[orteeze]

I recently signed up for performance driving school sponsored by our local SCCA auto club that involved a full day of autocross. It was an absolute riot and my 11' 335i E90 did great. I'm hooked and want to participate in this year's events. The only concern is limiting myself on modifications (which are sitting in my garage) that would keep me in the "stock" class. As it sits, my car can compete in stock class. I'd like to go FBO without getting beat by several seconds every weekend. So here's a few questions..

1) What class is everyone competing in? I was told is should be FS when the local website showed my car in DS.

2) Would an E90 be competitive in STU? From the rules listed in the SCCA a FBO E90/E92 can fall within this class.

3) What classes are members running in?

Thanks!

[Cloud9blue]

Extra power of FBO is not gonna help a whole lot on this car, especially in low speed autox. Invest in chassis mods instead.

[orteeze]

Originally Posted by Cloud9blue

Extra power of FBO is not gonna help a whole lot on this car, especially in low speed autox. Invest in chassis mods instead.

Understood. Suspension mods would definitely be in the equation. I bet I didn't break 45mph on the course. Since my "spirited" drives consist of short bursts of acceleration, I'm power hungry. I don't want to limit my daily driving experience in order to be competitive in the stock class. If I can have a nice setup and go STU, I would have best of both worlds.

[justpete]

Originally Posted by orteeze

2) Would an E90 be competitive in STU? From the rules listed in the SCCA a FBO E90/E92 can fall within this class.

If you're reading 9.1.4 and 9.1.4.1 of the GCR you'll see that an FBO 335i would likely not be competitive against a purpose built 335i, check the restrictor vs min weight table in addition to the displacement vs min weight table. A purpose built car can have a much lighter chassis and then add ballast to meet the min weight in the passenger floorboard at the center of gravity making the car quicker to turn with less weight transfer. More to it than that, the experts will correct me if I'm wrong about any of it but this is what I'm finding so far, among other things. Good luck!

[Kgolf31]

Originally Posted by justpete

If you're reading 9.1.4 and 9.1.4.1 of the GCR you'll see that an FBO 335i would likely not be competitive against a purpose built 335i, check the restrictor vs min weight table in addition to the displacement vs min weight table. A purpose built car can have a much lighter chassis and then add ballast to meet the min weight in the passenger floorboard at the center of gravity making the car quicker to turn with less weight transfer. More to it than that, the experts will correct me if I'm wrong about any of it but this is what I'm finding so far, among other things. Good luck!

You're getting STU Autox mixed up with STU for Racing.

OP - To be blunt and honest a 335i isn't going to be competitive in either setting. Current the 335i is classed in FS (it was in DS awhile back). You have to compete against current Gen M3s and Mustangs, both which are substantially better than a 335i in stock trim.

In STU you'll need to compete against C5 Vettes, 350zs, Evos and Subarus. In all honestly it's a losing battle.

If you're just starting out, I would just look at modifying your car per the ruleset to still maintain STU legality but just have fun.

PS - Purpose build 128i here, I run in STX

[justpete]

Originally Posted by Kgolf31

You're getting STU Autox mixed up with STU for Racing.

OK, thanks. Confusing though, can't tell the difference in the GCR. Gonna have to read it yet again, I think.

[E30_335i]

You did great your first time out. If you leave FS class, you will be destroyed unless you spend 5k on mods. You can beat the Muscle cars, I can in my '11 335i. Invest in the best 200TW tires, Bilstein HD's, and lots of seat time.

[orteeze]

Is that you Gary?!

[Kgolf31]

Originally Posted by E30_335i

You did great your first time out. If you leave FS class, you will be destroyed unless you spend 5k on mods. You can beat the Muscle cars, I can in my '11 335i. Invest in the best 200TW tires, Bilstein HD's, and lots of seat time.

Locally, yes.

Nationally? No way.


PS - 5k is probably a bit short. If you want to do a full prep STU build budget 10-15k

[z3papa]

I'd have to agree with Kyle. I own a 2011.5 E92 M3 and my wife owns a 2007 335i. There is no comparison. I could be locally competitive on my wife's car but would smoke the shit out it in my M3. Beyond the fact it is simply a better car, the wider wheels/tires and better suspension geometry in the front with the better diff makes the difference very pronounced. I'd suggest getting seat time and if this seriously something you want to pursue, hold off modifications and get a better car for class. There were guys in full prepped 235's that were in class last year that found out really fast what this is about.

[orteeze]

I appreciate the input so far. Sounds like STU is out of the question. I'll stick to FS and hold off on my power adder mods. Maybe next year I'll add some Bilsteins and a sway bar; understeer was evident during my first couple of runs.

[E30_335i]

Originally Posted by Kgolf31

Locally, yes.

Nationally? No way.


PS - 5k is probably a bit short. If you want to do a full prep STU build budget 10-15k

Locally is where he will be competing, locally you can do well in FS.

[Cloud9blue]

$5k is probably doable if you pick the right mods.

Including labors, here is how I would break it down:
LSD - $1500
Full M3 suspension control arm swap front and back and rear subframe bushings - $1500
Entry level 2-way coilovers w/ camber plates (TCK, KW, Bilstein) - $2-3k

Unlike HPDE, you don't really need extra cooling and BBK upgrade if you are sticking with autox. But they would be nice to have if you have the extra budget. If you plan on having more power down the line, just do some basic FBO mods, but I am just not sure how that would impact your car's classification.

Didn't include tires and wheels, since those are kind of given. So you can add on another $2K for that. Stick some nice and sticky 255 or 265 tires up front and dial in some extra neg. camber btw. All BMW tends to understeer more than it really should in stock configuration, for safety reasons.

FYI, a nicely modded E9x 335i can be almost just as fast as a stock F8x, and much faster than E9x M3.

[Kgolf31]

Originally Posted by Cloud9blue

$5k is probably doable if you pick the right mods.

Including labors, here is how I would break it down:
LSD - $1500
Full M3 suspension control arm swap front and back and rear subframe bushings - $1500
Entry level 2-way coilovers w/ camber plates (TCK, KW, Bilstein) - $2-3k

Unlike HPDE, you don't really need extra cooling and BBK upgrade if you are sticking with autox. But they would be nice to have if you have the extra budget. If you plan on having more power down the line, just do some basic FBO mods, but I am just not sure how that would impact your car's classification.

Didn't include tires and wheels, since those are kind of given. So you can add on another $2K for that. Stick some nice and sticky 255 or 265 tires up front and dial in some extra neg. camber btw. All BMW tends to understeer more than it really should in stock configuration, for safety reasons.

FYI, a nicely modded E9x 335i can be almost just as fast as a stock F8x, and much faster than E9x M3.

Control Arm Swap + Coilovers w/camber plates is illegal.

I think your diff price is underestimated. If you were to do it right.

LSD - $3599 (DiffsOnline 3 Clutch)
Coilovers - $3000
Wheels/Tires - $2000
Swaybar F/R - $500
Brake Pads - $250

That's a pretty minimal build.

If you're going more prep, you have to get a STU Legal Tune, Exhaust, Race Seats + Brackets, LTW Battery, CAI, Bushings...etc etc.

I don't think a 335i can compete with a F9x M3 on mod for mod, because afterall this is what we'd have to compare it to.

[Cloud9blue]

Originally Posted by Kgolf31

Control Arm Swap + Coilovers w/camber plates is illegal.

I think your diff price is underestimated. If you were to do it right.

LSD - $3599 (DiffsOnline 3 Clutch)
Coilovers - $3000
Wheels/Tires - $2000
Swaybar F/R - $500
Brake Pads - $250

That's a pretty minimal build.

If you're going more prep, you have to get a STU Legal Tune, Exhaust, Race Seats + Brackets, LTW Battery, CAI, Bushings...etc etc.

I don't think a 335i can compete with a F9x M3 on mod for mod, because afterall this is what we'd have to compare it to.

All I am saying there are more cost effective options and smarter ways to spend your budget out there, such as getting a Torsten type Wavetrac or M factory instead of an expensive clutch type diff, TRW control arms instead of M stamped ones, and etc. Of course, keep a sharp eye on for sale sections will save you quite a bit of money as well. I actually these number based from my own build, just FYI.

Mod for mod, F8x will be faster by a huge margin, no doubt, that car is 8 year newer and cost 3-5x as much as our car is worth these days, so it better be. But the keywords here are modded vs stock, which I think I was being pretty clear in my previous message. Of course, there are some stuff you just can't improve easily on our e9x platform. Such as front stance, chassis stiffness , and the DCT drivetrain.

[Kgolf31]

Originally Posted by Cloud9blue

All I am saying there are more cost effective options and smarter ways to spend your budget out there, such as getting a Torsten type Wavetrac or M factory instead of an expensive clutch type diff, TRW control arms instead of M stamped ones, and etc. Of course, keep a sharp eye on for sale sections will save you quite a bit of money as well. I actually these number based from my own build, just FYI.

Mod for mod, F8x will be faster by a huge margin, no doubt, that car is 8 year newer and cost 3-5x as much as our car is worth these days, so it better be. But the keywords here are modded vs stock, which I think I was being pretty clear in my previous message. Of course, there are some stuff you just can't improve easily on our e9x platform. Such as front stance, chassis stiffness , and the DCT drivetrain.

We're talking about SCCA Classing though, so why compare a modded car versus stock?

The E9x M3 is STU as well, and I don't even think that's a good candidate.

I don't think a Torsen is a good call for competitive AutoX, and M Factory Diffs aren't the greatest, they develop some pretty awful push issues (Thinking of a 128i that had one installed, drove a car with DiffsOnline Diff in it and instantly bought one).

TL;DR version. If you want to have fun, sure modify away. However if you're going to go to the National Level...be prepared to get another car

[Cloud9blue]

Originally Posted by Kgolf31

We're talking about SCCA Classing though, so why compare a modded car versus stock?

The E9x M3 is STU as well, and I don't even think that's a good candidate.

I don't think a Torsen is a good call for competitive AutoX, and M Factory Diffs aren't the greatest, they develop some pretty awful push issues (Thinking of a 128i that had one installed, drove a car with DiffsOnline Diff in it and instantly bought one).

TL;DR version. If you want to have fun, sure modify away. However if you're going to go to the National Level...be prepared to get another car

I didn't until you misread my post. Anyway...

Let's be real here. Op just started on autox with a bone stock 335i. Sooner or later he will realize there is no way to make this car competitive at a national level even if he has an unlimited budget. The chassis just isn't build for this sort of things...

But sounds like the guy wants to mod away anyway, so might as well give him some advice on what parts will improve the car and also won't break the bank. I doubt most people who buy a used 335 is interested in shelling out $3-5k for just a diff... IMO, things like bucket seats, cage, 2 way locking diff are relative low return mod items, while as control arms, tires, and shocks are pretty very high return mods and might not even affect the classification of the car.

And for the record, I have absolutely no problem with my Wavetrac for two years I have tracked the car with. Probably not as responsive as a clutch type, sure, but I think the $2-3k saved can be put to better use elsewhere on the car.

[Kgolf31]

Originally Posted by Cloud9blue

I didn't until you misread my post. Anyway...

Let's be real here. Op just started on autox with a bone stock 335i. Sooner or later he will realize there is no way to make this car competitive at a national level even if he has an unlimited budget. The chassis just isn't build for this sort of things...

But sounds like the guy wants to mod away anyway, so might as well give him some advice on what parts will improve the car and also won't break the bank. I doubt most people who buy a used 335 is interested in shelling out $3-5k for just a diff... IMO, things like bucket seats, cage, 2 way locking diff are relative low return mod items, while as control arms, tires, and shocks are pretty very high return mods and might not even affect the classification of the car.

And for the record, I have absolutely no problem with my Wavetrac for two years I have tracked the car with. Probably not as responsive as a clutch type, sure, but I think the $2-3k saved can be put to better use elsewhere on the car.

I read it, and realized it's not a valid point because you're not even comparing a like for like car, which is what the case is when you run IN THE SAME CLASS.

Like I said before (noting the bold statement), that Coilovers that utilize camber plates and then adding control arms is ILLEGAL. So if you want to keep on recommending things to the OP to add which will then he will sooner or later find out that he cannot run his car in STU anymore, then please go ahead.

Also, there is no mod that has a return on investment. You'll never make money.

Anyways, OP should drive his car in stock form and start to figure out what he doesn't like about the car and what he wants to change. Throwing any money at the car to add parts is no value when you don't even know what you're changing

[Cloud9blue]

Originally Posted by Kgolf31

I read it, and realized it's not a valid point because you're not even comparing a like for like car, which is what the case is when you run IN THE SAME CLASS.

Like I said before (noting the bold statement), that Coilovers that utilize camber plates and then adding control arms is ILLEGAL. So if you want to keep on recommending things to the OP to add which will then he will sooner or later find out that he cannot run his car in STU anymore, then please go ahead.

Also, there is no mod that has a return on investment. You'll never make money.

Anyways, OP should drive his car in stock form and start to figure out what he doesn't like about the car and what he wants to change. Throwing any money at the car to add parts is no value when you don't even know what you're changing

I have no idea why are you keeping trying to twist what I actually mean from my post... I think it is already pretty clear from multiple previous posts, including mine, that modding for the sake of remaining competitive is pointless on this platform. But if you just want to have a blast, there are some decent and cost effective ways to do so with these cars if you do your research.

And by "return", I mean dollar spent vs fun extracted sort of things... Come on man, didn't think I have to explain that too...

[r4dr]

You guys are both kind of missing the forest for the trees.

OP is just starting out, the only way he's going to get competitive, even locally unless his region really sucks, is to get seat time. That will not only give him a better idea of what he wants to fix, but if he actually likes autox enough to dump thousands in.

You can spend a couple grand on your car, staying in a certain class, and be "theoretically" competitive, but OP still has to have the skills to push this setup... I guarantee he doesn't have this yet.

At most OP should get some tires (especially if he's on some stock RFTs), build a basic skill set, then figure out what he wants to do if autox is something he wants to dedicate lots of $$ and time to. This could be modifying his 335i to a desired class, or starting with a different car that's going to be something he can take to nationals.

You guys bicker like a married couple!

Edit: OP, at most you should keep the classing rules in mind when you mod. But even if you go "FBO" and max it out, there will be a lot of people who can drive rings around you in the stock version of your car.

For an example, there's a guy with a bone stock E92 M3 at my local PNW autox events (except wheels + tires). His times hang out with some of the guys who are competitive nationally in whatever cars they bring. Is he FBO? No, he's an incredible driver.

[orteeze]

I'm completely aware that adding power in these events is not of any gain; seat time and a firm understanding of suspension dynamics and driving techniques will supersede. Like I posted initially, I don't want to be restrained on the modifications to my car just to stay within a class where I can be somewhat successful. Thanks for the input thus far!

[z3papa]

Originally Posted by Kgolf31

Control Arm Swap + Coilovers w/camber plates is illegal.

I think your diff price is underestimated. If you were to do it right.

LSD - $3599 (DiffsOnline 3 Clutch)
Coilovers - $3000
Wheels/Tires - $2000
Swaybar F/R - $500
Brake Pads - $250

That's a pretty minimal build.

If you're going more prep, you have to get a STU Legal Tune, Exhaust, Race Seats + Brackets, LTW Battery, CAI, Bushings...etc etc.

I don't think a 335i can compete with a F9x M3 on mod for mod, because afterall this is what we'd have to compare it to.

Probably the difference in prospective you and I versus the other posters here is that we've both been down this path, you with your Nat'l competitive 128i in STX and my less competitive Z3 in STR which has now led me to FS in a M3. About the only exception I'd make is the cost of the diff since you can get a Blanton built 3 clutch for less than Diffsonline but still pricey at $2500. It would be a tragic shame to build a 335i for STU if you wanted to make it decent. The ancillary costs of the build (seats, exhaust, etc) would be another huge chunk of $$ and would take a great driving car and make it something it's not. To the OP, once you stray out of FS, you better be prepared to put the car on a serious diet and even then, will never get it light enough or enough tire into the wheel wells to make it work the way the 350Z or Vettes due in STU. It's not just how wide of a tire you can cram in there, it's whether you can fit enough wheel to support the tire. On M3, I can easily fit 18x10 or even 18x11's on my car, whereas there is no way you can fit 18x10's up front. The key to autocross is less about hp to weight, and more about tire to weight, and the 335i is fairly piggish in that regard. On top of what's been discussed as a minimum, you'd have to be willing to pull those two anchor seats out and replace with shells.

Originally Posted by Cloud9blue

All I am saying there are more cost effective options and smarter ways to spend your budget out there, such as getting a Torsten type Wavetrac or M factory instead of an expensive clutch type diff, TRW control arms instead of M stamped ones, and etc. Of course, keep a sharp eye on for sale sections will save you quite a bit of money as well. I actually these number based from my own build, just FYI.

Mod for mod, F8x will be faster by a huge margin, no doubt, that car is 8 year newer and cost 3-5x as much as our car is worth these days, so it better be. But the keywords here are modded vs stock, which I think I was being pretty clear in my previous message. Of course, there are some stuff you just can't improve easily on our e9x platform. Such as front stance, chassis stiffness , and the DCT drivetrain.

There are more cost effective (read cheaper) modifications but the axiom I've learned the hard way was "build it right, once". I went through a cheaper set of Bilstein coilover conversions, TCKline SA, and ended with AST DA 4200's, losing money on each set as I progressed to better units. Torsen type diffs go open when one (inside) wheel is lifted. A friend in a similarly prepped STR Z4 chose the Wavetrac route citing longevity and analysis it would perform as well as my Performance Gearing 3 clutch only to watch side by side videos of runs me killing him in tighter turn arounds. That quite an expensive lesson to learn. An F8x is not classed in FS and won't be.....trust me. Until BMW 335i and M3 are allowed to run in STP, they might as well stay stock.