D BERRY

Hope I'm in the right place here. There is a lot of discussion about suspension but there doesn't seem to be much of what I'm looking for. I'm not into autocross or corner carving but my area of interest is drag racing specfically 60 foot times. I usually have to leave the line at an idle because any more power gets me wheel hop. My 60s are terrorable running from 2.2 to 2.25 I'd be happy to get down to about 2.0 Whats required to get rid of this horrendous problem with the hop!

Jazzer The Cat

I am an all-out twisty psychopath.... so cannot be of much help to you

I am going to send this thread over to the S197 Performance Handling section, as those pepes will be of more help. You are gonna want to be looking into some aftermarket LCA's and probably a UCA as well.

Jazzer, your friendly pass along to the other guys, Cat

D BERRY

Thanks Jazzer didn't even know there was a specific S197 handling section. I was reading about the Steeda LCA yesterday which they claim will cure wheel hop problems. Guess I should be clear that I'm looking to eliminate my wheel hop not build a race suspension. I am a little leary about claims that this one part will fix all my problems when there are so many contributing factors in a rear suspension. Just don't want the rearend trying to come out from under the car when the wheels start spinning. Thanks

Norm Peterson

You'll find this topic has been discussed pretty frequently.

Cliff's Notes version, try LCAs with stiffer bushings and/or a spherical of some sort (roto-joint, johnny-joint, rod end) in one end first. Then a UCA with stiffer bushings. Possibly an engine torque limiter or stiffer engine mounts, though with the 3.7 I don't think you'll need to go that far yet. There may be a few other things that you can do, but reducing the amount of energy that gets stored/released in any of the OE bushings anywhere in the drivetrain should come first. You do not need a full spherical setup for a street/strip car that's still mostly street.

Don't throw everything at it at once. Do it in stages and stop changing things once the hop has gone away or at least becomes manageable enough to suit you and meet your performance target.


Norm

Ford_Dude

1st LCA's
2nd UCA
3rd LCA reloc brackets

assuming the suspension is somewhat the same on 2011 as on 2005-2009 this will fix the issue

one part of the issue (atleast in 05-09) was the stock LCA's were not stiff enough and would flex under hard load (solution stronger LCA's)

another issue is the LCA angle (under hard launches they would go to where the axel end was higher and then the wheel would puch forward and hop) (solution LCA reloc brackets)

the UCA helps aswell to make the rest of the mounting more solid

assuming the LCA design is the same then they are c channel and not all that rigid

if you lower then the reloc brackets become more important as lowering will alter the LCA angle

on mine I did the full LCA's, LCA brackets, UCA, and just to add a bit more stiffness UCA bracket and I don't get any wheel hop (even with my nice new nitto tires)

JimC

I went to the J&M HotPart fixed length LCA's several years ago. The rear end was much tighter and wheel hop gone with no appreciable difference in noise, but the car handles much better off the dragstrip as well with the HotPart arms.

I upgraded to the HotPart adjustable UCA last year and it got rid of the little "clunk" and shift to the rear end on stops because it uses an insert to take up the slack that the stock set up has in the UCA mount. Haven't had to adjust the UCA because when we checked the pinion angle last month it was still within the proper range.

I also added the UMI Performance relocation brackets last year after I put in the rear FRPP springs and dropped the rear end about an inch. (front springs are still the stock, I just wanted to level the stance out a little bit).

Doing it in phases I could see the difference each made at the track. The LCA was the most change - planted the rear tires and the 60's dropped. Each of the others also made a difference, but not as big (or I was just launching better due to more seat time at the track)

Norm Peterson

It's not the metal part of the rear control arms that's a problem, it's the bushings that are supplied with them.

The rear control arms are not loaded in any of the flexible directions of the arms until you're starting to pull the LF tire on launch. Until you're at that point (where you really start twisting the arms from the car torquing over under engine torque reaction), talk of control arm lack of stiffness is meaningless.


Norm

Ford_Dude

I hadn't looked over the specifics of where the weakness was but it makes sense that its the bushings

Roys07GT

In my experience you will have more success with some stickier tires as your first modification, just the 18" Mickey Thompson ET Street II's got me under 2.0 60' times.

With the Mickey's and UMI LCA's (not adjustable, no roto joint, just the standard LCA's) I got lots of 1.9xx 60' times last year (the occasional 1.87x).

I just had the UMI Relocation brackets removed yesterday and a UMI UCA installed, I installed the Relocation brackets and UMI SubFrame connectors about a month ago and my 60' times got worse (there was also an Aluminum DS install 2 months ago), plus the NVH was terrible when I lifted the gas at 100MPH+, already tested and the NVH is back to normal, racing tomorrow so should know if the UCA helps (but then again 2 changes at once, so won't really know).

That said I know of other S197 people getting 1.7 60' times with the 17" Mickey ET Street tires, LCA's, UCA, and Relocation Brackets (the one guy has all BMR), on a well tuned engine and 5 speed...

wrxified

Like others have said, approach it in stages so you understand how each part is affecting your launch.

If you're spinnning more than you're hopping, you want to look at stickier tires, adjusting air pressure or just plain throttle control.

If you're hopping around, you need to address both the lower control arms and upper arm. If you're just spinning at the tree and you do these you'll most likely just make your problem worse