Draglites

[KStromberg]

I'm looking to pull the trigger on some draglites for Big Red but I am having a bit of trouble understanding the sizing. Any input from you guys that have done this is greatly appreciated.

First off, I am swapping over to Mustang hubs so no worries there.

I am looking to run 15x9s out back and 17x4 or 17x4.5s up front. I need to run 17s up front due to the larger Cobra brake setup that I have.

In order to stay as close as possible to the +36mm offset at all four corners I am coming up with what I need as a 15x9 with 6.5" backspacing for out back which will give me 38mm of offset and a 4-4.5" backspacing up front with the skinnier 17s depending on whether I get 4 or 4.5" wheel. Does this sound right?

I seem to be finding the 15s that I need with the proper backspacing but the 17" fronts I found on American Muscle all have too shallow of backspacing like 2.5" or even less. Or does that matter?

Is there something I am missing? Where else should I look? Etc etc?

 

[driller]

15x8 w/5.5" backspace Weld Draglites/ProStars fit on the Blue Flame with some grinding on the rear calipers. The 15x9 w/6.5" backspace should fit with the same offset. You need to make sure the e-brake cable is secured and clear of the inside of the wheel.

I have the matching 15x4 ProStars for the front but with a 1" spacer to clear the Cobra brakes.

I have considered a set of 15" Bogarts along with a drag brake setup from AeroSpace, Strange or Baer. Those 15" Weld wheels are actually heavier than the stock 16" snowflakes I used to run.

 

[KStromberg]

The draglites bigs n littles are going to be a go on Big Red this year! This weekend I just test-fitted on Luke's car which is already hubswapped. Rears will need e-brake cable delete and trimming of the upper and lower control arms and notching an ear of material out by the rear subframe mounts in order to run 28" slicks. Very minor tweaks. An added bonus, I will be able to upgrade from stock 10" Mark8 rotors to 11.5" Mustang Cobra rotors out back and the calipers will still clear. That was surprising to discover as well.

Here are some pictures showing fitment and points of interest for interference with the exception of the tiny spot on the lower control arms out back which is VERY minor.

The first 3 pics are obviously the fronts. They sit just about perfect. Just a TINY bit of poke but almost darn near flush.







Upper control arm interference out back.


E-brake cable interference out back.

 

[KStromberg]

Another shot of the upper control arm interference. I will be doing the same as Racebronco did and notching out the very top portion of the arm.



Calculating for tire. The fender liner may need trimming.



Calculating for tire. Here is the trouble spot at the rear subframe. I will need to notch out a little here.



Mark 8 calipers and 11.5" Cobra rotors.....PLENTY of clearance.

 

[KStromberg]

This shows how flush the rears are going to sit. Can't get much better! I think they have a very slight tuck, but again just like the fronts, darn near perfect.





For reference.

The fronts are 17x4.5 with a -25.4mm offset 1.75" backspace Part# 92-745142 DP

The rears are 15x10 with a +44.4mm offset 7.25" backspace Part# 92-510154 DP

Both pictures calculating for tire out back are for a 28" tire. If you run shorter tires than that, which most here do, the subframe clearance and fender liner clearance may be a non-issue. I'm only running 28" tires this year due to lock-up refusal with my current poor choice converter that way I can run it completely unlocked and have enough mph left at the traps without blipping the rev limiter. It is just about there now at 110 mph and that was my trap speeds last year warbling the lockup clutch full weight on pump gas. She will want a lot more mph this year on e85 and lightened up.

15x10s with 6.5" backspace have TOO MUCH POKE. I do not suggest them.

These turned out darn near perfect and I wont have to run any spacers PERIOD. :wave:

 

[tixer]

Notching out that rear subframe would make me real nervous..

Could you just remove the fender liners? Since you're basically just building a race car, do you even need 'em?

 

[chris2523]

Notching out that rear subframe would make me real nervous..

its not actually the subframe, just a locating bracket.
i ran without them for who knows how because they had completely rusted out and didn't notice much difference when i put new ones on.

 

[tixer]

That's reassuring. I assumed those things were weight/load bearing..

 

[driller]

For reference.

The fronts are 17x4.5 with a -25.4mm offset 1.75" backspace Part# 92-745142 DP

The rears are 15x10 with a +44.4mm offset 7.25" backspace Part# 92-510154 DP

Both pictures calculating for tire out back are for a 28" tire. If you run shorter tires than that, which most here do, the subframe clearance and fender liner clearance may be a non-issue. I'm only running 28" tires this year due to lock-up refusal with my current poor choice converter that way I can run it completely unlocked and have enough mph left at the traps without blipping the rev limiter. It is just about there now at 110 mph and that was my trap speeds last year warbling the lockup clutch full weight on pump gas. She will want a lot more mph this year on e85 and lightened up.

15x10s with 6.5" backspace have TOO MUCH POKE. I do not suggest them.

These turned out darn near perfect and I wont have to run any spacers PERIOD. :wave:

I believe everything you said except I disagree with running the converter open. You're leaving a lot on the table IMHO.

What tires are you planning on?

 

[KStromberg]

I believe everything you said except I disagree with running the converter open. You're leaving a lot on the table IMHO.

What tires are you planning on?

The immediate plans are going to be running all Mickey Thompson stuff. I'm going to get drag radials out back and run Sportsmans up front that are more of a skinny street tire rather than a true front-runner like a racemaster. 28s out back, 27s up front, t/c off and eff the abs if it faults.

 

[KStromberg]

I just ordered these for Big Red. The ET Street drag radials have been discontinued. These are the same R2 compound so should work well. They are 28-11.5-15 According to my calculations this should be enough tire for 125mph in 3rd gear on open converter.




The fronts I'm going to order will be a 26" Sportsman S/R.

The car is going to have a nice rake to it.

 

[KStromberg]

Rear tires arrived. Here they are mocked up. Ride height will need to come up. No surprises there. One question if anyone knows. My car likes to jack up the ride height out back into "4x4 mode" with the switch off in the trunk. Is this normal? I was told it stays where it was at when the switch was turned off, but not on my car. Sensor-lowered out back the car would already be on top of the tire in this picture and it's not. Regardless I need to come up probably another inch at least.

By the way, the picture is deceiving. It's not as tight as it appears. There's probably 2 inches of clearance all the way around.

 

[KStromberg]

Again. Deceptive angle here. The tire is NOT jammed into the fender. Only appears that way. Lol

 

[driller]

Best of luck with those Kirk! :thumbsup:

 

[KStromberg]

26" Sportsman S/R ordered for the front. Premium pads all around and rear rotors on order as well. Next Saturday is hubswap time. Then off to the big garage.

Do I need to consider addressing the driveline geometry after all of this? Particularly pinion angle?

 

[driller]

The pinion angle does not change unless you modify the engine mounts, transmission mounts or the differential mounts.

 

[KStromberg]

26x6x17s

 

[tixer]

those look just like the one in my trunk!

 

[KStromberg]

Mounted up and ready to go. Hubswap shenanigans and putting a mean rake on this car begins at 9am tomorrow. Off to work I go. Work hard play harder.....

 

[KStromberg]

Well, they're on along with the poly knuckle bushings. It rides like a brick now. LOL

We encountered a bit more interference than we originally had calculated for. The upper control arms needed a tab of material cut off and the height of the sides of the arm closest to the wheel ground down a bit. The lower control arm at the rear corner needed to be ground back a fair amount. The big ADDCO bar I have out back was going to be an issue hitting the sidewall along with a portion of the k frame itself near the wheel well by the subframe mounts. The banjo bolts for the stainless lines going into the caliper had to be ground flat like a buttonhead so those wouldn't groove the inner barrel. So those bolts are done for once it comes time to remove them. So I might ditch the relocation brackets and go back to the factory brake setup out back possibly unless I can find a flat torx head type banjo bolt that will work. With all that said, we were in a crunch for time and had to pick up some 5/16" spacers from the auto store (biggest they had) to resolve the swaybar issue and k frame issue. All of the other clearance issues would have been there regardless. The airride had to be adjusted to full max in the back to give me enough wheel well clearance that I feel comfortable with.