85gulstrandTA

Hey everone just looking for some Tachometer Information.
I have a 85 TA TPI, LB9, 700R4, that yellow lines on the factory tach of 5500 and red lines at 6,000 . Now from what I have read yellow should be 4500 or 5000 and red should be 5000 or 5500 depending on what your OEM cam spec's are. The car had a 3.23 posi rear B4 I put in the 3.73 posi. I've talked with other 85 and 86 TPI TA owners and my seams amist from others. To make things more strange to me is the speedo only go's to 85 mph. I'm thinking A 305 TPI 700R4 with 3.23 gears at 6,000 would be moving even out of overdrive. I'm in California but I got the TA from Nevada. What does your show ? Any ideas? Thanks

John in RI

iTrader: (167)

Web resources indicate that a 5000 and 5500 RPM linits should have been standard for these cars - but as you already know; that is not very accurate !

From the http://www.f-body.org/tech/


1985 vs. 1986 305 TPI cams:

1985 305 TPI vs. 1986 305 TPI
215 hp / 275 lbft vs. 190 hp / 285 lbft
Tach:
yellow 5000 vs. yellow 4500
red 5500 vs. red 5000
Lift:
intake .404 vs. .350

exhaust .415 vs. .385

Duration: intake 320 vs. 307
(crank) exhaust 320 vs. 311




The 85 TPI used a different Cam and the engine produced more power / less tourqe than the 86 TPI motor. The 85 TPI TA I had had a 5500 Yellow and 6000 Red line tach. The 85 MPH speedo was also mandatory in 85. That 85 Trans Am also had the very rare 25mm Rear Sway Bar and SOLID 34mm Front sway bar on it.

Here's a pic of the 85 Tach I've got:

85gulstrandTA

Hey Thanks
I wonder if anyone has driven an 85 vs 86 TA that could feel the differance? All things being even.
What if you had both motors rebuilt to stock spec's would a machine shop know the differance in one years grind vs the other ? I guess most would up grade the cam at this point anyway.
I assumed my sway bars where after market, because they are huge solid steel and baby blue. I took the front one off and found out how heavy it was...like 30 or 40 lbs I thought it was stuck on something and would not come ouy. Turns out it was just really heavy. Also I was told the car had a **** Gulstrand suspention. I took it to Burbank and had them looked at it and they said it looked like work they would do. But no way to comfirm as the guy that worked there for many years was gone. But It looked like how he would have set up the car.
Cheers

rdog30

I have an 85 TA and my tach is exactly like yours. That's how it is suppose to be.

85gulstrandTA

Hey Thanks Guys It just struck me as odd when say an 86 TPI is yellow at 4500 rpm. Thanks again for the help.
Cheers