How well will a early 260z handle with 345/35r15 and 245/50r15?

[5.Z]

My z has a 5.0 v8 turbo and pushing around 350whp low boost. Plan on running 450 till I get an aftermarket block. Then I will be looking to get 600whp.

 

I would like the wheels to be just one set so I can take it to the strip and be able to go to the back roads and have a spirited runs.

 

 

Why so wide? While 275 dr would have probably been sufficient I really like WIDE tires. But at the same time small diameter.

 

So at these sizes it should give me enough straight line traction. Enough braking traction. But how well will it handle with such staggered set up? It's already heavier up front due to turbo.

 

What's your take?

 

Edit: has poly bushing all around and tokico springs/shocks.

Edited November 30, 2010 by 5.Z

[johnc]

My z has a 5.0 v8 turbo and pushing around 350whp low boost. Plan on running 450 till I get an aftermarket block. Then I will be looking to get 600whp.

 

I would like the wheels to be just one set so I can take it to the strip and be able to go to the back roads and have a spirited runs.

 

 

Why so wide? While 275 dr would have probably been sufficient I really like WIDE tires. But at the same time small diameter.

 

So at these sizes it should give me enough straight line traction. Enough braking traction. But how well will it handle with such staggered set up? It's already heavier up front due to turbo.

 

What's your take?

 

Edit: has poly bushing all around and tokico springs/shocks.

 

It will push until you get on the power and then it will snap oversteer once your right foot over-powers rear grip.

[5.Z]

What would you recommend? Would 265/50 work out better even though it's 1" taller than the 345"?

 

I don't want an unstable responding car that understate off throttle and oversteer on gas. Seems too unstable for me. Specially since I'm not a hardcore auto crosser.

 

 

What's about 275 front 315 rear in 17".

Will be a bit more money on rims but should bring in better performance?

[Dan Juday]

I have 245's on the front and 305's on the rear. "How will my car handle?" is a question with too many variables. Shocks, springs, ride height, corner weights, I could go on and on. And then how do you plan to drive it? If you're drag racing and mild to spirited street driving you should be fine. Beyond that, John had probably the most accurate answer you're going to get.

[5.Z]

I have 245's on the front and 305's on the rear. "How will my car handle?" is a question with too many variables. Shocks, springs, ride height, corner weights, I could go on and on. And then how do you plan to drive it? If you're drag racing and mild to spirited street driving you should be fine. Beyond that, John had probably the most accurate answer you're going to get.

 

Yes this car is basically build for drag racing more than anything. I even have 325/50r15 dr ready for next season . Just once in a while strip car. mostly will see street driving.

 

Now with wide rears traction should be plenty and I want at a minimum 245 so I atleast have some rubber upfront.

 

 

And yes I know it will depends on a lot of factors but would a 265 handle better than a 245 on the same car with 345 rears? At 265 front will be about 1" taller than rears.

 

 

As for driving I'm a light to very light grip racer or driver. I go to the back roads with twisties once in a while and I would like my car to be able to handle that. Or at the very least be able to gun it at an on ramp without the car feeling unstable.

[mxgsfmdpx]

It's all about the tire you choose. A 345 width t snow tire obviously isn't going to handle better than a 225 performance tire just because it's wider. Just like a 225 width drag radial will give you way more traction than the widest performance strret tire on the market...

 

I wouldn't get so hung up on specific widths, especially if you don't have the rim width to support wide tires. How wide are your rims? Do you have flares to fit 345's?

[johnc]

What would you recommend? Would 265/50 work out better even though it's 1" taller than the 345"?

 

I don't want an unstable responding car that understate off throttle and oversteer on gas. Seems too unstable for me. Specially since I'm not a hardcore auto crosser.

 

 

What's about 275 front 315 rear in 17".

Will be a bit more money on rims but should bring in better performance?

 

I didn't say the above. The car will handle with a steady state understeer and will feel like any Pro-Touring Mustang or Camaro as you add throttle until your right foot overpowers rear grip.

 

Here's what will happen.

 

1. You enter the freeway on-ramp and start squeezing down on the throttle.

2. The front starts pushing so you add more steering.

3. You keep adding throttle and that causes you to add more steering because weight is transferring to the rear tires and reducing grip on the front tires.

4. At some point you will exceed rear grip and the back end will start to break loose.

5. You'll immediately lift off the throttle.

6. This causes weight to suddenly transfer forward increasing front grip and reducing rear grip.

7. This forward weight transfer causes the front tires to now go in the direction you have the extra steering.

8. At the same instant you've lost rear grip and now the back end starts coming around.

9. You try to counter steer to correct the slide but you've got so much steering in the wrong way that you have no chance to catch it.

10. You're now facing the wrong way on the on-ramp.

 

A closer balance in tire width is always better. It allows the front to delay steps 2 and 3 until you can start unwinding the steering and get on to the freeway.

[5.Z]

It's all about the tire you choose. A 345 width t snow tire obviously isn't going to handle better than a 225 performance tire just because it's wider. Just like a 225 width drag radial will give you way more traction than the widest performance strret tire on the market...

 

I wouldn't get so hung up on specific widths, especially if you don't have the rim width to support wide tires. How wide are your rims? Do you have flares to fit 345's?

 

 

Yes i am aware of this. and in my defense I did not name the tire because only one manufacturer make it in that size. Pirelli PZero. and that seem to provide plenty good traction.

 

I have also stated that Im not just going super wide tire for just plain performance I simply Like WIDE tires on small diameter.

 

I have a custom diamond racing wheel now 15x10 with 4" BS. which i originally got for the back but will be putting it in the front. then will be ordering another pair in 15x12.

 

At just $100 a wheel and 1 week downtime its just a phone call away.

 

and no flare. I plan to make a widebody kit (im working on my fiberglass hood scoup to clear my blowthrough carb right now after that im making my widebody fenders.

 

heres the look that im after this is one of my favorite datsun. and plan on making similar setup.but in all white.

 

 

[5.Z]

I didn't say the above. The car will handle with a steady state understeer and will feel like any Pro-Touring Mustang or Camaro as you add throttle until your right foot overpowers rear grip.

 

Here's what will happen.

 

1. You enter the freeway on-ramp and start squeezing down on the throttle.

2. The front starts pushing so you add more steering.

3. You keep adding throttle and that causes you to add more steering because weight is transferring to the rear tires and reducing grip on the front tires.

4. At some point you will exceed rear grip and the back end will start to break loose.

5. You'll immediately lift off the throttle.

6. This causes weight to suddenly transfer forward increasing front grip and reducing rear grip.

7. This forward weight transfer causes the front tires to now go in the direction you have the extra steering.

8. At the same instant you've lost rear grip and now the back end starts coming around.

9. You try to counter steer to correct the slide but you've got so much steering in the wrong way that you have no chance to catch it.

10. You're now facing the wrong way on the on-ramp.

 

A closer balance in tire width is always better. It allows the front to delay steps 2 and 3 until you can start unwinding the steering and get on to the freeway.

 

 

oh okay. sorry completely missunderstood you. my autocross vocab is at a bare minimum that i thought push=understeer and when i read your coment i thought you meant dual characteristic when on/off throttle. makes a lot more sence now thanks alot.

 

 

 

Couple of question. Will a taller diameter in the front help reduce the understeer? as much as i would like to put wider up front it simply isnt made.

 

and my other question is.

 

is the understeer that extreme? i havent really driven a lot of cars besides mk3 supras(i have owned a few before this)

I guess what im asking is will an amateur driver like myself notice it. b/c i simply doubt ill be able to even push this machine close to its limit. i simply lack the practice or skill in autocross.

[Dan Juday]

 

I have also stated that Im not just going super wide tire for just plain performance I simply Like WIDE tires on small diameter.

 

 

I understand this. Keep in mind these cars don't have power steering. With 245's on the front, cranking the car through a parking lot is a real upper body workout. I can't imagine what any wider fronts would be like.

[5.Z]

I understand this. Keep in mind these cars don't have power steering. With 245's on the front, cranking the car through a parking lot is a real upper body workout. I can't imagine what any wider fronts would be like.

 

ya I know this aswell. Its actually wasnt as bad as i thought it was. I used to run 255 in 17" upfront and didnt have problem with that. The only problem i had was the tire I had for some reason used to chase the road. Hopefully it was just because of the tire not size.

[EMWHYR0HEN]

If your car is front heavy I would go as wide a possible up front.

 

Your suspension setup will also play an important role on how much understeer you have.

[sticky280zx]

coils would help your car alooooot more than tires imho because of the amount of adjustability, height, stiffness, etc....and youre going to need all the help you can get with a turbo 5.0...i still have the turbo my buddy used on his efi 92 5.0 that made 566 on 10 psi and had plennnnty more left in it (think it was finally 850+ on race gas and a built block maxing out his 1000cc's)

[B00STDZ]

I understand this. Keep in mind these cars don't have power steering. With 245's on the front, cranking the car through a parking lot is a real upper body workout. I can't imagine what any wider fronts would be like.

Hahaha +1 I have 245's all around and steering isnt impossible in parking lots, its just a pain.