Lost power
Lost power I was making 400rwhp/390rwtq with an LPE gt2-3 cam.
I rebuilt the motor added long tubes and FM13. Results were 398RWHP/379RWTQ and the torque curve sucks. This seems strange to me. Both tests were on the same dyno.
Here is the only thing that I don't know for sure. I had the heads surfaced and when I picked them up from the machine shop they told be they milled them. I asked them about that because when I had it done at MTI they came back shaved just enough that you could still barely see the gasket material. This time they came back completely clean with a lot of metal shavings on them. I asked them how much did you mill them and the answer was I don't know, a couple of thousands. Anyways, they were already milled .15 plus the MTI cleaning now this unknown amount.
I notice that the engines valves aren't as loud(slaming shut). Do you think that the pushrods(7.4s)are now too long and the valves aren't closing? Would this cause a lot of power loss? Anyone have a different idea. The heads btw are GTPs. Thanks.
I rebuilt the motor added long tubes and FM13. Results were 398RWHP/379RWTQ and the torque curve sucks. This seems strange to me. Both tests were on the same dyno.
Here is the only thing that I don't know for sure. I had the heads surfaced and when I picked them up from the machine shop they told be they milled them. I asked them about that because when I had it done at MTI they came back shaved just enough that you could still barely see the gasket material. This time they came back completely clean with a lot of metal shavings on them. I asked them how much did you mill them and the answer was I don't know, a couple of thousands. Anyways, they were already milled .15 plus the MTI cleaning now this unknown amount.
I notice that the engines valves aren't as loud(slaming shut). Do you think that the pushrods(7.4s)are now too long and the valves aren't closing? Would this cause a lot of power loss? Anyone have a different idea. The heads btw are GTPs. Thanks.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
As stated above, it could be a variety of things and too long p-rods could be the problem causing too much preload (W/ non adjustable rockers)
IMO measure the head deck thickness, that will tell you how much it is milled. Once this is known, you can make a decision on the p-rods.
Can you post a graph of your dyno??
IMO measure the head deck thickness, that will tell you how much it is milled. Once this is known, you can make a decision on the p-rods.
Can you post a graph of your dyno??
Last edited by cyphur_traq; May 31, 2005 at 12:15 PM.
Originally Posted by Drew778
Dude, he came here asking for help and all you guys have to say is you should change the title, STFU ALREADY 
And one of the things the fixed my problem was going back to my LS1 edit tune so HPT STILL SUCK IN MY BOOK
And one of the things the fixed my problem was going back to my LS1 edit tune so HPT STILL SUCK IN MY BOOK
The reason this site even exists for him to ask his questions is because of sponsors, one of which is Futral Motorsports. Why would any business in their right mind allow someone to bash a sponsor's product without evidence that it actually caused a problem?
He came here asking for help, and I see none offered in your reply so I guess that makes us both equally helpful.
Also, he could have asked for help without bashing any product...Regarding your tuning problems... I can't help it if you can't figure out how to use HPT...
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Guys, there was no bashing IMO.
It was evident from the rest of this thread, that the FM 13 was not the culprit.
This is not editing. This is censorship.
Pardon me for saying that the power given to directors is being slightly overused here.
You guys know that I love being here, but please, let us not turn into media freaks.
Respectfuly
Mark
It was evident from the rest of this thread, that the FM 13 was not the culprit.
This is not editing. This is censorship.
Pardon me for saying that the power given to directors is being slightly overused here.
You guys know that I love being here, but please, let us not turn into media freaks.
Respectfuly
Mark
Trending Topics
I didn't edit this thread b/c Futral was mentioned, I edited it b/c those posts were entirely off topic and didn't help him achieve his goals whatsoever. Please keep this thread on track and address any issues you have with me via PM.
If you notice the first post still claims the F13 is the culprit. Don't you think if I was protecting Futral's interests I would edit that out as well?? C'Mon now....
If you notice the first post still claims the F13 is the culprit. Don't you think if I was protecting Futral's interests I would edit that out as well?? C'Mon now....
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Verdad Gallardo No Fm bashing from me, there are too many people making good power with them(cam only), that's why I went with this cam. What I am asking for are ideas of why I would lose power when clearly the changes I made should have gained me some power. I suspect that the heads might be milled more that my guess of .20th. BTW, I fly cut my pistons but the cam should have cleared with the heads milled .30 as long as my valves weren't 2.05's. I was hoping to hear the pushrods were my problem since I don't have the valve clatter I used to have with my last 2 cams. The heads have isky dual springs on them. Thanks again.
Originally Posted by PREDATOR-Z
I PM'd you back. After reading it, I hope you understand my reaction.
No harm intended.
No harm intended.
Speedfreak, find out exactly how much your heads are milled, figure out how much your pistons are flycut, and call FMS. They should be able to help you out a little.
Have you tuned for this cam already?
