Official 135i/128i SCCA FS/STU/STX Chat thread

[Kgolf31]

If anyone isn't doing anything this weekend, and want to hear some STX action tune into the NCM Match Tour

http://www.solomatters.com/tune-in_2...cky_match_tour

Links are in the thread to follow and listen. I run Heat 2

[Ginger_Extract]

Originally Posted by Kgolf31

If anyone isn't doing anything this weekend, and want to hear some STX action tune into the NCM Match Tour

http://www.solomatters.com/tune-in_2...cky_match_tour

Links are in the thread to follow and listen. I run Heat 2

Is it happening on Saturday or Sunday? If it's Saturday, I'll broadcast it while working in the garage. If Sunday, I'll be preoccupied with my own event.

[Kgolf31]

Originally Posted by Ginger_Extract

Is it happening on Saturday or Sunday? If it's Saturday, I'll broadcast it while working in the garage. If Sunday, I'll be preoccupied with my own event.

Saturday and Sunday.

Saturday there is a AM and PM run sessions for class positions

Sunday is for super shootout and knock out rounds

[Kgolf31]

Ended up 2nd Today.

Was leaving in the AM by 0.091 seconds. Went into the PM session and couldn't match the time.

Oh well, we will see what shootout brings tomorrow.

[Ginger_Extract]

Event today was a bust, couldn't tame the under steer.

However, I happened to meet someone selling a pair of 17x9 ET40 wheels with a pair of 255/40 RS3 mounted on them. Bought them on the cheap and promptly did some test fitting. Pictures and commentary incoming.

[Ginger_Extract]

Boom, here's a full write up on fitting a 17x9 with a fat 255 tire under our 1'ers.

http://jakestumphracing.tumblr.com/p...l-fitment-test

[Ginger_Extract]

Originally Posted by Kgolf31

Well done. I calc'ed ET33 for my setup to good to see I'm in the right range.

That should be fine, since you have a good fender roll and the camber, etc. I clear the fender, but I still need to roll em, just so don't have the possibility of snagging the fender under compression.
Was hoping that I could get away with ET37 (i.e. Apex' common 17x9 ET42 with a spacer), but it's too tight for that with fat tires. With the Bridgestones and ET33, you'll have more than enough room.

[Kgolf31]

Here's my fastest run from NCM Match Tour this weekend.

I'll write up some more, but was leading the class in the AM Saturday, and couldn't improve from AM runs in the afternoon (ran another 47.1) and lost the class by 0.24 seconds. Disappointing really because the car had the pace to be fast.


Sunday qualified for the Club Shootout and made it through the first round by throwing down a 46.186. Second round I spun after trying to throw a flyer and didn't work. Oh well.

All in all it was a decent weekend. Still need to get use to the diff and how to drive it. Also need to get close to cones, left way too many out a couple feet.

[The Nebulizer]

I was able to directly compare my 135i and e46 M3 each prepped in FStreet and each on 245/275 Rivals. My M3 was 0.9sec faster on a small 38 second course. But even more than that the M3 was a lot more fun to drive. Unfortunately, this ends the prep of my 135i for FS. It will now be a backup or just for kicks autocrosser and full time daily driver.

135i:

It is rather easy to drive and feels very confident and balanced. It lacks power or at least the ability to put power to the wheels (maybe electronic dif?). It's not a bad autocross car, just not very exciting and a bit off pace in FS. Too refined?

M3:

It's a beast. It is not refined and not especially easy to drive. It is wild and powerful and begs you to push it. You can't help but have a smile on your face after driving this car. Great autocross car.

[Kgolf31]

Yea. I'm not honestly surprised the 135i is slower. It just doesn't add up to being a competitive car.

Picture from this weekend

[Ginger_Extract]

Originally Posted by The Nebulizer

I was able to directly compare my 135i and e46 M3 each prepped in FStreet and each on 245/275 Rivals. My M3 was 0.9sec faster on a small 38 second course. But even more than that the M3 was a lot more fun to drive. Unfortunately, this ends the prep of my 135i for FS. It will now be a backup or just for kicks autocrosser and full time daily driver.

135i:
It is rather easy to drive and feels very confident and balanced. It lacks power or at least the ability to put power to the wheels (maybe electronic dif?). It's not a bad autocross car, just not very exciting and a bit off pace in FS. Too refined?

M3:
It's a beast. It is not refined and not especially easy to drive. It is wild and powerful and begs you to push it. You can't help but have a smile on your face after driving this car. Great autocross car.

Can you quantify what made the 1'er slower? Surprised you're using the words confident and balanced with a 135i. My choice of words would have been more along the lines of "hard to predict" and "understeer/snap over steer."

[Ginger_Extract]

Feel free to mock, drove like garbage this past weekend. Always seemed to lock in the wheel, causing the car to plow. Never seemed to find the right line ever. If you see where I lost time (besides everywhere), please let me know.

[Kgolf31]

I know the mic is near the exhaust, but it doesn't sound like you're ever pushing the tires.

What were your shock settings? Car always looked upset and bouncing around.

[Ginger_Extract]

Originally Posted by Kgolf31

I know the mic is near the exhaust, but it doesn't sound like you're ever pushing the tires.

What were your shock settings? Car always looked upset and bouncing around.

The car was skating, never felt like the tires had bite. Front rebound about 2/3 stiff, rear rebound about 1/2 stiff.

[Kgolf31]

Originally Posted by Ginger_Extract

The car was skating, never felt like the tires had bite. Front rebound about 2/3 stiff, rear rebound about 1/2 stiff.

Probably too much front rebound. If you're experiencing push:

(If you can)

1: Lower front pressures
2. Adjust front swaybar to be softer
3. Soften front rebound
4. Stiffen rear rebound
5. Increase rear pressure

I'd do it in that order.

Honestly conventional wisdom says fix the end that you have issues on. In my case this past weekend I couldn't get the rear to rotate on throttle like I wanted it to, so I increased rear rebound, went up a click in compression, then once I started developing a push I softened the front rebound a bit and lowered compression one click.

Ran it like that, the front started to skate some, lowered the front pressures 1 pound and dropped 0.6 seconds off of time.


Do you know how many runs are on those RS3v2s?

[Ginger_Extract]

Originally Posted by Kgolf31

Probably too much front rebound. If you're experiencing push:

(If you can)

1: Lower front pressures
2. Adjust front swaybar to be softer
3. Soften front rebound
4. Stiffen rear rebound
5. Increase rear pressure

I'd do it in that order.

Honestly conventional wisdom says fix the end that you have issues on. In my case this past weekend I couldn't get the rear to rotate on throttle like I wanted it to, so I increased rear rebound, went up a click in compression, then once I started developing a push I softened the front rebound a bit and lowered compression one click.

Ran it like that, the front started to skate some, lowered the front pressures 1 pound and dropped 0.6 seconds off of time.


Do you know how many runs are on those RS3v2s?

I'll keep these in mind for my next event in two weeks.

Prior to this event, fronts had 2 D.E.s and about 20 runs on them, plus some street miles driving to and from events, rears had 16 runs on them, pretty damn fresh. 36PSI F, 30PSI R. Pressures set based on wear/rollover.

[Kgolf31]

Woah, 36 PSI?

For reference, with my setup I run 30-31 PSI up front on RS3s

[Ginger_Extract]

That's ET33 up front, right? How does the rear look at ET45? Those Bridgestones are NARROW!

[Kgolf31]

Originally Posted by Ginger_Extract

That's ET33 up front, right? How does the rear look at ET45? Those Bridgestones are NARROW!

Correct.

Not too small compared to 8.5 245/40 RS3s

[Ginger_Extract]

Any profile shots? Curious how those wheels look on the car? When I test fit the 17x9 ET40 with 255 RS3 in the rear, it was way more aggressive looking than that. Must be the virtue of your fender roll, and the slightly narrower tire.

[Kgolf31]

Originally Posted by Ginger_Extract

Any profile shots? Curious how those wheels look on the car? When I test fit the 17x9 ET40 with 255 RS3 in the rear, it was way more aggressive looking than that. Must be the virtue of your fender roll, and the slightly narrower tire.

I'm also 5mm more in than you in the rear.

Tire specs match exactly up. Not a narrow tire by any means

[Nugget]

Maybe I missed it but what are the wheels/tyre specs and brands?