track question,, when is it time to run skinnies vs wider wheels??

currently i have 17x9 03 cobras on my 89 gt vert w/ sn95 spindles 13" cobra brake setup, last year i had bilsteins shocks/struts with 250# spring rate up front upr coil overs, launching at ~6-8# when i shifted into 3rd and 4th the ass end would get a lil loose mid track, get outta it and get back in it, managed 11.1 @ 123mph with it, car is 347 t-76 hp kit at 11# making 600RWHP AND 611RWTQ @ 3200 rpm

since then i have swapped to a 175# spring rate up front and strange adjustables all around, airbag in rear right coil,

since i have the cobra brakes have to run a 1 1/16" or so spacer to clear the calipers, this makes my prostar 15x3.5" with 1.75" bs stick out from the fender ~1/4-1/2", just wondering if i am going to come down hard enough to hit the tire and cut it up on the track???

will me running skinnies up front help out with the ass swaying around any down the track?? some people have said that pushing a 9" wheel up front is not only dangerous but makes the car unstable?? ive been 126mph on DRs and didnt see that just on the slicks at 11#s in each tire

any reason for safety that i should be running the skinnies??

the other option to not run a big spacer is to swap back to fox spindles and buy some aerospace pro street kit (still a street car) but some say that they still have to run a 1/2" spacer and sticks out a lil bit

i know i will reduce at least another 100#s up front if i swap brakes and skinnies which is a plus trying to make the correct decision here and for the future of the car which should run 9s or high 8s with more boost/fuel thanks in advance

The wide tires on front will cause the car to move a bit over bumps in the surface. On the track I wouldn't think it to be that much of a problem though. I think your answer might lie in the shock/strut combo you use. If your just going to drag it I would get some valved specific for drag racing or somthing adjustable. My guess is if its getting squirly on you the rear is unloading too soon and not staying planted.

Is there a way to test this on or off the track? If he hooks and has good lift...the force being applied downword would bring the tire deep in the fender well. How close is the tire to the inside edge as it sits?

use your spare tire wheel and put tire on it that will not blow at more than 75mph... buy another and duplicate

i do not have an 03/04 cobra as far as a spare goes, i have an 89 vert

right now the 15x3.5" with 1.75" bs prostar with 1 1/16" spacer up front sits outside the fender ~1/4-1/2", just dont know if it will come back into the fenderwell if i come down on it hard if i even pick up the front wheels

currently i have strange adjustables on the front and rear as well as air bag in rear right coil ready to dial in maybe this weekend

Dont run bias and radials together. I had the rear of mine swaying with bias on the rear and street tires on the front. put skinnies on the front with the slicks on rear rides down the track perfect

How much air are you expecting Steve? Just plain physics will tell you if you have enough downward force, the tires (being that they already stick out 1/4-1/2) will hit the fender wells and possibly rub and or blow.

Like others have said running a radial with a bias does feel a little weird and gets squirly on the big end. The skinnies would serve you much better.


Like you Im just worried if you hook hard...raise the tires...they come down...then boom. But Im no expert

havent ran down the track with them on yet, got a buddy going to lend me a 1" spacer for this weekend if i decide to try and run the skinnies, it says on the side of my moroso DS-2s 35#s max but ppl say they have been putting anywhere from 30-60#s in their skinnies, i wouldnt however go over that 35# limit just to be on the safe side,,

i will prob start out at like 14#s in the slicks this year since i only launched with boost at the mods/rods shootout, got some pretty nice tire wrinkle in some of the pics so prob could air them up a lil since i had 11 and sometimes 10#s in them and that too could have affected me down the track

as of tonight a guy on turbomustangs is buying my complete 5 lug cobra front setup, i am going to put in an order tomorrow for a Pro Street Kit drilled/slotted rotors from Aerospace, going back to stock fox spindles and the front skinnies should fit under the fenders nicely, as for my 17x9s who knows, but they make spacers for that i guess :(

really want to be able to go balls out at the track the entire time an 11.1 sec @ 123mph does the car no justice should be running 10.40s 10.50s trapping 132mph or so

i dont think i will have a problem breaking into the 10s even with the wide wheels up front, im planning on going to TRP this saturday to get my yearly tech inspection and then making a few passes,, the weather looks like crap only round 50degs so prob wont hook that good, if it even looks like rain i will not go out there

so i guess i will end up losing another ~50-75#s up front with just the spindle/brake swap then another ~40#s or so for wide wheels to skinnies, that should help me another 0.1 or so plus the new adjustable suspension and air bag should be good fora nother 0.1 or 0.2, will let the car do the rest of the work

prob get kicked off the track if it dead hooks and i roll out 10s in the vert with a 6 pt roll bar

I honestly think your car def has mid 10s in her with the wide tires on the front.. ......im going off hearing your car during the dyno day at gregs.

Its a beast thats for sure. I think your on the right track with your tire pressure....have any pics of the wrinkle?

Awesome sell on your cobra front setup...that pro street is going to be sweet! We expect pics when it comes in...Im curious to see how well you hook up at the track with the new setup.

No worried about getting kicked off the track...thats a good thing hehe Just says you sir are one kick ass Mofo

hes a lil wrinkle



just a few small burnouts







look my hood is already popped, glad i saw it 1/2 track and shut it down, think i still ran a 14sec pass, haha hood pins go on soon



thanks man shooting for solid 10s this year

Nice Wrinkle! Is that you getting drug by the wagon? hehe I remember that thing.

No worries man...With your setup...10s should be in the bag...if you can hook and keep her straight

yeah i was getting drug around by that wagon, haha, first day out at the track launching with boost was a lil shakey with it at first but finally calmed down

still waiting on my payment for the brakes then i order my new ones!