what tires in rear

[rdsk8ter]

I have these rims and I am concerened that the 14x7 wont give me enough traction. My question is what rims can I find that would look good with these wheels for the rear of my car? The car being a 1979 280zx. Im shooting for around 600-650hp and 600lbs tq when done. Or will i have enough traction?

 

[Savage42]

Even with a limited slip, you'll probably have traction issues at 400 HP. Anything more will only be useable above 70 mph. Heavy car, skinny tires (not to mention the bad rear suspension geometry) and monster HP don't make for a fast accelerating combo. I'd bet a car with half the HP will be dead even from 0-60 and really clost up to 100 mph, so I guess it begs the question: "Why so much HP and what is the purpose for the car?" If you are just looking to go fast in a quarter mile, an S30 would be way better suited for that. Major flares, sticky tires and trimming some weight would make it fast, but not a nice street car at that point.

[rdsk8ter]

Right now Im looking at trying to stuff a 8.5-9.5 inch rim under the rear to help. I have some ideas about suspention work I want to try but I dont want to be laughed at until I get the bugs figured out on my draft program. Also i am looking for a serious track build and to do something diffrent. I dont see many modded zx cars out there. Also im thinking highly about a welded diff.

[Savage42]

Since the 510 & ZX suspension is very similar, here's what a buddy & I came up with for our 510s. This solved the problem of binding caused with poly bushings and slotted crossmembers. We raised the pivot points, enlarged the exhaust hole and made it adjustable with shims, so alignment stays in place.

 

As for a welded diff, guess it's just a drag car? Wouldn't ever run one on a street car, as they push bad and are undriveable in the wet.

 

[tube80z]

Raising the pivot points an inch is going to be about as useful as drinking a big gulp to keep your personal fire extinguisher primed in case you're car catches fire. 600 ft-lbs is going to make the back squat because of the design.

 

If you don't want to use seriously stiff springs I could see a couple alternatives. Using packers on the rear shocks to engage the bump stops early, possibly a third-spring setup using the sway bar, and droop limiting the front. All these could be done at the track without ruining the street ride.

 

Of course the best plan would be to put a live axle in it at that level of HP/torque. Having driven Gary's old car and another car with equally wild mods and a live axle, the latter worked much better.

 

Cary

[rdsk8ter]

Raising the pivot points an inch is going to be about as useful as drinking a big gulp to keep your personal fire extinguisher primed in case you're car catches fire. 600 ft-lbs is going to make the back squat because of the design.

 

If you don't want to use seriously stiff springs I could see a couple alternatives. Using packers on the rear shocks to engage the bump stops early, possibly a third-spring setup using the sway bar, and droop limiting the front. All these could be done at the track without ruining the street ride.

 

Of course the best plan would be to put a live axle in it at that level of HP/torque. Having driven Gary's old car and another car with equally wild mods and a live axle, the latter worked much better.

 

Cary

 

any pics of the third spring setup this is kinda what i had in mind also what do you mean droop limiting the front? never heard of it

[HB280ZT]

rdsk8ter,

 

I have one question for you.

 

How much track experience do you currently have?

 

If the answer is nil to none then I would not worry about the car at this time, because your car is more capable then you.

 

You see I have been working on my 77 280Z turbo for quit a while now and have just started the High Performance Driving Education (HPDE) training. I really wish my car had not been modified as much as it has, because I think it is hampering me some in my learning. That is why I have stopped working on the car, other then normal maintenance and safety items. I want to learn to drive the car in its current condition to its fullest, and then make improvements to help both with car and driver performance.

 

Now planning the cars future is not a bad idea, but I would not go over board until my driving skills were at that level. So go ahead and figure out what you will need to do to the car get there but worry about learning to drive first.

 

Now this is the advice of a level 1 HPDE student with only 5 events under his belt, so take it as you will and enjoy yourself because the training and track time is a lot of fun!!

 

Also do you really need that much power on a track?? If you are driving on a road course I am not sure it will benefit you with the car you have. We have a 240Z over here called the Red Bird and it is just plain fast on the track. It only makes about 300 rwhp so how much is really enough on the track, who knows!!

 

Good luck.

 

HB280ZT