Rebuilt LS1 under performing for cam/head combo
08-10-2016, 08:47 AM
#22
I ran that cam when I first did an LS swap. Best it ever dynoed with stock ls1 heads and a Fast 90mm intake was 350 rwhp through an unlocked auto and 12 bolt.
You definitely need more spring. Change them before valve float kills the lifters and cam lobes. Once you have better springs you might be able to turn a few hundred more RPM before it falls off...this would get you some more power.
Geoff who works for EPS now designed that cam. He also specced the cam I used to replace mine. He said his later testing found a wide traditional split made more power everywhere than the reverse splits. I replaced my 230/224 with a 230/238....I replaced the stock heads with 799s with mild porting on the intake runners only and the car went from 12.24@110.39 to 11.67@114mph and a best MPH of 116mph.
The first thing I would do since you don't mention what kind of air filter and tract you're using is do a log and see how much variance you have between engine off key on MAP readings and wide open throttle MAP readings. I see swap guys all the time use a dinky little filter on the end of a pipe with several 90* and 45* bends. If you have more than 2 kPa variance, try running it without a filter and see what it does.
If the portwork on the LS2 intake is junk it could be flowing worse than a stock LS2 intake which is already bad. The reverse split cam should help compensate for this though since your exhaust is good.
Passed that I would do a leakdown test to make sure valves are sealing, make sure all cyl are firing consistently, make sure it's getting WOT, talk to the tuner and confirm you are around 12.7-12.8 air/fuel ratio and 26-28* timing, and look for vacuum leaks.
This particular Mustang could be a stingy one. If so you might not ever see more than 380 on it.
You definitely need more spring. Change them before valve float kills the lifters and cam lobes. Once you have better springs you might be able to turn a few hundred more RPM before it falls off...this would get you some more power.
Geoff who works for EPS now designed that cam. He also specced the cam I used to replace mine. He said his later testing found a wide traditional split made more power everywhere than the reverse splits. I replaced my 230/224 with a 230/238....I replaced the stock heads with 799s with mild porting on the intake runners only and the car went from 12.24@110.39 to 11.67@114mph and a best MPH of 116mph.
The first thing I would do since you don't mention what kind of air filter and tract you're using is do a log and see how much variance you have between engine off key on MAP readings and wide open throttle MAP readings. I see swap guys all the time use a dinky little filter on the end of a pipe with several 90* and 45* bends. If you have more than 2 kPa variance, try running it without a filter and see what it does.
If the portwork on the LS2 intake is junk it could be flowing worse than a stock LS2 intake which is already bad. The reverse split cam should help compensate for this though since your exhaust is good.
Passed that I would do a leakdown test to make sure valves are sealing, make sure all cyl are firing consistently, make sure it's getting WOT, talk to the tuner and confirm you are around 12.7-12.8 air/fuel ratio and 26-28* timing, and look for vacuum leaks.
This particular Mustang could be a stingy one. If so you might not ever see more than 380 on it.
08-12-2016, 12:26 AM
#23
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Great advice. I'm putting my windows in and am hunting a deal on a fast intake. Should be able to run it on the 1/4 soon. Would hate to have to do a cam swap.
05-01-2017, 04:40 PM
#25
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I put a fast 102 on I got a good deal on and had a different tuner tune my car. Came out with 402rwhp and 385trq. Just about what I was expecting. Guess the tuner does have a lot to do with it
05-02-2017, 03:23 PM
#26
Best way to determine power gains is before/after results at the track.
KW
05-10-2017, 05:47 AM
#28
I would do valve springs ASAP.
What plugs and gap?
How's the clutch holding? Easy to lose hp if the clutch is slipping. The LS7 clutch set up is also heavy.
I would also check the brake pads and make sure they aren't dragging on the rotors on the rear. Check rotors for run out. Sometimes that will kill 10-20hp.
Best wishes with finding the missing hp.
What plugs and gap?
How's the clutch holding? Easy to lose hp if the clutch is slipping. The LS7 clutch set up is also heavy.
I would also check the brake pads and make sure they aren't dragging on the rotors on the rear. Check rotors for run out. Sometimes that will kill 10-20hp.
Best wishes with finding the missing hp.
