Shocks & Tires

Looking for opinions

1983 Mustang 3,100 lbs with Boo Boo in the seat.

Back halfed 4-link with Goodyear 32 X 14.5 (D-5 compound)

QA1 single adjustable coilover shocks

Car has a Evans Racing built 572

Last time this car was at the track was the BBF Bash in June. Made it to the semi-finals (Dan Hobbs showed us to our trailer) but I think we could have been much faster? Car ran very consistant 5.98 - 6.0 but we just couldn't get it to launch straight? Track was not the problem as those really long cars with the tenny, wenny tires were putting down 4.60s!

I want to put a pair of double adjustable shocks and maybe new slicks??

We know we have some wrench turning to do on the 4-link to make it go straight but maybe some new shocks and tires will help?

Any suggestions? Hope to get the car to BG this weekend to test with Blake, Damon, Dan, Moe, Larry, Curly



Bruce

The car launching straight (or not) is probably going to be a side to side preload adjustment thing more than anything. Next would be if there was a tire roll out difference. Collapsed or dead springs can also be a preload problem. But with an anti-roll the effect of a spring going away might not be as drastic since the anti-roll does help spread the load around helping to "crutch" a weak spring along. But if you keep adding & adding more & more preload and the crooked launch never corrects, then there might be a big problem to sort out.

Now having said that a set of double adjustable coil overs are always a good idea on a car with wheelie bars. Not for preload reasons, but just to increase the size of a car's violent/lazy fine tune adjustment window. And it's hard to beat a fresh set of slicks.

Dave,

What tire would you recommend for our car? Would a stiff sidewall tire help?

Bruce

Bsherry wrote:Dave,

What tire would you recommend for our car? Would a stiff sidewall tire help?

Bruce

Depends upon how the sidewalls are reacting on your present tires. Are they wadding up bad, or not? Stiff sidewalls aren't always a cure all. I would go with new tires first and then you need to get it launching straight with your present shocks before making a lot of other changes, in my opinion. Once it launches straight, I would then go to the double adjustables. On thing at a time, or you will never know what cured the problem. I've been down that road, believe me!

Nevs wrote:

Bsherry wrote:Dave,

What tire would you recommend for our car? Would a stiff sidewall tire help?

Bruce

Depends upon how the sidewalls are reacting on your present tires. Are the wadding up bad, or not? Stiff sidewalls aren't always a cure all. I would go with new tires first and then you need to get it launching straight with your present shocks before making a lot of other changes, in my opinion. Once it launches straight, I would then go to the double adjustables. On thing at a time, or you will never know what cured the problem. I've been down that road, believe me!

I hear ya, hopefully the car will make it to BG this weekend. We won't make any changes before that test & tune. The Goodyears on it are fairly new, we don't HAVE to change tires but I'm willing to do whatever it take to make it go straight and try and keep up with Blake, Damon, Dan, Nick--dam this list of spunky cars is getting long

Bruce

I guess you could get a general idea if the car might like a stiffer sidewall by adding a little more air pressure than "normal" and see what happens. If you can keep adding a little more air each pass without spinning, and the car likes it, that might be a good indication the car might like a stiffer sidewall. As far as brand goes sure Good year makes a great slick, but I just have never liked them. I'm always going to suggest either Hoosier or M/T's. I know KY slowed down when he tried Hoosiers a while back. But I think that had more to do with the harder C07 compound. Since he doesn't use a power adder the C07 compound was probably a little too hard.


But as mentioned if the current tires are in good enough shape to actually hook lets get back to the launching straight thing for now . What exactly is it doing when it wont launch straight? Is it launching right or left, then driving straight as an arrow down track? Is it launching left and driving to the left down track? Is it launching right, and driving to the right down track? Is there any stagger in the wheelie bar wheel heights (sometimes stagger is needed)? Is there any difference in the roll out? Is there any unwanted stagger in the front/rear spring height adjustment? Is there any unwanted preload in the anti-roll (preload with the 4-link, not the anti-roll)?

Dave,

If you watch the 2009 BBF Bash DVD the car is launching to the right. It's almost like the right rear tire was squatting too much? I tried to compensate with a little more tire pressure and that seems to help a little but we were in the middle of the elimination rounds and didn't want to get too aggressive and "bust out". That is one of the reasons I was asking about stiffer sidewalls?

Because of the squatting I adjusted the right wheelie bar a little higher so it wouldn't unload the tires. After Boo Boo compensated for the pulling to the right on launch it seemed to track fine down the track?

If you have any suggestions for adjustments, Boo Boo is headed to Bowling Green this weekend to T&T with the "Boys".

Thanks,

Bruce

Bsherry wrote:It's almost like the right rear tire was squatting too much?

Ahh, your describing the little quirk where even though a car might have an anti-roll, it kinda looks like it doesn't have one because you still see the body rolling over some amount. And yes running the air pressure too low can aggravate the problem in effect compressing/collapsing/over-wadding the passenger slick's sidewall too much.

In this situation the anti-roll is doing it's job correctly, but by design that rotational loading has to be transferred from the anti-roll to somewhere else. And the passenger slick is where that load is transferred to. So if there's not enough air pressure in that slick to help support the wound up sidewall, the car will roll over on it more.

Bsherry wrote:Because of the squatting I adjusted the right wheelie bar a little higher so it wouldn't unload the tires.

Raising the right (pas) wheelie bar trying to keep from unloading that slick (and thus trying to drive the launch back "left" to center it) probably did help drive the launch back center some. But it also probably allowed that sidewall to collapse/over wind even further.



What air pressure are you guys running now? And how much more air could you run before it would flat-out spin it's nuts off? If you can add some more air (and still hook) I say give more air a try with the wheelie bars level. If more air helps to cure the over wadding/collapsing passenger side slick (and body roll) and also help some/all of the "to the right" launch, then any needed right/passenger side preload increase will probably be a small adjustment. If more air helps the over-wadding, but not the "to the right" launch, a bigger increase in right side preload adjustment will probably be needed.


Just keep an eye on what any preload changes do at both ends of the track. The "perfect" preload setting for a straight launch doesn't always end up being the "perfect" setting for the car to also drive straight at the finish line. In this situation you use the preload setting that is needed to drive straight at the top end, then stagger the wheelie bars to help that same preload setting to also work at the launch.

Dave,

During the test & tune on Friday we were running 10 lbs and on Saturday I went up to 11 lbs and that seemed to help but as I said earlier I didn't want to go higher and see the car run a better time and break out during eliminations.

So maybe they should start at 11 lbs on Saturday at BG and go up from there?

Bruce

Bsherry wrote:So maybe they should start at 11 lbs on Saturday at BG and go up from there?

Yea, that sounds like a plan.

If they think they will have time for a bunch of passes they could make 1/2 pound jumps each pass. If they will only have a limited few passes they might have to make 1 pound jumps. One pound jumps aren't as accurate, but either way it should point to what the max air pressure is the car can handle before it starts to free spin on the launch & down track.

I am planning on being there Mr Sherry , I don't mind helping you with the 4 link. I also have a set of D-1 16 X 32 that have a little life left in them if yall would like to try them I will bring them.

I myself am going to try a d-5 on my car next , a friend of mine went from a d-6 (which is what I am running now) to d-5 and his car started snatching the front end up a lot better. I only got 30 good passes out of the d-6 's I cant afford to be buying tires that often . I suspect my car is just beating the sidewalls out of them.

KY JELLY wrote:I am planning on being there Mr Sherry , I don't mind helping you with the 4 link. I also have a set of D-1 16 X 32 that have a little life left in them if yall would like to try them I will bring them.

I myself am going to try a d-5 on my car next , a friend of mine went from a d-6 (which is what I am running now) to d-5 and his car started snatching the front end up a lot better. I only got 30 good passes out of the d-6 's I cant afford to be buying tires that often . I suspect my car is just beating the sidewalls out of them.

We can use all the help we can get

Keith will be taking the car to BG, I'm still working in Vladivostok. I don't think we could fit a 16 inch tire on our car? So you like the Goodyears? Whatever tire we get I will probably buy some new rims so we can switch tires if the track doesn't like what's on the car. You all be safe now!!

Bruce

Thanks for the help Dave and thanks Randy for helping and for offering up the tires. We have the D-5 compound on there now and there is plenty of life left in the tires. I think poppa bear is just being a little too precautious. We have rotated these tires after every time out and tryto do everything we can to make sure the tires are well kept. Ya'll are THE BEST!!!!
And yes poppa bear, we could get a 16 under there

Boo Boo

Didn't you guys make some decent runs late last year after you put the glide in?

Didnt really get many in and we didn't lean on her hard. Now that we're trying to leave harder, the chassis needs to catch up. Never adjusted after the C-4 deal. Hopefully I'll get a few passes in up BG this Saturday and tweek here and there and get her running what she's supposed to. She tracks straight, just leaves hard right. It's like she thinks she's a circle queen


Boo Boo

stangr8cr wrote:Never adjusted after the C-4 deal.

Then it makes sense if the suspension is still setup in "calm it down" mode for the C-4 (super long I/C & super tight shock valving), you might have to make a few changes down the road for the calmer hit from the 'glide. Hopefully more track testing will help tell which way (and how much) the adjustments need to go.

wow --- Dave lots of great information