Can't get the car to RPM pass 5100?????
- Thread starter Chris McDade
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Thanks for all the sugestions guys. I have noted them all and will try them all. I have yet to find the the problem. I just ordered a new coil pack and module from the dealer (GM) so im going to try that this weekend. I don't the ME chip has a rev limiter in it. Does it Steve?
I have the valve covers off the car right now checking the lift on the cam to make sure I don't have any lopes going out. Everything looks good so far.
I will keep yall updated.
Thanks
I have the valve covers off the car right now checking the lift on the cam to make sure I don't have any lopes going out. Everything looks good so far.
I will keep yall updated.
Thanks
turbov6joe
Signal 1 J-12
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Chris,
I had a similiar problem with my GN that turned out to be too much fuel at the upper end of the rpm range. I had the chip leaned out up high... BANG, the EGT's were up where they should have been (1600º-1670º) and it pulled crisp to 6000rpm. What are your EGT's on a WOT pass for a 1/4 mile? Something else I would see is the boost would flutter up high...lack of exhaust velocity....spitting raw fuel. When it was leaned out it was rock solid! With my TTA I also ran into this problem once again with a chip that had an injector DC of 90 something %. When I switched over to alky/pump and the TE45a, 72%-76% DC seemed to be just about perfect, ~86% DC for just race gas.
I had a similiar problem with my GN that turned out to be too much fuel at the upper end of the rpm range. I had the chip leaned out up high... BANG, the EGT's were up where they should have been (1600º-1670º) and it pulled crisp to 6000rpm. What are your EGT's on a WOT pass for a 1/4 mile? Something else I would see is the boost would flutter up high...lack of exhaust velocity....spitting raw fuel. When it was leaned out it was rock solid! With my TTA I also ran into this problem once again with a chip that had an injector DC of 90 something %. When I switched over to alky/pump and the TE45a, 72%-76% DC seemed to be just about perfect, ~86% DC for just race gas.
Chris McDade
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Joe,
You right it could be the fuel in the chip. About a month ago I took the car to the track fighting this same problem and on one pass the EGT read 2001. I about sh%t! I think it was nothing but raw fuel. I didn't blow a head gasket so it must of been raw fuel. Im sending my chip back to steve Y to do some tweaking to it. Im going to tell him to take some top end fuel out of it. The boost does tend to creep a little on the big end.
Thanks
You right it could be the fuel in the chip. About a month ago I took the car to the track fighting this same problem and on one pass the EGT read 2001. I about sh%t! I think it was nothing but raw fuel. I didn't blow a head gasket so it must of been raw fuel. Im sending my chip back to steve Y to do some tweaking to it. Im going to tell him to take some top end fuel out of it. The boost does tend to creep a little on the big end.
Thanks
Chris McDade
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Yes, Steve I know 
The chip is on they way to you Steve. You should have to tomorrow. Im overnighting it to you.
The chip is on they way to you Steve. You should have to tomorrow. Im overnighting it to you.
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How fresh is the motor? Do you hear any noise from the bottom end? How is your oil pressure? Had this issue with an old combo, and the cam was wiped and the main bearings were showing wear.
Don't like to sound negative, but it appears you have tried and checked everything else it could be.
Don't like to sound negative, but it appears you have tried and checked everything else it could be.
Chris McDade
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I just checked the cam so I know it's good. I also just put new bearings in the motor about 5 months ago. Oil pressure is good.
Just did a compression check and all was good there.
Thanks
Just did a compression check and all was good there.
Thanks
Chris McDade
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Steve,
Using Stock Balancer
Using Stock Balancer
Chris McDade
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Right now the boost is around 20-21lbs. Im trying not to push the car to hard right now until I find the problem. When the car is running good I will go up to 27-29lbs. 30lbs is about the limit for me.
Later
Later
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In that case, please post what caused this once you fix it. Sounds like it may be something out of the ordinary.
One change Chris made at the same time this problem arose (from what I understand) was switching to 1.65 ratio rockers with the same cam. I am wondering if he should switch back to stock ratio because it acts like he is losing cylinder pressure for some reason after the motor gains rpm's.
Steve
Steve
Chris,
I had this happen to me on 3 different occasions. Twice was worn cam lobe, once it was worn valve springs. It would pull fine to 5200 then it was exactly like I had a rev limiter set at that pint. Did on the Dyno, did it at the track. I didn't see any mention of valve springs so may want to check those as well.
HTH
Sully
I had this happen to me on 3 different occasions. Twice was worn cam lobe, once it was worn valve springs. It would pull fine to 5200 then it was exactly like I had a rev limiter set at that pint. Did on the Dyno, did it at the track. I didn't see any mention of valve springs so may want to check those as well.
HTH
Sully
Reply
Try gapping your plus to 025 & see if proplem goes away. If it does your ignition system isin't keeping up with demand. If you havent already test your fuel pressure at WOT do so. Should be 1# increase for # of boost over base FP . Check in tank pump & sock. Make sure there is no leakage @ pump hose connection where it is clamped to the sending unit. I have also seen where people get too carried away with jacking up fuel pressue. A properly designed chip shouldnt require much more base FP then stock. Assuming that you have chosen the correct injectors for the application. Good Luck!
Try gapping your plus to 025 & see if proplem goes away. If it does your ignition system isin't keeping up with demand. If you havent already test your fuel pressure at WOT do so. Should be 1# increase for # of boost over base FP . Check in tank pump & sock. Make sure there is no leakage @ pump hose connection where it is clamped to the sending unit. I have also seen where people get too carried away with jacking up fuel pressue. A properly designed chip shouldnt require much more base FP then stock. Assuming that you have chosen the correct injectors for the application. Good Luck!
