I’m having constancy issues at the track and I’m thinking part of it is that I’m running street tires. I’m going to get a set of drag radials and throw them on an old set of rims and just put them on the car when I go to the track which is about 15 minutes from my house.

Anyway, I’m thinking that adding the drag radials will make the car launch harder and put more stress on the frame. I really don’t want to twist the crap out of the car so my thought is that I should add sub frame connectors before I consider the drag radials. Does this sound like the best way to go or would I be good with just going with the radials?

I’ve also heard that adding the drag radials really increases the chances of snapping the 28 spline stock axles. Anyone have any input on that? I was thinking of just taking my chances on that. I have access to 2 trailers about 20 minutes from the track so I could get the car home plus I can use that as an excuse to redo the whole rear if it happens.

 

Since you have a auto, it won't be subjected to near the shockload of drop clutch starts so I wouldn't worry about the axles unless you get a transbrake or the like. I would say get the subframes and torque boxes welded up for extra stiffness and peace of mind being the SN-95 chassis aint the stiffest anyway. I don't run DR's(yet) but still have full length subframes and TB reinforcements.

 

You should do a bunch more bracing before running drags. Welded sub frames, strut bar wouldn't hurt, maybe reinforce the bracings on the axle, I would even go as far as getting a roll cage.

 

Thanks guys. Torque boxes and subframe connectors sound like a plan for now. I only run the car once or twice a month at street nights right now and just wanted to get it more consistent so I could jump into the occasional street class race for some cash.

It's still a DD so I don't want to go all out with it yet. Once I retire it to the garage and weekend duty, I plan on redoing the rear end and suspension and then working on adding more HP.

 

As a point of reference I use 275/40/17 M/T DRs on 17x9 Cobra replica wheels on my Mach.

I have . .

Welded Subframes
Welded Rear Strut Tower Brace
MM Adjustable LCA
MM 4-Bolt CC Plates
MM K-Member Brace
Vogtland Springs

I have pulled a best 1.77 60ft and a 1/4 mile best of 12.97 @ 106.6 with a 1.87 60ft.

I have a set of 4.10s waiting to go in . . . at some point but not until I have a 31 Spline carrier and 31 axles.

I run about 3-5 times a year (with ~4 runs per outing).

 

They're real good numbers Evil. I wish I could get my 60 foot under 2. maybe with a little more work.

Out of curiosity, what height front tire are use using with the 40's on the back? I was thinking of going with the 275/40 DRs but I would still be running the 245/45s up front and I don't know how well that would work.

 

275/40/17 and 245/45/17 have the same O.D. so you wouldn't have any problem.

 

Cool, thanks.

 

Yeah, what CircuitBreaker stated . . . .

I usually run my stock Mach 1 wheels/tires when I go to the strip, but I have run my 18x9s (265/35/18, which is still shorter than a 275/40/17) in the front as well . . . though 18x9s weigh more.

 

For drag radial use, a cage is a bit overkill. On the cobra I had, I ran drags for awhile and moved up to full blown slicks. Drag radials dont grip near like a slick does.

For drag radials, I would recomment a good set of lower control arms (possibly upper if you get GOOD ones, not cheap knock offs, stay with stock untill you get something good), and subframes welded in.

That right there will be about the most you'll need for using a set of 17" DR's. If you went with a 15" DR, i'd look at getting the trq boxes welded up and also the axle tubes welded so that they dont twist.

I only did the first part (subframes and control arms) on the cobra and ran slicks without a problem. I knew however I was a time bomb waiting to happen.

With an automatic and as long as your track isnt consistently top fuel prepped, you'll be fine as far as your rear end not breaking on DR's. Of course the performance you can get out of a traction lock and beefier axles may be worth the upgrade later

 

Thanks Scott. Thinking of MM upper and lower control arms when I have the cash. I'm going to do the subframe connectors soon and I might do the torque box welds since I'll be welding anyway or I also plan on doing gears and upgrading the axles eventually so I might do the torque boxes then since the rear will be out already.

The track I run at the most is hardly prepped for anything most times so I shouldn't have to worry about it.

 

I just reccomended a roll cage b/c if you serious enough about racing to get DRs, it's only a matte of time before you want more and you try to get into the 12 second range. Which is where most people reccomend having a roll cage.

 

not trying to hijack your thread, but scott what size wheels and tires did you put on the back of your mystic? i definitely need something for my 98. i want 15X10 draglites for the back and slicks but will they clear the cobra brakes on the rear? i know the front wont clear 15 in skinnies

 

When do I need a roll bar or roll cage, and what should it look like?
A roll bar is required in any convertible running 13.99 seconds or quicker in the quarter mile, and in other cars beginning at 11.99. The roll bar is accepted in vehicles running as quick as 10.00 second e.t., provided the stock firewall and floorboard is intact, other than for installation of wheel tubs. The rollbar must be constructed of minimum 1 ¾ inch o.d. x .118 inch wall mild steel tubing, or 1 ¾ x .083 chrome moly tubing.

 

Wow, I actually thought it was under 11, not 12 for the roll cage. Good to know. I doubt I'll be getting into the 11's with this car, I have a full drag car that runs in the 10's so I can get my race fix there. I just wanted to make this car leave more consistently so I can enter a few street races here and there with it since it's a little easier and cheaper to get out and run compared to the other car.

 

15x10's would be over kill. Funny thing about my setup was, i went the budget route and it worked great. Find you someone with a 1999-2004 v6 that have upgraded rims and see about getting 2 of thier stock 15x7.5" rims from them. They will clear your rear brakes with no problems and bolt right up on a 96-98 cobra and 03/04 mach1. You'll have to go with a 16" wheel i believe on any IRS equipped cobra due to some bolt clearences.

On the 15x7.5" rim you can mount a 26x8.5"x15 e/t drag on it with no problems and trust me, you wont have any traction problems at the track. I had 4.10's, spec stage II clutch, subframes, LCA/UCA's, and did everywhere from a 4500-6k clutch dump on them and got NO wheel spin.

 

outstanding. i didnt think the v6 wheels would clear the rear cobra brakes. will have to find a set. what about from a 96 V6? i know my parents still have the set from theirs. i know in 99 some of the v6 came with the older wheels.

 

Only one way to find out, Test fit em.