Power Loss after 1.8 rocker and LT headers install
01-14-2006, 09:13 AM
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Power Loss after 1.8 rocker and LT headers install Folks,
Ok maybe I should explain that it wasn't a loss exactly but it was only a gain of 4RWHP and 0 torque. The parts have been on the car for around 500-700 miles, I have double checked the rockers and no leaks on the headers.
On the dyno the two graphs (the current setup and the old setup from two months ago) were idntical A/F and HP curve until the new setup peaked 4 more. What I wanna know is the roller rockers hurting what power the headers are making? Shouldn't the toqure be higher? I had stock rockers before with Mac headers. I might need to redo my SD tune but it is not off enough to make a difference. Let me know if you have any ideas.
Tom
Mods are:
Comp Cam 212 218 523 528 114
Port Heads with Manely undercut stock size valves
JetHot LT
HS 1.8 Roller Rockers
HP Tunners Tune
Ok maybe I should explain that it wasn't a loss exactly but it was only a gain of 4RWHP and 0 torque. The parts have been on the car for around 500-700 miles, I have double checked the rockers and no leaks on the headers.
On the dyno the two graphs (the current setup and the old setup from two months ago) were idntical A/F and HP curve until the new setup peaked 4 more. What I wanna know is the roller rockers hurting what power the headers are making? Shouldn't the toqure be higher? I had stock rockers before with Mac headers. I might need to redo my SD tune but it is not off enough to make a difference. Let me know if you have any ideas.
Tom
Mods are:
Comp Cam 212 218 523 528 114
Port Heads with Manely undercut stock size valves
JetHot LT
HS 1.8 Roller Rockers
HP Tunners Tune
01-14-2006, 09:34 AM
#2
TECH Senior Member
Well a swap from Macs to LTs have proven little gains many times berfore. That is why I never bothered switching.(mine are modified)
But I would say retune and you may find some lost ponies.
But I would say retune and you may find some lost ponies.
01-14-2006, 01:29 PM
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Ya, make them play with that tune until it is right. I have 1.8 Gold Race Rockers and along with a whole valvetrain upgrade (cam) and exhaust, LTs, and I gained about 60 HP / 80 torque. They should not have made you lose HP. You might check the valve lash too cause this could be affecting your #'s. Mine had to be re-set after a few visits to the track.
