Guest DaneL24 Posted June 1, 2003 Share Posted June 1, 2003 I know that both NA and Turbo L6's have similar peak HP potential (If L28ET has stock T3)...Its just that with turbo motors peak HP is usually reached by increasing torque through boost...and with NA motors, peak HP is reached through both torque increase with more displacement and compression, as well as raising the powerband through camming and porting. I have heard of and read about highly built NA L6's reaching 300 peak HP, as well L28ETs with stock T3s having peak HP potential around 300 HP. My question is, despite the similarities in peak HP potential, what are the similarities in torque numbers? I'm sure turbo motors have much more torque potential, but I have heard of many NA L6 motors having well over 200 ft/lbs of torque. I just think people talk about peak HP too much and am interested in seeing some torque numbers from both NA and turbo L6s. Like I said, I know turbos generally produce more torque...but I'm still interested to see some of your dyno numbers for torque...both NA and turbo. Motor specs/mods would be appreciated too. Thanks guys. This should be interesting. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted June 1, 2003 Share Posted June 1, 2003 Turbo can can have more flat torque curve. When I dynoed mine with stock T3, I was getting over 200ft/lb from 3000rpm to 5300rpm. peaking @ 218ft/lb @ 4400rpm with 11.5:1 A/F ratio. Quote Link to comment Share on other sites More sharing options...
Guest z1 performance Posted June 1, 2003 Share Posted June 1, 2003 Exactly, and in some case with the turbo motors, torque can surpass HP...thats exactly how it was with my own L28T (albeit with a T3/T4, so not stock turbo). In my case, Torque was 456 to the wheels, HP was 402 with nice rich A/F's as well <12.5:1>, though it was on race gas at the time. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 2, 2003 Share Posted June 2, 2003 A lot depends on what goals the engine was built for. A person can build a peaky turbo engine that makes 300hp or a torquey NA engine that makes 300hp, both of which are generally counter to conventional wisdom. My NA 3.0L makes at least 200 ft. lbs. of torque from 3,600 to 7,200 rpm (IIRC - dyno sheet's not handy) with a peak of 257 around 5,600. Soft redline of 7,500 rpm and a hard redline of 8,000 rpm with 305hp at 6,500 rpm. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted June 2, 2003 Share Posted June 2, 2003 Turbo has WAY more torque and hp potential. At the same power level, the turbo will have a MUCH better torque curve, as YO said. It'll be making close to peak torque for a much broader rpm range, starting at much lower rpm. If torque is bigger than hp, you've got way more power potential, turbo or NA. The nature of the engine's torque delivery will change, though (greater lag for the turbo, reduced low to midrange torque for NA). If peak torque is greater than peak hp, torque must be falling off relatively early, given that a stock L6 is good for 7000 rpm or so. O' course if you're making 456 lb-ft to the wheels, it's going to take a mighty big turbo to keep that up at 6000 rpm (I think, not a turbo expert here)! z1, how much boost are ya running? Damn those numbers are BIG! Link to dyno sheets? One of my 3.1 NA dyno runs from last year can be seen here: http://www.classiczcars.com/photopost/showphoto.php?photo=2274&password=&sort=2&thecat=500 I later gained 5hp (different dyno, went from 228 to 233) by going to smaller air jets, improving the lean condition at the top end. Don't know what's up with the RICH spot and corresponding hole in the torque curve. Hopefully the recently corrected cam timing (I was running it ~4 deg retarded) has fixed that to some degree. Feels better for sure. The dyno will reveal... I've gotten reports of a 10.4:1 3.2 NA motor making 280+ lb-ft at the crank (seems pretty optimistic, I'm only making 200 to the wheels), with a much lower peak hp figure. It all depends on where the torque curve is. Mine was all above 4500 (hopefully more like 3000 and up now). Anyway, to make big hp numbers NA, you've gotta rev it, and be willing to sacrifice low-end to some degree. With a turbo you have options. Lower boost and highish revs, or higher boost and lower revs. For maximized power you'd want to maximize boost and revs. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted June 2, 2003 Share Posted June 2, 2003 Turbo has WAY more torque and hp potential. At the same power level, the turbo will have a MUCH better torque curve, as YO said. It'll be making close to peak torque for a much broader rpm range, starting at much lower rpm. If torque is bigger than hp, you've got way more power potential, turbo or NA. The nature of the engine's torque delivery will change, though (greater lag for the turbo, reduced low to midrange torque for NA). If peak torque is greater than peak hp, torque must be falling off relatively early, given that a stock L6 is good for 7000 rpm or so. O' course if you're making 456 lb-ft to the wheels, it's going to take a mighty big turbo to keep that up at 6000 rpm (I think, not a turbo expert here)! z1, how much boost are ya running? Damn those numbers are BIG! Link to dyno sheets? One of my 3.1 NA dyno runs from last year can be seen here: http://www.classiczcars.com/photopost/showphoto.php?photo=2274&password=&sort=2&thecat=500 I later gained 5hp (different dyno, went from 228 to 233) by going to smaller air jets, improving the lean condition at the top end. Don't know what's up with the RICH spot and corresponding hole in the torque curve. Hopefully the recently corrected cam timing (I was running it ~4 deg retarded) has fixed that to some degree. Feels better for sure. The dyno will reveal... I've gotten reports of a 10.4:1 3.2 NA motor making 280+ lb-ft at the crank (seems pretty optimistic, I'm only making 200 to the wheels), with a much lower peak hp figure. It all depends on where the torque curve is. Mine was all above 4500 (hopefully more like 3000 and up now). Anyway, to make big hp numbers NA, you've gotta rev it, and be willing to sacrifice low-end to some degree. With a turbo you have options. Lower boost and highish revs, or higher boost and lower revs. For maximized power you'd want to maximize boost and revs. Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted June 2, 2003 Share Posted June 2, 2003 Turbo has WAY more torque and hp potential. At the same power level, the turbo will have a MUCH better torque curve, as YO said. It'll be making close to peak torque for a much broader rpm range, starting at much lower rpm. If torque is bigger than hp, you've got way more power potential, turbo or NA. The nature of the engine's torque delivery will change, though (greater lag for the turbo, reduced low to midrange torque for NA). If peak torque is greater than peak hp, torque must be falling off relatively early, given that a stock L6 is good for 7000 rpm or so. O' course if you're making 456 lb-ft to the wheels, it's going to take a mighty big turbo to keep that up at 6000 rpm (I think, not a turbo expert here)! z1, how much boost are ya running? Damn those numbers are BIG! Link to dyno sheets? One of my 3.1 NA dyno runs from last year can be seen here: http://www.classiczcars.com/photopost/showphoto.php?photo=2274&password=&sort=2&thecat=500 I later gained 5hp (different dyno, went from 228 to 233) by going to smaller air jets, improving the lean condition at the top end. Don't know what's up with the RICH spot and corresponding hole in the torque curve. Hopefully the recently corrected cam timing (I was running it ~4 deg retarded) has fixed that to some degree. Feels better for sure. The dyno will reveal... I've gotten reports of a 10.4:1 3.2 NA motor making 280+ lb-ft at the crank (seems pretty optimistic, I'm only making 200 to the wheels), with a much lower peak hp figure. It all depends on where the torque curve is. Mine was all above 4500 (hopefully more like 3000 and up now). Anyway, to make big hp numbers NA, you've gotta rev it, and be willing to sacrifice low-end to some degree. With a turbo you have options. Lower boost and high revs, or high boost and lower revs. For maximized power you'd want to maximize boost and revs (big turbo(s), big intercooler). Right? Quote Link to comment Share on other sites More sharing options...
Bob_H Posted June 2, 2003 Share Posted June 2, 2003 Dan, I didn't quite catch that the first time, could you post that again? :flamedevil: -Bob (also an internet retard...) So did you finally get the new clutch pedal? Shoot me an e-mail to find out the new route of the project. I just picked up the shell I was telling you about. The measurements got me excited about the posibilities... Quote Link to comment Share on other sites More sharing options...
z-ya Posted June 2, 2003 Share Posted June 2, 2003 Dan, How's the new motor running? Bill was telling me that you were passing everyone at last weekends COM event. I'm still waiting for my replacement driver's seat from Corbeau to arrive. I'm hoping to do one, maybe two COM events this year. Pete Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted June 3, 2003 Share Posted June 3, 2003 Rebuilt motor runnin' GOOD, though I did get reports of trailing exhaust smoke coming out of 3, hmm... It is nice for the oil pressure not to take a dive during right-handers. Competition pan is just what the doctor ordered. $200 used, deal of the century! Corner workers in 6 said I was fastest on the track in Group 1 (experienced big-bore). Wheee! That was after putting the Hoosiers on. First two sessions I spun due to street tires heat cycled to death (couldn't be MY fault, right?). Gotta start saving the street tires for wet track conditions. Which means I'll be using up Hoosiers more quickly. $$$$$ Quote Link to comment Share on other sites More sharing options...
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