Chassis tuning for 325 Drag Radials?
Did any of you run the 275/60 radial before going to the 325, did you find a big traction improvment from going to the parger size, especially off a transbrake? Also, if you are seeing any of the shake/hop, did you have the same probelm with the 275 size?
I am havign decent results with the 275/60 off the footbrake but the transbrake blows the tires off bad, I was considering the 325 before goign back to a non-radial tire, but have questionable thoughts as to wether it will be enough for transbrake use, and I was also curious if the added weight/width would slow the car down dispite the possibility the car would leave better.
I am havign decent results with the 275/60 off the footbrake but the transbrake blows the tires off bad, I was considering the 325 before goign back to a non-radial tire, but have questionable thoughts as to wether it will be enough for transbrake use, and I was also curious if the added weight/width would slow the car down dispite the possibility the car would leave better.
Originally Posted by JL ws-6
Did any of you run the 275/60 radial before going to the 325, did you find a big traction improvment from going to the parger size, especially off a transbrake? Also, if you are seeing any of the shake/hop, did you have the same probelm with the 275 size?
I am havign decent results with the 275/60 off the footbrake but the transbrake blows the tires off bad, I was considering the 325 before goign back to a non-radial tire, but have questionable thoughts as to wether it will be enough for transbrake use, and I was also curious if the added weight/width would slow the car down dispite the possibility the car would leave better.
I am havign decent results with the 275/60 off the footbrake but the transbrake blows the tires off bad, I was considering the 325 before goign back to a non-radial tire, but have questionable thoughts as to wether it will be enough for transbrake use, and I was also curious if the added weight/width would slow the car down dispite the possibility the car would leave better.
I tried everything from 14 to 20psi, pretty much the same. I was hoping to do better on the 325s, I must have something messed up because even in the heat I can cut 1.28-1.29 60's with 10.5x28 ET drags and 1.4s with the 325s - at the same track, same day. Thats when I stay in it instead of letting out because I think I just tore the ring and pinion out
I already wore a set out playing with them and have another new set mounted up, I kinda give up on them though for now. Car works fine on ET drags so why fix what isnt broke.. I hear what you are saying believe me, I'm very tempted to put a set of 28x10.5S tires on and call it a day, but all the racing for cars in the range of speed I'm in are going to radial tires, and I suspect there's a reason for it. I want them to work, but I have doubts if I'm going to have any better luck.
The 30x9 inch hooiser radial slick is starting to seem like a possible option as well.
The 30x9 inch hooiser radial slick is starting to seem like a possible option as well.
I dont know, its only 400 a pair to find out..
Radial tires are better for rolling resistance no doubt, they seem a little more stable then the slicks but I run 15psi cold and tubes in the ET drags so they arent that bad. I'm not trying to discourage anyone from using them, lot of guys running very well with them. Plus its a great street/strip tire.
Radial tires are better for rolling resistance no doubt, they seem a little more stable then the slicks but I run 15psi cold and tubes in the ET drags so they arent that bad. I'm not trying to discourage anyone from using them, lot of guys running very well with them. Plus its a great street/strip tire.
On a DR mustang (different animal but same tire) we were having good luck with the rears semi tight and the fronts 3clicks stiff.
Leaving on 5psi and ramping up within 1/4 second we were going 1.27-1.31 range on a 325.
It wheel hopped BADLY on one run, but we put some more air in the tires (15 cold) and it went away...This was at Jackson SC during the last ORSCA event.
Leaving on 5psi and ramping up within 1/4 second we were going 1.27-1.31 range on a 325.
It wheel hopped BADLY on one run, but we put some more air in the tires (15 cold) and it went away...This was at Jackson SC during the last ORSCA event.
Thread Starter
Joined: Nov 2001
Posts: 45,362
Likes: 1,792
From: Chicago, IL
Thanks guys. So the common themes are run the rears at 16 - 18 cold, run the rear shocks medium to stiff, and the front a little loose like a few clicks from full loose.
For NA cars, or those that don't have the ability to ramp in power on their cars, couldn't the unloading and subsequent tire shake / wheel hop that a lot of you are describing be eliminated by running the front shock extension on the loose side and the compression on the *very* firm side. Get the nose up and transfer the weight, then keep it up there till you're out of the shake zone.
Just a thought. Please someone tell me if this is a sound theory or not?
Just a thought. Please someone tell me if this is a sound theory or not?
Originally Posted by Pro Stock John
Thanks guys. So the common themes are run the rears at 16 - 18 cold, run the rear shocks medium to stiff, and the front a little loose like a few clicks from full loose.
Just be careful with the front...one click too loose and you will end up on the bumper. We did in the second round of eliminations.
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Would the 275/60/15 work with a 10" wheel? I tried them last year but on a 8" wheel and they did fine but im not so sure on a wider wheel.
My next tire will be either one but it's always nice to know which is better than the other before you buy.
My next tire will be either one but it's always nice to know which is better than the other before you buy.
JL: The radial slick is awesome. You won't be disappointed. I gained .08 from just swapping to them even though I killed my gear ratio a bit going from 28x10.5x15 hoosier slicks to 30x10.5x15 hoosier radial slicks. I ran them at 18psi, another buddy of mine said go 22 so once the car is up and running we'll see. The car just feels so much better down the track over a bias ply.
Originally Posted by TTPMatt
JL: The radial slick is awesome. You won't be disappointed. I gained .08 from just swapping to them even though I killed my gear ratio a bit going from 28x10.5x15 hoosier slicks to 30x10.5x15 hoosier radial slicks. I ran them at 18psi, another buddy of mine said go 22 so once the car is up and running we'll see. The car just feels so much better down the track over a bias ply.
Same reason I am a little hesitant with the 30x9 radial slick. Supposedly they're 29.5 tall and don't grow at all. If that's true, if they have a 1/2 inch around them they probably won't hit anything at all, depending on how they distort on launch.
KP you're on a bogart/stock width rear right? If so what did you have to do to get the 325 on? The 275's clear with no problems at all, even the rear bumper clears, just barely, but at 126 they don't hit at all. I already have the bump stops off and the front inner was beat in to clear a set of factor z-6 wheels a while back.
KP you're on a bogart/stock width rear right? If so what did you have to do to get the 325 on? The 275's clear with no problems at all, even the rear bumper clears, just barely, but at 126 they don't hit at all. I already have the bump stops off and the front inner was beat in to clear a set of factor z-6 wheels a while back.
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Joined: May 2007
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Yes. you might also want to consider putting in a down travel limiter setup in the front. Once you get the desired wiegth transfer rate then you are going to want to police how much down travel you give it.
For instance I know of a local car that hits hard as hell. But kept going on the bumper. Tried a ton of chassis changes everything killed the luanch. Put in a travel limiter to limit front end down travel went back to the bumper slammng setup and with the travel limiter it was easier to kep the front end at a respectable hieght.
This is F-car specific.
For instance I know of a local car that hits hard as hell. But kept going on the bumper. Tried a ton of chassis changes everything killed the luanch. Put in a travel limiter to limit front end down travel went back to the bumper slammng setup and with the travel limiter it was easier to kep the front end at a respectable hieght.
This is F-car specific.
Originally Posted by Pro Stock John
Thanks guys. So the common themes are run the rears at 16 - 18 cold, run the rear shocks medium to stiff, and the front a little loose like a few clicks from full loose.
Thread Starter
Joined: Nov 2001
Posts: 45,362
Likes: 1,792
From: Chicago, IL
Thanks Sean, I did get some travel limiters from Madman and put them on the car, though to be honest, I'm not sure how to adjust them.
I have a bunch of pics of the 325's/stock length rear/bogarts here:
http://www.fquick.com/garages/viewga...action=&page=4
I already had fit 28w's on the car, so I had to buy an adjustable panhard bar to center the rear, and did a little trimming of the rear bumper.
I have a bunch of pics of the 325's/stock length rear/bogarts here:
http://www.fquick.com/garages/viewga...action=&page=4
I already had fit 28w's on the car, so I had to buy an adjustable panhard bar to center the rear, and did a little trimming of the rear bumper.
Originally Posted by LS1curious
Yes. you might also want to consider putting in a down travel limiter setup in the front. Once you get the desired wiegth transfer rate then you are going to want to police how much down travel you give it.
For instance I know of a local car that hits hard as hell. But kept going on the bumper. Tried a ton of chassis changes everything killed the luanch. Put in a travel limiter to limit front end down travel went back to the bumper slammng setup and with the travel limiter it was easier to kep the front end at a respectable hieght.
This is F-car specific.
For instance I know of a local car that hits hard as hell. But kept going on the bumper. Tried a ton of chassis changes everything killed the luanch. Put in a travel limiter to limit front end down travel went back to the bumper slammng setup and with the travel limiter it was easier to kep the front end at a respectable hieght.
This is F-car specific.
JL, just had to beat the the inner wheelwells to get them to fit, the 325s are shorter then the 28' ET drags so the only problem is on the inside. One still rubs a little on the inside on turns so I'll have to do a little more beating.
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Joined: May 2007
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typically 4-4.5 inches of front down travel seems to get it done. Depends on the TQ arm and other factors but thats the biggest one.
Originally Posted by kp
I have way better luck with no travel limiter on the front with the radials, problem with that is the unpredictable wheelstands. The radials will lose traction on mine while the front is in the air and it hits the limiters, not when it comes down. I have no problem setting the car up to run the radials, I know with 275lb front springs and no limiters they will work, but that doesnt work with the bias slicks. Well it works but I hate the car on the top end with the 275 springs, bottoms out too much on the brakes and just handles like crap, not to mention the wheelstands. Cant have everything i guess
JL, just had to beat the the inner wheelwells to get them to fit, the 325s are shorter then the 28' ET drags so the only problem is on the inside. One still rubs a little on the inside on turns so I'll have to do a little more beating.
JL, just had to beat the the inner wheelwells to get them to fit, the 325s are shorter then the 28' ET drags so the only problem is on the inside. One still rubs a little on the inside on turns so I'll have to do a little more beating.
