Not so straight anymore...

So the Maverick has been running real well, smooth and straight passes until the last couple of weeks.  Then it started to gradually try to leave the groove, pulling slightly to the right.  I started out blaming track prep. Last week it got worse, pulling hard right.  Last pass attempted  in the left lane, it went right so hard that it would've hit the tree had I not lifted. 

I've been looking for chassis issues all along, all looks good...4-link stuff all in place, nothing bent or broken, rod ends look perfect, jam nuts all tight, no cracked or broken welds, Strange shocks only a month old.  I haven't put a string and plumb-bobs on it yet, but I will.

In talking with Lem this morning, he asked if it was possible I may have killed a sidewall in the Goodyears.  That thought hadn't occurred to me yet.  Does this sound like a phenomenon you guys have encountered?

Mild steel, 2525 lb. car, 4-link, Strange strut front, pump gas 514, 'glide, 4.86 gears, ARB set neutral, 32 x 16 Goodyear slicks.  5.70's car.
Probably 30 or 32 passes on the tires.

I considered testing by swapping the tires side to side but I'm not crazy about the idea of launching this thing again if it promises to be as thrilling as the last attempt.  Been looking around for a buddy with a similar size set of tires to try, but.....

Short of buying new tires (probably will anyway) or making a second suicide attempt, does anybody know of a way to check for hurt sidewalls?...visual inspection of the tires shows nothing unusual.

The rear housing twisting? Do you run wheelie bars?

No wheelie bars. Also, it's a chromoly Fab 9 housing with Strange center section. I haven't checked it for twist, but I doubt I'm making enough oats to twist it.

Kim have you check to see what the roll out on the tires, might be one has grown more than the other Rick had a set on his RX7 make it pull hard

69F100 wrote:Kim have you check to see what the roll out on the tires, might be one has grown more than the other Rick had a set on his RX7 make it pull hard

That's a good question. I'm always fussy about rollout when I put a new set of tires on, but I haven't checked these since the trouble started. I'll check 'em out and let you know what I see.

If it just started this and is getting worse something has got to be bending or binding. take the shocks off and make sure they're ok.

cool40 wrote:If it just started this and is getting worse something has got to be bending or binding. take the shocks off and make sure they're ok.

Will check that too.

If you have an arb check it too....

I agree check your shocks I see where you said they was only about a month old did it start pulling after you put them on if so that where I start. You may have gotten hold of a bad one.

Does it have a wishbone or diagonal link? How many passes on the Goodyears?

You might want to also check for a possible collapsed shock/strut spring. Or that a spring seat didn't loosen and spin down a little.

It's a 4-link with diagonal. Probably have 30-32 passes on the slicks. Spring seats don't appear to have moved. ARB at neutral with my butt in the seat. Right now, my prime suspects are tires and shocks.

Gonna recheck rollout at normal psi, then overinflate a bit and recheck just to ease my mind. Then pull shocks, remove springs and look for travel/damping issues, ensure no binding at mounts. Then string and plumb-bob it, reset square, pinion angle, preload and ARB. I was hoping for the quick & easy fix here, but going sideways sux so I'll just set it all up again, start to finish.

You guys may have a point...this problem started after the shock swap, but it's gotten progressively worse over 3 weeks or so. That threw me off a bit. I've kinda been looking for an excuse to try a set of Hoosiers, but I won't buy 'em until I'm sure the Goodyears are dead. Will report back when I'm smarter.

Sometimes you guys are SO smart...and sometimes I'm a duma$$.

I found the left lower shock mount binding. When I switched shocks to the Strange deals, it required the lower mounts to be inverted. I had free movement of the shocks at the time of installation, but when the car was lowered and the springs compressed, the mount would bind at the bottom of the shock body. This car is REALLY low, so in order to inspect the rear suspension, the car had to be raised...eliminating the bind.  I didn't spot the problem until the shocks were off for testing. Then I noticed the shiny spot on the underside of the aluminum shock body...and a corresponding wear mark on the lower mount. A little massage with the grinder and all seems well.

If I can find my chalk line, I'll reset all the 4-link parameters just to be safe.

Thanks a heap, boys. 

Glad you found it.

cool40 wrote:Glad you found it.

X2. Glad you found it plus sounded like a easy fix. Put the tires up on blocks so you can get under it and inspect everything like it is sitting on the ground and over it real good and make sure that all you had binding

I ran the chassis centerline, hung the plumb-bobs and reset the 4-link, too.  Also had enough time to load up and haul it to the tnt at Atmore.  It's a good track on race days, but tnt is usually a skating rink until plenty of cars have been down the track.  I waited until cars were hooking a little better and made a nice straight pass...a bit of wheelspin but I didn't have to do any driving.  Straight down the groove.  The car ran like it came out of a crossbow.  Had the place not been so crowded with spectators (yes, they JAM the place for tnt and grudge.)and if some a-hole hadn't parked his Impala behind my trailer:shock: , I might have stayed and flogged the car a bit.  I had to get the local cops to find the clown:suspect:  just so I could get my racecar off the pit road.  That pissed me off so I loaded up, satisfied the car would be good on race day.  No more Sundays for me.  Race days only.

Off topic a little, but I can't figure out why on race days the place is packed with good racecars, but very few spectators.  Then on tnt day, the place is jammed with people who came to watch a few street cars and crotch rockets.

maverick wrote:I ran the chassis centerline, hung the plumb-bobs and reset the 4-link, too.  Also had enough time to load up and haul it to the tnt at Atmore.  It's a good track on race days, but tnt is usually a skating rink until plenty of cars have been down the track.  I waited until cars were hooking a little better and made a nice straight pass...a bit of wheelspin but I didn't have to do any driving.  Straight down the groove.  The car ran like it came out of a crossbow.  Had the place not been so crowded with spectators (yes, they JAM the place for tnt and grudge.)and if some a-hole hadn't parked his Impala behind my trailer:shock: , I might have stayed and flogged the car a bit.  I had to get the local cops to find the clown:suspect:  just so I could get my racecar off the pit road.  That pissed me off so I loaded up, satisfied the car would be good on race day.  No more Sundays for me.  Race days only.

Off topic a little, but I can't figure out why on race days the place is packed with good racecars, but very few spectators.  Then on tnt day, the place is jammed with people who came to watch a few street cars and crotch rockets.

Glad you got it fixed and running straight again
they need to have the spectators park some where beside the pit so it want be so hard to get around in the pits. but I like parking in the pits when spectating sometimes but I make sure I am not blocking a racer from his pits.

dd post

Another thing you may want to check is rear shock travel. As we lower the rear of our cars and run the spring seats down on the coil overs its easy to over look. I like to see a minimum 1 inch shaft showing and it could need more if your car has a lot of squat. If the shocks bottom out it really upsets the chassis. I've seen a car fought all season long to finally discover this. It can be okay on a marginal track and then raise its ugly head on a good hooking track.

Steve