I have read some of the threads on where shift points should be in MPH, and my car seems to be off considerably from the consensus. I am a new GN owner (about 1 month now), and the car I bought has had the tranny and rear-end rebuilt about 3 years (15k miles) ago(previous owner said 3.73 gearing, builder thought 3.42).
Problem is if I shift at 5,000 RPM (per stock tach, which of course is probably wrong), I am at 35 MPH from 1-2, 55 from 2-D and about 85 from D-OD. Tire size is 265/50/15.
I would have thought that especially in second gear and drive my top speed would have been much higher (I read about guys tripping the lights well over 100 MPH in Drive).
Is it possible that I have 3.73's? or does something else need to be adjusted? TCC or TV Cable or ?
Could my tach be off that much? At 60, it seems to be running about 2,400, which seems a few hundred RPM's higher than what I read should be normal.
Any thoughts would be much appreciated.
Chris P.
Get an accurate tach or a scantool to verify rpm. These factory tachs generally read high now.
Jack it up and turn the wheel and see what rear end it has.
I agree with Steve,
The factory tach is about as useless as can be. If you want to enjoy your "new toy" before you do anything GET A SCANTOOL--- Turbolink, Direct Scan, or Scanmaster. They should have been origional issue with these cars. Without it you can be guaranteed of a lot of problems that you cannot diagnose. Also, you will want to learn about your car as much as possible (Using the GNTTYpe web page resourses naturally.) If you depend on a local mechanic or buddy who is not well versed in GN and TRs you will be throwing $ down a rat hole. Amazingly there are a LOT of mechanics who are very good at normal cars but don't have a clue regarding these cars.
Welcome to the dark side :^)
Thanks guys, I have been thinking about getting a Scanmaster II. I saw that Kirban has them for $250. Anywhere else to get one cheaper?
I also am going to take the car to local guy here (Seattle area) who just moved from CA where he worked at Mr. Buick's at did a lot of Turbo work.
Thanks, Chris
If you have 3.73s, that combined with the slightly shorter rear tire you're running could run the RPM's up quite a bit.