I've been thinking about this for a long time, and thought some of you might be able to shed some light on this:

Why is it that (for the most part, without generalizing) when people start making over 300whp, their torque curves aren't as aesthetically pleasing?

I mean, with the dyno graphs of ~300whp setups it seems that the hp curve just keeps going up until redline, and the torque curve seems to be very strong and straight, either going down a little toward redline or even peaking near there.

But it also seems that on many 400whp+ dyno graphs I've seen, the hp keeps climing hard, but the tq curve falls off more towards redline..... like this:




I remember itr206 had a neat setup when he built his motor and wasn't making ungodly amounts of whp, maybe 350-400whp at low boost, but his torque was still climbing at redline..... I really liked that graph. It seems fairly easy to duplicate his power output, but how could you do this with a higher whp setup?

something like this would be nice:



Now when you're racing, assume two motors make the same peak at ~500whp, and one has a straight and flat torque curve of 350ft-lb which peaks at 8600, whereas the other has a higher peak torque of 400ft-lb at 6000, and then falls off from there..... I know they have the same horsepower, but which motor is actually "stronger" and "faster"? Assume all other variables being equal (conditions, chassis, tranny, weight, etc).

Thoughts?


*(pics were taken from this thread: https://honda-tech.com/zerothread?id=923069)

 

I'm interested

 

With ITR206 I believe his kept going up due to his cams and Intake manifold. That has alot to do with where your torque will make power, and ITR cams are aimed for top end, which is probably why his kept going up.

I dont know what was on the other graph so I can only guess it was b16 or GSR cams which are more mild on the top end...

 

Setups that have the torque still climbing at 9,000rpm...are boost creeping.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">Setups that have the torque still climbing at 9,000rpm...are boost creeping.</TD></TR></TABLE>

ding ding ding!!!!!!!

 

could it be boost creep, or could be something similar to a scaled boost MAP???

i have always tried to maximize torque because after all its torque that makes you go fast and the HP just kinda keeps, or "carries" you there.

I THINK A CAM SHOOT OUT IS IN ORDER!!!!!!

all the way from ITRs, B16s, gsRs, to other makers like rocket, blox, and such

good thread

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mrbsponge &raquo;</TD></TR><TR><TD CLASS="quote">could it be boost creep, or could be something similar to a scaled boost MAP???
</TD></TR></TABLE>


What the hell are you talking about? It's Boost Creep.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Suprdave &raquo;</TD></TR><TR><TD CLASS="quote">


What the hell are you talking about? It's Boost Creep.</TD></TR></TABLE>

What i meant was something along the lines of boost by RPM or speed......take it easy bro'

i had mine set like that for somewhat of traction control thru the AVC-r

 

No boost creep

 

Yea I am going to have to jump on the boost creep wagon too. Too prove this, someone needs to make a dyno pass with a tial wastegate (no creeping), then use the deltagate (creep). Look at the difference in that, and then make your theories unmistakably* correct.

 

Exactly...its funny when some guys post up these 325whp @ 7PSI dynos, and you see the curve shooting up 5500+....its not magic, its creep.

Everything you guys are mentioning makes a difference...intake manifold, cams, the turbocharger itself obviously...there are tons and tons of variables. A good setup will have a minimal drop off. But when you see these 9000RPM torque climbs...like Dave says, its creep.

 

something i was thinkin about is safe or "conservative" tunes. if the tuner didnt attempt to tune each rpm when in boost, and the tuner kept taking the same or larger increments in timing out as the boost was rising, then that would cause the torque to level out or fall off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jordo@KAP &raquo;</TD></TR><TR><TD CLASS="quote">
No boost creep</TD></TR></TABLE>


I would be VERY happy with a graph like this..... assuming I could rev it to 9500-10000 or so.....

HP keeps climbing and tq is pretty flat.....!

 

boost creep? wtf? how the hell would a engine be able to make tons of hp@10krpm if the torque curve drops drastically from 5k??? its impossible! hp @ a certain point is calculated with the torque number @ that same rpm point. almost everybody doesnt understand what torque is. before you tell me im wrong, think about this: what is the difference between torque and hp?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dnbruut &raquo;</TD></TR><TR><TD CLASS="quote">boost creep? wtf? how the hell would a engine be able to make tons of hp@10krpm if the torque curve drops drastically from 5k??? its impossible! hp @ a certain point is calculated with the torque number @ that same rpm point. almost everybody doesnt understand what torque is. before you tell me im wrong, think about this: what is the difference between torque and hp? </TD></TR></TABLE>

noice, you just didn't read into whatever you read enough! Dont forget RPM is a multiplier in that equation. Torque drops off slower than rpm increace? probably.

 

The funny thing about that 2nd graph that has the tq increasing is look at where it finally reachs 200 lb/tq. Around 5500 RPMS, now look at the other 2, they have 250 lb/tq by that rpm. That is a HUGE difference.

Shoot jordo had 300 lb/tq

The only place it really makes more tq than the other 2 graphs is at 7500 rpms.

Just food for thought.

 

here is mine

B16-T

first baseline was at 10psi

final results were 15psi on my OLD drag III kit

 

torque is the only measurable force...hp is nothin but a calculated # (so we can all bench race like ricers) you will accelerate at the same rate with 300ft/lbs@1000rpm that you will with 300ft/lbs@9000rpm, the best torque curve is a flat one

 

compare these two graphs...one has more hp and the other has more torque (the one with the less hp will pull harder)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by z6 &raquo;</TD></TR><TR><TD CLASS="quote"> the best torque curve is a flat one</TD></TR></TABLE>
like this?

 

i think codys torque curve is tEh hotness, but damn for my motor being an 81mm B16 its torque isnt too bad. it looks pretty decent even next to a monster like the S2k

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by z6 &raquo;</TD></TR><TR><TD CLASS="quote">you will accelerate at the same rate with 300ft/lbs@1000rpm that you will with 300ft/lbs@9000rpm, the best torque curve is a flat one</TD></TR></TABLE>

Depends how fast you're going. If you're going the same speed, 300ft/lbs@9000rpms means that you are at a gear ratio 9x lower than if you were at 1000rpms, which means the torque at the wheels will be 9x higher....which means you'll be accelerating 9x faster. That's a hell of a difference for something that most people think doesn't matter because it's "nothin but a calculated #"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by z6 &raquo;</TD></TR><TR><TD CLASS="quote">torque is the only measurable force...hp is nothin but a calculated # (so we can all bench race like ricers) you will accelerate at the same rate with 300ft/lbs@1000rpm that you will with 300ft/lbs@9000rpm, the best torque curve is a flat one</TD></TR></TABLE>

So if TQ kept rising that would be boost creep?

 

if you are looking for a good driving car(not just drag car) you need power under the curve. I just posted a thread about my 18G dyno. it was conservative tuning wise but the HP and Torque are only about 50 apart or so. it is about how fast you can hit your torque peak and hold near that peak RPM wise.

if a turbo boost creeps the power will continue to rise because the air is flowing faster and there is more of it. that is a good way to make your power band look great but isn't the greatest when it comes to holding boost obviously

 

hp is the same as torque multiplied by the number of rpm where its @ (dont take this litteraly but there is a formula)
you cant FEEL the difference between torque and hp.
its impossible 2 have higher torque @ a certain point and not rais hp @ that same point! the hp line always follows the torque line perfectly. its only'multiplied' by rpm.
if one car drives from 2krpm till 3krpm with a flat hp line of 300hp and another car drives 9krpm till 10krpm with a flat hp line of 300hp (the second car will have a lot less torque @ that rpm range 2 make the same amount of hp)(both with 'perfect'' drivetrain setup) the cars would pull exactly as fast!
and please dont tell me that i havent read enough!
the most people should use low end or wide powerband for what they are trying to say with torque.
btw dynos dont measure hp only torque and rpm! and hp is not just invented for ricers! hp shows what your engine can actualy do!(not saying that a wide powerband isnt important!)