Where does your hp curve peak?
05-15-2013, 11:48 AM
#1
TECH Resident
Thread Starter
Where does your hp curve peak? So I had my car on the dyno the other day... 3rd gear pull it put down 485/484 with peak hp around 5200 rpm. Back in December, same thing, 490/550 with peak hp at 5100 rpm and peak torque at 4200 rpm. (December pull was on a Mustang Dyno. Recent pull was on a stingy Dynojet - All other cars were putting down 30-40 rwhp less than what they normally put down. Point of reference 2013 ZL1 Automatic put down 447 rwhp.)
Relevant info: 2002 Z28 A4 (Stock), Stock Bottom LS1 (65k miles), Stock heads/bolts, Stock Exh. Manifolds, LS9 Cam w/springs, Rear Mount Turbo - On3 Performance 76mm Ceramic BB w/.96 housing @10psi, Yank SS3200, FMIC w/ progressive Methanol Inj., SD Tuned.
When going down the track, I can feel the car peak and the acceleration taper off a little bit just before it shifts at 6k. Obviously I'm coming down the peak hp curve at that point. Sucks because I feel like I'm on the brakes as I cross the line.
Is this a "normal" peak point for my given setup?
Should I be looking for something wrong?
What can I do to push the curve further to the right and keep under the curve area?
As a temporary fix, I'm thinking of changing my shift point to 5400 instead of 6k, with the thought that I'd get back into power curve faster. I ran a 12.4 @117 a few weeks back (with a DA of about 3800). Goal with this car (Daily driver) is 11.8.
(Car in left lane was 2013 Porsche 911 Turbo S - http://www.porsche.com/usa/models/91...turesandspecs/)
Thoughts?
.
Relevant info: 2002 Z28 A4 (Stock), Stock Bottom LS1 (65k miles), Stock heads/bolts, Stock Exh. Manifolds, LS9 Cam w/springs, Rear Mount Turbo - On3 Performance 76mm Ceramic BB w/.96 housing @10psi, Yank SS3200, FMIC w/ progressive Methanol Inj., SD Tuned.
When going down the track, I can feel the car peak and the acceleration taper off a little bit just before it shifts at 6k. Obviously I'm coming down the peak hp curve at that point. Sucks because I feel like I'm on the brakes as I cross the line.
Is this a "normal" peak point for my given setup?
Should I be looking for something wrong?
What can I do to push the curve further to the right and keep under the curve area?
As a temporary fix, I'm thinking of changing my shift point to 5400 instead of 6k, with the thought that I'd get back into power curve faster. I ran a 12.4 @117 a few weeks back (with a DA of about 3800). Goal with this car (Daily driver) is 11.8.
(Car in left lane was 2013 Porsche 911 Turbo S - http://www.porsche.com/usa/models/91...turesandspecs/)
Thoughts?
.
05-16-2013, 06:05 AM
#2
I think you should check to see where your cam is degreed in at. I think you could be off a full tooth as most LS1's with a LS6 style intake peak tq around 4800-5000 rpm and peak hp around 6000-6200 with some variations depending on camshaft / heads.
Here mine peaks right around 6100 rpm. This graph shows my N/A curve compared to a TC76 on 7lbs. Mine doesn't fall off up to almost 7000 rpm and I shift around 6600-6800.
Here is the same setup with a Precision 76GTS on 11.5lbs
Here mine peaks right around 6100 rpm. This graph shows my N/A curve compared to a TC76 on 7lbs. Mine doesn't fall off up to almost 7000 rpm and I shift around 6600-6800.
Here is the same setup with a Precision 76GTS on 11.5lbs
05-16-2013, 07:48 AM
#3
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Two combos for referencing:
Engine : Totally stock 2001 LQ4 6.0L longblock
Mods : 80lb inj & pt8847 & W2A
at 11psi (17*) it did 579whp and peaked 5950 rpm (TH400 & 9")
Engine : Stock LM7 5.3L Longblock
Mods : PTE74 gts/ 60lb inj/ ebay front mount/ ZO6 cam/ hand ported heads
at 12psi (15*) it did 557whp and peaked at 5300rpm (was running out of fuel pump and laid over at 5300 because of this) (TH350 & 8.8")
Engine : Totally stock 2001 LQ4 6.0L longblock
Mods : 80lb inj & pt8847 & W2A
at 11psi (17*) it did 579whp and peaked 5950 rpm (TH400 & 9")
Engine : Stock LM7 5.3L Longblock
Mods : PTE74 gts/ 60lb inj/ ebay front mount/ ZO6 cam/ hand ported heads
at 12psi (15*) it did 557whp and peaked at 5300rpm (was running out of fuel pump and laid over at 5300 because of this) (TH350 & 8.8")
