i already did the tv cable thing
and have heard there r sum springs or wieghts
near the shaft that u can adjust? in the tranny

right now my car shifts at 4300 at WOT want to make that
near 5k

what can i do to beef up the tranny without taking it out?
besides shift kit(plates?)

servo,boost valve???

 

If you have TPI you really don't want to shift much higher then 4300 because you power drops off real fast after 4500. You can buy a shift kit that will help you shift higher.

 

i dont have TPI

 

Get the Trans-Go Shift kit, this will fix the TV problems and allow you change shift timing springs and governor springs. If this does not give you the hi-rpm shifts you want, then try a lighter weight governor. If you want firmer shifts then put in larger boost valves pssibly the Corvette servo. If I can be of help, let me know.

 

Something is wrong with my weights then cuz mine shifts at just over 6000. Did it do this from the factory?

Patrick DeGrosse Jr.

 

yo patrick
. i dont think a chevy engine can rev upto 6000 rpm (without special valve springs and lifters and cam)

its power band is much before the 5500 range

6000 rpm i havent seen a camaro engine do that stock

ur tach might be wrong/.....

are u sure it revs so high??

 

yeah and an after market prom raises shift points as well... but not that much...

 

Our eproms do not control anything on the transmission other than converter lockup.

 

I dont think my tach could be off that much. But in first.. at a WOT run.. it will tap 6500 before it shifts. Obviously I've only done this like twice for fear of breaking stuff. But why does it rev so damn high? Also, it is definietly making power that far up.. seems to pull its hardest at like 5500. Whats the deal..

Patrick DeGrosse Jr.

 

hey the hypertech advanced my shift points byy a lot

1-2 takes place (if i stepp on the gas hard) @ like 5200 RPM at most

but most of the power is by 5000 rpm u are right

ur tach must be offf
at 6000 rpm
engine should sound as though its gonna break up .. too much vibration...

 

umm
anybody have a dyno sheet for stock TBI

but i think toque peak is at 2400?
its prolly a little more with those mods maybe 3k

i would think shifting a mostly stock tbi would do well
right after 5k

i dont think power is made after 4500 but i think thats tpi

 

yeah tallboy u are right

i have a v6 MPFI mine revs upto 6000 rpm
but its after a lot of mods on the engine and its not good too to rev it that high


i have not seen a v8 tbi go that high on the revs

thats why i was asking patrick here as to his tach is working or not

 

Well now i'm really interested... cuz at say... 5500 or 6000 it sounds just fine. Sounds like a strong pulling V8 at the end of its usefull wind-up. I can't see how my tach could be off though. Any other thoughts on the matter? As my sig says... i think it had a chip put in it at one point by a previous owner. Not sure though.. i really should check i guess. Thnx guys..this has really got me going now...

Patrick DeGrosse Jr.

 

Hey, ive had the same problem. Dont lecture me on how bad this is, but my TBI car has seen 6500 rpms before. But, as someone mentioned earlier i think my tach may be off somehow because in overdrive on the highway it says im cruising at 3000 rpms @ 70mph, and yes my overdrive works. At the same time though, i get a good 26 mpg on the highway. So, the tachs gotta be off, because otherwise with my driving style and those rpms my car should have blown up long ago.

85 Berlinetta 2.8 Auto
91 RS 5.0 TBI Auto, 14x3 K&N open element, Cat removed, Flowmaster exhaust

Future mods: 4 inch cowl hood, complete MSD ignition, manifold, ultimate TBI, and injector upgrade.

 

Is there a way to calibrate the tach? Or can i check its accuracy with a multi-meter (one for a car that has a tach on it.. along with dwell.. amps.. volts.. etc.)? Thnx

Patrick DeGrosse Jr.

 

This is on your 89? How did it do that? Since the computer does not control the shift points.

 

As pointed out, the '89 only has ECM L/U control. If the shift points went higher with this alone, BACK OFF! It means that your tranny is now slipping!

 

yeah guys u are rite ... its the cable that was adjusted... i asked my mechanic he did it when i did the rebuild...

and transfixleo ...even b4 that i had that drop problem in revs

b4 adjusting that shift cable it used to drop 2800-2600 after adj it drops from ~3400 to ~3000

my mechanic thought it will fix the problem... but no it didnt

 

So.. any ideas for me? Could my tach be that far off? like more than 1000 RPM it would seem...

Patrick DeGrosse Jr.