Hey everyone... Well, here's the dyno chart first off



I like the horsepower curve... but that torque curve is much to be desired. Is there anything I can do, with the TPI system, to broden that curve more? I don't mind losing a bit to get a brodened curve. Any Ideas?

I am guessing its the whole TPI design that causes this.. here's what I have done so far.

MSD Blaster Coil and 8.5mm wires
Air Foil
Ported Plenum
3" Exhaust from y-pipe back w/high flow cat and flowmaster muffler
Performance Resource chip
K&N cone filter
Flow matched injectors
AFPR

and thats it so far

Will headers broaden that torque curve?

 

I would say headers should be your next mod. they will give you more power at upper rpms, for a little loss of torque down low.

nick

 

I was fooling around with Desktop Dyno... got the graph similar to what I got at the dyno yesterday. I added small tube and large tube headers to the equation, and it increased torque at bottom end still I would have thought headers would give me more top end torque.. Unless Desktop Dyno is wrong... hmmm... If I do some ignition timing, will that shift the torque noticeably?

 

Headers should actually give you power throughout the rpm range if sized correctly for your engine. DD 2000 is not to far off, but remember, crap in = crap out. It also assumes no detonation, perfrect timing, etc. The tpi manifold is gonna limit you in the upper rpm's. If you wanna raise power up there, you'll need to do some more intake mod's. Timing will help.

 

siamese your TPIs intake base. go in 3-5 inches, this will give you a much broader torque curve. it wont really hurt your low end much either. madmax did his like this and achieved peak torque at 4800rpms!

 

Would a better flowing aftermarket intake base and large tube runners broaden the torque curve?

 

Hmmm... sounds good Tuned Port... But, I am not going to have the intake off again until I get new heads, which in turn I have to get a different intake base anyway... But siamesing the intake ports on the intake will raise the torque in the higher rpm's.. I'll remember that. Thanx

 

Welcome to the world of TPI. You can't really gain a whole lot of topend torque without swapping the manifold. Check my dyno graph (in the sig) for proof of that. The intake is about the only thing that I haven't changed yet. Hopefully it'll change soon though...

Definately do headers though, they are the best bang for the buck mod on a L98. Those stock manifolds are horrible.

 

So, besides bottom end, which I don't plan on doing... you have heads, cam and headers... and custom chip. Your torque curve is a lot more desireable than mine.... So will the aftermerket intake and large tube runners fix the torque problem?

Seeing this torque curve explains why it seems to "die" at higher rpm's, which sux.. becuase my peak horsepower hardly has any torque to back it up..

Could I shift my torque curve up more with a cam without shifting my horsepower peak?

 

For the mods you have, it sure is a healthy motor!!

 

Actually our torque curves have the same basic shape. They both drop off rapidly after 4k rpm, yours doesn't have as sharp of a corner though.

Yes, a larger tube runner intake will help this quite a bit. But the length of the runner is the biggest factor in deciding where the power band is. Sticking with the long tube runner design you'll probably still drop off after 4800 at the highest. Going to a Super, Stealth or Miniram is the best way to shift the powerband up higher, since they all have shorter runners.

And your horsepower peak will always stay in the same relative position. Because horsepower is a number calculated from torque.

HP = Torque*RPM/5252

So any time the torque increases so does the HP, and vice versa.

 

Damn those those numbers look bad-*** considering your mods. You're probably pushing 260-265 hp at the flywheel (15% gain). I have the same car as you with identical mods plus hooker headers and i definately hope to be making that kind of power once i get a few bugs out of my tpi system......

 

Scott.... I know about the torque and horsepower relation.. guess i had a mind block.. LOL

I htink headers will be the only other thing I do this year, besides maintenance. I was told not to go with MAC headers.. But they are decently priced.

 

MAC headers are fine, so are Hooker and SLP. Just stay away from Edelcrock!

Here's my dyno chart. An intake manifold and runners (or siamesed intake) along with headers will pick that upper torque right up.
http://para.noid.org/~thresher/dyno.jpg

 

See.. thats what I want, a nice long torque curve

 

What was wrong with the mac headers? I am just curious, I know their mustang products are top quality.

nick

 

Kevin, was that dyno with the TPIS runners, or those custom SLP ones you were working on a while ago?

 

OK, I got a little curious so I plotted our three dynos on the same scale. And honestly, Kevin's torque curve isn't that much broader than ours. It's just up higher on the scale. You can see that both the torque and HP curves have the same basic shape between all three of us in the graphs below.

(these are just rough estimates from me picking them off the graph by eye, but are close enough)

 

Actually, it was a Mustang guy that told me not to get them because they are garbage... only problem with my friend, is he never gives you a reason.. LOL

 

No, I dont have the SLP siamesed runners on yet. When I do, I will post it for the world. This dyno is a year ago with my current setup, in my sig. (with the T5 tranny)

I like having my curves higher than the others. :lala:

 

4800!



It was actually 4000 for the torque (or close, I didnt look for the exact number) and HP I never got to the peak, we shut it down.

Anyways, here's the same graph above with my TQ added Its close anyway, I didnt feel like putting in all those numbers (read: photoshop job)

 

If you dont believe in siamising the intake...... just check out this site!!!
http://www.mycar.net/mafb/registry/detail.cfm?id=201
11's NA, street legal, looks completely stock