Project 135i Autocross/Street Sleeper: A Comprehensive Journal

[aisthetes]

Now that I’m starting my second BMW CCA autocross season and have the car fairly well dialed-in, I feel it’s an appropriate time to share my experiences and give credit to the good folks who advised me along the way. I’ve been a casual 1Addicts.com poster and serious lurker for long enough that it’s time I gave a little back. Hopefully my experiences will help some of you in your own projects, and give validation to those who’ve already been down the same road. Perhaps it’ll save some of you some guesswork or expensive mistakes as you navigate your own path.

My goal was to keep my 135i as close to factory stock as possible, while being able to actively enjoy autocrossing the car with minimal compromise on the street. I’ve found that just a few carefully chosen, simple modifications can dramatically transform the car’s character and performance.

For track/autocross, the 135i already has ample power which outshines the stock suspension. Knowing this, I chose to keep my powertrain factory stock for reliability, warranty preservation and to work on obtaining an overall balanced package. The N54’s stock power level and broad torque band is already strong enough out of the box to be competitive, particularly in an autocross setting.

Stage 1 - Tires
The first change I made was swapping the factory runflats for upsized 225/40/18 F & 255/35/18 R Dunlop Star Specs on stock M sport wheels. The car was instantly highly competitive in the BMW CCA D Stock class with this change alone, allowing me to lead the class during the end of ’08 and first half of ’09. While effective in adding more grip, the outside edges quickly got trashed from a lack of negative camber. This is where critical decisions need to be made as to your car’s intended usage and how aggressive you want to take it.

Stage 2 - Camber
I wanted to learn to drive the car competitively which each modification before upgrading further. You can always “buy time” by changing parts all at once, but I feel learning to maximize each modification will ultimately make you a faster driver as you master each stage. I also wanted to keep the car close to factory stock and invest as little as possible for race time, so I opted to keep my shocks and springs stock. After talking with San Diego BMW CCA instructor and multi-SCCA regional autocross champion Chris Teague (who also has a 135i he brings to CCA events), it became clear that negative camber was needed to actively race the car and get reasonable tire life, by allowing more of the tire tread to come into play versus riding the outside tire edge. Armed with this knowledge, I focused on finding ways to get more negative camber on the front wheels.

I chose BMW tuning expert Harold Lin from HP Autowerks (HPA) of Santa Barbara to walk me through my options. He has one of the fastest N54 pro time attack cars and intimately understands how to unlock the performance potential of the 135i/335i platform, arguably better than anyone in the industry. For my goal of obtaining maximum negative camber, we chose Vorshlag camber plates adapted for the stock struts and OEM E92 M3 front control arms (more negative camber, less camber deflection under cornering, better steering response, wider front track). The Vorshlag plates are extremely robust, well-engineered pieces with independent camber and caster adjustability. On the 135i, they sit below the strut tower housings, giving a stealthy look I appreciate. The M3 front control arm kit is the OEM quality you’d expect from BMW’s M Division, made of all-aluminum construction with factory stampings and part numbers.

HPA installed the parts and had their partnering shop set the car up on the alignment rack. I think it’s extremely cool that the new M3 parts bolt right up to our chassis with no modifications. These are the same suspension pieces used on the forthcoming 1M, as well. Ultimately, I’d love to complete the OEM M3 swap with the rear-end subframe bushings and control arms, but that’s the much more expensive side to undertake, and if you have to choose, not as critical as the front-end parts.

Getting back on the road, the newfound steering responsiveness combined with the car’s willingness to change direction quickly was immediately noticeable. Right away, I knew the autocross game would be much more fun and more enjoyable. Back at the track, the parts made a significant difference, allowing me to get more needed front-end bite to tackle the tighter layouts and more steering responsiveness for the slaloms. I noticed less tire wear from rollover than before, however, the outside of the front tires were still taking the brunt of the beating. After downloading with Chris Teague, we decided a front sway bar would be next in getting the front-end to stay flatter with less body roll, which would allow me to utilize my tires more effectively.

Stage 3 – Front Sway Bar
We have many options when it comes to front sway bars, from OEM M3 upgrades to massive adjustable competition bars from Hotchkis. Knowing your long-term goals is the key to selecting the right bar, as each complements a different setup and usage. Since I wanted factory quality and stealthy appearance, I went OEM M3. I also didn’t want too beefy of a front bar in the event I upgrade to competition coilovers later on, as they’ll already have the stiffness needed, and in combination with an aggressive front bar can lead to unwanted understeer. With OEM front sway bars, we have two choices: E92 M3 Coupe or E93 M3 Convertible. The convertible bar is 1mm thicker, so I opted for it as a “middle-of-the-road” option in stiffness between the E92 and Hotchkis. Once again, Harold from HPA provided the part and quickly shipped it to my house. From my research, stiffer rear bars are not advisable on BMWs without a limited slip differential, as the added stiffness can actually lift a rear wheel during cornering, leaving compromised traction.

For the installation, I called a friend-of-a-friend, Chris Snaidy, of CS Motorwerks in Westlake Village. For SoCal residents, finding a high quality independent BMW mechanic isn’t easy. Chris is a master BMW technician who has made the rounds at local BMW dealerships, most recently at Bob Smith BMW in Calabasas. He’s now ventured out on his own and started his own shop, and has all of the tools and knowledge of the best dealerships, at less cost. He’ll even work on Saturdays! From routine maintenance to aftermarket modifications, Chris is the man. He had the sway bar swapped in no time, and immediately the front-end felt crisper and more tied-down around turns. At the track, the upgrade was noticeable, particularly in the tighter 2nd gear turns where I could get the power down a bit sooner to throttle-out faster. I was able to lead the new CCA TM class (Turbo Modified – any modified BMW that came from the factory with a turbocharged motor making more than 295hp, and the E30 M3) with these simple tweaks.

Stage 4 – Dedicated competition wheels & tires
To start off the 2011 season, I decided the most effective modification would be to get more rubber under the car. The stock wheels are very heavy (26-27 lbs) and greatly add to unwanted unsprung weight. When it comes to lightweight 135i specific wheels, really the only choice is the Apex ARC-8. The wheel’s 135i specific offsets, 18 lb. weight and classic BBS design are a phenomenal value at around $300 each. Eddy P. of Apex is a great resource for street to competition setups, and he has seen just about every combination out there. We went with the ARC-8 in 18x8.5” F & 18x9.5” R, for an inch wider width on each end. The guys on the boards using these wheels who already blazed the trail typically go with 255/35 F and 275/35 R Dunlop Star Specs, and with tons of camber (at least -2 deg) and a fender lip roll, report no rubbing issues. Since I had already used Star Specs before, I wanted to try the slightly stickier Yokohama AD08 street tire, which is the same tire used on the Berk Technology Time Attack 135i monster. I selected a 255/35/18 F & 265/35/18 R, as a 275 width isn’t available. Since they run wide, it’s probably very close in size with a Star Spec 275, and I didn’t want a large front-to-rear bias to keep a more neutral setup versus looking at using the heavier 285 width available. In talking with Eddy, this is uncharted territory in a 255 F fitment for a 135i street car, as the AD08 runs slightly wider than the Star Spec. In comparing my old Star Specs to the new AD08s, the Yoko is just slightly wider, but it’s the squared-off shoulder design that makes it a tougher fit.

Enter my buddy from way back in our VW roots and legendary underground fender guru, Tony. As a writer for Performance VW and Performance BMW, car show addict and all-around car nut, just about everyone into cars in CA knows Tony, or knows someone who knows Tony. From the BMW CCA racers to VIP show boys, JDM fans to Euro bagged tire stretchers, they call Tony to make their style drivable. According to Tony, the curvature and design of modern BMW fenders are amongst the toughest to work on without damaging, so he’s become a leading source of expertise in this regard, as many shops refer such work his way and don’t want the headache themselves. For SoCal residents, we have one of the best at our disposal.

My charge to Tony was to make the tires fit without any on-track rubbing, while making his work nearly imperceptible to the untrained eye from the outside – no easy task. Tony started by heating up the fender lips to get them pliable, then hand-hammered the lips flat. In his opinion, the complexity of the 135i’s fenders are better approached carefully by hand, rather than with a one-size-fits-all fender roller approach. Test driving afterward showed tire rubbing on the front most section of the fender lip down to the bumper tab, as the tire was moving forward under full compression. Tony grinded down the bumper tab and cut a small section of the front fender liners on each side to give more room to roll the fender lips completely flush against themselves. He then engaged in the black art of mallet-to-inner-fender pounding, as he hand-formed the heated fender, pulling it out for tire clearance. The results are very subtle from the outside with no paint cracking or fender distortion, but the inner clearancing made a big difference in allowing the setup to work.

While I still get a quick tire rub under full compression on freeway dips driving to the track, on track there’s absolutely no rubbing, period, and that’s the key. I must note that it took me maxing out my camber plates to -2.6 degrees to make this setup work. The rears required absolutely no modification of any kind. If this was my daily driving setup, I couldn’t recommend it as no compromise, but as a track only setup, it’s perfect. Then again, I doubt many will opt to run 255s up front full-time anyway along with the camber needed. Now, for those with quality coilovers, such extensive fender work shouldn’t be required to run AD08s, as the stiffer springs and better shock valving will allow for less suspension compression than my stock parts. Plus, unlike my setup, you have the option to raise the car a touch, if needed, before doing anything other than a mild fender lip roll.

From mild to wild, I highly recommend Tony for your own project. Most shops charge $100-$250 per fender for this type of job, but since it’s just an enjoyable hobby on the side for Tony, he’ll do it for only $40 per fender! Plus, if you’re in SoCal, he’ll come to you. It’s a no-brainer.

Putting it all together
The litmus test for the Apex/Yoko combo was the Los Angeles BMW CCA autocross season opener over the weekend. The venue was held at the renowned Streets of Willow race track in Rosamond, a favorite test bed for enthusiast automotive magazines. We had beautiful weather and an incredibly varied group of cars, including everything from 2002s to full race E36s, a pair of gorgeous Porsche Boxster Spyders, 993 Turbo, C6 Vette, every vintage of M3, and even a Geo Metro rallycross car – about 90 cars in all including 18 CCA instructors.

The additional contact patch and front-end grip was immediately noticeable over the stock-sized setup. This is an absolutely massive amount of rubber on a car of this size. When you consider we can run more rubber up front than a factory E92 M3 or 1M, it puts the performance potential in perspective! I was relieved not to have any rubbing anywhere, even in the tight sections with heavy steering input. I had my buddy Bill, a CCA instructor, ride with me in the warm-up session, and his weight still didn’t’ cause tire-to-fender contact. You can see from the action shot below that the tire fits nicely underneath the fender under full compression in a turn. I’ve been used to a year of judicious throttle usage coming out of 2nd gear turns to keep the rear-end planted, so the extra grip from the new setup was a revelation. It was a good shakedown, but I know I’m still not getting the most out of the grip available in maximizing even earlier throttle openings and faster corner entry. That’ll be my challenge this year.

At the end of the day, I led the TM class and took 2nd fastest time of the day for BMW and non-BMW cars (excluding CCA instructors). All-up including the pros, I missed the top ten by a few hundreths. Top all-up times of the day were set by instructors: a track-tuned Porsche 996 GT3 crushed the field, followed by a full-race E36 weighing 2,900 lbs with driver and M3 motor swap, with my buddy Bill Hinomoto (SCCA regional auto-x champ) in his relatively lightly-tuned S2000. Seeing these guys in action was inspiring and sets a high benchmark to aspire to. Competition was stiff, even amongst non-pros, and I know it was the Apex/Yoko combo that gave me an edge in light of my basic mods. It goes to show just how good the 135i package really is, and that just a few key changes can dramatically alter the car’s performance and allow it to compete with many of the best sports cars out there.

I still have plenty of refinement of my skills to get the most out of my car, and that’s the fun of it. There’s always another tenth to gain, no matter how good you ultimately get. With the top-tier CCA instruction available, the journey is fast-tracked. It’s the BMW CCA instructors, particularly Chris Teague, that have allowed me to progress quickly through consistent seat time, and this is just the beginning of the story for me – I’m hooked! There are many other 1Addicts that have the same addiction and are kicking butt in their own states with their 1s, and I’d love to see more come out to fly the 1 Series flag. The BMW CCA and the professional autocross and track events they host were a major reason why I chose to buy a BMW and have made the ownership experience very rewarding.

I highly encourage anyone interested in safely learning to control their car at the limit, while having some good fun at the same time, to contact your local BMW CCA chapter and get involved.

-Doug


Credits / Contacts:

HP Autowerks / Harold Lin: http://www.hpautowerks.com/performance.htm

Tony the fender guru: (818) 368-4395

CS Motorwerks / Chris Snaidy: http://www.csmotorwerks.com/

Apex Wheels / Eddy P: http://www.apexraceparts.com/

Chris Teague (decorated autocross expert and driving instructor): 1addicts user name “cpt97m3”

[sodara]

Awesome read! Front cover material here, thx for sharing.
I much rather enjoy reading about track set-up/experiences instead straight line/power tuned uber PSI boost 10sec fast n furious set-ups/experiences.

[Groundpilot]

Very nice, informative and detailed article. 135i is a nice daily driver, and could be an impressive track car if set up properly. I take mine to the track a few times a year and surprize a lot of people in advanced group how fast this car is. This car is a sleeper. My set up is somewhat similar to yours but i went a step further and in addition to front m3 control arms got rear arms as well with rear subframe bushings. KW3 coilovers, vorshlag plates, e92 m3 front sway bar, apex weels with (BFG R1 tires for track use only). The car is lowered by 1 inch that allowed me to get -3 camber which made a huge difference in the handling dept. It turns out that KW3 coils are not a real hard core coils because of the soft springs and the progressive character. But as Harold from HP suggested it can be fixed with Swift conversion kit that includes linear stiffer (400f/800r) springs.I am planning to get that kit for upcoming track season here in the northeast. Just received iCarbon vented hood that is much lighter than the stock one and will adress some engine overheatting issues as open vents should allow hot air that builds up under the hood to escape. Really want stop tech BBK, but its getting very expensive. Maybe in a coupple years. Engine is stock as i agree with you that tuning may compromize reliability and induce unwanted limp mode at the track.

[GaryS]

Great post aisthetes! Sorry to ruin it with such a shallow question, but are your Apex wheels hyper silver or hyper black? I have been losing my mind trying to decide between the two colors.

[HP Autosport]

Originally Posted by GaryS

Great post aisthetes! Sorry to ruin it with such a shallow question, but are your Apex wheels hyper silver or hyper black? I have been losing my mind trying to decide between the two colors.

Those look like hyper silver with some brake dust on them. They look good regardless...

[aisthetes]

Originally Posted by M3 09 AND135I 11

Very nice, informative and detailed article. 135i is a nice daily driver, and could be an impressive track car if set up properly. I take mine to the track a few times a year and surprize a lot of people in advanced group how fast this car is. This car is a sleeper. My set up is somewhat similar to yours but i went a step further and in addition to front m3 control arms got rear arms as well with rear subframe bushings. KW3 coilovers, vorshlag plates, e92 m3 front sway bar, apex weels with (BFG R1 tires for track use only). The car is lowered by 1 inch that allowed me to get -3 camber which made a huge difference in the handling dept. It turns out that KW3 coils are not a real hard core coils because of the soft springs and the progressive character. But as Harold from HP suggested it can be fixed with Swift conversion kit that includes linear stiffer (400f/800r) springs.I am planning to get that kit for upcoming track season here in the northeast. Just received iCarbon vented hood that is much lighter than the stock one and will adress some engine overheatting issues as open vents should allow hot air that builds up under the hood to escape. Really want stop tech BBK, but its getting very expensive. Maybe in a coupple years. Engine is stock as i agree with you that tuning may compromize reliability and induce unwanted limp mode at the track.

Nice, David! That's a heck of a setup. I can only imagine how incredibly well your car must perform. Add an LSD and you have a junior supercar killer. I agree that the factory KW spring rates are too soft for track use, particularly when used in combination with r-comps. The Swift spring upgrade should bring it all together nicely. When you consider even the Berk & HPA time attack cars are on still on street rubber, yours will at be an even higher level of grip. Too bad you're not in CA so I can see it in action!

Any pics?

[aisthetes]

Originally Posted by GaryS

Great post aisthetes! Sorry to ruin it with such a shallow question, but are your Apex wheels hyper silver or hyper black? I have been losing my mind trying to decide between the two colors.

Not at all, bring on the feedback and comments.

They're hyper silver, and when clean, have a finish like the factory wheels.

[Eddy@ApexWheels]

Doug,

Fantastic write up! I know you went through a lot to get those AD08's on up front. You really are breaking new ground with that setup. 255/265 is how I envisioned those wheels being used. And as you know it's not a simple bolt on fitment for anyone, but well worth it.

Thanks for the shout out to ApexRaceParts

I look forward to seeing the progress and development of your car.

[pixelblue]

great write up/review! I went down the same road as you did. I upgraded my suspension after each track event (M3 control arms, M3 ARB, Vorshlag, Bilstein Pss9) . this way I really got to know the cars handling characteristic intimately and noticed each improvement as I upgraded. I don't plan on tweaking the engine this year but I may do so for next year. the next upgrades will be an upgrade oil cooler, BBK and a LSD. for this track season I have already upgraded my rear bushings and purchased a set of track wheels LTW5 with 245/40x17 BFG R1 in all four corners. oh, and I have gotten a lap timer/data logger to measure my times and stats after each event. hopefully this will serve as a useful tool. a friend of mine who has a E92 M3 always tracks with me and I am always 2-5 seconds behind him a lap. I am hoping to close that gap with the addition of track wheels and R comps can't wait to hit the track in two months. cheers

[aisthetes]

Originally Posted by pixelblue

great write up/review! I went down the same road as you did. I upgraded my suspension after each track event (M3 control arms, M3 ARB, Vorshlag, Bilstein Pss9) . this way I really got to know the cars handling characteristic intimately and noticed each improvement as I upgraded. I don't plan on tweaking the engine this year but I may do so for next year. the next upgrades will be an upgrade oil cooler, BBK and a LSD. for this track season I have already upgraded my rear bushings and purchased a set of track wheels LTW5 with 245/40x17 BFG R1 in all four corners. oh, and I have gotten a lap timer/data logger to measure my times and stats after each event. hopefully this will serve as a useful tool. a friend of mine who has a E92 M3 always tracks with me and I am always 2-5 seconds behind him a lap. I am hoping to close that gap with the addition of track wheels and R comps can't wait to hit the track in two months. cheers

Nice spec sheet. With the R1s, you'll definitely close the gap on your buddy. Add that LSD, and it's game on! Keep us posted.

[aisthetes]

Originally Posted by paintpro21

Doug,

Fantastic write up! I know you went through a lot to get those AD08's on up front. You really are breaking new ground with that setup. 255/265 is how I envisioned those wheels being used. And as you know it's not a simple bolt on fitment for anyone, but well worth it.

Thanks for the shout out to ApexRaceParts

I look forward to seeing the progress and development of your car.

Definitely well worth it. I'll work on providing regular updates to download for our group after events this season and share my findings, with pics, of course.

[nordique14]

fantastic write up.

I did many of the same things as you in the front (stock springs/shocks with Vorshlag camber plates, E93 sway bar and M3 suspension bits). They certainly make turn in much better. I also ended up in the -2.5* range for front camber.

I also broke down and am trying to fix the rear. I just did the M3 subframe bushings and the E93 rear sway bar. I have yet to properly test those pieces out at the autox though.

I went a bit different route with the wheels are I want to have a square setup.

Good luck this season. Keep us posted on your progress.

[jb2178]

Only halfway through your post but I wanted to thank you for the post. I've run the past two years SCCA D-Stock and I'm looking forward to March when our events start up again. The first year I ran dead stock on run flats but my first season ate those so I to upgraded to upsized star specs (225/45 front 235/45 rear on my 128i 17 inch sport wheels) which definatly helped. I probably could have won D-Stock if I made it to all the sessions last year. This year I added the E93 front sway and I can't wait to see how it helps. I really wish I could get into camber plates but I'm content to compete in stock for now... keep it up!

[aisthetes]

Originally Posted by nordique14

fantastic write up.

I did many of the same things as you in the front (stock springs/shocks with Vorshlag camber plates, E93 sway bar and M3 suspension bits). They certainly make turn in much better. I also ended up in the -2.5* range for front camber.

I also broke down and am trying to fix the rear. I just did the M3 subframe bushings and the E93 rear sway bar. I have yet to properly test those pieces out at the autox though.

I went a bit different route with the wheels are I want to have a square setup.

Good luck this season. Keep us posted on your progress.

We're definitely on the same page. I'm interested to read your impressions after you test the rear-end mods.

After consulting Harold, TC Kline and Chris T., all agree that the rear subframe bushings are the key to getting the most out of the 1 Series' chassis, particularly if adding stiffer shocks and springs. I certainly don't care for the factory rear bushing deflection. Chris T. did his rear bushing swap in his garage, and noted that he could compress the factory bushings by hand, whereas the M3's are hardened for increased performance.

There's a turn I take every day to work, where there's a railroad track crossing immediately after turning right onto the street. When I go over the tracks, my steering wheel is still turned to the right, and I can feel the rear-end take a set well after the front from the delayed rear bushing response. It feels like two different cars welded together! At a track like Buttonwillow Raceway (Time Attack home), there's a fast right-hand sweeper called "Riverside" that I take in 4th gear, full-throttle coming out, and those bushings allow enough movement (in combo with stock shocks/springs) to give the "heart-in-mouth" feeling - until you trust that the car will grip. Not exactly confidence inspiring stuff.

[aisthetes]

Originally Posted by jb2178

Only halfway through your post but I wanted to thank you for the post. I've run the past two years SCCA D-Stock and I'm looking forward to March when our events start up again. The first year I ran dead stock on run flats but my first season ate those so I to upgraded to upsized star specs (225/45 front 235/45 rear on my 128i 17 inch sport wheels) which definatly helped. I probably could have won D-Stock if I made it to all the sessions last year. This year I added the E93 front sway and I can't wait to see how it helps. I really wish I could get into camber plates but I'm content to compete in stock for now... keep it up!

I'm glad you've found value in it. I wouldn't be able to post if others didn't already share or advise me in the past, so I'm happy to give back.

You're on the right track. You'll like the E93 FSB. It really pays off in an autocross setting and will help control the massive body roll on stock suspension with grippy tires better. Once you get tired of riding on the outside edges of your tires and their shorter shelf life, you'll be looking for your camber fix.

[GaryS]

Originally Posted by aisthetes

Ultimately, I’d love to complete the OEM M3 swap with the rear-end subframe bushings and control arms,

I think you should consider better shocks next - Koni Sports or FSD. The OEM shocks are so bouncy, I think they are the weakest link. Then get the M3 rear subframe bushings if the back end is still too bouncy. My two cents.

[jsublime]

That was a great detailed post. Good luck with the new season. Hopefully I can get my 135 to some events this year.

[Rafax28]

Hi folks,

I'm considering install the BMW PS on my 135i, but I want to complete my upgrade with E92 control arms and camber plates Vorshlag. It's possible? BMW PS is a good option for the track?

Aisthetes,

Thanks for the post I'm sure that help me in my future decisions.

Cheers

[aisthetes]

Originally Posted by Rafax28

Hi folks,

I'm considering install the BMW PS on my 135i, but I want to complete my upgrade with E92 control arms and camber plates Vorshlag. It's possible? BMW PS is a good option for the track?

Aisthetes,

Thanks for the post I'm sure that help me in my future decisions.

Cheers

Sure, the combo you're after will work. The PS doesn't alter the control arms, and the E92 kit are factory parts that will work with any shock/spring or coilover choice. The Vorshlag camber plates will work with the setup as well - just be sure to let your retailer know to supply the proper kit for stock struts.

PS is a good all-around upgrade - essentially a notch up from stock, but not as aggressive as an all-out coilover setup. If your intentions are like most enthusiasts: comfort on the street with occasional track day fun, it'll work great. If you're a time attack warrior whose focus is on lap times, you'll need a higher-end coilover setup with more aggressive spring rates/shock valving and adjustability. For most of us, the latter isn't a necessity to build a competitive platform, but it's certainly nice to have.

[Rafax28]

Great!!

Thanks again for your comments. I will start with the upgrade and I will comment on the result. Finally my plan will be to acquire Advan RZ wheels in 18x8 y 18x9 for my PS2 225/40F 255/35R. I can not wait more.....

Kind regards

[larryn]

Awesome write up, Doug! Thanks. i love your research-driven approach. Very well thought out. Sorry I didn't get back to you.. I was in Mexico on vacation, and not checking things here. Sounds like you got the front worked out, hopefully not too much time went into that.

Definitely do the rear bushings next. They rock. I have everything you have, plus Koni Sports/H&R Sports and rear bushings. The car is certainly more predictable. Have fun! We have 4 more months before driving events start, and I just finished snowblowing the driveway.

[aisthetes]

Originally Posted by larryn

Awesome write up, Doug! Thanks. i love your research-driven approach. Very well thought out. Sorry I didn't get back to you.. I was in Mexico on vacation, and not checking things here. Sounds like you got the front worked out, hopefully not too much time went into that.

Definitely do the rear bushings next. They rock. I have everything you have, plus Koni Sports/H&R Sports and rear bushings. The car is certainly more predictable. Have fun! We have 4 more months before driving events start, and I just finished snowblowing the driveway.

Not a problem, Larry. I appreciate your insight in the past. Good to hear another rave review about the bushings. Perhaps I'll approach the swap next season. We are lucky here in SoCal that we can have the option of racing all-year long. It was 80 degrees today in the dead of winter!