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Old 03-14-2007, 07:42 PM   #1
kinada423
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Question Wheel hop woes. Need some advice.

Well I've done some searching around on the forums and haven't really come up with the best route to try and cure my wheel hop and wanted some suggestions. I'm currently running and 02 wrx with megan racing coilovers with the 8k springs in rear and 6k springs in the front. Perrin rear swaybar and endlinks set on the lowest setting and a Perrin front swaybar with stock endlinks. -2.5 camber in front and -2.0 camber in rear. I run 17x7.5 rota subzero rims with 235/40/17 hankook ventus rs-2 tires running around 40psi in front and rear.

I didn't start to have any wheel hop until I did a 2.5hybrid engine swap with a td0620g turbo and deatschwerks injectors. I then started to notice wheel hop.

Now that I have added the Perrin front swaybar I started to get more push but gained increased turn-in response and even more wheel hop. I softened up my front suspension which removed some of the push. This is still too much push compared to what I had running the stock front swaybar and the wheel hop is more dramatic now. I understand this could be due to the fact that I now maintain more negative camber during turns.

I have been told to soften up the rear suspension, replacing the rear subframe and diff bushings or get a LSD. What is the best place to start? I have seen some pictures of my car during autocross events with noticable wheel lift on the inside rear tire.

Any suggestions would be greatly appreciated. I'm running way too much power for my gearset as it is and would like to prevent the wheel hop as much as possible and eventually get a new gearset since I'm still running the stock 5 speed tranny.
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Last edited by kinada423; 03-21-2007 at 09:14 PM.
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Old 03-20-2007, 07:46 PM   #2
kinada423
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Bump. Seriously can someone chime in?
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Old 03-20-2007, 09:41 PM   #3
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Originally Posted by kinada423 View Post
Well I've done some searching around on the forums and haven't really come up with the best route to try and cure my wheel hop and wanted some suggestions. I'm currently running and 02 wrx with megan racing coilovers with the 8k springs in rear and 6k springs in the front. Perrin rear swaybar and endlinks set on the middle setting and a Perrin front swaybar with stock endlinks. -2.5 camber in front and -2.0 camber in rear. I run 17x7.5 rota subzero rims with 235/40/17 hankook ventus rs-2 tires running around 40psi in front and rear.

I didn't start to have any wheel hop until I did a 2.5hybrid engine swap with a td0620g turbo and deatschwerks injectors. I then started to notice wheel hop.

Now that I have added the Perrin front swaybar I started to get more push but gained increased turn-in response and even more wheel hop. I softened up my front suspension which removed some of the push. This is still too much push compared to what I had running the stock front swaybar and the wheel hop is more dramatic now. I understand this could be due to the fact that I now maintain more negative camber during turns.

I have been told to soften up the rear suspension, replacing the rear subframe and diff bushings or get a LSD. What is the best place to start? I have seen some pictures of my car during autocross events with noticable wheel lift on the inside rear tire.

Any suggestions would be greatly appreciated. I'm running way too much power for my gearset as it is and would like to prevent the wheel hop as much as possible and eventually get a new gearset since I'm still running the stock 5 speed tranny.

I'm confused - are you getting wheel hop or are you getting wheel lift?
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Old 03-20-2007, 10:18 PM   #4
kinada423
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I guess I described it incorrectly then. I would say it's wheel lift since it only happen when going around turns. It seems to lift and set the wheel back down over and over again which forces me to lift off the throttle to prevent any driveline damage. I would love to be able to get all the way on the gas again at the correct point in an apex. I have yet to notice any wheel-hop during straight line autocross starts.

Last edited by kinada423; 03-20-2007 at 11:07 PM.
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Old 03-20-2007, 11:23 PM   #5
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Originally Posted by kinada423 View Post
I guess I described it incorrectly then. I would say it's wheel lift since it only happen when going around turns. It seems to lift and set the wheel back down over and over again which forces me to lift off the throttle to prevent any driveline damage. I would love to be able to get all the way on the gas again at the correct point in an apex. I have yet to notice any wheel-hop during straight line autocross starts.
Ah! Now we're on even ground and I can help. I can tell you all about wheel lift and the loss of traction right at apex.

What are your ride heights? Measure center of centercap to edge of fender.

Are you sure you have the stiffer springs on the rear? This is important as springs not only contribute to ride stiffness, BUT also roll stiffness. If you truly have the 8K springs on the rear then coupled with the rear bar you are overpowering the front springs. You are fully compressing the front suspension while the crossloading, and lack of droop travel in the rear is allowing the wheel to lift.

What are your alignment settings?


Here's a quick and easy way to see what's going to happen in gross quantities without spending a few hours swapping the springs. We can fine tune a little bit down the road once we've ruled some things out.

1) Turn front dampers to full stiff and then down 1 click. This is to be consistant on both sides as some dampers are sensitive to which direction you approach the setting from.
2) Turn the rear dampers to full stiff, and then down to the middle setting.
3) Disconnect rear swaybar. Zip tie it up so it doesn't smack around on anything back there.

Go find an large empty parking lot where you won't get in trouble and see what happens.

The back end should not rotate like you want, but at the same time it should stick a whole lot better.

Now - how's the ride? Does it feel good? Ignore roll stiffness for this one.

Adjust rear dampers to the point where you like the ride, but feel you need a little more roll stiffness in the rear. At that point reconnect the rear sway and put it on the softest setting. At the same time turn down the rear adjustment by two clicks (remember - go full stiff first and then count down to soft).

Fine tune and let me know what you think.

If you feel that the roll stiffness is there in the rear, but the front is still pitching more than you'd like then it's time to start looking at putting the 8K springs up front.
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Old 03-20-2007, 11:33 PM   #6
kinada423
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I listed my camber settings in the first post but to reiterate. -2.5 in front and -2.0 in the rear. I have camber bolts ready in case I need to change the rear settings. The perrin front bar is on it's lowest setting. This combined with the engine swap are the major changes I have done to my car last season which appears to be causing the wheel lift although last season I did have mild lift noticeable in some pictures but never making me feel the driveline shock from the wheel regaining contact.

I have the megan racing coilovers set -3 from the stiffest setting and the rear set to the stiffest setting. After your thankful recorrection on my misuse of verbage I did some hunting on the forums for wheel-lift and it seems like my problem is due to too much rebound in the rear or overloading the front springs as you suggested. Some posts mentioned softening the rear or stiffening the front swaybar.

I will try and measure the ride height and your other suggestions but would like to start with adjusting the softness in the rear suspension first.

Last edited by kinada423; 03-21-2007 at 09:20 PM.
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Old 03-21-2007, 09:09 PM   #7
kinada423
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I took the back seat off today and turned my my rear coils to -10 clicks. The megans supposedly have something like 32 levels of adjustability. Once this was done I did a few hard laps around our warehouse and it stopped the wheel-lift/driveline shock almost completely although i did notice more roll in the rear end. I'm sure a small amount of wheel lift is inevitable from what I've been reading but I was more concerned with damaging something in my driveline due to this impact of the wheel lifting and touching down again hard.

So I guess the real questions now are:
1) Should I change my spring rates back to 8k front and 6k rear and use more rear swaybar stiffness to get the rotation I want?

2) Should I leave the springs/rear swaybar as they are and play with rear dampening?

3) #2 + stiffen the front swaybar?
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Old 03-23-2007, 01:20 PM   #8
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swap the springs to they are stiffer in the front.

You're going to have to play with damping a bit

stiffen the front bar, and keep the rear soft for now

Turn rear camber down to -1.0*

See how that feels. If you still need rotation and stiffness to the back then adjust damping (keeping the front a little stiffer), and then fine tune by bumping the rear sway up a setting.
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Old 03-23-2007, 07:38 PM   #9
kinada423
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So after the spring swap and install of camber bolts I'll get it realigned to -2.5 in front and -1.0 in rear. Then stiffen the perrin front sway to the stiffest setting and keep rear sway on softest setting.

Should I keep the dampening in the front stiffer and the rear softer which allows for more rear travel?

Then fine tune rotation with the rear bar setting possibly up to the middle setting.

Sound right?

Last edited by kinada423; 03-23-2007 at 08:03 PM.
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