350 w/posi, shouldn't you leave some rubber on the road?

[ruby76]

Hey guys/gals,
I've got a basically stock 350, with NO EGR or any smog stuff, true duals, no cats, 4 barrel carb and of course the vette has posi-trac rear end gears. I think I've got 3.70:1,

My question is this: If you rev er up and pop the clutch, shouldn't you see some rubber behind on the road, or is positraction just that good. It doesn't peel out at all, and hooks up real nice.

I ask cause I had a car in highschool with pretty much same 350, stock, no egr, true duals, no cats, 4 barrel carb, it however had an open rear end, I know. If you popped the clutch in it, you could sit and spin a tire all day.:confused - its easier to spin 1 tire than two

Is positraction THAT big of a difference, or is something else at play?

I recently purchased the vette and haven't had time to look deeper into it. I have had to readjust timing and carberator to get it to stop dieseling after I turn it off. And if it aint broke, Im not going to pull the engine to rebuild it until it starts using oil or is in obvious need of a rebuild. If/when I do go the rebuild route, I'll take care of this problem though! :s

 

[wishuwerehere82]

1976 L48 180 HP or L82 220 Hp. Won't burn the tires with 225's or 255's.

 

[ruby76]

255 60's. Both the truck and the vette have same size. So the 255's with posi is the difference eh? I think the carb is out of whack or something too. I don't have vacuum gage to dial it in right, same with timing. Have timing light, but I don't know what has/hasn't been done internally to the engine.

Thanks,

Jeremy

 

[wishuwerehere82]

The posi rear end is doing what it's supposed to, glued to the pavement. It's not a bad thing, but frustrating when you want to punch it and smoke. The 255/60's are too sticky to break loose. I can't even spin them on wet pavement with 200 HP.

 

[81 Corvette]

you need to add some ponies to that puppy. my 190 rated 81 was teh same way, then i added 3.54, headers, intake and a couple of other minor things. it'll leave a little rubber now

 

[Derrick]

When I had my 235s I could sit at a stop light and burn the tires down until there was so much smoke around that no one could see me inside. When I upgraded to 255s up front and 275s in the rear I can still get the tires to spin, but not nearly as good, and no more smoke! According to my GTech meter I have 190 rwhp.

 

[OLDCHEV]

You want to be QUICK or make smoke? My 1990 Vert. will not smoke the tires with
275 zr 40's which is a good thing! My puny 240 HP engine will beat any car that smokes the tires until they hook up. With the Vette positraction rear suspension, there is little chance that you could hit a bump in the road surface on one tire that would break it loose. Both rear wheels keep Planted!

Don

 

[OLDCHEV]

Bye the way, I had a new 1968 Vette with a 427, 390 HP, 4 speed when I was young in years that I know that my 1990 Vert could beat the ShXt out of off the line. The wheels would still be smoking on the 68 at 60 MPH and basicly going nowhere in a hurry!

Even a stock l-98 with aluminum heads will scare the hell out of you when at wide open throttle from a standstill.

 

[76 Sting]

Ruby,

I have the same problem and want to spin the tires a little, but not too much because it will take away ET times.:confused Some of my spec's 1976, 350 rebuilt bored .030 over, Auto trany rebuilt with shift kit, no emissions, true dual's w/ Borla and 2.25 exhaust, Shorty ceramic headers no cats, Edelbrock RPM intake, Edelbrock 1405 carb, Accel HEI disty, NOS PowerShot 125 hp, K&N Extreme filter, Stinger hood with direct type ram air injection, 360lb Monospring suspension and Blistein shocks, 3.55 gears, tires 15/225/70's.

Not using the NOS I cannot break the tires, but 80% of the time catch second gear with a cherp .

81 Corvette is right...you need to add some ponnies.

I thought after what I did to my car I would be able to do the same, but so far no luck...guessing around 250hp. . My last option is to put it on the dyno and let someone professional tune it in and see what happens.

Does anyone have any ideas??

 

[nicky d]

hope i can help
if you can replace those stock heads ,advance your timming,also use lighter advance springs in your distributor,make sure the wieghts are not sticking.
i also suggest a stall converter . read my thread posted on 1-30-05
wish you lots of luck

nicky d

 

[76 Sting]

hope i can help
if you can replace those stock heads ,advance your timming,also use lighter advance springs in your distributor,make sure the wieghts are not sticking.
i also suggest a stall converter . read my thread posted on 1-30-05
wish you lots of luck

nicky d

Nicky thanks for the reply. I knew sooner or later the heads had to be replaced and the converter too. Personally I think a lot of it is the converter. I was told the stock converter is around 1400 to 1600 stall? I am probabally looking at around $2300 for everything and cannot go there yet (the wife will kill me). So I am thinking of the stall from B&M Nitro Hollshot 2400. what do you think.

Do you know if it made a big difference off the line? Are you using a additional trany cooler?

 

[81 Corvette]

you could also put some over inflated rock hard tires on the back. then pull into a puddle of bleach. That make some smoke.

 

[76 Sting]

you could also put some over inflated rock hard tires on the back. then pull into a puddle of bleach. That make some smoke.

But then I couldn't breath and enjoy what I have accomplished.

 

[Wolverine]

Ruby76,

I agree with some of these posts - you have something out of whack. I have a nearly stock '76 L82 with 255x60's and I can SMOKE those tires when I pop the clutch.

 

[ruby76]

Ruby76,

I agree with some of these posts - you have something out of whack. I have a nearly stock '76 L82 with 255x60's and I can SMOKE those tires when I pop the clutch.

I agree, I'm betting on the carb is just WAAAY out of whack. This spring I'll buy (or borrow) a vacuum gauge and tune the carb in. I've heard the vacuum test is the best way to adjust carb and timing.

Thanks folks, I figured something was out of whack.

 

[hzl6cm]

My 70 with basically a stock engine, 4-speed and the factory posi easily burns rubber, bath tires, in first and when I shift in to second. Even my '03 Siverado with a locking diff, 5.3 V-8 and an auto easily burns rubber with the stock 275 width tires. Of course my '04 Z06 burns rubber when I shift from third to fourth at 95mph!


Kevin