| View previous topic :: View next topic |
| Author |
Message |
91camaro_rs Member

Joined: 03 Dec 2008 Posts: 1712 Location: Fox Island, Wa
1991 Chevrolet Camaro RS
|
Posted: Mon Jun 04, 2012 7:03 pm Post subject: dyno dissapointment |
|
|
so expecting to have at least the same or better numbers than last year, the dissapointment continues..
last year i was at 200hp and 300tq
after my first pull engine light came on, i had been having troubles with a chip i have so i swapped it out on the dyno, this chip has been good so far no engine light its the stock AUJP. i think the only thing i did was turn off EGR. i may have put a tune on there i made previously, where i just adjusted AFR vs RPM by what my WB02 says as im driving.
anywho, what do you guys think is causing this?
is it something in the tune? if its a tune i made then it should get richer not leaner cause i only made adjustments to 4000rpms, didnt know my car would make it to 5k on the dyno
besides fixing the tune, what else can i do to the car, would a LT1 cam help at all?
i know TPI is garbage beyond 4000rpm but i love the look of it, i just wanna get the most out of it i can, aluminum heads are in the future _________________
'91 Camaro RS 5.7 TPI- 700r4- 3.27 posi- headers- chambered exhaust- |
|
| Back to top |
|
 |
jchaussee Member
Joined: 14 Nov 2010 Posts: 1318 Location: renton
|
Posted: Mon Jun 04, 2012 7:18 pm Post subject: |
|
|
| That some nice torque though. |
|
| Back to top |
|
 |
chevymad Master B
Joined: 11 Jan 2004 Posts: 5476
1987 Pontiac Formula
|
Posted: Mon Jun 04, 2012 7:38 pm Post subject: |
|
|
| Graphs make more sense, at least to me anyway, when you graph vs rpm instead of mph. |
|
| Back to top |
|
 |
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Mon Jun 04, 2012 7:38 pm Post subject: |
|
|
| chevymad wrote: | | Graphs make more sense, at least to me anyway, when you graph vs rpm instead of mph. |
You can more easily spot issues that arise at a certain RPM.
Some other thoughts:
No sense spinning a TPI past 4500.
What code was the old chip throwing? If it wasn't a code for bad prom then the issue may well still exist.
Is this still a MAP TPI on a 350 with a carb Summit cam in it? |
|
| Back to top |
|
 |
91camaro_rs Member

Joined: 03 Dec 2008 Posts: 1712 Location: Fox Island, Wa
1991 Chevrolet Camaro RS
|
Posted: Mon Jun 04, 2012 7:44 pm Post subject: |
|
|
code was 51 bad prom
its a speed density TPI on a factory roller cam
ill email carb conn and get my other graph with RPMs instead of mph _________________
'91 Camaro RS 5.7 TPI- 700r4- 3.27 posi- headers- chambered exhaust- |
|
| Back to top |
|
 |
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Mon Jun 04, 2012 8:05 pm Post subject: |
|
|
| If you have the DRF file you can do it yourself in WinPEP. |
|
| Back to top |
|
 |
Twilightoptics Hardcore (12sec Club)

Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
|
Posted: Mon Jun 04, 2012 8:38 pm Post subject: |
|
|
Change that to RPM.
Looks like a rich condition, especially if you were in limp home. _________________ A redline a day keeps the carbon away! |
|
| Back to top |
|
 |
91RSVert Member
Joined: 16 May 2007 Posts: 2736 Location: AR
1991 Chevrolet Camaro RS
|
Posted: Tue Jun 05, 2012 12:33 pm Post subject: |
|
|
From my readings, an LT1 cam isnt much more agressive then the stock TPI cam. That being said, if you can get an LT1 cam for next to nothing, give it a try.
I have corvette alumn heads on mine, for my driving, I wish I would have kept the crate/truck heads. Alot more low end tire frying. If I could find another, I would likely go back. |
|
| Back to top |
|
 |
91camaro_rs Member

Joined: 03 Dec 2008 Posts: 1712 Location: Fox Island, Wa
1991 Chevrolet Camaro RS
|
Posted: Fri Jun 08, 2012 8:13 am Post subject: |
|
|
so if i upgrade to aluminum heads im gonna lose low end power? what heads should i get if i wanna upgrade? _________________
'91 Camaro RS 5.7 TPI- 700r4- 3.27 posi- headers- chambered exhaust- |
|
| Back to top |
|
 |
91RSVert Member
Joined: 16 May 2007 Posts: 2736 Location: AR
1991 Chevrolet Camaro RS
|
Posted: Fri Jun 08, 2012 12:07 pm Post subject: |
|
|
That would depend on what heads you have, and what you go with. As well, a cam can help change that.
My "810" heads that I had were TBI swirl port heads. Supposibly they had a "wall" at 4k just like TPI does. I rarely spin there so it doesnt matter to me. |
|
| Back to top |
|
 |
91camaro_rs Member

Joined: 03 Dec 2008 Posts: 1712 Location: Fox Island, Wa
1991 Chevrolet Camaro RS
|
Posted: Fri Jun 08, 2012 3:41 pm Post subject: |
|
|
idk what the casting number is but they are just stoke iron L98 heads _________________
'91 Camaro RS 5.7 TPI- 700r4- 3.27 posi- headers- chambered exhaust- |
|
| Back to top |
|
 |
chevymad Master B
Joined: 11 Jan 2004 Posts: 5476
1987 Pontiac Formula
|
Posted: Fri Jun 08, 2012 4:46 pm Post subject: |
|
|
L98 heads are decent heads. Especially ported. You'll need to step up to really surpass them. Just generic or vette aluminum heads might even cost you power. In fact, I'm not sure that a good head will even help you as long as you keep the tpi intake. Making a port bigger increases upper rpm hp which you cant use anyway, it also costs you velocity in the lower rpm. Possibly costing you power. So that would limit you to a small port head. Then aluminum sucks heat out of the combustion chamber. This is the reason you can add compression with an aluminum head. Adding the compression balances out the hp loss due to material.. So you break even there.
Frankly I dont see any large gains possible without ditching the tpi intake. Tuning should get you into the 230rwhp range though. After that you'll need to decide whether you want looks or hp. |
|
| Back to top |
|
 |
Twilightoptics Hardcore (12sec Club)

Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
|
Posted: Fri Jun 08, 2012 4:48 pm Post subject: |
|
|
| chevymad wrote: | L98 heads are decent heads. Especially ported. You'll need to step up to really surpass them. Just generic or vette aluminum heads might even cost you power. In fact, I'm not sure that a good head will even help you as long as you keep the tpi intake. Making a port bigger increases upper rpm hp which you cant use anyway, it also costs you velocity in the lower rpm. Possibly costing you power. So that would limit you to a small port head. Then aluminum sucks heat out of the combustion chamber. This is the reason you can add compression with an aluminum head. Adding the compression balances out the hp loss due to material.. So you break even there.
Frankly I dont see any large gains possible without ditching the tpi intake. Tuning should get you into the 230rwhp range though. After that you'll need to decide whether you want looks or hp. |
 _________________ A redline a day keeps the carbon away! |
|
| Back to top |
|
 |
QwkTrip 11sec Club

Joined: 17 Feb 2004 Posts: 3942 Location: Peoria, IL
1989 Pontiac Firebird
|
Posted: Fri Jun 08, 2012 7:35 pm Post subject: |
|
|
Um.... horsepower always looks good.
That's why a 500Hp beater looks good. Take away the 500Hp it's just an ugly beater. |
|
| Back to top |
|
 |
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Fri Jun 08, 2012 10:18 pm Post subject: |
|
|
| QwkTrip wrote: | | Um.... horsepower always looks good. |
No, half finished crap in your shop looks the best.
| chevymad wrote: | | Frankly I dont see any large gains possible without ditching the tpi intake. Tuning should get you into the 230rwhp range though. After that you'll need to decide whether you want looks or hp. |
My L98 made 240/320 with a decent custom chip I burned for it. I think there were probably a couple more horses to had with further tuning and fixing the exhaust but the simple fact is that the math doesn't work out for TPI. |
|
| Back to top |
|
 |
Quasi-Traction "I have petals"

Joined: 24 Oct 2005 Posts: 3873 Location: stumptown
1986 Chevrolet Camaro Berlinetta
|
Posted: Sat Jun 09, 2012 11:33 am Post subject: |
|
|
The mirrors on the "Banana"?
If you were going for weight reduction, why not just keep a Drivers side only? |
|
| Back to top |
|
 |
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
|
| Back to top |
|
 |
91camaro_rs Member

Joined: 03 Dec 2008 Posts: 1712 Location: Fox Island, Wa
1991 Chevrolet Camaro RS
|
Posted: Sat Jun 09, 2012 1:48 pm Post subject: |
|
|
aaron was your motor pretty much stock when you had it at 240 whp?
if so wanna do some tuning??  _________________
'91 Camaro RS 5.7 TPI- 700r4- 3.27 posi- headers- chambered exhaust- |
|
| Back to top |
|
 |
aaron_sK Member
Joined: 23 Jan 2006 Posts: 8834 Location: Back in beautiful Tacompton
1987 Chevrolet Camaro IROC-Z
|
Posted: Sat Jun 09, 2012 2:52 pm Post subject: |
|
|
| 91camaro_rs wrote: | | aaron was your motor pretty much stock when you had it at 240 whp? |
Stock heads, unknown cam (but mild) LT1 injectors, mildly ported upper plenum.
I started with an ARAP BIN and imported the stuff from a manual BIN (forget which one) to get it to run a little better off idle. Adjust all temp related stuff to your thermostat (very important) then zero all spark tables but the startup and main. Curve the main table nicely and adjust the startup table so it doesn't run pig rich when cold. Do the fueling last. Mine needed hardly any changes to fueling after everything else was done. |
|
| Back to top |
|
 |
Twilightoptics Hardcore (12sec Club)

Joined: 13 Jan 2004 Posts: 9191 Location: Auburn , WA
1987 Chevrolet Camaro IROC-Z
|
Posted: Sat Jun 09, 2012 2:59 pm Post subject: |
|
|
If you get 250 at the wheels out of a TPI, the TPI gods have shined down on you.
Does anyone have Cheezx numbers from the monster 400SBC he built? It was a crazy awesome motor, with the biggest TPI parts possible, and he put down ungodly torque, but IIRC it was still well under 300HP. _________________ A redline a day keeps the carbon away! |
|
| Back to top |
|
 |
|