straightline 928

Jseuss · Jseuss's Garage

Ive been considering a 928 project and was hoping for some advice on a few things. Im not looking to be told again that the 928 is not meant to be a drag racer, ive heard that enough. Im looking for helpful advice. In any case im looking to move the powerband on and early 928 into the lower range that one would use in the day to day driving and stoplight antics. Another problem i know quite well is axle hop with the wheels spinning, has anyone seen a decent remedy for this, or would a stiffer set of dampeners do the trick? There isn too much im not open to, but at the moment i'm looking to leave the engine largely alone and to get a good suspension and transmission setup that can take a beating, this car will see some straightline racing and perhaps some sideways action. Any ideas would be greatly appreciated.

Danglerb · 05-19-2009, 10:24 AM

People serious about straight line remove the rear suspension and put in a drag system same as every other drag car.

Stiffer shocks have no effect on wheel hop, afaik.

More bottom end around town is what a stroker is all about.

How fast do you want to go = How much do you want to spend.

123quattro · 05-21-2009, 06:57 AM

One trick to get rid of axle hop is to fabricate a custom tube halfshaft for one side of the rear. It's spring constant is significantly different that the other side so the wheel hop happens out of phase. It's not nearly as bad. They do this on lots of new IRS cars.

Jseuss · Jseuss's Garage

Quote:

Originally Posted by 123quattro

One trick to get rid of axle hop is to fabricate a custom tube halfshaft for one side of the rear. It's spring constant is significantly different that the other side so the wheel hop happens out of phase. It's not nearly as bad. They do this on lots of new IRS cars.

That sounds interesting, can you give some more specifics or send me in the rght direction? Will that affect the ride any other time?

rhjames · rhjames's Garage

two ways to do this is build a tube frame car or install a Viper/Corvette rear. just back halfing the 928 won't get it done. there are no good fixer for wheel hop with the 928 (weissach) rear suspension that I am aware of.

you'll need to connect the subframes, install either a 4-link or ladder bar rear w/coil overs suspension, and then a solid rear axle (narrowed 9 inch Ford or Dana 60). with this, you can then concentrate on a front trans that will bolt up to the 928 engine---good luck on this.

928 drag cars have been done before, but usually it's trash the entire drivetrain and install domestic pieces......

it can be done, but I wouldn't do this to anything but a $100 beater body.

--Russ

devilinblack · 05-22-2009, 12:17 PM

Just buy a Fox body Rustang and be done with it.

Danglerb · 05-22-2009, 02:09 PM

Quote:

Originally Posted by devilinblack

Just buy a Fox body Rustang and be done with it.

Except for the rust comment I agree, my 91 Mustang has a bit of fine rust in the cowl vent area in front of the windshield, but thats it.

Kinda funny really, its cheaper to make my old Mustang straight line fast, but cheaper to make my 928 track car fast than to teach a Mustang to turn and brake.

Hey, if you got the bug to make a hot rod, don't let my opinion get in your way.

If you can sort out the wheel hop stuff without hosing the handling, that would be great news for everybody. I say go for it, see what you can do.

devilinblack · 05-22-2009, 02:17 PM

Yeah, I wasn't being entirely sarcastic. I just call them Rustangs out of habit. If I were building something for the 1/4 mile it's certainly one of the platforms I'd look at first. The old 5.0 is well loved in that crowd and lots of people have been there/done that and can point you in the right direction.

My instructor for my first track day with NASA runs a mustang in the Time Trial event and took me for a ride. They can be taught to turn and brake, pretty damn well actually but I have no idea what something like that costs and I think a major portion of his speed was just coming from good torque and a lot of power.

It just seems like a waste of effort and money to try and reverse engineer a car to do something it wasn't designed to do when there are much better starting points available. Just ask all the kids that want to drag race Mark VIII's. It's a great car, but you'll spend 2-3x as much making it go fast straight as you would on a Mustang.

But, if it floats your boat and makes you happy, go for it.

Jseuss · Jseuss's Garage

im not interested in swapping in anything domestic, the whole reason for the build is to make a fun v8 car from the marque im most familiar with and love. Anywho, the axlehop is now my main concern, and it seems to me that some sort of secondary stiffening apparatus would be the way to go, as im also not into changing the whole suspension out for anything else. ive seen traction braces/bars for volkswagens with IRS, and that looked like a simple enough construction, though i honestly dont know what they do to help, or how much they help. Has anyone got an idea of how to set up a rig like that for a 928's transaxle?

Danglerb · 05-25-2009, 04:33 PM

I don't know of anybody doing anything for the wheel hop. People that make dragsters out of 928's generally swap in a conventional rear end. Until you have the motor doing what you want, why worry about it?