alright check this out...my 88 305 TBI
5 speed used to max out at 130 MPH....
then i put a ram air induction kit on it..
(ran 4" alumin. tubing from the bottom
of the car to the intake neck...gutted
the thermvac flap and plunger)then took it
out and topped out at 110MPH...went back to stock air intake setup and im still maxing out at 110...help me out!!!!!!Whats wrong???
------------------------------------------
SPEED

 

Hmm.. This is a long shot, but did you plug the vacuum line running to the thermac?

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

did you get rid of your speed limiter by chance

 

I would say if he lost 20mph on top his speed limiter decided that he is a crazy man, and decided to work again, ALL 305 TBI engines in RS's and firebirds 88-92 had speed limiters at 110-118mph (fuel cut off)

if it is an 88 Iroc with 305 TBI (88 or 87 last year, can't remember) then I don't know.

------------------
1989 Trans Am GTA

 

You did not run 130 MPH originally with a stock 305 TBI motor. It doesn't have nearly the Wheaties to pull that kinda top end, cold air kit or no.

 

The wheaties, lol. What about the 305 TPI cars, whats their top end around?

------------------

1992 Formula 350
-SLP 1 3/4 Headers
-Ported Plenum, Polished w/ polished runners
-Airfoil and other small bolt on mods

 

My 89 305 TPI with 2:73's would get to 120 or so and then the stupid upshift/downshift issue would come into play. That reminds me, i have to install the valve to stop that. My 85 LG4 T/A with 3:23's maxed out at 137 MPH.. and that was on a slight down hill.

 

yup..... i did

 

alright it was 127........

 

Like the others have said, if you have a 305tbi engine the limiter is right at 108mph, atleast from all of the stock 305tbi bins I've seen, If you haven't disabled the speed limiter(either by reprogramming the prom or disabled the VSS "temporarily"), How do you know you were going 127mph? Do you have a speedo that goes past 85 or 110mph? Or are you guessing about the speed??


Brendan


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1987 IROC-Z L98,SR,EB 6085's,LPE 219/219 Cam, Crane 1.6RR, EB TPI Base, 58mm TB, Stock T5, 30lb SVO, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, Aluminum DS, 94 Disk Rear, Adjustable Prop Valve, Precision 3.73 Gears, Weld in Sub-Frame Connectors, Hotchkis LCA's, KYB Shocks/Struts, Poly Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm, Big stereo, 730SD Conversion.

To see the ROC, Check out the webpage Here

 

What kinda E.T's are you turning
how much was the cost of those parts in your car???

 

Perhaps you overrevved the engine and the valvesprings lost their temper.