Wheel hop - what more can I do?

[Funkjaw]

Chiming in with 24 MT. Never experienced wheel hop with either my stock wheels and tires or my BC Forged wheels on 305s.

I drive fairly spirited.

What's funny about this is I had someone DM me saying they had no wheel hop when they lived in California, but then they moved to Texas (like me) and now they have wheel hop...

Guess the answer is move back to California. (I do quite miss the roads there).

Sponsored

 

[DisMahhhlon]

What's funny about this is I had someone DM me saying they had no wheel hop when they lived in California, but then they moved to Texas (like me) and now they have wheel hop...

Guess the answer is move back to California. (I do quite miss the roads there).

That's wild! If you do and ever looking for an alignment shop, I love West End.

 

[Thraxbert]

Texas person, here. An Austin person, specifically.

The asphalt mix in Texas has a relatively high calcium content relative to asphalts in other states. Some of the mix is dredged from the Gulf of Mexico, which has a relatively high percentage of crushed shells from marine life. The calcium content is actually quite nice for durability, but it makes our roads pretty slippery compared to other states.

The insane "thud thud thud thud" judder video I saw somewhere in this thread is certainly like nothing I've experienced in the same city, on the same roads, in the same car. But, on the whole, it's harder to get traction here.

I run 42 peak PSI on a 65 Omega and the worst condition I face is that the back end steps out. No wheel hop.

 

[Funkjaw]

Texas person, here. An Austin person, specifically.

The asphalt mix in Texas has a relatively high calcium content relative to asphalts in other states. Some of the mix is dredged from the Gulf of Mexico, which has a relatively high percentage of crushed shells from marine life. The calcium content is actually quite nice for durability, but it makes our roads pretty slippery compared to other states.

The insane "thud thud thud thud" judder video I saw somewhere in this thread is certainly like nothing I've experienced in the same city, on the same roads, in the same car. But, on the whole, it's harder to get traction here.

I run 42 peak PSI on a 65 Omega and the worst condition I face is that the back end steps out. No wheel hop.

Thnx for the insight Robert - and nice to meet a fellow Austinite. You've probably been on the exact road I recorded the video.

I've got new rims and tires going on and then will reevaluate after that. I suspect it will still be there, but hey who knows.

Is there a shop in Austin you would recommend could look at it? I haven't been here long enough to figure out where the good BMW shops are.

 

[Thraxbert]

Thnx for the insight Robert - and nice to meet a fellow Austinite. You've probably been on the exact road I recorded the video.

I've got new rims and tires going on and then will reevaluate after that. I suspect it will still be there, but hey who knows.

Is there a shop in Austin you would recommend could look at it? I haven't been here long enough to figure out where the good BMW shops are.

I would recommend Torqqe Performance, but be warned it might be pricy. They tend to handle vehicles in the "one of a kind" or "rare" categories, and is $$$$ accordingly. But they do full race prep and have an absolute maniac (in the best way) running the alignment rack; I would trust them to fix it if there's something in the alignment or geometry that isn't right.

I would also call other shops that specifically deal with chassis prep for racing, as they will have the most experience dealing with these sorts of unusual traction issues.

 

[Twisted Tuning]

This is something I need to check on - make sure myself or the one previous owner didn't hop a bolt into oblivion. It's also interesting that you too have a 23' manual and you are experiencing exactly what I am going through - meanwhile the guys in automatics seem to not have this issue so much. Guess this is what we get for buying the cooler version of the car



I have the twisted tuning diff mount brace/lockdown kit... so in theory my diff should be a lot more solid than factory but unfortunately that still doesn't seem to be the case... Or it just means the problem is outside of the diff.



On this note - I have now lowered my tire pressures to 32psi and still have hop. I refuse to go any lower simple because I don't want to murder my fuel economy or wear my tires faster.

I think the next order of business is to get a camera under the car and see if I can pinpoint what exactly is allowing so much movement - Gives me an excuse to order a new gopro or something similar

wheel hop is not just result of a moving Diff alone. its a few things. the diff brace decreases the chance of wheel hop. other things like subframe bushings, other suspension parts and ets can also cause wheel hop. can also be tires or uneven surface

 

[Katsuragi]

Texas person, here. An Austin person, specifically.

The asphalt mix in Texas has a relatively high calcium content relative to asphalts in other states. Some of the mix is dredged from the Gulf of Mexico, which has a relatively high percentage of crushed shells from marine life. The calcium content is actually quite nice for durability, but it makes our roads pretty slippery compared to other states.

The insane "thud thud thud thud" judder video I saw somewhere in this thread is certainly like nothing I've experienced in the same city, on the same roads, in the same car. But, on the whole, it's harder to get traction here.

I run 42 peak PSI on a 65 Omega and the worst condition I face is that the back end steps out. No wheel hop.

Thanks for this info!

I’m the other Texas person (Georgetown) and get the wheel hop specifically on farm to market roads when hitting about 4500 RPM in second gear with my 25 MT. It makes the VSC go nuts for a second then calms down. There’s generally a fair amount of gravel and it doesn’t happen on city streets. Haven’t had it happen driving in other places like Cali or Colorado.

This is all on stock rims and tires so an upgrade may help along with suspension and getting the alignment right. Will eventually report back as well.

 

[Funkjaw]

Update:

Got a response directly from Verkline on the issue and have posted it in my original post in this thread. It provides a wealth of information so I suggest those in this thread go give it a read
https://www.supramkv.com/threads/wheel-hop-what-more-can-i-do.27820/post-435926

Long and short, Verkline has two more options for parts that could potentially eliminate or at least further reduce wheel hop: Rear Knuckle Bushings (WAS-426) and Upper Traction Arms (WAS-422)

However, I will be getting a go pro under the car before anything as suggested.

Kudos to Verkline for responding with such a thorough response! They kick ass.

 

[lucky phil]

Thanks for this info!

I’m the other Texas person (Georgetown) and get the wheel hop specifically on farm to market roads when hitting about 4500 RPM in second gear with my 25 MT. It makes the VSC go nuts for a second then calms down. There’s generally a fair amount of gravel and it doesn’t happen on city streets. Haven’t had it happen driving in other places like Cali or Colorado.

This is all on stock rims and tires so an upgrade may help along with suspension and getting the alignment right. Will eventually report back as well.

So you want this sport car to never under any situations get wheel hop ever? Good luck with that. Like saying I want my track bikes to never ever ever get any sort of head shake no matter what. Ain't going to happen.
Phil

 

[lucky phil]

Update:

Got a response directly from Verkline on the issue and have posted it in my original post in this thread. It provides a wealth of information so I suggest those in this thread go give it a read
https://www.supramkv.com/threads/wheel-hop-what-more-can-i-do.27820/post-435926

Long and short, Verkline has two more options for parts that could potentially eliminate or at least further reduce wheel hop: Rear Knuckle Bushings (WAS-426) and Upper Traction Arms (WAS-422)

However, I will be getting a go pro under the car before anything as suggested.

Kudos to Verkline for responding with such a thorough response! They kick ass.

Verkline have a "possible" but not guaranteed possible solutions to something they can't identify the exact cause of. I'm shocked.

Phil

 

[Hasan]

Is there any tyre pressure that minimizes the wheel hop, or the pressure is irrelevant?

 

[i3igpete]

In our acceleration scenario (inboard drivetrain) we can apply longitudinal force in the wheel center instead of contact patch.

I am curious how they drew that force balance such that the tire tractive force is teleported to the hub center.

Regardless, its nice to see they confirm the upper arm will help.

 

[Loco38SUP]

Update:

Got a response directly from Verkline on the issue and have posted it in my original post in this thread. It provides a wealth of information so I suggest those in this thread go give it a read
https://www.supramkv.com/threads/wheel-hop-what-more-can-i-do.27820/post-435926

Long and short, Verkline has two more options for parts that could potentially eliminate or at least further reduce wheel hop: Rear Knuckle Bushings (WAS-426) and Upper Traction Arms (WAS-422)

However, I will be getting a go pro under the car before anything as suggested.

Kudos to Verkline for responding with such a thorough response! They kick ass.

Yes put a GoPro or Insta360 camera down there to confirm where the oscillations are coming from. I would do that before randomly changing parts.

-RJM

 

[Funkjaw]

Verkline have a "possible" but not guaranteed possible solutions to something they can't identify the exact cause of. I'm shocked.

Phil

I see your point Phil. But we both know nothing is guaranteed in life and their response IMO was very well thought out and analytical while at the same time not making BS promises to try and force the sale of any particular part. The fact that they didn’t make any promises is indicative of a good company. I for one am very happy with their response

 

[Funkjaw]

Is there any tyre pressure that minimizes the wheel hop, or the pressure is irrelevant?

IMO, it’s irrelevant. I’ve played with tire pressure between 30psi and 40psi and lower helps a little, but simply because it gives the tire a better coefficient of friction. I think in reality as verkiline and others have pointed out the issue is inherent in the factory suspension geometry.

Sponsored