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heads and cam swap and no hp gains

This is a discussion on heads and cam swap and no hp gains within the Internal Engine forums, part of the LSx Technical Help Section category; ya there has to be a problem somewhere. i hit 360 with just the G5X1 cam and stock heads. i ...

  1. #21
    Member stephen02ws6's Avatar
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    ya there has to be a problem somewhere. i hit 360 with just the G5X1 cam and stock heads. i know LG doesnt give you cam cards with their cams and you just install them dot to dot. my guess would be maybe fueling or posibly just the tune. a FAST would see a nice gain with that setup. but something has to be holding you back unless there is an issue with the dyno.

  2. #22
    Senior Member Z28_Driver's Avatar
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    Quote Originally Posted by stephen02ws6 View Post
    ya there has to be a problem somewhere. i hit 360 with just the G5X1 cam and stock heads. i know LG doesnt give you cam cards with their cams and you just install them dot to dot. my guess would be maybe fueling or posibly just the tune. a FAST would see a nice gain with that setup. but something has to be holding you back unless there is an issue with the dyno.
    If its not a fueling issue I would tend to agree that the problem is with the dyno.
    It sounds like the cam went in correctly. That's not the problem.

    I'd like to see if other cars are having the same problem on that particular dyno.

  3. #23
    Moderator 35th-ANV-SS's Avatar
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    I hit 330/342 on a MUSTANG DYNO with just LT's/lid/exhaust and that was through a Moser 9", which is the least efficient rear end out there almost.

  4. #24
    Slow'er'Ass Mr. Luos's Avatar
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    If I didn't get a cam card with my cam....I would send it back.

    If this car has a big converter in it....360 may not be that far off.
    You aren't 100HP off, highly doubt you were going to see 460RWHP through the automatic. What intake?


    I am curious about the fuel pressure regulator you mentioned. Regulator is in the tank from the factory, did you just get a pressure gauge on it?

  5. #25
    Visualize°Design°Create SSwt00SS's Avatar
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    i agree with Luos, 460rwhp with the H/C through an A4 simply doesn't add up. was the converter locked or unlocked? stall or gears? i would see you around the 420rwhp max through the A4.

    what was the A/F ratio? fuel wise you are fine. i don't see it being a pump or injector issue. also, don't see it being a lifter issue, you would know!

    are you sure they actually installed the parts!?

  6. #26
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    2010 sprint car

    The car this 5.7 is in isn't your typical vehicle. It weighs 1800lbs, I have a 3500rpm stall, 5.57 gear in the rearend. The fuel pump and pressure regulator are external there is no pump in the fuel cell. I went out and bought a 5.3L out of a silveraro to put in and see what my drive train loss was. It made 240 at the rear wheels with my ls6 intake and a set of headers on it. So that eliminated major loss of power through my drive train. The 5.7L is at the machine shop now, he got it torn down completely and the bearings were all fine. When I first put this motor in my car I had stock heads and a comp. thumpr cam. It made 340HP which everyone told me was low for a 5.7L with headers and a cam with the LS6 intake. SO I'm thinking the problem is in the lifters and not having the cam degree'd in. We're going to put in all new bearings, and a new set of lifters, with a new timing chain set and see what happens. We did use a wideband in the pipe during the tune and the A/F ratio was good throughout the RPM range with stock 28# injectors. My guess is that since i pretty much run open headers, that if I have a lifter or 2 partially collapsed that I may not even hear it at idle, and at higher RPM'S it would just be starving the motor of flow by not opening the valve all the way.
    The guy at the machine shop has a tool to check the reluctor to make sure it is set where it's suppose to be. That could also be causing some problems.

  7. #27
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    2010 sprint car

    I finally got the motor back together and tuned. and the only thing that got replaced that could have made any difference in HP was the lifters. It made 415HP this time, I guess my engine at one time or another sat for too long and a few lifters went down and didn't pump back up like they should have. Thanks for all the help and ideas.

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