What compression should the cylinders be in a low compression FI motor?
Originally Posted by Mike 01WS6
You need to start running better gas at the power levels your pushing. Damn near 900rwhp on 91 octane is just asking for it. Run at least some 100 for those power levels just to be safe. 104 or 110 when you're beating on it wouldn't be a bad idea either...but anything is better than 91!
Ya, well I was told I can run 91 octane and be perfectly safe on this tune (which I havent touched at all)...
The whole purpose was to have a build that was a somewhat streetable pump gas setup, so im not gonna throw race gas in there unless I need it like during the summer time for securitys sake.
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
Originally Posted by mahhddgtp
You come online, post your problem, and bail on the thread.... Do not bail on this thread 
. Keep us updated. Good luck on the motor.
. Keep us updated. Good luck on the motor.I think we might try to pull the head after we check compression on the other side to see if its just that one main cylinder thats having issues or if its a general lack of compression for the whole motor.
But hearing the car idle it just idles a little bit rougher then normal, you wouldnt be able to tell theres something wrong until you start getting into part throttle under load.
Originally Posted by F8LWS6
Don't start or run that thing until you pull the head. That spark plug damage might be serious. I hope its nothing bad. Your car is flat out amazing. Good luck!
I just have bad luck with this car, lol. Maybe one day it will be good to me for longer then a week.
Originally Posted by BIG BAD BLACKSS
Id imagine detonation, bad detonation. What octane fuel were you running? Who dyno'd the car? They didnt say anything?
I guess it was running about 15 lbs too that day... Its wierd cause the boost is set to run 14 or so, could the excessive humidity with cold air cause the boost to jump a lb or too in boost?
Arizona dyno chip dynoed the car, the guy who ran it "NicD" the local tuner guru here said it looked to be ok but any more is definately not good.
He mentioned something about it reaching burst knock or something?
And for a smaller amount of time it was reaching 110% DC, so maybe lack of fuel could have done it...
I dunno, I guess I'll just have to take it one step at a time and see what happens.
Originally Posted by mikep2002
Pull those heads!!!!!!!! Did you try to rotate motor by hand before you started it up to see if anything was getting hung up. Is it a new build?
Remember those posts you had about the car overheating? This is the result of that.
900hp on pump gas and beating on it all the time takes it's toll.The motor wears out extremely fast.We always recommend driving at a low boost level and only turn it up if it calls for it.
More than likely you need to pull the heads off and really see whats going on.I'm guessing the pistons are junk.
900hp on pump gas and beating on it all the time takes it's toll.The motor wears out extremely fast.We always recommend driving at a low boost level and only turn it up if it calls for it.
More than likely you need to pull the heads off and really see whats going on.I'm guessing the pistons are junk.
Originally Posted by ddnspider
i dunno my motor was 103-107 across all cylinders and runs fine.if theyre supposed to all be within 10% of eachother that 90psi cylinder might be toast.did you do a leakdown test or just a compression test?
edit....trans zam you have more car problems then me and i didnt think that was possible.just try to keep going cause evertime you go WOT it makes it worth it.
edit....trans zam you have more car problems then me and i didnt think that was possible.just try to keep going cause evertime you go WOT it makes it worth it.
Ya, it seems like a never ending battle and just gets so discouraging. It was hard enough to have the initial investment, but having to put more and more money and time into this car each week just isnt as feesable for me as I like.
Its not even a matter of that, I just dont have the time, patience, or know how to diagnose problems as they come, so the car sits for a while till Im able to get it figured out.
At least I still have my health, lol.
Originally Posted by Slowhawk
Remember those posts you had about the car overheating? This is the result of that.
900hp on pump gas and beating on it all the time takes it's toll.The motor wears out extremely fast.We always recommend driving at a low boost level and only turn it up if it calls for it.
More than likely you need to pull the heads off and really see whats going on.I'm guessing the pistons are junk.
900hp on pump gas and beating on it all the time takes it's toll.The motor wears out extremely fast.We always recommend driving at a low boost level and only turn it up if it calls for it.
More than likely you need to pull the heads off and really see whats going on.I'm guessing the pistons are junk.
believe it or not, Id assume I only put maybe 500-1000 miles of actual hard driving on it, and maybe 100 have been done while it was having those overheating issues.
Other miles were from breaking in the motor, new clutches, and just freeway driving back and forth to work.
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Originally Posted by Pro Stock John
When I have seen spark plug gaps get closed up by something else, it's been pieces of piston. It could be part of a valve too.
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Joined: Jul 2005
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Likes: 3
Originally Posted by 2000 Tran Zam
believe it or not, Id assume I only put maybe 500-1000 miles of actual hard driving on it, and maybe 100 have been done while it was having those overheating issues.
Originally Posted by 2000 Tran Zam
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
Originally Posted by ddnspider
damn that thing is chewed up,why does the base of it look clean?
Originally Posted by 2000 Tran Zam
Ya, well I was told I can run 91 octane and be perfectly safe on this tune (which I havent touched at all)...
The whole purpose was to have a build that was a somewhat streetable pump gas setup, so im not gonna throw race gas in there unless I need it like during the summer time for securitys sake.
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
The whole purpose was to have a build that was a somewhat streetable pump gas setup, so im not gonna throw race gas in there unless I need it like during the summer time for securitys sake.
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
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Joined: Jul 2002
Posts: 1,218
Likes: 1
From: MI
Originally Posted by 2000 Tran Zam
Ya, well I was told I can run 91 octane and be perfectly safe on this tune (which I havent touched at all)...
The whole purpose was to have a build that was a somewhat streetable pump gas setup, so im not gonna throw race gas in there unless I need it like during the summer time for securitys sake.
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
The whole purpose was to have a build that was a somewhat streetable pump gas setup, so im not gonna throw race gas in there unless I need it like during the summer time for securitys sake.
Plus its been in the 40's and 50's F* so heat wouldnt be an issue if detonation is the cause.
.02
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Joined: Mar 2004
Posts: 604
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From: Loganville, GA
Air in the winter is cooler, thus denser... Your motor will be taking in more air than normal! So yes, you'll run leaner in the winter... I can see this being your problem. Like spider said, 1.5 POINTS leaner!!!
It's winter, since you're going to have traction issues, why not turn that boost down? Yeah, you'll make less power, but what's the point if you can't put it anywhere! Sorry to kick a man while he's down, but it's the truth... (or you could've thrown more fuel at the problem, allowing you to keep 15psi)
It's winter, since you're going to have traction issues, why not turn that boost down? Yeah, you'll make less power, but what's the point if you can't put it anywhere! Sorry to kick a man while he's down, but it's the truth... (or you could've thrown more fuel at the problem, allowing you to keep 15psi)