80CamaroTPI

I have a 1980 Camaro with an '86 Vette L98, 700r4, 10 bolt rear with 3.73's, and 24 inch(ish) tall tires.

3 summers ago, I replaced the stock (for the Camaro) 2.56 rear gears for the 3.73's and a posi unit. I was so excited to drive the car to see the huge difference. However, I was disappointed. If I am crawling around the street (15-20 mph), and floor it, it just lugs and chugs. I want to say it was around 2k rpm like this. No tire spin, no great lunge forward. Is the trans shifting into 2nd, and not shifting back, or is the converter (stock) at full lock up?

If my memory serves me correctly, I think I have kept it in first, and was at a pretty high RPM (3k rpm-ish?) at that speed.

Any ideas from you guys?

P.S. I'm pretty terrible explaining things by typing them out, so if you need clarification on any of this, please feel free to ask.

confab

You may need to change your governor springs, because it is spinning much faster now. There are kits available for tuning the governor. They're pretty much all the same.

Not a real picky part.

gerardvg

Hi is your TV cable adjusted correctly?

I usually adjust mine so there is no slack at full throttle, it governs line pressure and can affect shift points.

For reference my corvette with T700 and 275 40 17 tires with 3.07 rear runs at 62mph = 1800 rpm with torque converter locked.

The torque converter wont lock with hard acceleration, I can easily light the tires up without trying. The stall speed should be around 2,200rpm.

With shift points will shift at around 5,500 rpm flat out or very low rpm when just running around town with very little accelerator travel.

confab

He's right about that, btw. Do not let people talk you into backing your TV pressure off to adjust shift points on the 700/4L60.

If you want maximum life from your trans, do it just like he says. Fully taut at WOT.

80CamaroTPI

Ok, so I will definitely check the TV cable, and make sure its taught at WOT.

I talked to a good friend of mine who used to build dirt track engines, and worked on many dirt track cars. He mentioned the governor springs as well.

I remember I used to fry the tires from a standstill with the 2.56's, and chirp them in 2nd. I cant remember how it acted at WOT while traveling at the same speeds. The car is usually on the road every other summer. I'd replace one thing over winter, drive it in the summer, then want to do more work next winter, turn into a bigger project, and not have it ready for the next summer. Rinse and repeat. My memory gets foggy over time.

Thanks for the help guys. I (should) be working on it this weekend, and let you know how I make out. If there is anything else that ya's think of, I'd love to hear it.

I have a couple questions regarding the engine, but I'll save that for another thread

tunedport85inject

be very careful working on your TV cable set up since if you fail to do that you can burn your clutches in about 100 miles ,cable has to be taught at WOT.As for the shifting point and your new set up, obviously a posi rear needs more torque to spin your tires since now you spin 2 tires at same time not just one when you floor the gas pedal.When you compare these different set up, posi rear VS non posi,new big tires,there are total different conditions WITH the SAME engine ...yes,you'r running a new 3,73 rear and it helps but...to re-tune your shifting point ,as told,you must change springs and weights in your governor (easy with transmission on the car),you can also add an oversized boost valve in your transmission pump (easy just drop the pan and remove the old valve by loosing the snap ring and plug)this improves line pressure .There are shift kit on the market you can buy a shift kit choosing from different stages...this totally change your transmission character...there are video on you tube...