I was wondering if it is normal for my year of 928 not to be able to spin the tires even a little bit from a dead stop? The car has been sitting for a few years but has been started every now and then. I finished putting in new suspension in the back and decided to take it for a ride. It has decent pick up but I was surprised that it wouldn't lay down even a little bit of rubber. Any suggestions? Thanks.

 

I have an '82 and I have to do evil things to my clutch to lay rubber.

I feel your pain with the lack of off the line power in the early models, but these cars weren't designed for stoplight racing. They were made to travel long distances at extremely high speeds. Anyway that's the general consensus that I've gathered about sharks. If you wanna dust cobras off the line, geta z28 or a ricer. I wouldnt trade my shark for one of those, though.

 

johnny928,

I have the same engine as yours, with an auto as well.

Most of the easy hop-up stuff I did only added or moved power to the high end.

Not to dishearten you, but I was only able to make those dogs bark by advancing the cams a few degrees (increased the torque).

 

Why not look at the rear axle ratio? Do it with gears.
But the truth was said by Drew: these are not drag race cars, but high speed GT cars.

 

The 1980 928 ain't gonna squeel the tires from a dead stop. You go WOT at peak troque on a cold day, you'll probably do it, but only once you get going, by which point...

You've already got one of the highest ratio rear ends Prosche made.

Your next best option would probaly be a transmittion or gear swap from an 83-84. It's a major job, probably expensive. This would change the over all ratio for first gear from 9.6:1 to 11.5:1. Much more stop light special abilitys. Almost certanly enough to spin the rears regulary...

I'be been thinking about getting an 80-82 rear end for my 83. Would be fun.

 

I have a 86, chiped, 32v, unless is cool out (65) or so she will not smoke em.
The car is made go!!! 140+ all day long.
This fall it was a cold day (35) she would lay a good one!
but the car is NOT made to do that.

 

Oh, one more thing. Because of the gearing ratios of the 83-84, it wouldn't change the top end, or fuel milage of you car at all.

The 83-84 has the first 4 gears lower, but 5th grear is exactly the same as every other 928, it's a 1 : 1.

I belive this is because Porsche tryed to eek out a few more miles per gallon by installing a lower ratio rear end. To give the 83-84 a bit more low speed get up and go, they then seem to have lowered the first 4 gears. As a result, the gears are spread wider apart.

 

I just read your posts about the cam advance. That looks very very cool. I want to do that when I do my t-belt and water pump and fix my leaks in the cam area.

How much would it run me? I don't have the ability or resources to mill that steel peice, is there something I can buy that bolts on?

Ron, what's your pic of? Every time I see a post by you I am hypnotized by its quiet, green weirdness.

 

drew_816,

I am looking into having the plate laser cut out of stainless steel plate.

I'm still getting the various costs together but I expect to be able to sell them for less than $160 for the plate and pulley.

 

drew:
That is my company logo. It stands for Verdant Ventures, which is a dba for Verdant, Inc.

 

Thanks for all the feedback guys! From reading all of these posts on this forum I knew that the 928 was more for long distance at high speed driving and not for stop light racing. I would never trade my 928 in for a crappy rice car or some cheaply made mustang or Z28. I just thought that with those engines putting out around 250 ftlbs of torque that I would have at least got a chirp out of the rear wheels. I guess these cars are pretty heavy and built really well. I think I might do that cam advance to get a little more power out of the car. Porken, is there any drawbacks to doing this to the car? Will it damage the cam or anything over time? Also, how much more torque/horsepower does that put out with the cam advance? I was also thinking of advancing the timing a bit as well. Let me know once you have some of those kits put together and I will buy one off of you. I will be doing my timing belt and waterpump over the winter so I should install that while i am doing the timing belt. Also, does anyone know what the 928 is supposed to idle at in park? I believe mine is 1400rpm while cold and 800 rpm when warm. It also has a miss to it as well. Thanks again to everyone for all the feedback!

 

750 rpm for a warm idle, IIRC.

You can set this with the big screw on the frount of the throtl body.

However, be advived that it'll probably make your miss worse.

You need to find and take care of the miss.

The 928 won't chirp the tires because there's too much weight on the rear ones, and the gearing isn't low enough. It puts out 250+ ft/lb of torque when it's running right, but that torque isn't properly multiplyed by the transmittion for the low speed stuff. That plus the fact that it's about 51% of the weight on the rear axle, and it takes alough of torque out of the engine to spin the wheels.

 

My 84 auto US model from a dead stop will break loose and spin big time at WOT. I have brand new tires on the back and it isn't cold outside.

It is very easy for me to break loose at start...I often give it just a little chirp 'cause I love knowing 'she' has that much grunt.

....but I've laid down an impressive patch a couple of times.

Pappy

 

The answer lies with Murph and the Valley of the Super-Chargers.

 

Yes, but then the next question may very well become "How can I keep from having so much wheelspin?"

You know, some people are just never happy.