SCCA STX E30 Build/Introduction

[race2win]

275's

Sorry, let me clarify...anything larger than 245s isn't possible WITH STOCK FENDERS ;) 285/30-18s have been done on E30s, I'm fully aware you can fit a lot of tire under an E30, but not in STX trim unfortunately.

[Winton88]

I have been autocrossing for almost 20 years now in various cars from the stock to street modified level. I have countless local & regional victories, as well as some Divisional, National Tour & Pro Solo championships. Most of my success has been behind the wheel of Miatas, as quite simply they are the fastest & most capable autocross car there is. But I am ready for a change, & for the 2012 season I intend to prep my E30 to compete at the National level in the SCCA's STX class. I believe the E30 has what it takes to win STX, but most in the autocross community rule it out for various reasons. My goal is to document my build process here in this thread while including all of the experts here on set-up ideas, to ultimately provide an easy-to-duplicate in-expensive build that others can follow in the future :mrgreen:.

[Lof8]

My goal is to document my build process here in this thread while including all of the experts here on set-up ideas, to ultimately provide an easy-to-duplicate in-expensive build that others can follow in the future :mrgreen:.

Here in race2win's thread? It kind of souds like you are race2win under a different name?


edit: oops, thanks for the clarification

[race2win]

Here in race2win's thread? It kind of souds like you are race2win under a different name?

They quoted me but took out the "quote" part. It's just a spammer plugging a link into their signature....

Back to our regularly scheduled program ;)

[funcrew]

First, you car is very good looking. Doesn't look like an autoX car at all; you're going to need a lot of stickers to even have a shot at winning.

Second, the E30/M3 has more power and slightly better F/R weight balance than the 325i and may be able to run wider tires within STX rules. Weight is very close. So how can the 325i expect to compete where the M has failed so far? Or has no top driver seriously campaigned an E30/M3 over enough seasons to prove or disprove its competitive potential?

[race2win]

First, you car is very good looking. Doesn't look like an autoX car at all; you're going to need a lot of stickers to even have a shot at winning.

Second, the E30/M3 has more power and slightly better F/R weight balance than the 325i and may be able to run wider tires within STX rules. Weight is very close. So how can the 325i expect to compete where the M has failed so far? Or has no top driver seriously campaigned an E30/M3 over enough seasons to prove or disprove its competitive potential?

Thanks for the comments, yes some people have told me it is too nice to race, but all of my past race cars have been extremely clean examples. Might as well have a race car that not only is fast, but look great too ;)

Yes, there has been a lot of debate as to which E30 would be better, & I think most would agree with your comments. Although, I would NOT agree in regards to the M3 failing...Chris Conant has had a lot of success at the National level in his M3, including many trophies & a podium at Nationals.

The M3 has the advantage in peak power, is able to fit a little more tire, & has a better weight balance than the 325. However, the 325 has more torque & much more broad power band, is almost 2" narrower, & should be around 100 lbs lighter. Everything else is a wash between the 2 cars...

I'm not saying the 325 will be better than an M3 by any means, but I believe it can be just as good over-all, & with the pesky Civics vacating STX next year that means a good driver could put a 325 in the trophy hunt at Nationals :)

[Nsquared97]

As for the M3 vs 325 debate, isn't the gearing lower on the M3? I could be completely off on this, but it would seem that if that's the case you may have to use 3rd a lot more in a M3 than a 325.

And about having a clean racecar, my dad has always preached that a clean racecar is faster. It seems to have worked for him ;)

[race2win]

Update on my progress :D Sorry for the long read & all the pictures, hope you guys enjoy!

With a crazy work schedule the past couple of months, there has not been much time to devote to this car, but I was able to get some maintenance done, as well as some minor upgrades...

First off, brand new OEM Z3 1.9 shifter with 5-speed ZHP knob. Aslo installed all new shifter bushings, clips, lower boot, etc....



In STX, any mechanical shift linkage may be use, so the options are pretty wide open. I chose this set-up because it's a much cheaper alternative to the aftermarket set-ups such as UUC, yet still has a great feel & looks great. The knob is simply fantastic, one of the best I have ever felt in my hand!

Next, since I had to remove everything to get to the shifter, new driveshaft center bearing, guibo/flex disc, & new transmission mounts...



I also cleaned off the 23 years worth of grime off the exhaust shielding ;)


Some will say, "why not just remove the shielding?". Unfortunately, in STX we cannot remove any shielding or brackets unless it originally attached to the exhaust system. I figure I literally removed almost a pound of dirt & grime from it though...

The last thing I did was remove the sound system & alarm that the previous owners had installed in the car, plus the original cell phone brain & wiring. This required a little more work than I had originally thought....

The wiring for the amplifier was run under directly under the carpet under the front seats, & the alarm system was a rat's nest of wiring under the dash...



After I was done, I ended up removing 19.5 lbs of electronics that doesn't need to be there for autocrossing ;)



In STX, if the car came with a stereo system standard, then it needs to retain one. However, head units & speakers may be changed as long as they do not materially reduce the weight of the car. In my case, the amplifier & all related wiring were not neccessary since the 325i did not have an amplified sound system stock, & the cell phone equipment was a dealer installed option, so again I can legally remove it. I do have to have a head-unit & at least 4 speakers, so I left my Sony CD player & MB Quart speakers in the car.

I was able to complete all of this last week, just in time to take the car out for some fun autocrossing!! Details on the car's first event coming up!

[Nsquared97]

Very cool! I need to go through the wiring on my car, it's a complete mess after someone installed an aftermarket HU.

How did you get that shielding so clean?? Looks like it was just stamped out at the factory!

[SoloSol]

Sell me that amp!

[McCall]

You may be interesting in the build that the folks @ Vorshlag did for an E30 318is a few years back. They were aiming to tackle the Civics in ST but didn't get there. http://vorshlag.com/forums/showthread.php?t=5181 Sure it's a different engine and all but the suspension and chassis are the same and you might get some ideas from the thread.

I acutally own that car now('91 318is) and ran it in ST for another year after Vorshlag sold it. Feel free to ask me any questions during your build as the car is still on the ASTs with the Vomo suspension parts.

Now do I think a 325is will do well in STX? That's a big maybe. The big thing that always was a detriment to my car in ST was the lack of a LSD (not allowed). I one-wheel peeled out of pretty much every corner and that was always were I felt the time was lost to the Civics as I couldn't put the power down. The best I could usually get was within 1-1.5 seconds of a nationally competitive ST Civic driver depending on the course.

For what it's worth, my car weighted in right at 2400 lbs in full ST trim and I might have been able to get 10-20 more lbs out of it if I had gotten a bit creative. It also made about 125 whp.

Hmm, it makes me wonder if I throw in a LSD, some 245s on 8s, and maybe do something about the 200k mile motor if I should give the new STX ruleset a try...

[race2win]

First Event

This past Sunday was Round 2 of the San Francisco Region SCCA winter "Slush" series. It was forcast to be a beautiful fall day, the E30 was up & running again after completing the previously mentioned work, so even though I know the car is nowhere near competitive in it's current state I decided "what the hell" - let's have some fun!


How did it do?? Well...not bad, but not great either, overall I have work to do ;)

There were 6 drivers in STX besides me...a late model Mustang GT, a WRX, 2 drivers in a very well prepped RX8, & 2 National-level drivers in a top-level ST Civic (keep in mind it is still 2011, therefore the Civic can still run STX ). No surprise, the Civics were one-two, then one of the RX8 drivers, then me in 4th. I ended up about 2 tenths out of 3rd...or 1st non-Civic ;) However, the bigger news to me was that I was only a little more than a second off the leading Civic on a 48-second course. I know that's a lot of time, but considering how under-prepped the E30 is I now firmly believe it will compete! One of the great things about living hear in the SF Bay Area is that we have some of the fastest autocrossers in the country...if you can do well here, you can do well almost anywhere. So at least I feel I can get some meaningful information out of the results, the cars/drivers that finished ahead of me can finish well anywhere, so I was encouraged to be within striking distance.

So how did it drive? Well, as you would imagine, it's VERY soft! Vogtland springs & Bilstien Sports might feel great on the street, but they make the car painfully slow to respond & lean like crazy! This is nothing I didn't already know of course, a new (yet to be determined) suspension set-up will go in the car this winter. Positive notes are the power...the car pulled out of corners great, & the LSD diff I recently installed is working well. So well in fact I was battling power-on oversteer all day, which hurt my ability to get the power down coming off the corners...but I'll take that over inside wheel-spin or understeer any day!

What's next? First thing is to remove the aftermarket rear sway bar the car has installed. This should help plant the rear of the car on corner exit. Next will be to go through the brakes...although they weren't BAD, they were a little mushy & slow to respond at the limit. So, steel braided lines, DOT-4 fluid, & some agressive street/track pads that have good cold bite are on the menu. Those are the immediate plans before the next event, then in December (if work & family permit) it will be on to the bigger items, such as the suspension, exhaust, race seats, etc. :D

[Nsquared97]

Just a little more than a second? Honestly I find that very promising with the work yet to be done to the car. Keep us posted with the updates!

[race2win]

How did you get that shielding so clean?? Looks like it was just stamped out at the factory!

Honestly just some Simple Green (a lot actually) & lots of scrubbing. Here is what it looked like before....

Sell me that amp!

Sorry, not for sale at this time. That's a classic Soundstream 4-channel bridgeable amp with built in crossovers, I used to install those professionally back in the late 80s-early 90s. I think I am going to keep it around for my next street car project, it's a very nice sounding amp.

[race2win]

I acutally own that car now('91 318is) and ran it in ST for another year after Vorshlag sold it. Feel free to ask me any questions during your build as the car is still on the ASTs with the Vomo suspension parts.

Now do I think a 325is will do well in STX? That's a big maybe. The big thing that always was a detriment to my car in ST was the lack of a LSD (not allowed). I one-wheel peeled out of pretty much every corner and that was always were I felt the time was lost to the Civics as I couldn't put the power down. The best I could usually get was within 1-1.5 seconds of a nationally competitive ST Civic driver depending on the course.

For what it's worth, my car weighted in right at 2400 lbs in full ST trim and I might have been able to get 10-20 more lbs out of it if I had gotten a bit creative. It also made about 125 whp.

Hmm, it makes me wonder if I throw in a LSD, some 245s on 8s, and maybe do something about the 200k mile motor if I should give the new STX ruleset a try...

Hey, it's great to hear from you! Yes, I followed that build closely, before my current E30 I had a 91 318i 4-door that I was considering an ST build with. It's great to hear the car is still in competition, even if it's been an up-hill battle. No question the lack of LSD hurt the car's chances, it's too bad the ST rules only allow Viscous LSDs.

From what I remember, Terry was saying the car was in the mid-2300 lb range at one point...does it have a different tire/wheel package now or something? Still, 2400 lbs is very light, I wish I could get my 325i that low.

Put a 4.10 LSD in your car & come play with us in STX!! I seriously considered doing that with my 318i because it had a factory LSD. It would definitely be down on power, but the tire-to-weight ratio would be by far the best in STX. I wouldn't try 245s though...you would have to run 17" wheels, & even IF you could get them to fit, they would hurt gearing & carry too much of a weight penalty over 15s.

For that car I would carry 2 sets of wheels/tires...a set of 15x8s with 225/45-15 Hankook RS3s (like I am running), & a set of 15x7.5s with the 195 Toyo R1Rs (which you may already use). On heavier cars, the 195 Toyos just don't work very well, but on the lighter cars (like yours & the Civics) they have proven to be very fast...plus they are a great tire in the wet, unlike the RS3s.

The only issue with running your car in STX is that you will have to request to the STAC & SEB for it to be included in STX. The way the new rule-set works is that the cars listed are the ONLY cars eligible for National events. Locally you could run it just fine, but if you decide to compete nationally you would need to send a letter & request it be included...which I'm sure they would do.

Thanks for the offer for set-up advice, I still haven't decided on a suspension package yet, but ASTs are on my list of packages to consider. Both Doug Hitchcock & Chris Conant are on ASTs & apparently love them, I have just been on Konis for so long I have gotten used to the way they feel & work. I am also considering a custom Bilstien set-up, I am good friends with the owner of Fat Cat Motorsports who is a Miata/Bilstien suspension Guru. The E-Stock Miata I was co-driving earlier this year is on some Fat Cat Bilstiens, I REALLY like how those shocks work & feel. His shocks have been on more National Champion Miatas that I can count, I was talking with him at this past Sunday's event about shocks & he really wants his shocks in my car...he just hasn't done very many BMW set-ups in the past. More to come on that, stay tuned!