Wheel hop - devastating for your driveline components...how to fix it?

Former_Boosted_IS · 10-21-2010, 04:59 AM

Quote:

Originally Posted by shiv@vishnu

I don't know if this is pertinent to the problem but I always found ceramic clutch disks to bite way too abruptly. Which leads to excessive stress downstream in the system. They are great for road racing conditions where they can take a lot of heat and never slip between gears. But going from 0 torque to big torque instantly (at a launch) can shock the rest of the driveline badly. I've got over a hundred max power launches (slicks, 20psi, race+meth) and have yet to break a drivetrain component. Even my orginal clutch lasted 60k miles before slipping in 4th gear. Upgraded with a Spec stg 2 with light flywheel since then. I'm sure a bent/broken axle is somewhere in my future but I think keeping things somewhat pliable (organic disk, flexible drag tires, etc,) has helped a bunch.

Shiv

Shiv, you strongly hinted at snapping a half shaft about 6 months ago. What did that problem end up being?

kanecvl · 10-21-2010, 07:53 AM

Quote:

Originally Posted by Mr. 5

I'm sure you meant 275 but you're right, that's a pretty tall tire for our setup.
That's the same as what I've used and had no wheel hop. I run about 20 psi.

I think I might no what the problem is...
I bet you are warming up your tires in 1st gear huh?

You still have GIAC?

dzenno · 10-21-2010, 07:59 AM

Quote:

Originally Posted by Former_Boosted_IS

Shiv, you strongly hinted at snapping a half shaft about 6 months ago. What did that problem end up being?

+1 That vid on youtube showing one of your (shiv) runs shows about the same amount of wheel hop that I got with my car. Happened for you on both burnout and especially at/after launch...

dzenno · 10-21-2010, 09:22 AM

Ponied up for m3 rear guide rods as well. Minues the rear sway bar which I see no purpose for in dealing with wheel hop, I've got everything required it seems (m3 rear subframe bushings, m3 rear wishbones, m3 rear guide rods)...i'll check my rear damper settings and spring compression rates when I get the car for this install...hopefully this solves wheel hop once and for all...

OpenFlash · 10-21-2010, 09:42 AM

Quote:

Originally Posted by Former_Boosted_IS

Shiv, you strongly hinted at snapping a half shaft about 6 months ago. What did that problem end up being?

Turned out that it was just chunks of rubber that splattered in the wheel wells during my burnouts fell on my street tires while driving home causing a thread imbalance that lasted until they hardened up the next day and dislodged from the thread. Crazy.

Former_Boosted_IS · 10-21-2010, 10:04 AM

Quote:

Originally Posted by shiv@vishnu

Turned out that it was just chunks of rubber that splattered in the wheel wells during my burnouts fell on my street tires while driving home causing a thread imbalance that lasted until they hardened up the next day and dislodged from the thread. Crazy.

Ahh, I am shocked your car has held up so well with such violent wheel hop I saw in some of your videos. Regardless we know the condition exists on a lot of cars.

OpenFlash · 10-21-2010, 10:08 AM

Quote:

Originally Posted by Former_Boosted_IS

Ahh, I am shocked your car has held up so well with such violent wheel hop I saw in some of your videos. Regardless we know the condition exists on a lot of cars.

I wouldn't say it's held up that well from all this launches. The rear of the car feels like noodles are holding the rear subframe to the chassis. Ive been meaning to upgrade all the subframe bushings for a while now. I'm sure there is excessive play in other rear suspension bits as well. It's going to get a full m3 makeover very soon. It's horrifying to drive hard on a windy road

Former_Boosted_IS · 10-21-2010, 10:28 AM

Quote:

Originally Posted by shiv@vishnu

I wouldn't say it's held up that well from all this launches. The rear of the car feels like noodles are holding the rear subframe to the chassis. Ive been meaning to upgrade all the subframe bushings for a while now. I'm sure there is excessive play in other rear suspension bits as well. It's going to get a full m3 makeover very soon. It's horrifying to drive hard on a windy road

LOL! I think I may follow your guys lead on this one. We need one to make the full make over and see if it fixes where the x35i has fallen short.

Mr. 5 · 10-21-2010, 10:35 AM

Quote:

Originally Posted by kanecvl

You still have GIAC?

I do.

Also, to those curious about the 2nd gear burnout, I did the 2nd gear burn out here:

[u2b]3XqBUgPjGFA&[/u2b]

Jeff@TopGearSolutions · 10-21-2010, 10:48 AM

^ I need drag radials....That looks fun.

kanecvl · 10-21-2010, 10:54 AM

Quote:

Originally Posted by Mr. 5

I do.

Also, to those curious about the 2nd gear burnout, I did the 2nd gear burn out here:

[u2b]3XqBUgPjGFA&[/u2b]

I didn't know GIAC would go that high on boost. Was there anybody in the left lane?

Mr. 5 · 10-21-2010, 11:49 AM

Quote:

Originally Posted by kanecvl

I didn't know GIAC would go that high on boost. Was there anybody in the left lane?

no no. I wasn't boosting at 20 psi. That was the air in my drag radials. lol.
I'll edit my statement so nobody else gets confused.
I don't think there was anyone to the left of me.

dzenno · 10-21-2010, 12:18 PM

Looking at your vid you really took your time shifting..i think you could've gotten at least 0.2 off your ET if you sped up all your shifts..awesome ET and trap for that shifting speed

kanecvl · 10-21-2010, 12:46 PM

Quote:

Originally Posted by Mr. 5

no no. I wasn't boosting at 20 psi. That was the air in my drag radials. lol.
I'll edit my statement so nobody else gets confused.
I don't think there was anyone to the left of me.

LOL!Ok.

Mr. 5 · 10-21-2010, 01:26 PM

Quote:

Originally Posted by dzenno

Looking at your vid you really took your time shifting..i think you could've gotten at least 0.2 off your ET if you sped up all your shifts..awesome ET and trap for that shifting speed

Thanks. I think that's the best I could do though lol!

techlogik · 10-21-2010, 01:33 PM

Wheel hop is caused by the change in the toe of the wheel, as it slips/gains traction, it begins the cycle of hopping.

The independent suspesion and axles could be part of the issue as it drives forces the axles causing a change in toe on the tire/wheel.

Or, it could be bushings, RTABs etc...allowing the toe to constanting change.

Upgraded busings/suspension parts will help. Next, you might not be able to do anything about the drivetrain/independent suspension in the rear from changing the toe of the wheel and force is applied.

There are a couple of threads already discussion the two issues. One thread discusses the drivetrain/axle issue, the other I posted discusses the bushing/toe issue.

Former_Boosted_IS · 10-22-2010, 06:03 AM

If we don't care about tire wear, what do you suggest on the toe? I could careless how fast my tires wear, but would love to remove the minimal wheel hop I have.

Clap135 · 10-22-2010, 06:42 AM

a 275/40/17 is nto a tall tire. It might for our standards, but not for drag racing standards. Theres a reason why most serious drag racers fit the smallest 15-16in rim they can while running a 28in overall diameter.

turb0mik3 · 10-22-2010, 03:29 PM

I agree with the second gear burnout. I would also suggest running a stiffer spring rate on your kw v2s. The springs that come with the kws are really shitty, so you should try the swift spring conversion for the kw suspension. Also, adding the m3 rear bushings will help greatly. The most important suspension component for eliminating wheel hop are the m3 rear guide rods. They help dramatically.

dzenno · 10-22-2010, 03:44 PM

M3 rear subframe mounts, rear guide rods and rear wishbones along with new rear diff bushings are going on the car (awaiting rear guide rods from Harold at hp autowerks)...

Alignment will be done after that and here's specs I'm going with:

Front (to minimize drag):
OEM camber
1/16" total toe

Rear (max contact patch for straight line):
Camber to minimum, no more than -1.5
3/16" total toe in

Alignment specs courtesy of Harold..thanks

If this doesn't address it then I'll be looking at springs, but it should..

dzenno · 10-22-2010, 04:27 PM

Just got word from DSS that my monster axles have shipped

Amazing turnaround time...they received them 11:35AM yesterday, shipped at 5PM a day later...nice...initial turnaround time was 4-5 days...

Invoice states "E92" Bar and CV internal upgrade...FBIS, I guess they have it named E92 because you were in there first with your E92 right? John (ultimateracing335i) did his upgrade there as well but he has an E90 like me...i just checked realoem.com and the axles are the same (same part #) for manual transmissions...i'm assuming this is fine...

turb0mik3 · 10-22-2010, 04:32 PM

Quote:

Originally Posted by dzenno

M3 rear subframe mounts, rear guide rods and rear wishbones along with new rear diff bushings are going on the car (awaiting rear guide rods from Harold at hp autowerks)...

Alignment will be done after that and here's specs I'm going with:

Front (to minimize drag):
OEM camber
1/16" total toe

Rear (max contact patch for straight line):
Camber to minimum, no more than -1.5
3/16" total toe in

Alignment specs courtesy of Harold..thanks

If this doesn't address it then I'll be looking at springs, but it should..

You should be perfect then.

10-21-2010, 09:22 AM	#26
dzenno Banned 275 Rep 5,876 Posts Drives: Join Date: Feb 2006 iTrader: (1)	Ponied up for m3 rear guide rods as well. Minues the rear sway bar which I see no purpose for in dealing with wheel hop, I've got everything required it seems (m3 rear subframe bushings, m3 rear wishbones, m3 rear guide rods)...i'll check my rear damper settings and spring compression rates when I get the car for this install...hopefully this solves wheel hop once and for all...
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10-21-2010, 10:48 AM	#32
Jeff@TopGearSolutions 3455 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	^ I need drag radials....That looks fun.
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10-21-2010, 12:18 PM	#35
dzenno Banned 275 Rep 5,876 Posts Drives: Join Date: Feb 2006 iTrader: (1)	Looking at your vid you really took your time shifting..i think you could've gotten at least 0.2 off your ET if you sped up all your shifts..awesome ET and trap for that shifting speed
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10-21-2010, 01:33 PM	#38
techlogik Lieutenant Colonel 70 Rep 1,568 Posts Drives: 2020 M340i Dravit Grey Join Date: Dec 2006 Location: FL iTrader: (2)	Wheel hop is caused by the change in the toe of the wheel, as it slips/gains traction, it begins the cycle of hopping. The independent suspesion and axles could be part of the issue as it drives forces the axles causing a change in toe on the tire/wheel. Or, it could be bushings, RTABs etc...allowing the toe to constanting change. Upgraded busings/suspension parts will help. Next, you might not be able to do anything about the drivetrain/independent suspension in the rear from changing the toe of the wheel and force is applied. There are a couple of threads already discussion the two issues. One thread discusses the drivetrain/axle issue, the other I posted discusses the bushing/toe issue. __________________ 2020 M340i: Dravit Grey Mettalic. Loaded.
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10-22-2010, 06:03 AM	#39
Former_Boosted_IS Major General 310 Rep 5,175 Posts Drives: 4 Wheels Join Date: Aug 2007 Location: Planet Earth! iTrader: (15)	If we don't care about tire wear, what do you suggest on the toe? I could careless how fast my tires wear, but would love to remove the minimal wheel hop I have.
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10-22-2010, 06:42 AM	#40
Clap135 Brigadier General 105 Rep 3,460 Posts Drives: 2009 N54 Join Date: Jul 2009 Location: Sticky's Mom House iTrader: (1)	a 275/40/17 is nto a tall tire. It might for our standards, but not for drag racing standards. Theres a reason why most serious drag racers fit the smallest 15-16in rim they can while running a 28in overall diameter.
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10-22-2010, 03:29 PM	#41
turb0mik3 246 Rep 2,781 Posts Drives: E90 335i Racecar Join Date: Jan 2010 Location: San Diego, CA iTrader: (1) Garage List 2010 BMW 335i [8.90]	I agree with the second gear burnout. I would also suggest running a stiffer spring rate on your kw v2s. The springs that come with the kws are really shitty, so you should try the swift spring conversion for the kw suspension. Also, adding the m3 rear bushings will help greatly. The most important suspension component for eliminating wheel hop are the m3 rear guide rods. They help dramatically. __________________ HG Motorsports \| Motiv Motorsport \| Sparta Evolution \| BBS Motorsports \| Sabelt \| JRZ \| NASA ST1 SoCal --- 554whp/487wtrq --- 3200lbs <<YouTube Channel w/ Race Videos>>
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10-22-2010, 03:44 PM	#42
dzenno Banned 275 Rep 5,876 Posts Drives: Join Date: Feb 2006 iTrader: (1)	M3 rear subframe mounts, rear guide rods and rear wishbones along with new rear diff bushings are going on the car (awaiting rear guide rods from Harold at hp autowerks)... Alignment will be done after that and here's specs I'm going with: Front (to minimize drag): OEM camber 1/16" total toe Rear (max contact patch for straight line): Camber to minimum, no more than -1.5 3/16" total toe in Alignment specs courtesy of Harold..thanks If this doesn't address it then I'll be looking at springs, but it should..
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10-22-2010, 04:27 PM	#43
dzenno Banned 275 Rep 5,876 Posts Drives: Join Date: Feb 2006 iTrader: (1)	Just got word from DSS that my monster axles have shipped Amazing turnaround time...they received them 11:35AM yesterday, shipped at 5PM a day later...nice...initial turnaround time was 4-5 days... Invoice states "E92" Bar and CV internal upgrade...FBIS, I guess they have it named E92 because you were in there first with your E92 right? John (ultimateracing335i) did his upgrade there as well but he has an E90 like me...i just checked realoem.com and the axles are the same (same part #) for manual transmissions...i'm assuming this is fine...
	Appreciate 0 Quote