Cliff's Grey Hare

[Cliff]

I autocrossed it today with the BMW club and got my first taste of the mods. I was slower than I usually am. While I am more than happy to blame the brand spanking new tires on the car for some of that, it is clear that I need more time to practice and tweak settings.




I need to check and see what rebound setting Griffin used for the shocks. I am inclined to leave them where they are for next week's HPDE. The car's balance was fairly neutral today and maybe a bit more stable than I'd prefer. I expect I will want to stiffen the rear shocks relative to the front a bit, but I want to see how they feel on a race track first.

The Wavetrac seemed to let me apply power while turning without the car plowing. I did not feel any intervention from the braking system. Traction control was fully defeated and I did not mess with any XDS settings.

 

[Mini7]

I am interested in the benefit of the Wavetrac for your HPDE vs. the electronic Help the GTi provides.

It will take some dialing in of the suspension. I’m expecting better support under the car from the Öhlins. You are running similar
/same springs rates. I will be upping spring rate from stock by going to 8k F/R.

 

[Cliff]

I am running much stiffer rear springs than those you are contemplating at 110n. I confirmed with the shop that they have the shocks set to 7 clicks from full stiff. I will probably soften the fronts slightly to dial in a touch more oversteer.

I am not going to be able to compare the GTI's fluid e-diff with the Wavetrac. I have a little time driving student GTI's in anger at autocross schools, but only enough time to determine that I am really glad I bought an R.

 

[Mini7]

I am running much stiffer rear springs than those you are contemplating at 110n. I confirmed with the shop that they have the shocks set to 7 clicks from full stiff. I will probably soften the fronts slightly to dial in a touch more oversteer.

I am not going to be able to compare the GTI's fluid e-diff with the Wavetrac. I have a little time driving student GTI's in anger at autocross schools, but only enough time to determine that I am really glad I bought an R.

Cliff, I believe you are running the right spring rates. More so for an AWD. Getting the right balance of rotation is important to be fast around a track. Running a much higher rear spring rate is a typical FWD setup. Two reasons: one is rotation and the other is traction out of corners because of the weight transfer to the front wheels under acceleration. Ive gone conservative on the spring rate to start with my large 034 RSB. I’ve not driven an R but would expect better ability to go to power compared to FWD.

I have a PP FWD, so have the VAQ haldex plus the XDS.
A mechanical LSD made a big difference on my Mini which didn’t have the electronic gizmos of the GTi. I’m just curious on how much of a difference the wavetrac makes punching out of corners. Just realized that I’m still using some of my Mini driving style of going to throttle hard. Something I could do with the OS Giken LSD. Point where I want to go and roll onto the throttle hard.

 

[Cliff]

oh I should have mentioned I have the tyrolsport deadset also and previously I was on bilstein coilovers. At that point, my alignment was spot on. But even since switching to the superpro arms and hr coils, the alignment is whacked. I'm going to switch back to Bilstein's and suprpro camber plates though. Hopefully then the alignment will be equal on both sides.

I chose Griffin Motorwerke for this project because they have been specializing in VW/Audi cars for 40 some odd years and have an excellent reputation in the SF Bay Area. My expectation is that everything is aligned correctly and if not, they will fix it.

2.2 degrees of negative camber is in the right ballpark given the ride height was raised and 65mm ID springs were required for the Ohlins. I think the ride height can come down and give me a bit more camber, but I think the shop said the car would need adjustable end links on the rear sway to do that and corner balance the car.

 

[Cliff]

The toe setting up front seems pretty minimal, but I am getting fairly bad feathering after 200 miles of street driving along with about 6 minutes of autocross. I am going to head back in to Griffin tomorrow to have the alignment redone. I've been running 0.00 toe up front for the last 3 1/2 years without experiencing this kind of wear.

I am also ordering some Eurocode length-adjustable rear sway bar end links so we can lower the car about a half inch, remove preload from the sway, and get it corner balanced. That won't be happening tomorrow though.

 

[Cliff]

A few photos

 

[Crild]

I see you cut the towers and don't run the top plate on the GC stuff.

 

[Autobahn]

Was that tire wear mostly from autocross or street or combo?

 

[Cliff]

Street, probably. I need to check my tires this morning. I rolled into Salem, OR after a 600 mile road trip yesterday and I want to make sure the alignment solved the problem.

edit: the alignment solved the problem

 

[q74]

Street, probably. I need to check my tires this morning. I rolled into Salem, OR after a 600 mile road trip yesterday and I want to make sure the alignment solved the problem.

edit: the alignment solved the problem

Whats your alignment sit at now? Also curious why you didn't put the GC strut reinforcements on (I guess maybe they are purely decorative then?).

 

[Cliff]

Whats your alignment sit at now? Also curious why you didn't put the GC strut reinforcements on (I guess maybe they are purely decorative then?).

It is possible that GC changed their product design. The reinforcement on the prototype plates that I was running was just a horseshoe-shaped piece of steel (5th photo in previous batch - prototype plate is on the right). They have done a few versions of their coilover conversion kit, and it wouldn't surprise me to see some iteration with the camber plates too. I'll ask Griffin when the car is in next. I doubt they left something off.

I think Griffin forgot to tighten something down the first time - check the front toe on the before measurements. My goal is for 0 toe up front, and a little toe-in on the rear.

 

[Cliff]

Let me add some additional observations now that I have done a 2000 mile road trip and an HPDE in the car.

This setup is comfortable for me on the road, but I am probably more tolerant of road and track compromise setups than most people reading this. The ride is definitely firmer than stock. I set the rebound for the front struts to 9 clicks from full stiff and the rears to 7 clicks from full stiff. The reduction in rebound stiffness up front from the 7 click setting Griffin originally dialed in smoothed out the ride considerably. The spring rates that I opted for on the Ohlins are higher than their OE rates but slightly less than the rates I was running with the Ground Control coilover conversion kit, so the ride quality is similar. The springs make some noise at parking lot speeds. This may be interaction between the helper springs and the main springs, but quiet they are not. The Ground Control camber plates add no discernible NVH. The bushings and deadset kit tightened up the suspension considerably, but without introducing harshness. The steering feel is tight with no deadness on-center.

On the track, the setup is solid. I went out at first with traction control fully enabled. It intervened once so I partially defeated it and it did not intervene again. I will continue to adjust the shock settings to see what works and what doesn't. The back end started to come around on me a couple of times out on track but it was easily tucked back in, so the balance between over- and understeer is about where I like it. I should be able to adjust that balance with the rebound settings. The LSD seemed to allow me to apply power while turning without inducing understeer and I did not detect any intervention by the XDS system. The catch can seemed to catch quite a lot and I was a quart low on oil Sunday morning.

My best lap times were 2 seconds quicker than a friend's times in his Mk2 TTRS. It was the first visit to the track for both of us. He is running a bigger turbo and KW Clubsports in his car and he typically runs in the advanced run groups.

The car goes back to Griffin on Monday for a final ride height adjustment along with corner balancing and alignment. I ordered adjustable rear swaybar end links from Eurocode and Griffin will use those to relieve preload on the rear sway and*lower the car a bit more. I want the car lowered about a half inch from where it currently site, which is roughly the stock ride height. The front can accommodate that half inch, but the rear maybe not quite that much.

 

[Mini7]

Thanks for the update Cliff.

The higher rear spring rate will help keep weight transferred to the front for acceleration out of corners. More noticeable on FWD only vs. AWD. Does the car oversteer more than your original setup? Or was that more due to the cold track conditions?

I am planning on getting my Ohlins in next weekend. Waiting on new rear shock mounts. I will start on your current shock settings to feel things out. Most run the shocks full soft for the street.

 

[Cliff]

Thanks for the update Cliff.

The higher rear spring rate will help keep weight transferred to the front for acceleration out of corners. More noticeable on FWD only vs. AWD. Does the car oversteer more than your original setup? Or was that more due to the cold track conditions?

I am planning on getting my Ohlins in next weekend. Waiting on new rear shock mounts. I will start on your current shock settings to feel things out. Most run the shocks full soft for the street.

The higher rear spring rate reduces traction in the rear, which in effect increases traction at the front of the car and reduces understeer. Basic suspension tuning and it applies to FWD, AWD, and RWD cars. The ratio of front to rear spring rates is similar to what I was running with the Ground Control setup. Both aftermarket suspensions reduced understeer relative to the stock suspension, that was the point of making the change.

The attached copies a whiteboard presentation from a youtube video on chassis tuning by O'Neill Rally School.