Drag Racing Tech - Making 325/50/15's fit 02 SS

ok guys so what all is involved for me to fit 325/50/15 mt's under my 02 SS i remember seeing a thread about this awhile back but i unfortunately couldnt find it. so what methods and tools have you guys used. this isnt a drag car so it has to be clean and look professional im not wanting to "cut" on the car unless i have to.

thanks

Unless you mini-tub the car you're going to have the beat the living sh*t out of the fenderwells and cut off the bump stops. - Which is what I did. My car is also lowered a fair amount vs. stock so that might play into it some.

I used a 9" at the "stock" third gen width with 10" wide and 6" back spaced wheels.

http://photos-a.ak.fbcdn.net/photos-ak-snc1/v2510/142/38/78300224/n78300224_30844705_3797917.jpg

Another in progress picture.
http://photos-d.ak.fbcdn.net/photos-ak-sf2p/v188/142/38/78300224/n78300224_30582324_7232.jpg

the wheels im using are the fbody specific billet specialties 15x10 rear with 7.5 spacing, car is stock height in rear

The math will work out the same. I'm using a rear end that is roughly 1.75" narrower on each side, and you're using a wheel that is 1.5" deeper.

Get out your 15lb sledge.

Here is a pic Chris @ The Southern Outlaw Shop sent me. This tire is a 325. I have a pic of the mini tub, but I'm having problems with the file. If you have any questions, please email me, call, or pm me on here. KY-Turbo is looking to become the first place you go for quality performance parts.

http://i112.photobucket.com/albums/n170/jj50_2006/Parts/Southern%20Outlaw%20Shop/Minitubfbody325tire.jpg

I'll have other pics available soon. Go to the KY-turbo sponsor gp thread to see cage pics. Thanks guys.

As stated above. Cut the Bump Stops off. Hammer the shit out of the inner fenders and you are good. Stock width 9" and 15x10 7.5BS Pro Star's here.

http://www.fquick.com/images/vehicles/full/223360586.jpg (http://www.fquick.com/garages/viewgallery.php?action=viewimg&id=60586)

http://www.fquick.com/images/vehicles/full/223360587.jpg (http://www.fquick.com/garages/viewgallery.php?action=viewimg&id=60587)

whats the price of the material for the mini tub? how do they install do you just cut out the bumpstops and all the metal in that area and weld them in? are there any downfalls to losing the bumpstops?

the tires will fit without mini tub we did it on a stock length 9" takes a little clearing but its not that bad we were running a 15x10 billet speciality wheel as well

Takes lots of beating the inner fender wells, especially the front by the control arms. You'll need adjustable control arms to center the tire in the well and adjustable panhard to center the rear end. Will also need to roll the outer fender lips. I didn't touch my bumpstops. My car has stock rear springs with the "hose mod". I'm also running .125" spacers, I couldn't grind my brakes any more w/out punching through to the slide pins.:eek2: This is with a stock width 9" btw.

http://i85.photobucket.com/albums/k57/jmm98ls1/summer09022.jpg

http://i85.photobucket.com/albums/k57/jmm98ls1/summer09027.jpg

http://i85.photobucket.com/albums/k57/jmm98ls1/summer09031.jpg

yeah i have stock springs that are uncut and the wheels wont require caliper grinding im curious if i could get away with leaving the bumpstops on there... how did you roll the fenders?

I rented an eastwood fender rolling tool & heat gun from a member on here.

I am doing 15x10 BS 7.5 wheels and 275-60's, They fit easily. If your car rarely will hit the track why bother running the 325.

I am doing 15x10 BS 7.5 wheels and 275-60's, They fit easily. If your car rarely will hit the track why bother running the 325.

well since its a 6 speed and they tend to be harder to get to work with drag radials i figured that the extra contact surface would be good.... whats your opinion?? its just bolt ons heads cam nitrous & 9"

I think you should have two sets of rear rims, and one set would have a set of 28x10.5x15 ET Drag stiff sidewall slicks. Hooking a really quick stick shift car on a DR is not easy.

I think you should have two sets of rear rims, and one set would have a set of 28x10.5x15 ET Drag stiff sidewall slicks. Hooking a really quick stick shift car on a DR is not easy.

problem is i drive it on the street alot but only have the 1 set of wheels for now later im wanting to get some others to be street wheels then change out the drag radials for slicks. i know its hard but thats kind of the reason behind me wanting to do this i like the challenge i guess

I wouldn't go through the trouble of 325's. They look killer, but not worth the trouble IMO. I'm going back to 275's as soon as these wear down. i've rolled the fenders and the tires keep rubbing the fenders around curves cause i dont have adj. control arms or an adj. panhard bar.

http://i41.photobucket.com/albums/e280/JRStephens21/2-3.jpg

http://i41.photobucket.com/albums/e280/JRStephens21/0517091438.jpg

I think you should have two sets of rear rims, and one set would have a set of 28x10.5x15 ET Drag stiff sidewall slicks. Hooking a really quick stick shift car on a DR is not easy.

Agreed.....that's what I do.

damn those wheels are hugh

don't do it 275's are enough,315's max

I think you should have two sets of rear rims, and one set would have a set of 28x10.5x15 ET Drag stiff sidewall slicks. Hooking a really quick stick shift car on a DR is not easy.

So you like a stiff sidewall slick for a stick car versus a soft sidewall?

So you like a stiff sidewall slick for a stick car versus a soft sidewall?

so do most racers.

don't do it 275's are enough,315's max

i think you are confusing this discussion with 17" wheel tire sizes.

http://i240.photobucket.com/albums/ff43/zssman/LSX%20Showdown%20Memphis%202009/100B0510.jpg 02 ss. stock width 12bolt w/bmr adj control arms. non adj panhard bar. bfh trick to the front of wheelwell. stock springs w/ garden hose mod. Still have the bump stops. fenders rolled. more pics at my photobucket site.

so is anyone with an m6 hooking with 275 or 325 drag radials???????????????????????

I cut consitant 1.6's on my 325's. Been as low as a 1.62. I'm six speed.

damn i cut 1.50's on 265 radials thorugh an m6 with stock shocks and springs all the way around...

I cut consitant 1.6's on my 325's. Been as low as a 1.62. I'm six speed.

what kinda suspension do you have?

Qa1's all around. Both sets are single adjustable. I run the fronts set on 2, and rears on 7. Bmr lower control arms, bmr full length TA set at -2 pinion angle. No front sway bar and stock rear bar.

I think you should have two sets of rear rims, and one set would have a set of 28x10.5x15 ET Drag stiff sidewall slicks. Hooking a really quick stick shift car on a DR is not easy.
I have an auto it takes a lot of work to get my 325's to hook. It generally takes me 2-3 passes and making adjustments to get it hooking. I am going to a full slick next year (28x10.5x15).

so do most racers.

Ok......

Just wondering why and the difference. Ive heard abunch of different things. Just curious!

I've run 28W's and 325's on the same car, TH400 trans. The radials liked more air, like 16 vs 12 in the slicks. On radials the car was less forgiving if it spun a bit. On average I'd run the 28W's at 12 psi cold, and the front shocks at 1/1 and the rears at 6/6. With the 325's I ran them at 16/15, and front shocks at 1/1 and the rears at 7/7.

I am in the same process right now. Cut a 1.62 rolling the clutch a bit on a 275 MT DR 26' tall not 28'. I have been wanting to do a 325. I have coil overs front AND rear, adj lower's, and adj. panhard, rolled fenders as well. BS street Lites 15' with the correct Fbody backspacing 7.5. How hard should this be for me to do? Does the bumper have to be cut? I see most of you have cut bumpers to clear a 28' tall tire.

yeah im curious to know this as well ive seen some when running 28" or taller tires they have to modify the bumper is this true in all cases? if not why in some and not others

I am in the same process right now. Cut a 1.62 rolling the clutch a bit on a 275 MT DR 26' tall not 28'. I have been wanting to do a 325. I have coil overs front AND rear, adj lower's, and adj. panhard, rolled fenders as well. BS street Lites 15' with the correct Fbody backspacing 7.5. How hard should this be for me to do? Does the bumper have to be cut? I see most of you have cut bumpers to clear a 28' tall tire.

No you woill not have to cut the bumper. I have ran 325's on pro stars, alumastars, and now Holeshot wheels. Never have I had any contact with the bumper. And I have ran 28x10.5 slicks and never had contact on the bumper or fenders anywhere.

Stick with 275 you might have to heat them up a little more at the track but they will work. I have cut 1.52 60 ft. on 275/50/15 and handle great on the street.

Yes, but most of you guys are auto..radials work great from the get-go. The OP and myself are 6sp.
blk00ss- How low is the car? Most with easy sucess are on stock springs, i like my car sitting in the dirt, granted i can move the coil overs to where ever needed,

Ok......

Just wondering why and the difference. Ive heard abunch of different things. Just curious!

if you are a stick car, you want the 28S sidewall. remember its the sticky material that plants the car but its the sidewall that rebounds and propels the car forward. its why, if you can hook teh radials, you will fly. the problem is the radials dont like the immediate impact of the stick compared to a hard hitting converter. the converter can keep the tire planted while the stick car shocks it and the radial will NOT recover.

if i were a stick car, i would not waste my time with a radial, no matter the size. you will end up having to slip the clutch and burning that up. the slick will take the impact, spin slightly and recover, thus producing a MUCH better 60' time. the radial will not.

PS - i am talking hard 60' type cars.

I think getting radials to work on automatic cars is not very hard. Sure as the car gets quicker and quicker it gets harder but on average it's easier to get it to work.

I think manual transmission cars are different, and a lot harder.

I think to get it figured out, you might want a 2 step to get the leave-rpm consistent, and you'd need to experient with a lot of settings for the shocks and travel limiters. Best bet would be to work with Madman (www.madmanandcoracing.com).

I think getting radials to work on automatic cars is not very hard. Sure as the car gets quicker and quicker it gets harder but on average it's easier to get it to work.

I think manual transmission cars are different, and a lot harder.

I think to get it figured out, you might want a 2 step to get the leave-rpm consistent, and you'd need to experient with a lot of settings for the shocks and travel limiters. Best bet would be to work with Madman (www.madmanandcoracing.com).

actually i did think of that and me and him have already been pm-ing each other and just as you said alot of experiments will have to be made with the shocks and stuff he said this as well

I didn't really do shit but bolt my 325s on. I use 15x10 7.50" Weldstar Wheels (stock rear-end length) so I didn't have to grind my brakes or use spacers. Then I just gave my inner fenderwells a couple taps with a rubber mallet, tossed them on and was good to go. Took me about 4 minutes to get 325s to fit my car. Still have bumpstops, and havn't rolled my fenders. Stock springs minus Isolators.

I didn't really do shit but bolt my 325s on. I use 15x10 7.50" Weldstar Wheels (stock rear-end length) so I didn't have to grind my brakes or use spacers. Then I just gave my inner fenderwells a couple taps with a rubber mallet, tossed them on and was good to go. Took me about 4 minutes to get 325s to fit my car. Still have bumpstops, and havn't rolled my fenders. Stock springs minus Isolators.


Wow I have a T/A and had to cut my bumpstops, cut my rear bumper cover, beat the hell out of the inner fenders and it's still close in some spots. You are lucky.

Most guys who have little problems are sitting at stock height or on stock springs.....

this isnt a drag car so it has to be clean and look professional im not wanting to "cut" on the car unless i have to.

thanks

run a 275/50 or a 275/60. without a minitub or taking a hammer to your car, that big 325 hanging out the side wont look clean. the 275 is a pretty healthy tire.

A 275 tire can handle a ton of power. For those of you who need a 325 to hook, or are even spinning that, you need to stop and first address your suspension. Don't use that 325 as a band aid.

The suspension to control that tire is just as important as the tire itself. With out one, the other isn't doing you any good.

also keep in mind those 325's weigh 37 pounds. that rotational weight will hurt your et

I swapped from the 255/50-16 on stock wheels to the 325/50-15 on prostars and the results were baffling. My car, which was a 6 speed at the time, hooked okay on the 255 but wouldn't hook at all on the 325. This was with a UMI tunnel mount torque arm. BMR lowers, BMR panhard, BMR drag sway bar, and Strange SA shocks all around. I could not even slip the clutch and walk the 325 out the hole, it was like driving on ice. I went with the 28x10.5S and they worked great.

If you need to run a radial my vote is for the 275. In my case the narrower tire worked better, so I don't see any advantage in the 325.

I had to cut my bumpstops off, roll the fender lips, and do alot of beating on my TransAm to clear the 325. This was with stock springs with the stock insulators in place. When I went to the 28" slick I had to adjust the rear end forward and cut some of the rear bumper for clearance. The 28" slick is a good bit taller than the 28" radial and it grows under acceleration.

I am currently running a 275/50/15 MT Radial, for that little 26' DR i have it working quite well. On a 10' wheels you get a FULL patch for that tire. Thinking of going with a 28' next trip, and possibly a Hoosier DR since the sidewall is a lil softer.