Drag Racing Tech - how can i stop wheelhop after s60 install?

Went to the track this week for a street night. On radials, the car wheelhops violently on the 1-2 shift(T56). Off the line it is ok, but the shift is awful. I have everything upgraded suspension wise other than the sway bars. Car has koni DA's front and rear. Hooks good on et drags, 1.5 60 ft, no problem with the shifts. Just on radials. I think it is just the extra weight of the s60. How can I get it under control? Thanks

Ryan

MT ET Drags

They are the tires you NEED.

Trying to race on radials with a m6 is very tough, do a search here, tons of post on that.

Yes I know. I have them already. But it does the same thing on the street on the 1-2 shift and i cant use the et drags there. I want to solve the problem, not band aid it with the tires. Thanks

Stiffen thd shocks up about the only thing you can do unless the geometry is totally fubar due to the brackets on the new rear being in different locations...

Yes I know. I have them already. But it does the same thing on the street on the 1-2 shift and i cant use the et drags there. I want to solve the problem, not band aid it with the tires. Thanks

Running a radial requires heavy suspension, and a 2 step at min, also better shocks with more adjustibility. I am running 10 way QA1's which may not be optimal. Race weight factors in, as well as weight transfer. I've spent the money and broke the parts, it sucks but it is what it is.

Your not going to "solve" any problem as the car sits. Very few examples of competitive/consistant racers winning with a M6/Drag Radial set ups and the ones out there are in a whole different cost range and the type of clutch you needs is not really a street clutch at all (see Soft Lok from Mcleod).

If you want/need to run a radial throw a TH400 in there with a trans brake, good converter, and maybe still a 2 step to dial in.

JL been getting me to change to a Th400 and I've been hard headed but that my choice, all depends on what you can handle.

car is 3900# with 430rwhp. So I think the geometry and setup are reasonably good other wise it wouldnt go 1.5 60ft times on the et drags. I already have a 2-step. But this is not a launching problem. I expect it to suck on the launch on radials. This is a problem with when I shift it, it wheelhops bad on the shift. I don't expect it to be fast or competitive on radials, just like to be able to shift it without breakin something. Changing shock settings could help. Do I go stiffer on both comp and rebound? Also would a drag sway bar help it? Thanks

Ryan

Drag bar may help but that probably isn't going to solve the issue. You need to stiffen the rear shocks both compression and rebound.. you're going to end up really stiff if it's like every other car with this issue.

i bet its lowered, and you dont have enoght LCA angle to get the IC anywhere. They need to have some tilt up, if there parrell to the grond or tilt downward its gota wheel hop. your beating the crap out of the car it will break parts.

what size are the radials? how much psi, to low they will shake, try adding some air

275 40 17's for tires, approx 30 psi, never checked, no way to air them back up, so I left them as is. Shocks were in the middle, maybe 7 of 12 clicks stiff on both comp and rebound. Car is not lowered. Stock 1le springs with bags in both coils to add more if needed. Torque arm is relocated, but at stock height with -2 pinion angle. Lca's sloping up toward trans and in middle hole of the relocation brackets. Can change the IC either way, not sure which way is needed though. Shock setting could definitely be stiffer.

Like I said though, I don't expect great 60fts on radials. Was just looking to have fun without breaking it. 1.90's would be fine. It is the 1-2 shift that is the problem. Thanks

Ryan

Put the lower control arms down a hole, if it still wheel hops I would be surprised. Stiffen the shocks up as well.... should solve the issue.

that psi is more then fine. To low the will hop/chatter. Ive never had it hop in 2nd but not 1st, Once you get moving there fine.
Will it spin smooth in 1st when you over power the tire? Ever have it on the edge slow clutch out, so its doing that slow spinning? Like the cars ripping forward the 1st 6-10 feet. Thats when they get un happy and start to chatter. But fast dump and just instant spinning them away and little foreword motion I could see them no hopping with some un happy setup still. But still not sure about doing it on the 1-2?
whats different about the S60? The diff ok? I can't think of anything if it was fine before?

I would try the lower LCA hole unless its something crazy like 5* down and you get breaking wheel hop street driving. Or lower the front of the TA and re set the PA.

Not sure the valving on the koin DA, but normally keep the rear super stiff on DR and super loose rebound. So you cant even push the back end of the car down, but it comes up really easy. But all thats normally not gona be a problem on the 1-2.

Before the s60 it would kinda hop once and settle. Just a chirp then hooked. But that was on a 10 bolt with 3.73's. now i have the s60 with 4.30s, so it is heavier to control and easier to spin the tires.

Will spin smooth if overpowered in first. no hop at all.

I can lower the lca's, but that is how I originally had them with the et drags and it would hit the tire too hard and bounce and spin them. Which is fine, I am sure the settings needed for the radials are way different than for the bias ply's. How does lowering the front of the TA help? Does it hit the tire harder or softer? Or help with weight transfer?

From inside the car it seems like it is bouncing the rear one side then the other. Which is why I thought the drag bar might help.

Studderin runs a M6 on radials so he knows..FWIW from what ive seen/experienced, M6 cars are tricky when it comes a dig/radials..

I can lower the lca's, but that is how I originally had them with the et drags and it would hit the tire too hard and bounce and spin them.

Wouldn't that be a shock setting issue?

Air bags???

yes drag bags inside the coils. My car used to hit the rear bumpstops on the 1-2 shift. That was before I knew anything about setting the car up. Prolly could take them out now, but havent tried it. I run 6 lbs driver and 12 pass. Makes the car leave straight and flat.

Could be shock settings for sure. But it seems more like the car torques the rear to one side then bounces back and forth. If I pedal it at all, it hooks. It is just the initial shock of the shift that gets it started. That is why I was thinking a drag bar might keep the rear more level and plant both tires on the shift. But IDK. Looking for experienced help on this one. Thanks

Ryan

get the bump stops off if its hitting them.

It doesnt with the bags in it, I would have to test with them out to see if it does of not. I think I have changed the suspension enough to where it wont anymore. It used to squat pretty good, doesnt anymore, but that is on launch not shifts.

Good call on the bump stops. not sure if that is all of the problem, but the rear was definitely hitting them. I had the 1/2" spacers in there from slp, so I took them out. Ill try that and see if it helps. My guess is that I prolly need to cut them down more due to the change in axle tube size and doing the hose mod to the springs when I put the rear in. Thanks. Ill post results when I go back to the track.

Ryan

I run an A4 so my set-up is way different, but seems to me airbags with that much psi are working against your DA shocks. I use dragbags and psi is 2L / 6-8R. When I went to Moser12 lcas were in bottom hole and I got wheelhop on the street, moved them up 1 hole and it stopped. Car still dead hooks at the track with a new best 60' at Cecil Co. Md. Try lowering psi in the dragbags and work on shock settings for the street, when you change to drag tires change shocks to that set-up. Just my 2 cents, Larry.

"That is why I was thinking a drag bar might keep the rear more level and plant both tires on the shift."
Ditch the bags.. They are "basketballing"...Add the drag bar.

Both suggestions on the drag bags are things that I was thinking. But here is my problem, 5psi minimum in each bag because they are on an automotic compressor. If I take them out and am hitting the bumpstops on the 1-2 shift, how am I going to stop that? The drag bar, I think that is my next purchase.

Thanks

Ryan

ya I didnt even think about the air bags. I've seen local GTO guys use them, for the tires rubbing, but there not setup that well anyway, street car stuff. I wouldn't run them, whats the point of having good shocks there ghetto as shit.

And I dont think it should sqaut that much. You can have it push the tire (rim into the pavment) But if the tire it going up inside the wheel well, I think thats not good. I know most don't have that happen. I try not to.

30 psi in a drag radial will cause just as much if not more shake then having too low pressure. Seen it happen on my own car on the track AND on the dyno. Try 18-20 pounds.

How dose that happen? I seen the low do it on the super slow mo, the tire footprint cups, and the sidewall winkles and releases so the side lose contact, and the cycle repeats. Just can't picture how to much would do it?

Taking the bumpstops off definitely helped. This week I went on slicks, so no wheelhop. But also had very consistent 60ft times (1.60-1.62), track wasnt great, it was a street night. But now I think I can either lower the control arms or change the TA height. Before the car felt like it bounced the tire and spun, now it spins smooth. So im thinking it might have hit the bumpstops. And Im going to pull the air bags and see what happens. Hopefully a drag bar and ditch the front swaybar this week also.

What angles should I be looking for on the TA and LCA's as a starting point?

BMR adjustable, long style with the relocation crossmember that mounts it off of the trans. It uses a a poly bushing on the front, not a rod end. Thanks

put it on the lift today. So maybe I will get a chance to look at it this weekend. I believe the LCA's were at 2 degrees down toward the rear and the TA was in the fourth hole from the bottom( about middle of the road). Basically your thought is to go -2 on the lca's, then see how it hits the tire. If it hits hard and then spins, lower the TA a hole or two. If it doesn't hit the tire hard, I either need to raise the TA or lower the LCA's another hole. Is that right? Which change will give the car better anti-squat so that I am not slamming the rear into the bumpstops? Thanks

Ryan

Just got the car in the air. The LCA's were at .5 degrees downhill toward the rearend. That was in the middle hole. So I switched them to the lowest hole and it is at about 3 degrees downhill now. Better? The TA is in the fourth hole from the bottom, third from the top. I am thinking I will want to lower it down 1 or 2 holes, so that it plants the tire longer. What do you think? The bottom tube of the TA was at 4 degrees downhill to the rearend. Pinion angle was 2 degrees negative to the chassis. All measurements are with the chassis level. Thanks

Ryan

good info.

But 3 revs is a ton, thats over 20 feet, More like 1, 2 is alot, thats BIG power, beadlock setup

Regular clutch, Monster stage 3. Hose mod is already done. Flywheel is a 28 lb? I think, it was the heavier one that monster offers. Tried it before setup like this and it seemed to unload the tires after the hit, but that was with the airbags and brand new slicks. Ill try to get video of it and see what is happening. Thanks

Ryan