Low Power..need some new ideas.
Thread Starter
Staging Lane
iTrader: (1)
Joined: Mar 2003
Posts: 53
Likes: 0
From: Colorado Springs, CO
Low Power..need some new ideas. My last trip to the dyno was an hour+ of tuning. I got 8 runs in and changed fuel and spark independently. My end result was 358/351 SAE HP/TQ. A gain of <10 HP over my last dyno effort. Marginal for tuning after cam/header install, but I also installed an LS6 intake, TR ported TB and a Mezeire electric water pump, In short, this seems about 20 to 30 hp shy of what the average LS1 with my mods produces. In all I've gained about 40+hp with all the mods. I've just about exhasted my ideas in searching for the lost HP. Here is a list.
-LTFT both sides ~ -%5
-LTFT at WOT 0
-AFR steady at 13.4 (reacted predictably to PE changes)
-Total timing 29.5 deg (More timing did not result in more power on dyno so we left it)
-Knock sensors disabled (poly motor mounts cause false knock)
-Peak pwr happens about 5800-5900 rpm.
-Peak tq at 5000 rpm
-Exhaust back-pressure <2psi
-TR 224 cam timing double checked and w/i 1 deg of card. Lift checked as well.
-65,000 miles
-Compression test had one piston %15 higher than the rest. the rest are within %3 of each other.
-Leak down shows all cylinders <%5 leakdown.
-New Spec stg 3 carbon clutch
-plugs look good at 0.055" gap.
-LS6 pcv mod with in-line filter=very little oil intake.
That about sums it up. Any suggestions would be appreciated. I've considered the unhappy thought of my engine just getting tired, but the leakdown results are convincing. I posted this on LS1.com as well but only got one reply. Thanks for any help.
-LTFT both sides ~ -%5
-LTFT at WOT 0
-AFR steady at 13.4 (reacted predictably to PE changes)
-Total timing 29.5 deg (More timing did not result in more power on dyno so we left it)
-Knock sensors disabled (poly motor mounts cause false knock)
-Peak pwr happens about 5800-5900 rpm.
-Peak tq at 5000 rpm
-Exhaust back-pressure <2psi
-TR 224 cam timing double checked and w/i 1 deg of card. Lift checked as well.
-65,000 miles
-Compression test had one piston %15 higher than the rest. the rest are within %3 of each other.
-Leak down shows all cylinders <%5 leakdown.
-New Spec stg 3 carbon clutch
-plugs look good at 0.055" gap.
-LS6 pcv mod with in-line filter=very little oil intake.
That about sums it up. Any suggestions would be appreciated. I've considered the unhappy thought of my engine just getting tired, but the leakdown results are convincing. I posted this on LS1.com as well but only got one reply. Thanks for any help.
Thread Starter
Staging Lane
iTrader: (1)
Joined: Mar 2003
Posts: 53
Likes: 0
From: Colorado Springs, CO
Not sure what you mean 2 psi was about as little resolution I could get with the gauge I had. And I've always heard 2psi or less for exhaust back pressure was about as good as you can expect for a full exhaust system.
As for mods:
TTS long tubes w/ cats & ORYP
Borla cat back
TR 224 563 114 cam, comp springs, and TR hardened push rods
LS6 intake, TR ported TB, SLP 85mm MAF, suncoast raptor hood & airbox
M6 w/ spec 3 carbon disc clutch, stock 10 bolt w/ 4.10 gears
All the BMR traction stuff
Your setup is very similar to mine and you have 20 more HP. It is a common theme so I'm trying to figure it out.
Exhaust back-pressure <2psi
As for mods:
TTS long tubes w/ cats & ORYP
Borla cat back
TR 224 563 114 cam, comp springs, and TR hardened push rods
LS6 intake, TR ported TB, SLP 85mm MAF, suncoast raptor hood & airbox
M6 w/ spec 3 carbon disc clutch, stock 10 bolt w/ 4.10 gears
All the BMR traction stuff
Your setup is very similar to mine and you have 20 more HP. It is a common theme so I'm trying to figure it out.
Last edited by HellOnWeelz; Apr 22, 2004 at 12:24 AM.
TECH Apprentice
Joined: Apr 2002
Posts: 358
Likes: 0
From: Mahwah, NJ
I think you may be running too much timing. When doing so, I am learning, you will make best power very rich. What did you end with tuning -timing or fuel. Also, where is the AF being measured and by what. Your mod list says cats and ORY- which is it ?
