First AutoX with Hotchkis front sway, and DSC off

[MarkR171]

Had my first autocross event since installing the Hotchkis 32mm front sway bar today. Also, up until today, I had been autocrossing with DTC on and I've been satisfied with the results. Today, since adding the sway bar, I've noticed the traction control reducing the engine power a lot through slaloms and long sweeping turns. I did 7 runs with DTC on and my times were slowly improving from 41.4xx to my best 40.5xx.

At the end of the day in fun runs, I decided I was fed up with the traction control getting in the way and decided to turn it off (hold DTC button for DSC Off.) I've always thought the car would be tail happy if I did this because people on the boards like to refer to DSC Off as "Scary." I was wrong. The car handled so much more beautifully. The tail would swing around a lot easier through the slaloms and throttle through the sweepers actually allowed tighter cornering at higher speeds. It really did feel like I was driving a completely different car.

Right away I improved my time to 40.3xx then really went for it on my last run and ran a 39.511. I'm confident the car could have broken into the 38s with more practice driving DSC off. The FTD was in the mid 36s, so 38s in my opinion, would be very respectable for a stock 135i on street tires with a front sway bar.

Here's a video of that last run at 39.511.

[bluesunit]

Congrats!

The 1 is definitely not a "scary" car. It deserves respect, but it generally wants to go the way you as it to and will do what you ask of it as long as the tires can fit the bill.

I have the big bar as well (plus aggressive alignment and 245 R6's on all corners, stock rims). Car is on the understeery side of neutral. I believe I'm stiffer shocks up front from being where I want to be in the performance envelope.

Last autocross, I got stuck trying to fix our timers, so never got a chance to even unload my car, much less get the slicks on it or get setup. I ended up begging a codrive off another guy with an s2000.

Now that shit is scary. I'm not sure I want to work that hard to go fast.

[MarkR171]

The fronts were scrubbing a lot more with DSC off, but I fixed most of that by driving adjustments. Can't just floor it through a corner and expect DTC to adjust throttle for you, you have to do it yourself, which is more fun/rewarding anyway... and a lot faster when you get it right. Maybe wider tires in front or some camber would allow a higher limit.

[Focusedintntions]

Very nice drive my friend! Can't wait for spring to get my fist autox in the 135

[bluesunit]

Originally Posted by MarkR171

The fronts were scrubbing a lot more with DSC off, but I fixed most of that by driving adjustments. Can't just floor it through a corner and expect DTC to adjust throttle for you, you have to do it yourself, which is more fun/rewarding anyway... and a lot faster when you get it right. Maybe wider tires in front or some camber would allow a higher limit.

You did an excellent job in your video of not trying to correct the understeer with more steering input. That's 3/4 of the battle and something that took me two years of autocrossing to stop doing.

You would have definitely gone a bit faster in the sweepers by going slower (less throttle, you were driving over your front tires).

Like you said, on the oem runflats, myself, and other drivers, found the car to be faster with DSC on, as it would cut power before you put it in a death plow.

One there are sticky streets or slicks in the equation, I think the balance shifts over to DSC off.

[MarkR171]

You nailed it with less throttle in the sweepers. I plowed through the end of that long right and almost took out all the outside cones at the exit the first time I tried DSC off. Corner exit and slalom acceleration is a LOT better with the DSC off though.

[MarkR171]

By the way bluesunit, what else have you done to your D-Stock car? Is the area you run in flat? Or are there some dips/bumps? Just asking because I'm thinking of making the move to A6s in 245 all around some time. No rubbing with yours at all? There are some pretty big dips in the lot I run in so a bit worried about rubbing.

[MarkR171]

DTC reduces engine power to the wheels to maintain grip. That means you can't really apply a lot of throttle through slaloms and sweepers as the car will cut it and you can hear and feel it.

With DSC off, the engine power is not regulated. Instead, the e-diff is activated and applies braking to the rear wheel that's spinning more. It just felt like the car was more eager to switch directions in the slalom.

Tail swinging is probably a bad way to describe it. It felt more like the back end was shifting to the side without having oversteer.

[GaryS]

Nice. The DTC thinks you're too fast.

[bluesunit]

If this is a double post, sorry. The app accidentally my first post.

I'm racing in a fairly level asphalt lot. The R6s I have rub on the drivers side on the strut body and slightly on the inside fender lining. They also contact the front lower control arm at full lock. In both cases the contact is very very slight. I believe a 5mm spacer may help.

For the record: I have the 32mm bar, pins removed, negative camber maxxed, and the "stock" size Breyton GTSRs.

[MarkR171]

Yea that's next for me, removal of the pins for camber.

[Novator]

Driving with everything off is the most fun way to drive, that is a given

[jeremydgreat]

EDIT: Just noticed your sig... "225/255 Star Specs". So, now just go grab some camber plates! Here's where I ordered mine.

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Your video and commentary brought a smile to my face, because I was right there in your shoes a year ago. I had done a couple autoX events and a track day until I finally decided (towards the end of an event) to give it a try with no DSC. WOW! Two things became very apparent to me: 1) the DSC had been kicking in much more often then I thought it was, and 2) I was way faster without it.

I also noticed that by the end of the next track day (with no DSC this time) that something had to change- at this rate I was chewing through the sidewalls of my tires like crazy. I thought it might just be the runflats, so I had some Dunlop Star Specs put on.

Let me pause here and say that this was the most dramatic "mod" I've ever done to my 135i. Handling was significantly improved and I was gripping the course much better.

After installing coilovers, the car started to really feel planted... but I was still ruining my front tires. So, I installed some Vorshlag camber plates. That did the trick. Now, not only was I not driving on my sidewalls, but I could feel the front end digging in on those tight turns. Problem solved!

Since then, I've been to a bunch of different tracks and autocross events and the car feels very different then it did a year ago. With a JB3 and a Hotchkis bar, it's an animal (yet still a respectable daily driver).

So, if I was in your shoes (as I was 1 year ago) I'd say:

1) Go grab some camber plates as soon as you can. They are worth the money because you'll just be chewing through the corners of your tires if you don't get some camber into those front wheels.

2) Loose the run flats. I always thought that people exaggerated their complaints about the run flats (calling then "run craps", etc). But man... you will immediately feel the difference when you loose them.

That's my advice anyway. If you have the inclination and the money, doing coilovers or springs while you have the camber plates installed is not a bad idea.

Anyway- keep us posted on your progress. And yeah, loose the DSC forever. Every time I put it back on, thinking it might help a little, my lap times get worse. And I'm not even that great of a driver (yet).

[MarkR171]

Run flats are already long gone. I'm on Dunlop Direzza Z1 Star Specs. Very sticky street tires. Camber plates aren't an option while I'm in the lead for D-stock class this season. Next season, if I decide to move up to STU, I'll make the switch to coilovers and add camber plates. In the meantime, I'm going to look into alignment pin removal and try to get the most negative camber I can with a stock setup.

At every event so far this season, I've either run a time good for 2nd or 1st place in STU class out of 8-10 cars with my D-Stock 135i on street tires. Every time I came 2nd, I ran a time good for 1st place during fun runs at the end of the day. This car is definitely capable of being STU competitive, at least at the local level.