M/T Drag Radial Fitment Question

[classic boost]

here's the pics of my tires mounted. m/t drag radials 275/50-15, convo pro's 15x8.5 5in b/s. the tires fit great. there are no interference problems anywhere.

 

[washMO66]

here's the pics of my tires mounted. m/t drag radials 275/50-15, convo pro's 15x8.5 5in b/s. the tires fit great. there are no interference problems anywhere.

Thnink that sam size would fit on a 66 coupe w/ 15" & 4.5" bs? Or am I relegated to the 255/50/16?

I need some street traction, I'm tured of getting spanked in the first 60'.

 

[10secgoal]

Thnink that sam size would fit on a 66 coupe w/ 15" & 4.5" bs? Or am I relegated to the 255/50/16?

I need some street traction, I'm tured of getting spanked in the first 60'.

Roller perches man, 6cyl shocks, and 90/10's call it a day. Oh yeah, I don't know how you have gone as fast as you have get some TRACTION BARS !!

 

[mustangman70]

What are roller perches

 

[thehueypilot]

here's the pics of my tires mounted. m/t drag radials 275/50-15, convo pro's 15x8.5 5in b/s. the tires fit great. there are no interference problems anywhere.

Thanks! Great pictures! They sure don't look like they are 28" diameter tires so 275 does equate to a 28" tall tire right? I guess they are hanging so far down they look smaller compared to the wheel opening. Did you notice the shiney spot on the rear fender well in your picture? Was that from your pervious tires? Have you placed your jack to one side of the rear end and jacked up the car to see it it will hit the bump stop first before the wheel well to simulate a hard launch?

 

[classic boost]

Thanks! Great pictures! They sure don't look like they are 28" diameter tires so 275 does equate to a 28" tall tire right? I guess they are hanging so far down they look smaller compared to the wheel opening. Did you notice the shiney spot on the rear fender well in your picture? Was that from your pervious tires? Have you placed your jack to one side of the rear end and jacked up the car to see it it will hit the bump stop first before the wheel well to simulate a hard launch?

the 275-50's are 26" tall. the 275-60's are 28" tall. the car is jacked up by the rear end, so that is the ride height. the shiny spot is just the camera flash.

 

[thehueypilot]

Attached is a hard launch view that shows how far the rear tire moves into the wheel well. I have 26" tires now and they do not rub, but would like to go to 28". It looks like with a better tire another inch will pull the front wheels off the ground and improve my 60' time.

 

[classic boost]

you're squatting an aweful lot. some caltracs or lift bars should help. also, looking at your oil pan, you better keep an eye on your motor mounts.

 

[thehueypilot]

I figured out my confusion........It used to be that a 70 series tire was not as wide as a 60 series which is not as wide as a 50 series and the tires diameter was listed in "American" inches. Now I guess that is an aspect ratio applied to the diameter. I am looking for a 275/60R15 tire?

 

[classic boost]

go here to see the diameter and width of m/t tires: http://www.mickeythompsontires.com/strip_et_street_radial.html

 

[mustangman70]

Heres a picture of my stang with 275/60/15 BFG radials, the rims are only 7.5 inches wide But they do fit....They do rub a little bit but i am on 35 year old leaf springs lol, i need to raise my rear end up some either that or stiffin it.

 

[10secgoal]

Attached is a hard launch view that shows how far the rear tire moves into the wheel well. I have 26" tires now and they do not rub, but would like to go to 28". It looks like with a better tire another inch will pull the front wheels off the ground and improve my 60' time.

Getting a bigger tire, and squating like that will cause you to loose in your 60 ft. Mine used to do that real bad. I used to loose gas out the cap, so I started loosening the neck when I would race and face the thing forward.
By the picture I bet that you spin the first few feet and then hook up pretty good. Some stiff springs will solve that. As the car squats, you have no traction. Not until the cars suspension bottoms out, and plants the wieght, does it grip. Hell, I bet you get that rear to stop squatting and the front will come of the ground.

 

[10secgoal]

What are roller perches

http://forums.stangnet.com/showthread.php?t=480075
Traction be thy name !! I PM'd Opentracker and he explained how they work. I will swear up and down now by them. I used to get traction at good tracks and had no problems. But then I moved to where the tracks suck. Now I am the only one I know that hooks and runs fast with stock suspension. There are always the ladder bar, big tired guys that can hook anywhere. But for us normal folk with no tubs,and et streets, full of air...I just can't say enough good things. I am going to do two more things and I am going to end up having to strap the front end down to keep the tires down again.

 

[thehueypilot]

Getting a bigger tire, and squating like that will cause you to loose in your 60 ft. Mine used to do that real bad. I used to loose gas out the cap, so I started loosening the neck when I would race and face the thing forward.
By the picture I bet that you spin the first few feet and then hook up pretty good. Some stiff springs will solve that. As the car squats, you have no traction. Not until the cars suspension bottoms out, and plants the wieght, does it grip. Hell, I bet you get that rear to stop squatting and the front will come of the ground.

I know what you mean because I lose fuel out the back on each run as well and I thought about putting some kind of check valve in it. Why would roller perches keep the front end from coming up? I would think it would allow the front end to raise quicker which would than pull the tires off the ground. I am using the "grab-a-track" leaf springs which I thought were heavy duty?

 

[washMO66]

Attached is a hard launch view that shows how far the rear tire moves into the wheel well. I have 26" tires now and they do not rub, but would like to go to 28". It looks like with a better tire another inch will pull the front wheels off the ground and improve my 60' time.

Your car squats down very low in the rear. What are your leafs?

I run a 5 leaf reverse eye and even on launch my rear end doesn't get much lowere than when it is sitting there. 620lb front coils as well.

try a pic or two

 

[washMO66]

another view

 

[washMO66]

Pulling the front wheels is not really all that good for your 60'. Proper weight transfer is what we are all after. The reason I can run 1.59 60' times with what I consider a normal size tire (aka, no steamroller) is that 1. - I am launching with no transbrake and at a low RPM (3000-3200) 2. 3:70 gear and the obvious 3. killer motor.

Could they be improved? Yes, but at the sacrifice of streetability and I could not do it with just one change. It would take more tire ultimatley if I start messing with everything else.

my 2 cents

 

[10secgoal]

I know what you mean because I lose fuel out the back on each run as well and I thought about putting some kind of check valve in it. Why would roller perches keep the front end from coming up? I would think it would allow the front end to raise quicker which would than pull the tires off the ground. I am using the "grab-a-track" leaf springs which I thought were heavy duty?

I looked and looked, but I don't see where I said they keep them from coming up. But the stock perched will keep the front down. The springs you have may be stiff " compared to ", but are obviously not up to it the torque coming from that motor. Its hard to transfer wieght correctly when the car squats. When a car does not squat, the back tires become the fulcrum point..like a teeder todder. This puts all the weight on the back tires. When it squats, the new fulcrum point is now moved forward, and your car is in the same position, but not as much actual wieght is on the back tire. Basically any suspension movement is wasted energy, and therefore is wasted time. Such as pulling the wheels. Looks cool, but a waste of time. If it is the only you you hook, then so be it. But if you can lift the front only 2in and hook, the better you will be. So there is a give and take. Transfer as much wieght as needed, no more. Like slicks...if you hook on 15 psi, there is no reason to drop to 8psi. You just make it harder to turn your tires, lose MPH and have the same traction you have before. Same concept as weight transfer.

 

[Opentracker]

What are roller perches

The post about how to make some.
http://forums.stangnet.com/showthread.php?t=480075


John

 

[brianj5600]

Hey Paul, is that one of those plastic covers for a 9 inch? J/K, what is the rear out of?