Can you use taller springs in back to lift up car for larger tires?

[born2drv]

I know there are companies that make custom springs... So I'm wondering if I can find springs that can be made 4-5" taller then stock to lift up the rear end..... and since stock tires have a rolling diameter of 24.8", then I should be able to put aprox. 29-30" tires back there instead right?

Ultimately I want to be able to put some 17" rims in the back with drag racing tires that have thick sidewalls, with a really wide rim/tire combo (like 13-15" WIDE rim)

Any idea if this could work?

 

[gaboonviper85]

This will destroy your drag times! Thick sidewalls, larger rims, stupidly wide...unless you are just going for looks then this setup will kill it!

You need to figure out what size tire you want and make a cardboard cutout and see for yourself....

 

[dbsupra90]

well yes and no.

bigger rim and bigger tire is more mass. however, a larger sidewall will have more flex and more bite. 13-15" is kinda overkill. 27" works well, but 28" will rub. they make coil spacers that will raise it up some, but not to the extent you are talking. altho i think coil spacers are a little hobo. what about the bilstein shocks? anyone know the ride height on the highest setting?

 

[Poodles]

Highest setting is stock.

Why would you go with a 17" rim on the back when you could go 16" or even 15" in the back to get more sidewall?

 

[rocketguy13]

lol i want to see a pic of this car when you are done.

 

[rocketguy13]

maybe you could modify your spring perch. raise it somehow or put some kind of spacer between the spring perch and the spring. i noticed when i lowered my car the right front sat a little lower than the left so i put some heater hose on the bottom coil of the spring on the right side and it leveled it out a little better.

 

[dbsupra90]

Highest setting is stock.

Why would you go with a 17" rim on the back when you could go 16" or even 15" in the back to get more sidewall?

if highest is stock, how much lower than stock is the lowest?

yeah i love the 15x8 setup with 27x10.5

i had thought maybe he needed a larger rim in the back to clear bbk

 

[gofastgeorge]

Really, I don't see a thing in your currant set-up that suggests you have near enough power to use a 13"+ wide tire.

HKS's Mk3 drag car run big rubber, but.........
It was making almost 900 HP, was running 5.3 gears, a 4-link rear suspension with a Ford 9", and probably weighed a thousand pounds less than your car.

Maybe you should look at what guys with simular 7Ms are running successfully at the strip.

 

[tissimo]

28s are possible, a few people have done it.

 

[Evilempire1.3JZ-GTE]

Coilovers let you change hight but you want the softest ones you could get for drag racing disconnect sway bars & use no bigger then a 15" rear infact just get the smallest rim that will fit around your rear brakes.

To need drag slicks in the setup your mentioning do you loose traction on the drag strip with anything close to what you want you must be pushing > 500hp & ftlbs

 

[Guyana00]

Yes you can do it though.

 

[born2drv]

well i'm at 476 rwhp now, and just using stock rims with stock size 225/50/16 tires and they spin like crazy. i can't even keep the power on the ground in 2nd or 3rd gear.... launching is a nightmare i know i have more power then anyone on the road for the most part, but i can't launch worth a shit...

ya i know get some 245, 275... etc in the back with a sticky tire... but i just figure if i'm going to get a new rim setup might as well go all out, i love the look of huge fat ass tires.... and i think lifting up the read would look sweet too...

i would love to put a set of P345/35R18 M/T ET Street Radial II's in the rear, or something else in a 17/18" rim size... even if i have to jack up the back 5-6"... and i know it's way overkill... but again i just think it would be badass...

so if i could get custom springs for that height, would any aftermarket shock work?

 

[tissimo]

well i'm at 476 rwhp now, and just using stock rims with stock size 225/50/16 tires and they spin like crazy. i can't even keep the power on the ground in 2nd or 3rd gear.... launching is a nightmare i know i have more power then anyone on the road for the most part, but i can't launch worth a shit...

ya i know get some 245, 275... etc in the back with a sticky tire... but i just figure if i'm going to get a new rim setup might as well go all out, i love the look of huge fat ass tires.... and i think lifting up the read would look sweet too...

i would love to put a set of P345/35R18 M/T ET Street Radial II's in the rear, or something else in a 17/18" rim size... even if i have to jack up the back 5-6"... and i know it's way overkill... but again i just think it would be badass...

so if i could get custom springs for that height, would any aftermarket shock work?

LOL, get better compound tires with more width and maybe a bit more height.

Or even a drag raidial for your normal street tires. The nitto DR is a good option for a regular daily driven car. My buddys car is fine even in 1st gear with a 285/35/18 nitto DR with 490whp (though it is a 1jz with only 450ftlbs of torque).

You're not going to fit much more then a 295 under the stock body. Even a 295 would require a perfect setup (offset, rideheight, springs, etc).

 

[shaeff]

Wide tires do little for straight line grip. With only 320ish rwhp, I could light up 275/40/r17 Falken Azenis rt-615's on the rear of that car with little issue. Cool? Sure, until I actually wanted to launch...

Your best bet is a 15" rim w/ drag radials. That sidewall thickness has a lot to do with traction.

Give this a read: http://www.supramania.com/forums/showthread.php?t=14479&highlight=drag+racing

 

[supra90turbo]

Thanks for clearing that up Shaeff. I was about to say that, minus the link.

The simple truth is you could run a 425mm wide tire and still have traction issues. Why? The contact patch is still 2" front to back. The link Shaeff posted explains it all.

 

[tissimo]

Wide tires do little for straight line grip. With only 320ish rwhp, I could light up 275/40/r17 Falken Azenis rt-615's on the rear of that car with little issue. Cool? Sure, until I actually wanted to launch...

Your best bet is a 15" rim w/ drag radials. That sidewall thickness has a lot to do with traction.

Give this a read: http://www.supramania.com/forums/showthread.php?t=14479&highlight=drag+racing

Thats not entirely true. Width will give you extra grip but yea, a taller soft sidewall will do more then going wider.

And you just had a shitty tire/bad alignment (I even had 1.5* rear camber) if you could light up 275s with 320hp. On a harder compound tire and a smaller sidewall (275/35/18 Kumho supra 712s) I would barely haze the tires in 1st with 400whp.