We finished our season yesterday and I'm already thinking about next year. I have found some tire shake or spin at the hit at tracks that have marginal track prep. This is a 3300 pound door car that runs 5.60's in the 1/8th with a best 60' time of 1.18. Normal 60' is 1.23+/-

I have tried long and short burnouts and I've run 9psi to 11psi (landed on 10.5).

I have double adjustable shocks on all 4 corners and have made shock and 4 link adjustments throughout the year trying to get the car to dead hook anywhere we go. I made it "better" with shock adjustments but it will still spin at the worst possible time.

Currently running a MT 3074S but considering changing to a 3074 non-stiff for next year. The current tires have about 120 passes on them but I've seen inconsistency in 60' since they were brand new. Will be 1.21 off the trailer and slow down as much as 3 to 5 hundreths as the day goes on with increased spin or shake. I feel the shake obviously which doesn't seem to impact the run all that much however the spin usually requires steering correction and obviously changes ET.

Anyone running a non-stiff wall tire in a heavy car and if so, how many runs do you typically get on a set?

my car is light 2550 and loves a stiff side wall.
i use the m/t 3080

This is interesting. We have a Camaro that runs almost identically the same times. The car is about 100 pounds lighter with a ladder bar suspension and double adjustable shocks. We run the 3074s M/T's at 10.5 pounds pressure. Maybe once a year we will experience some tire shake on a 105 plus day. Never considered going to a different tire. When it cools a little, the shake stops. Right now 125 plus runs. I am interested to see what responses you get.

I had the 3074S on the Super Stocker. Went 1.26 60 with 8lbs of air. Car weight 2980..

I just put a set of 31.5 x 13.5 Hoosier Raidals on it. Same wheel. The 3074S were 48lbs and these new ones are 41lbs total

IMO, the stiff sidewall slick is needed in your application & think most cars over 3000+ lbs. needs them.

I'm at 3100 lbs. & 10+ years ago, I switch to the ultimate stiff sidewall; radial slick!

2BKING

quote:

Originally posted by SpeierRacingHeads:
I had the 3074S on the Super Stocker. Went 1.26 60 with 8lbs of air. Car weight 2980..

I just put a set of 31.5 x 13.5 Hoosier Raidals on it. Same wheel. The 3074S were 48lbs and these new ones are 41lbs total

Those Hoosier 31.5/ 13.5R radials could be close to 0.10 faster than the bias in that size. A friend showed me his Hoosier 32/ 13.5R in the back of his pickup at a recent race. 70 runs and they’re down to the end of the tread indicators and spinning. He’s not aggressive in the BO box in a car that runs 6.05 with radials and 6.15 on same size in bias. For a big tire SS class car I can understand the radial choice, but not for a bracket car.

I talked to MT tech support and they thought changing to a soft wall tire might help my situation, but also said they rarely recommend a soft wall tire at this weight. Not sure what I want to do yet.

I have not seen anyone on a radial tire at any of the events I attend going rounds so I'm not going down that path.

quote:

I talked to MT tech support and they thought changing to a soft wall tire might help my situation, but also said they rarely recommend a soft wall tire at this weight. Not sure what I want to do yet.

I’m not brand loyal when it comes to tires and use/d all three major ones. MT ain’t any better than Hoosier and vise-a-versa imho for door cars. The 3074S and 18245 are the same dimensional size in stiffwall.

Consider switching rear or even planet gearing. 99.99999% have a 1.80 gear……how can that be the best?????

quote:

Originally posted by markemark:
For a big tire SS class car I can understand the radial choice, but not for a bracket car.

There are many misconceptions of radials & you are a contributor to them!

Stock & Super Stock, the vast majority of elimination rounds are run as a bracket race or bracket mode as many call it. Stock is my favorite class in NHRA followed by Super Stock. I have been lucky enough to pilot a ride in both classes. The Stocker had radials on it & was in bracket mode; along with the 3 other stockers in the camp. I'm unsure on the Super Stock car in the camp, but I know how they roll.

As for Super Stock, we have been talking about bringing a car back out to compete. If & when the car comes back out, it will be run with a radial slick both in bracket & head-up mode.

I have a poll going on CR about using biased slicks or radials for bracket/heads-up racing. The preliminary results are pretty lopsided using radials for both bracket & heads-up.

I'm not forcing radials on anybody, just providing the facts. Both Chad & I provided info on what we're using or what Chad switched to. Do as you wish, but if you haven't run a radial; you're only spreading hearsay.

2BKING

quote:

Originally posted by B KING:

quote:

Originally posted by markemark:
For a big tire SS class car I can understand the radial choice, but not for a bracket car.

There are many misconceptions of radials & you are a contributor to them!

I said radials are faster than bias.
I said big tire (32x14 same as Chads) radial Hoosier wear out fast, based on a friend that ran 70 runs on that Hoosier 18247 radial and it was wore out of tread that I viewed. Never said anything about 10.5 or MT radials.
I said big tire (not 10.5) Hoosier radials are a poor choice for brackets imho, if 70 runs is the limit.

In the left lane is my friends car that runs 6.05 on 32x14 Hoosier radials that wore out in 70 runs. He got a set of used Hoosier 18245 bias with over 100 runs for free from a racer that has a tire deal. This is 3rd rd and I’m in the right lane on the same 18245 bias and it’s run # 271 on those tires. I went 3 more rds after this with 6.15 painted on the window. There’s easily another 50 runs and possibly 75 left in those tires.

The misconception according to you is "not for a bracket car." You & many others believe that. While not bracket cars, Stock/Super Stock do bracket race the majority of the time in eliminations. The poll on Class Racer, last checked was 85% use radials for both bracket mode & heads-up, I think I know the reason(s).

There are radial bracket racers. While I will admit we are the minority but growing. We go rounds & win; same as I did when I used bias ply slicks both standard & stiff sidewall. The biggest thing for me is at least double the runs on the radials over the bias slicks including the stiff sidewall.

Most of my radial passes have been on Hoosier 9" slicks from lightweight to standard in C06, C07 & C30 compounds. I got an easy 150 passes out of the lightweights. The 9" C30 compound Hoosiers I only have about 50 runs on that tire & have a new set to replace the M/T PBRs. The M/Ts have 200+ runs & after this weekend will be changed out with C30 Hoosiers; this is the most passes I've put on any of my radials. I'm sure my standard weight Hoosiers could get 200 runs but hasn't been tested that far. How many passes on the new to me Hoosier 9" C30 compound is still unknown.

I'll use my last win as an example. The track was all old asphalt with one light spray of glue & one drag that I saw. Nobody should have been racing on that track trying to go a 6.0 index with any type of slick, bias or radial. My opponent & myself in the finals was on radials. Radial slicks have come a long way.

2BKING

quote:

Originally posted by CSRacing:
Anyone running a non-stiff wall tire in a heavy car and if so, how many runs do you typically get on a set?

CSRacing, sorry for the radial rant!

To answer your question. When we were heavier (3400 lbs.) & slower mid to high 10s with 1.35 60'. We were getting between 75 to 100 runs depending on the tire brand. This was with a 9" or 10" bias slick. Higher tire pressure was key to getting the life out of the sidewall. The tread check hole always had plenty left.

It doesn't sound like you've been happy with that tire from the get-go. I would change to a different tire or brand but keep it a stiff sidewall.

I don't know what your rim width is but maybe you could widen it to help stiffen the sidewall even more.

A video of the launch would help.

2BKING

quote:

Originally posted by markemark:

quote:

I talked to MT tech support and they thought changing to a soft wall tire might help my situation, but also said they rarely recommend a soft wall tire at this weight. Not sure what I want to do yet.

I’m not brand loyal when it comes to tires and use/d all three major ones. MT ain’t any better than Hoosier and vise-a-versa imho for door cars. The 3074S and 18245 are the same dimensional size in stiffwall.

Consider switching rear or even planet gearing. 99.99999% have a 1.80 gear……how can that be the best?????

On a door car I would not hesitate to try Hoosier again. On a lighter car like an altered or Dragster I have ran Hoosiers (5 different sizes and compounds) and MT are way better for me. Way better, as of right now I do not ever see me running anything but MT. One of the cars I drive for someone has Hoosiers and I absolutely hate them. We will be changing them soon. As for the OP here in 3300 Lbs door car I know my 67 Camaro had good results on Hoosier many years ago but so much has changed since then.

quote:

Originally posted by CSRacing:
We finished our season yesterday and I'm already thinking about next year. I have found some tire shake or spin at the hit at tracks that have marginal track prep. This is a 3300 pound door car that runs 5.60's in the 1/8th with a best 60' time of 1.18. Normal 60' is 1.23+/-

I have tried long and short burnouts and I've run 9psi to 11psi (landed on 10.5).

I have double adjustable shocks on all 4 corners and have made shock and 4 link adjustments throughout the year trying to get the car to dead hook anywhere we go. I made it "better" with shock adjustments but it will still spin at the worst possible time.

Currently running a MT 3074S but considering changing to a 3074 non-stiff for next year. The current tires have about 120 passes on them but I've seen inconsistency in 60' since they were brand new. Will be 1.21 off the trailer and slow down as much as 3 to 5 hundreths as the day goes on with increased spin or shake. I feel the shake obviously which doesn't seem to impact the run all that much however the spin usually requires steering correction and obviously changes ET.

Have you considered using a programmable timing retard like MSD Grid and increase the 60’ time slightly until it repeats consistently. To me this would be an inexpensive fix with some added features.

This message has been edited. Last edited by: markemark,

quote:

Originally posted by markemark:
Have you considered using a programmable timing retard like MSD Grid and increase the 60’ time slightly until it repeats consistently. To me this would be an inexpensive fix with some added features.

Good tip!

Our quickest personnel best 60's have come with a mild launch retard & tripping the timer with the back tire. We also had an issue with mild tire shake then spin on a hot track this past May in the heat of the day. The mild retard took care of that issue & the 60' started repeating.

2BKING