VIR with TSCC: Feb 2024
Cold, but dry 2 days!
Changes to the car:
I found myself back at Virginia International Raceway with the Tidewater Sports Car Club Feb 9-10. There were some changes/repairs made over the winter which included:
Replacing worn out Powerflex forward offset LCA camber bushings (with Superpro poly non-offset)
Replacing worn out BFI “RS3 style” LCA bushings (with new ones of the same)
Installed 034 lowering springs
(Re)installed 034 RCO lower ball joints - wanted to test them out when lowered like they’re designed to be
Installed an 8Y aluminum subframe (same as 22+ GTI/R) - I actually got this LAST winter, but never installed it due to not having the correct LCA hardware (bolts are different for steel vs aluminum subframes) and just threw the steel one back in. Well it finally made it’s way onto the car to replace my dented factory subframe.
Installed 034 subframe collars (not so much to keep it in place, but for repeatability when dropping and reinstalling it, since I’ve had it out at least 4x in the last 2 years now)
Yet more PCV testing:
If you’ve checked out the Drivetrain/Cooling section recently, then you’re aware of the recent discoveries with regards to turbo inlet pipes and their huge effect on how well an OEM PCV system functions:
… Well I ended up running my crankcase and PCV sensors on track all weekend at VIR. I ran all sessions with the BMS turbo inlet pipe, which of the ones tested, is by far the “worst” offender as far as killing off the PCV vacuum source vs an OEM TIP (when the Venturi is not utilized)… and also seems to pair best with the Venturi. I ran it in both basic and full retrofit form, and the results on track should really speak to how effective the full retrofit is:
Other changes evaluated:
So for starters, several things were done to the car so I’ll do my best to assess what worked and what didn’t. This was definitely NOT dedicated testing, but this is more so my interpretation of what was done:
The lowering springs: I actually really liked them and had no real problems with wheel travel or hitting curbs etc due to travel limitations. For what it’s worth they’re not bad on the street either. The Koni Special Actives are not “meant” for lowering springs, but Koni does say they’re alright with <25mm drop (which these netted approx -20mm over my stock springs). The shocks have lost a bit of their “magic” I suspect due to getting into the bump stops sooner and the effective rate going up quickly. This can make the shocks “blow off” early, since they normally go into bypass for harsh, quick bumps or drops. I think that adding some softer or more progressive bump stops may be helpful. Possibly just trimming more would help as well. If I had known I was going to be lowering the car, I would have likely gone for Bilstein B8s or maybe Koni Yellows instead.
The subframe/locking collars: Not going to notice any differences from these. Anyone who understands bolted connections understands that if the bolts are torqued properly they’re not going anywhere with the original steel subframe. The OEM aluminum subframes have some little discs that are meant to help keep the subframe from sliding around due to the smooth interface. Steel subframes have serrated/knurled tops where they interface to the unibody which prevent this from happening. I mainly installed the locking collars just for repeatability in removing + installing the subframe, and because I didn’t want to bother with buying the stupid little OEM disc pieces mentioned above.
The 034 RCO ball joints: They added camber which is what the car definitely needed. It sits at -3.7 deg of negative camber now. The overall balance of the car was much improved. With the car sitting a bit lower, they don’t feel as weird as when they were tried at stock ride height (likely due to the roll center not being excessively high)… however they still add a ton of bump steer. It’s a geometry problem, not a ride height problem.
A new article with the bump steer gauge being run on the car (over it’s full range of travel) will be coming shortly, but in the meantime here was where it made itself plainly obvious:
To be fair, it’s not overly noticeable unless you’re using the curbs (and I mean the outside curbs when the suspension is loaded - there is no issue in the esses for instance since the inside corner is unloaded).
For the most part it just feels “odd” in most places (like between T3/4 and exiting Oak Tree) but not unmanageable. It was definitely not confidence inspiring though and it showed. Especially on the 245 wide tires vs the 255s. The car reacts a LOT faster on the narrower tire due to the sidewall being better supported. Having the wider tire doesn’t make bump steer go away, but it’s a lot less noticeable.
255/40R17 + 245/40R17 reverse stagger vs 245/40R17 square setup.
I was just burning through last year’s tires and the 245 fronts were mounted on slightly lighter Konig Hypergrams (vs the Apex SM10s for everything else). Running the two different front tire sizes feels SO different. I ran the 255s up front on Saturday and really the bump steer from the lower ball joints wasn’t nearly as noticeable and was able to push harder throughout the day. (For the record - I have previously run 245s and 255s on the same Apex wheels - there is a big difference in feel even without the wheel weight difference).
When I threw the 245s on for Sunday, it drove completely different. The car felt considerably “sharper” and would just change direction a lot faster… including when you hit that curb on the outside of T10. And again it felt “odd” hopping the curbs between T3/4 and outside of Oak Tree.
Due to the varying condition and age of the tires I ran plus the bump steer issues, comparing one vs the other isn’t necessarily “fair” (hence why I didn’t bother with swapping back and forth on same day) as far as overall grip goes.
One interesting observation (that would still be valid) was the consistent difference in speed on the back straight. Again, wasn’t a proper test, but one more anecdotal data point to add for future reference:
Now I wouldn’t go chasing time based strictly on straightaway speeds… but it really reinforces that such a small change such as this can make a measurable difference.
Other misc stuff:
It was a great weekend instructing Arek in his Hyundai Elantra N. Basically a Korean GLI. He had been to VIR back in December (and was actually instructed by my friend Bryan) and we worked Saturday building off of that.
He made a ton of progress working on braking technique (which was one of his primary goals), and we also good bit more speed in the esses and ended up with a really solid line through Oak Tree. His pads were cooked by the end of Saturday, and after pulling the wheels to inspect we determined they were not safe to run Sunday. We tried searching for some replacements locally but could not find any. He was a good sport about it and hung around for Sunday, rode along several times and still attended all the classroom sessions.
Summary
Had some fun, reinforced that the 034 ball joints are a fixing a problem while adding their own new one, and will be making some changes to correct this problem very shortly. Also the MK8 Full Retrofit is a winner.
