Car breaking up at 5,500 RPM Please HELP
10-11-2006, 05:53 PM
#1
Car breaking up at 5,500 RPM Please HELP I just got my car tuned , but we could not go past 5,500 due to my D1-sc making 10PSI at 5,500 with a 4.25 pulley.
It is a 01 SS M6
Stock motor with long tube FLP headers and the stock Duel duel SLP SS cat back. (sounds good too).
Testing the car out the other day, it would fall on its face at 5,700 RPM,
My A/R on the dyno was 11.0-11.2 so i know its not leaning out , I have a intank double staged fuel pump and Motron #60 injectors,
I am also running a Alky control Methanol injection kit.
I am abot to install a larger 4.5 blower pulley to get the boost down, i only want to make 9-10 PSI at 6,000 - 6,200 RMP.
I have new NGK TR6 plugs gaped at 35
i was thinking the plugs were maybe fould , because the car ran so rich during dyno sesion, but the car pulls very hard and smooth unti about 5,500 - 5,700 RPM, or that i have to gap the plugs to a tighter 30
Also maybe the valve springs were failing,
I dont know but realy want to figure it out.
Please help
Thank you
It is a 01 SS M6
Stock motor with long tube FLP headers and the stock Duel duel SLP SS cat back. (sounds good too).
Testing the car out the other day, it would fall on its face at 5,700 RPM,
My A/R on the dyno was 11.0-11.2 so i know its not leaning out , I have a intank double staged fuel pump and Motron #60 injectors,
I am also running a Alky control Methanol injection kit.
I am abot to install a larger 4.5 blower pulley to get the boost down, i only want to make 9-10 PSI at 6,000 - 6,200 RMP.
I have new NGK TR6 plugs gaped at 35
i was thinking the plugs were maybe fould , because the car ran so rich during dyno sesion, but the car pulls very hard and smooth unti about 5,500 - 5,700 RPM, or that i have to gap the plugs to a tighter 30
Also maybe the valve springs were failing,
I dont know but realy want to figure it out.
Please help
Thank you
10-12-2006, 10:27 AM
#6
yeah thats what i heard , the plugs can foul out and cause this up top,
I just cant believe how strong it pulls to 5,500 RPM,
The car made 533HP and 505 TQ at only 5,500 at 9-10 PSI
i have only 27,000 miles on the car , would the valve springs realy be bad, or that they just cant keep up with the inceased compression and power at the higher RPM range?
I just cant believe how strong it pulls to 5,500 RPM,
The car made 533HP and 505 TQ at only 5,500 at 9-10 PSI
i have only 27,000 miles on the car , would the valve springs realy be bad, or that they just cant keep up with the inceased compression and power at the higher RPM range?
10-12-2006, 04:20 PM
#7
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We had the same issue on my friends car when we put on the STS kit...... turned out the thing would not pull past 5500 without falling on its face. Installed new plugs, no change. Tested another catted y-pipe, no change.
Changed the valve springs, retainers, and pushrods out and that motor will now pull strong up to the redline. This motor had less than 25K easy miles on it before the install.
If you want to read up on the build it's in the High Performance Pontiac magazine. White 2000 Pontiac Forumla WS6 owned by the author of the articles (4 parts) Here is a link to the final article with the valve spring issue explained. Part 4: http://www.nelsonperformance.com/med...hpp2_page1.htm
Part 1: http://www.highperformancepontiac.co...ystem_install/
Couldn't find the other 2 parts online anywhere, but you can order copies from HPP's web site if you want them.
It was very dissapointing driving the car at the track in San Antonio the night after it was tuned and it wouldn't pull on the upper end on 5psi, so we tried the 8psi with meth and it actually ran slower........ spitting and sputtering. We knew something was up so the process of elimination began when we got back to Dallas the next day.
We were ready to rip off and 11 that night and get kicked off the track
Changed the valve springs, retainers, and pushrods out and that motor will now pull strong up to the redline. This motor had less than 25K easy miles on it before the install.
If you want to read up on the build it's in the High Performance Pontiac magazine. White 2000 Pontiac Forumla WS6 owned by the author of the articles (4 parts) Here is a link to the final article with the valve spring issue explained. Part 4: http://www.nelsonperformance.com/med...hpp2_page1.htm
Part 1: http://www.highperformancepontiac.co...ystem_install/
Couldn't find the other 2 parts online anywhere, but you can order copies from HPP's web site if you want them.
It was very dissapointing driving the car at the track in San Antonio the night after it was tuned and it wouldn't pull on the upper end on 5psi, so we tried the 8psi with meth and it actually ran slower........ spitting and sputtering. We knew something was up so the process of elimination began when we got back to Dallas the next day.
We were ready to rip off and 11 that night and get kicked off the track
Last edited by searay90; 10-12-2006 at 04:42 PM.
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10-12-2006, 07:20 PM
#9
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Had the same problem exactly, chased it around, no codes...turned out to be the crank position sensor. It could be in your valvetrain though if it is all stock. FWIW...for $35 and about 15 minutes you can try a new crank position sensor.
10-13-2006, 02:52 AM
#10
very possible its the valve springs i've had that issue. get a set of comp 918's if the valve springs are good i would check the tune over. running very lean will do the exact same thing. i found that out with my car today..
