Rebuilt LS1 under performing with cam/heads
Rebuilt LS1 under performing with cam/heads I did a LS1 swap in to my pro tourung 68 camaro I finally got everything dialed in and took the car to a tuner/dyno. The engine is a rebuilt short block LS1 with stage 1 port and polish 243's from PRC. The cam is a TR230/224 on a 111 reverse spilt. I have long tubes and true duals. Intake is a LS2 with DBW. T56 with ford 9" 3.89. The car put 340 to the wheels!!! It runs great, but I can feel there's more. Tuner told me the AFR #s are equal to a 400+ HP car. Any ideas? These #s are equal to a stock LS1 with headers!!!
TECH Resident
Joined: Mar 2012
Posts: 821
Likes: 4
From: Elkridge MD
A stock LS1 is not going to put 340hp to the wheels. Probably something close to that at the crank. 340 at the wheels is probably something like 390 at the crank, so the tuner is probably in the right ballpark calling it 400hp
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I'm 99% sure it's firing on all 8 based on how well it idles and runs. I pulled all 8 plugs last night they are all light brown and fairly consistent. The TB is a 90mm LS2 DBW. As far as the cam. I didn't install it. My buddy did who is a hell of a mechanic, but any one could make a mistake. I will post dyno charts soon. I doubt it's a timing issue based on how well it idles and runs. It revs super fast and runs good. Just is way under performing for the combo I have in it. I'm going to do a cylinder compression test on all 8 today or tmrw
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Your about on track. My buddies was just dyno tuned at 356hp. His is a fresh LS1 w/241 heads, LS6 intake, cam and headers.
Your forgetting about the loss through the drivetrain as stated above. The Ford 9" eats up more power then a 10 bolt so it's a bit more loss there. I would say your near 400hp at the crank which is 50 more hp then stock had.
Your forgetting about the loss through the drivetrain as stated above. The Ford 9" eats up more power then a 10 bolt so it's a bit more loss there. I would say your near 400hp at the crank which is 50 more hp then stock had.
I understand I may lose a few ponys through the rear end, but I've also seen many state high 300s low 400s with my same combo or very similar. The more I think about it Im starting to lean towards a failure in the valve train. I will run a compression check on all 8 tonight. Should get me closer. I probably need to drive it more to really find out where its lacking if it is. It did feel like is was running pretty solid though
Compression test revealed 195-200 on all 8. Reviewed the dyno. There was no drop off in power in upper rpm so unlikely the valves were floating. Well I guess I will have to put in windows and seat belts and take it to the track. Or take it to a different dyno
It was a mustang dyno. And that is a serious consideration about another tuner after I rule out a few more things. An LS6 zo6 was on the dyno rite b4 with a much milder cam and no port and polish on the heads and no headers put down 380 rite before me. So it probably wasn't the dyno
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Joined: Feb 2012
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My old stock LS1 M6 GTO 73k mi put down 340/350 with nothing but a CAI/Exhaust and dyno tune...(confirmed using 2 different dynos too)
I HOPE something is wrong for you to have freshened up LS1 with some goodies in it and only making 340 RW.
My stock 95 LT1 M6 54k mi with CAI, full exhaust and tune makes 311/340.
I have no drag times since I don't care to drag race. All I do is autocross/RR oriented.
I HOPE something is wrong for you to have freshened up LS1 with some goodies in it and only making 340 RW.
My stock 95 LT1 M6 54k mi with CAI, full exhaust and tune makes 311/340.
I have no drag times since I don't care to drag race. All I do is autocross/RR oriented.
Hey streSS, I'm betting the issue may be in the base tune.(not knocking your dyno tuner, just saying theres a lot of maps to go through and sometimes dyno operators don't have time to get through all of them AND be profitable).
Once under power(throttle position and MAP based), your ecm will enter PE mode and target whatever it is set to (12.5:1, 12.7:1...whatever), that number is independent of HP.(even Hondas target a richer AFR under power).
There are a number of maps that could be dialing back power: Intake Air temp can reduce timing, as well as coolant temp. There are also several maps associated with your DBW that either limit total opening or limit position based on abuse factors.
Burst knock on some ECm's is set quite aggressive and can linger for up to 10-15 seconds. I have an LS1b from an 05 6.0L and burst knock was yanking 5 degrees of timing right of the bat and wouldn't totally decay until about 10 seconds.
I'm just trying to give you some things to look at in your tune. It sounds like you have and LS1b ecm as well, I wouldn't mind helping if you can get the file in EFILIVE format. I'm not a professional or a dyno tuner, but I successfully calibrated my 6.0L (228R cam/longtubes, LS6 intake, M6 )and have helped a few others out over on Efilive's website.
Once under power(throttle position and MAP based), your ecm will enter PE mode and target whatever it is set to (12.5:1, 12.7:1...whatever), that number is independent of HP.(even Hondas target a richer AFR under power).
There are a number of maps that could be dialing back power: Intake Air temp can reduce timing, as well as coolant temp. There are also several maps associated with your DBW that either limit total opening or limit position based on abuse factors.
Burst knock on some ECm's is set quite aggressive and can linger for up to 10-15 seconds. I have an LS1b from an 05 6.0L and burst knock was yanking 5 degrees of timing right of the bat and wouldn't totally decay until about 10 seconds.
I'm just trying to give you some things to look at in your tune. It sounds like you have and LS1b ecm as well, I wouldn't mind helping if you can get the file in EFILIVE format. I'm not a professional or a dyno tuner, but I successfully calibrated my 6.0L (228R cam/longtubes, LS6 intake, M6 )and have helped a few others out over on Efilive's website.