TransAm

This is something i have observed time and time again. for some reason the bigger you make the motor the slower they seem to accelerate, even though they produce more Tq and in most cases more Hp. I cannot understand why. I will give a few examples.

This video is of a 4.8cid Turbo Trans am, that basically loses to everyone, bu tif you look at 3:31 into the video he races a turbo 5.3 with roughly the same power. and gets beat pretty bad.


Here is a video of flashws6. only 370 cubes and has no trouble with Bigger cube vettes and some exotics


While the LMR vette has troubles with lesser power GTR's


and again..


You would think. ok, well GTR's have great traction from its awd system. but Supras are RWD

7175 supra vs 7175 mustang



I can go on and on with videos where 4xxcid Turbo Fbodys or vettes with the same HP as a supra and either lose or barely win. while turbo 4.8's and 5.3's seem to fair a lot better.

If you look at a foxbody with a 1khp 2jz vs another fox with a 1khp 4xx lsx motor, they will run similar ET's but the Supra motor has a lot more MPH. I used to think Supras suck at ET but give high trap speeds because of IRS. but turns out they just lower their ET while still trapping very high when you put them in a Solid axle car. I also notice 4 bangers follow the same thing. once made rwd they seem to put a hurting on big power v8's. or sometimes put up a good fight when still fwd.

Ive honestly noticed this for years. and I really would like to know why. Im about to kick of a turbo 240 project and while I want the lq9. it just seems like the 4.8 would probably end up being faster pound for pound at the same HP level.

Look how this supra keeps up with similar power turbo and blown V8's


Ive honestly noticed this for years. and I really would like to know why. Im about to kick of a turbo 240 project and while I want the lq9. it just seems like the 4.8 would probably end up being faster pound for pound at the same HP level.

It just seems that smaller cube motors dont necessarily make less TQ, they just make it higher in the powerband. I dont know if my theory is correct, but I cant come up with any other explanation as to why big cubes and boost seem to be slower in engine acceleration which in turns seem to create overall slower accelerating car.

427zm

iTrader: (9)

And then.....

Not true....

TransAm

This is something i have observed time and time again. for some reason the bigger you make the motor the slower they seem to accelerate, even though they produce more Tq and in most cases more Hp. I cannot understand why. I will give a few examples.

This video is of a 408cid Turbo Trans am, that basically loses to everyone, bu tif you look at 3:31 into the video he races a turbo 5.3 with roughly the same power. and gets beat pretty bad.


Here is a video of flashws6. only 370 cubes and has no trouble with Bigger cube vettes and some exotics


While the LMR vette has troubles with lesser power GTR's


and again..


You would think. ok, well GTR's have great traction from its awd system. but Supras are RWD

7175 supra vs 7175 mustang



I can go on and on with videos where 4xxcid Turbo Fbodys or vettes with the same HP as a supra and either lose or barely win. while turbo 4.8's and 5.3's seem to fair a lot better.

If you look at a foxbody with a 1khp 2jz vs another fox with a 1khp 4xx lsx motor, they will run similar ET's but the Supra motor has a lot more MPH. I used to think Supras suck at ET but give high trap speeds because of IRS. but turns out they just lower their ET while still trapping very high when you put them in a Solid axle car. I also notice 4 bangers follow the same thing. once made rwd they seem to put a hurting on big power v8's. or sometimes put up a good fight when still fwd.

Supra's, GTR's evo's and even honda's seem to pull exponentially more in the top end even without the extra physical capacity over V8's with 2- 4 times the displacement.

Ive honestly noticed this for years. and I really would like to know why. Im about to kick of a turbo 240 project and while I want the lq9. it just seems like the 4.8 would probably end up being faster pound for pound at the same HP level.

badformulaLS1

iTrader: (1)

I think the 402, 408, and most (keyword "most") 4xx builds are overrated. Seems like everyone and their mom builds one. I'd prefer a 347 LS1 or 370 LQx, or a 5.3 any day. I don't have enough knowledge to really argue or agree with your post but I can kinda see what you're getting at. I've always thought a sleeved LS1 427 stroker would be badass but besides that I'd probably stick with the LQ, forged LS1, or 5.3 options.

I think it was speaking more strictly in terms of street cars^ but you do have a point.

JohnS Z28

iTrader: (1)

turbod 408...beating bikes, must be really slow.
http://www.youtube.com/watch?v=cmQCclu0zpQ#t=43

itsslow98

iTrader: (18)

You cant make judgement on cars that are likely not set up correctly. A properly setup 408 will beat a properly setup 346 if they are identical other then the engines.

TransAm

Beating bikes? he won one race then lost he second race to the same bike..if u notice that's an excerpt from the very first video I posted. but lets examine what you posted. the stang (light foxbody)with the TT 408. lost to a 205whp Bike. You can see Supras maul bikes that have more power than the one in this video, which would mean that the stang (although lighter and bigger engine) would have a hard time with some of the Supras out there.(even though heavier with a smaller engine)

TransAm

I agree the 408 would make more TQ, however, I cant say it would likely beat a 346 in a race when 183cid motors (supras), seem to beat 408's with the same power. within any reasonable margin of error.

itsslow98

iTrader: (18)

Im sayign with all else equal chassis wise. There are way too many variables between cars. A buddy of mine had a 408 with stock 243s on it. Of course it would have a hard time with an AFR headed ls1.

RPM WS6

iTrader: (3)

Yes and yes.

All else being equal about the cars in comparasion, and with both engines being optimized (this is key, since a "lazy" 408 build shouldn't be directly compared to a max effort 346 build, for example) to an equal degree, and with drivetrains equally well matched to their respective setups (meaning gearing/stall speed), I would expect the larger cube example to display superior acceleration and more average torque across its rpm range.

Forced induction is a popular way to increase power/torque, and at its most basic level it's really just artificial displacement (more air being pumped through the engine via pressure [boost], rather than more space [displacement]). More air in and out equals more power/torque, assuming comparably optimized overall engine builds. More cubes is a good thing, unless you're looking for sustained high rpms and want to reduce rotating mass and stroke, etc. But this is rarely optimal for acceleration when applied to a street car.

And lastly you absolutely can't directly compare cars that are completely different (or even just different levels of chassis optimization) and call displacement the primary factor for win/loss.

99z28monster

iTrader: (3)

So lets compare apples to apples instead of completely different cars. It comes down to power to weight ratio and the ability to put that power to the ground. Part of putting it to the ground also means running the vehicle in the power band. Not just a dyno queen that makes XXX amount of power in RPM ranges that will never be used at the track or the street.

Orange Juice

iTrader: (3)

Considering I don't have boost I'm happy with my lazy big displacement motor.

thunderstruck507

iTrader: (18)

You are comparing apples to bananas and asking why they aren't both red.

If you get your automotive knowledge from youtube, you're gonna have a bad time.
If you read youtube comments you will be retarded by 3pm today.

Roarin_8

iTrader: (5)

And to answer that question about Supras trapping high and their ET sucking (for example 130mph traps while ETing in the 11s), it's the transmission that they use. This is why they are often referred to highway cars. Once Supra owners use a TH400 or a transmission suitable for 1/4 mile racing, their ET drops dramatically.

TransAm

Rpmws6 I have a few problems with what you said. I've noticed that 1000 HP 2jz foxbodys pull much harder than this 408 tt . Unless you are saying they would be running way different suspension types. But I doubt it. And the 1k HP 2jz motors seem to perform with a consistency u see in supra I.E. very high traps for its relative elapsed time. It just seems like its the motor to me.

The other thing is, you mentioned "lazy 408's" but the thing is most of the 5.3's are stock! So are people doing such a bad job putting them together that that can't outperform a factory junkyard motor? I would think just the shear amount of cubic inches would offset the "non optimal" heads especially with boost. Am I wrong?

TransAm

Not true necessarily. Most supra with 400's and glides making 1400-1500 tend to trap upper 180'St with a mid to high 7 e.t. most 185+ Americans are sub 7'so and upper

To the person above u. I have had lots of lt1 and ls1 cars. And current own a decently nodded 2002 ws6 as well as a 600hp 2jz 240. And 385hp turbo civic. My other 240 I'm doing a v8 turbo. Just can't decide if it needs to be a 4.8/5.3 or bigger. I'm not getting my data from YouTube. I'm just being it to illustrate my point. I've witnessed these things.

408ws6ta

In this thread there are armchair racers arguing what they saw on a video as definitive proof of a correlation between bigger motors and slower acceleration. Throw in some regurgitation of "facts" from the youtube comments section, mixed with a little "my friend told me", and you have this thread.

From the OP's post all I see examples of one setup and driver beating a completely different setup and driver.
This is not proof that bigger motors are slower.

COSPEED2

iTrader: (7)

We agree completely that the vehicle (s) in question should be looked at as a whole.

Even max effort builds can be left in the losers bracket if the vehicle is not setup OR tuned properly.

Too many times now days you see builds being copied and they dont turn out quite as good as the originals for reasons too numerous to list. Cutting corners only hurts yourself and your ego and in alot of cases your pocketbook as well.

We dont just sell parts. We run quite a few of them and test some of them out. We try to supply what the customer wants, but what they want isnt always what they need.

FLYZNTN

There are so many variables to consider........ somebody is trolling.

RPM WS6

iTrader: (3)

Sounds like we are still talking about different cars with different (unknown) suspension/chassis/drivetrain [trans/gears/stall] setups. Too many variables to look at displacement as the main factor of win/loss.

Even a "lazy" 408 LS build (stock head castings warmed over, mildish cam, stockish compression) will make more power/torque than a "stock" 5.3, and will accelerate faster in the same car with equally well matched drivetrain (trans/gears/stall) for the respective powerband. I'm not sure where you are going with this, unless you're talking about an internally stock 5.3 + boost vs. a 408 NA build, but at that point the 5.3L has an artificial displacement increase (boost). If the drivetrains and chassis are not equally optimized respective to the engines, then yes it's entirely possible for the smaller cube engine to accelerate the vehicle faster. But then you're not really comparing displacement any more, but rather how well optimized each vehicle is to it's respective engine.