Hi Guys,
I have an 85 Camaro that has a sb 400, turbo 350, 373 rear. The car goes like hell, but tops out at about 120km doing around 4500 rpm. Is this normal? What if I was to swap the turbo for a 700r4? would that make a difference in top end speed? Maybe even a locking torque convertor?
I would love to drive this car over 90km safely while still being able to waste a Ford off the line. Thanks Guys!

 

Anyone?

 

What do you mean by "tops out"? You've got it floored and it won't go any faster than 75 mph? Or, are you just saying at that speed, your engine is turning 4500 RPMs?

Assuming it is the latter, a TH700R4 would lower your RPMs for a given cruise speed, but would have to be modified to shift into overdrive at WOT for "top end speed". The TH700 would also help you "waste" the Fords off the line because 1st gear is a higher numerical ratio than the TH350.

A lockup torque convertor can only be put into TH350C's, so unless that's what you have, you're stuck with a non-lockup convertor. If you want to know what you have, look just above the pan close to the shift lever on the tranny for a plastic electrical connector: It's there, it's a TH350C; nothing there, it's a non-lockup TH350.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.73 unlimited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, TBD heads, exhaust, paint, etc.).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

I don't mean to be argumentitive here but It's my understanding that a 700R4 is uses a lock-up converter also. You could swap in a 700. In that scenario you would launch harder due to the aformentioned lower ratio first gear and have a lower RPM at cruise due to the overdrive. Sounds like having your cake and eat it too....

 

I assumed he meant putting a lockup TC on his current TH350, not a 700R.

Yes, a TH700R4 has both overdrive and lockup TC, as well as the aforementioned lower 1st gear. If you can handle the bigger jump from 1-2 (and most people can), then you've got the best of all worlds. Still, with respect to the question about top end speed, an unmodified 700R would not make higher top speed because it won't go into overdrive.