I guess the next step.....4000+ stall....there goes streetability
Fast 90/90 Falling on it's face:(
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On The Tree
Joined: Jan 2006
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From: Jersey
Fast 90/90 Falling on it's face Have a friend with a '99 T/A ported heads, Cam roughly 242/248 .610+ lift 114+2 LSA, and 3600 stall/3.73's. He's thinks he's eliminated tuning as a problem....but launching...it totally falls on it's face until he hit's second, then it's pulls like a SOB. Does going from an LS6 to the FAST 90/90...require a higher stall, different cam? He thinks it's the manifold...but I think maybe a vac leak or the tune...hisses like a **** and doesn't idle for ****. The reason I think maybe the tune as well is because he's one of those guys that doesn't believe in dyno tunes 
The problems he has are under load...which is why he should stop getting second hand tunes from people who says it works! In my experiance every engine is different...why would you cut yourself short! Get the damn thing on a dyno, and find the problem 
Anyway...what are your thoughts guys.
The problems he has are under load...which is why he should stop getting second hand tunes from people who says it works! In my experiance every engine is different...why would you cut yourself short! Get the damn thing on a dyno, and find the problem Anyway...what are your thoughts guys. Last edited by Rabidbandit; May 28, 2006 at 11:01 AM.
i think he has too much cam and not enuff stall. another thing is the 90mm fast TB might be leaking and sucking in air other than where its supposed to. i have that problem right now, FAST was supposed to be fixing them but i think theres still problems with them, ppl began switching to the Nick Williams TB, spray the around the TB to find the leak with wd40...(this is what i did) this can really be a problem in idling. and look into a bigger converter
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Originally Posted by Rabidbandit
.hisses like a **** and doesn't idle for ****.
1) When you install the FAST intake you need to push the front LS6 coolant line downward to allow the the front, bottom of the intake to clear. This will allow the intake to seat properly on the heads. Also look at the front of the intake to make sure both sides of the intake are seated on the heads evenly.
2) Check the TB to intake area for leaks. Should be no gaps between the two surfaces. Also make sure the very top bolt (12 O'clock position) is installed and seated correctly.
3) The FAST intake has no clip to hold the MAP sensor in place like the OEM intakes, so you need to fab up a bracket to hold it in place. Some just cake RTV sealant. I just created a "L" bracket by extending the most rear intake bolt upward and adding a small metal bracket to extend over the MAP sensor which is held in place when the bolt is tightened down.
Another tip; The NW TB has no hole drilled in the blade so you need to really open up the blade with the set screw. I remove the bellows so I can visually check it.
Hope this helps.
Hopefully you didn't overtorque the bolts and crack the intake...worse case scenario. Maybe the intake is uneven on the heads...check placement. Could be an injector o-ring. My advice would be to take the intake back off and inspect all gaskets as well as the intake.
Definately needs to be dyno tuned with that setup... if anything at least dyno it to see how the combo looks on paper so you can see if there are any valvetrain issues, A/F ratio, ect and adjust from there.
Additionally, once the tune is good and leaks fixed (if any) most of the falling on its face is probably coming from the cam/stall combo. I had a 242/250 .612/.612 on a 109LSA installed on my previous SS and it did pretty much the same as you mentioned.... falls on its face on take off (I was launching with slicks off a 2 step at 6500 and had 4.30 gears in a 12 bolt
) but pulls like a raped ape once into second and definately through 3rd, 4th. Just the nature of the beast running an M6 with that size of cam.
A cam of similar size, as your friends is, has a very high power band and wont perform well unless its there (obviously). Depending on what brand of stall he's got, chances are its not enough for that cam.
Additionally, once the tune is good and leaks fixed (if any) most of the falling on its face is probably coming from the cam/stall combo. I had a 242/250 .612/.612 on a 109LSA installed on my previous SS and it did pretty much the same as you mentioned.... falls on its face on take off (I was launching with slicks off a 2 step at 6500 and had 4.30 gears in a 12 bolt
) but pulls like a raped ape once into second and definately through 3rd, 4th. Just the nature of the beast running an M6 with that size of cam. A cam of similar size, as your friends is, has a very high power band and wont perform well unless its there (obviously). Depending on what brand of stall he's got, chances are its not enough for that cam.
Originally Posted by LETHL_ZO6
Definately needs to be dyno tuned with that setup... if anything at least dyno it to see how the combo looks on paper so you can see if there are any valvetrain issues, A/F ratio, ect and adjust from there.
Additionally, once the tune is good and leaks fixed (if any) most of the falling on its face is probably coming from the cam/stall combo. I had a 242/250 .612/.612 on a 109LSA installed on my previous SS and it did pretty much the same as you mentioned.... falls on its face on take off (I was launching with slicks off a 2 step at 6500 and had 4.30 gears in a 12 bolt ) but pulls like a raped ape once into second and definately through 3rd, 4th. Just the nature of the beast running an M6 with that size of cam.
A cam of similar size, as your friends is, has a very high power band and wont perform well unless its there (obviously). Depending on what brand of stall he's got, chances are its not enough for that cam.
Additionally, once the tune is good and leaks fixed (if any) most of the falling on its face is probably coming from the cam/stall combo. I had a 242/250 .612/.612 on a 109LSA installed on my previous SS and it did pretty much the same as you mentioned.... falls on its face on take off (I was launching with slicks off a 2 step at 6500 and had 4.30 gears in a 12 bolt
) but pulls like a raped ape once into second and definately through 3rd, 4th. Just the nature of the beast running an M6 with that size of cam. A cam of similar size, as your friends is, has a very high power band and wont perform well unless its there (obviously). Depending on what brand of stall he's got, chances are its not enough for that cam.
Originally Posted by Jpr5690
Christ! Its Ovbious The Fast Dosent Make That Big Of A Difference If He Ddint Have The Prob Before The Intake It Has To Be The Intake Not To Mention The Strange Hissing Noise And Bad Idle Which Are Telltale Signs Of An Intake Leak.. Did Your Freind Follow The Tq Sequence On The Manifold ?
anyway sounds like a vacuum leak as suggested by everyone. Either a vacuum line or the intake is sucking air. Its either or. Get the leak fixed and then you can tune it.Now as far as tuning goes he isnt going to get a descent tune unless someone does some logging to see that the hell is going on and makes adjustments from there. Most people will use a dyno for this. But you can log while you drive. A mustang is the better of the two as it puts a "load" on which simulates real world driving to the car. Dyno jets only tune for WOT. Without a proper tune his car will never see its full potential.