accord with a compression ratio of 9.7:1 gets 160HP and 161 ft.lb.@4,500 rpm, the 2.4L I4 TSX with a compression ratio of 10.5:1 gets 200HP and 166 ft.lb.@4,500rpm.

    So a 0.8 increase in compression ratio yielded a whopping 5 ft.lb. of extra torque. Wow.

    I guess if the RL takes the MDX engine and boosts compression ratio to 11.0:1 (which is the same compression ratio as the TL), it may get to 260 ft.lb. We'll have to see.

    3. We're making a big deal out of getting the torque curve as flat as possible and as low down the powerband as possible, saying things like "90% of peak torque available at 2,000 rpms." But still, 90% of 160 ft.lb. is only a measly 144 ft.lb. of torque.

    At some point, you have to bump up displacement to boost max torque. It looks like multi-stage manifolds help flatten out the torque curve and broaden the powerband, but there is still no replacement for displacement (except supercharging perhaps) when it comes to increasing torque and low end power.
  • ksomanksoman Member Posts: 683
    >>>
    3. We're making a big deal out of getting the torque curve as flat as possible and as low down the powerband as possible, saying things like "90% of peak torque available at 2,000 rpms." But still, 90% of 160 ft.lb. is only a measly 144 ft.lb. of torque
    <<<

    GEEZ mang! If 144 is measly, then basically 160 is measly too. On a comparitive basis, 90% is a lot and very close to 100%.

    The fundamental reason to try to bring the torque curve flat (oxymoron) is try to bring torque as lower in the rpm range as possible. For big bad engines, they have a huge torque advantage in the lower RPM range purely because of size, not because of brains.... whereas for the small engines, they have to be smarter. I think the whole purpose of raw torque against raw HP is because torque really is what helps you break the coefficient of resistance of the myriad things that are at rest when a vehicle is at rest. Once you start spinning, the use of torque starts to lessen (not eliminate, diminish). That is where high RPM & screaming engines come into play, basically the reason why the s2000 is not the fastest from the readlight, but when its spinning, it can whoop anybody's "ahem", rear! Also, on that logic, just getting more and more torque is not necessary.

    Lets say Engine A is pumping 400 lb-ft of torque max, at 4500 rpm, and 120 lb-ft at 2000 rpm
    Enginge B is pumping 250 lb-ft of torque max at 4200 rpm, and 180 lb-ft at 2000 rpm
    Obviously engine 2 is better in my dishonest opinion. It is more capable of breaking resistance and getting the fat pig rolling. As the car speeds up and the gearing controls where the car can keep in the powerband, you are good to go. If you still can't get your car moving fast, one of two is likely, you either are incapable of shifting your gears if its a manual or if it's an auto, the computer controlling the shift points was just designed by morons and that car company needs to shutter down yesterday!

    couple of comparitive notes:
    the starter motor on your car, its a DC motor, cuz it pumps loads of torque up front, right of the bat... that's to break the resistance of non-moving parts quickly.
    the huge electric locomotive engines, they use DC motors, not AC motors. DC motors have a huge torque advantage in the lower RPM, where as AC motors have better torque later in the RPM range. Considering how much mass the locomotive is pushing or pulling, and that too on smooth steel wheels on a smooth steel rail, you want the torque up front to overcome the coefficient of resistance as quickly as you can. Have you seen a electric locomotive spin its wheels? Yes it actually does do that at times.

    ksso
  • varmintvarmint Member Posts: 6,326
    Without a VVT system, the engine must accept a compromise. There are three choices.

    1. Allow the engine to breathe freely at higher RPMS (producing good horsepower) and sacrifice the low end torque.

    2. Allow it to breathe efficiently at the low end (producing good torque) and sacrifice the high end horsepower.

    3. Pick a middle ground that does both well enough, but neither of them particularly well. Most engines would fall into this category.

    With a VVT system in operation, the engine can change breathing apparatus to match the situation (high or low rpm). In other words, the engine can have its cake and eat it too.

    In the past, Honda has used VTEC so that it produced the greatest amount of horsepower. Horsepower was the priority for cars like the NSX and Integra. The lower rpm intake cams were designed to function more like a number 3 engine. They serviced both the low end and the middle ground. Meanwhile the upper rpm intake was designed to get the most from the high end. So the second set allowed the top end to function like a number 1 engine. Honda still takes this approach with cars like the S2000.

    This approach spawned the myth that VTEC is only good for the top end. Truth is, those engines made decent torque down low for an engine of their size. It's just that most other cars were using bigger engines or forced induction.

    Anyway, it doesn't have to be that way. VTEC can also be used to make an engine work both as a number 1 and a number 3. It could produce good torque down low and hold it through the middle range. The original MDX engine was a decent example of this.

    What about an engine that works like a number 1 and a number 2? Why not build an engine that focuses on both the high and low ends? Well, the technology is good, but it's not the answer to everything. Such an engine would have a weak mid-range. That hurts driveability and smoothness. Remember, there is more to a good engine than just power output. There's also NVH, fuel economy, emissions, reliability, cooling, and a host of other considerations to juggle.

    With the addition of VTC, Honda is working out how to correct for problems with a smooth power curve. The addition of VTC is yet another way to manage air flow which can compliment VTEC. The combination is called i-VTEC in Honda speak. All three of the 2.4L engines I mentioned earlier use i-VTEC to produce what is essentially a very broad torque curve for an I4 engine. I mean, the torque curve for the TSX's I4 doesn't look as good as BMW's I6, but it's pretty darn impressive for a 4 banger.

    Okay, now imagine all this being applied to a 3.5L V6... Right now, none of the J series engines makes full use of the technology Honda has developed in recent years. Probably because of the expense. With cars in the price range of the RL, cost becomes less of a priority. So it's possible we'll see a fully blown V6 in the RL.
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