SCCA STX E30 Build/Introduction

[race2win]

Not a dumb question at all. Main reason is the only LSD's allowed in ST are OEM viscous type, and the OEM LSD's that BMW used are clutch type. For this reason the 325is isn't allowed in ST.

Exactly, Viscous LSDs only in ST. That being said, a car like mine (325i) could still run ST in the past since it came with an open diff. Technically, right now, my car can run both ST & STX in the same day/event...just swap out the diff.

As I have mentioned before, this will all be changing starting 1-1-2012, class hopping will be eliminated. Only cars specifically listed are able to run that class, & all E30s will be listed in STX regardless of model, diff, options, etc. Now, that doesn't mean you can swap pieces around to build the perfect E30...that would be Street Prepared ;)

Honestly though, you wouldn't want to run ST anyway...I know it doesn't seem like it, but ST is a faster class. That class is dominated by sub-2000 lb EF Civics...on a twisty autocross course, heavier cars such as most BMWs just can't keep up. Check out the STX results from this past Nationals...the top 4 or 5 cars were ST prepped Civics, & the top finishing BMW was well more than 2 seconds back!

STX is going to be a great class in 2012, a lot of top drivers are building a wide range of cars, now that the Civics can't crash the party more people (myself included) are willing to try new ideas. At next year's Nationals the top 10 in STX could include E30s (325i/is & M3), E36s (325 & 328i/is), Mazda RX8, Subaru WRX, Mazdaspeed3, Lexus IS300, Integra Type R, Mustang GT 5.0 (both new & old), & even a 67 Camaro Z28!! I have heard of potential builds being planned & completed on every one of those cars listed, it should be a very entertaining class!

[Nsquared97]

Great thread, thanks for doing this; I'm following closely.

Dumb question here I'm sure, I must be missing something. But, why not run in ST? Just looking at the 2011 rules here (maybe 2012 is different): http://www.scca.com:8090/documents/2...lo%20Rules.pdf

On page 175, it has BMW 3 series (non M) listed under ST and says normally aspirated up to 3.1 liters.

They do have the E30 M3 listed in STX.

Not a dumb question at all. Main reason is the only LSD's allowed in ST are OEM viscous type, and the OEM LSD's that BMW used are clutch type. For this reason the 325is isn't allowed in ST.

[Cinnabar325is]

Great thread, thanks for doing this; I'm following closely.

Dumb question here I'm sure, I must be missing something. But, why not run in ST? Just looking at the 2011 rules here (maybe 2012 is different): http://www.scca.com:8090/documents/2...lo%20Rules.pdf

On page 175, it has BMW 3 series (non M) listed under ST and says normally aspirated up to 3.1 liters.

They do have the E30 M3 listed in STX.

[race2win]

Here's the car in action at a National Tour-

Great looking car! I really miss my old 318i, it felt so much more nimble & light on it's feet than the 325i...just no torque what-so-ever:(

As far as tires, I’ve run 225 R1Rs, 215 Yokos, and finally the 225 RS3 on my 15x7.5 Rota Slipstreams. The RS3s were by far my favorite, followed by the Yoko. I'm just not a fan of the Toyos and it probably is because of the weight of the car. Also, you are probably right about the 245s not fitting. With some 8" wide wheels and some aggressive ST-legal rolling I could probably squeeze 235s but it would be tight with my ride height. 225s on 8's is probably the best combination.

As long as the temps are above 70*, no question the 225 RS3's on 8s will be best. However, if it rains, or is even cold out, they do not work very well at all...they NEED heat to work best. The Toyo R1R's are best when wet and/or cold, & the Yoko's & Dunlop Star Specs are in the middle...pretty much GOOD in all conditions but not the best in any particular area. To run a 235-wide tire, you would need to run a 17...I'm just not sure it would be worth the weight penalty to run those over the 15s. However, my plan is to test some 17x8s wrapped in 235/40-17 Dunlop Star Specs...

You mention the 225 R1R's...have you tried the 195s? That particular tire has a different tread compound than other sizes, this is why all the ST Civics use them. At your car's weight, they just might work, if I had your car I would try them.

Regarding class hopping, I believe I can. Here's what FasTrack just said-

Street Touring Xtreme (STX)
BMW 3-series (E30 chassis, including M3)


Of course there was this earlier this year from the Feb 2011 FasTrack-

Limited Slip Differentials – Option #1:
Status quo, no change to 14.10.K.
Note: Maintains parity by limiting the advantage of higher horsepower cars in
both ST and STS. If cars need to be down-classed in the future, then
competitors may have to remove LSDs.

Limited Slip Differentials – Option #2:
Modify 14.10.K to apply the existing STR/STX/STU LSD allowance to all ST
classes.
Note: This would minimize the LSD-removal impact of any future downclassing
of cars, at the expense of an immediate upgrade for most
current ST/STS competitors. Street Touring is premised as a bolt on
category and aftermarket diff installation is not generally bolt on. LSDs
are not available for many of the newer target ST cars which may hurt
diversity. May require moving some cars to different classes than those
listed in the above proposal to compensate for the addition of an LSD


I believe as of the Oct issue, Option #2 has been choosen but I'm just not sure yet. So if the LSD option #2 is good, I could actually get a LSD (hello OS Giken!) and heck that alone might make it worth it to go after God's Chariots (ST Civics) again. A Metric Mechanic ST-legal refreshed motor would go a long way as well. Who ever said autoxing at a National level was cheap!?! :D

That version of Fastrack is fairly old, they ended up keeping status-quo in regards to differentials. STC, STF & STS are OEM Viscous LSDs only, the rest get any LSD unit. For you (& myself) I honestly do not see the need to go with an aftermarket diff...just bolt in a good rebuilt S4.10 diff & call it good. You would have a hard time convincing me that an OS Giken, KAAZ, etc diff would be a significant improvement on the clock over a good BMW LSD diff...especially on anything with less than 200 WHP.

Most of the proposals in regards to Street Touring are still in the BOD's hands & not 100% official yet. There is one thing for sure though, as of 1-1-2012 class-hopping will be a thing of the past in the Street Touring category. Only cars specifically listed are eligible to compete in each class...so for you, & every other E30 in existence, STX it is :D That being said, I still think a 91 318i/is could be a dark-horse, especially at 2300 lbs !

[SoloSol]

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.

Too bad. I also appreciate this amp for what it is. Having installed and owned many of them in the past. Enjoy.

On topic
You mention removing the rear bar? In my head thats because you want less inside tire lift = more exit traction

[McCall]

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.

Here's the car in action at a National Tour-




Yes, the no LSD in ST really ended up being the downfall of the car. Regarding the viscous diff, remember it had to be factory installed in that model of car. I'd thought about dropping a 325ix viscous diff in the car but that was a non-starter with the rules makers. ;)

Regarding the weight, you are right. I forgot the last time I weighed the car I had added a 60lb 4-point roll bar for track days. So she could be down to sub 2340 easy if I put it back to full autox trim. Again, if I were to take the extra time, I’m sure I could get the car close to 2300lbs.

As far as tires, I’ve run 225 R1Rs, 215 Yokos, and finally the 225 RS3 on my 15x7.5 Rota Slipstreams. The RS3s were by far my favorite, followed by the Yoko. I'm just not a fan of the Toyos and it probably is because of the weight of the car. Also, you are probably right about the 245s not fitting. With some 8" wide wheels and some aggressive ST-legal rolling I could probably squeeze 235s but it would be tight with my ride height. 225s on 8's is probably the best combination.

Regarding class hopping, I believe I can. Here's what FasTrack just said-

Street Touring Xtreme (STX)
BMW 3-series (E30 chassis, including M3)


Of course there was this earlier this year from the Feb 2011 FasTrack-

Limited Slip Differentials – Option #1:
Status quo, no change to 14.10.K.
Note: Maintains parity by limiting the advantage of higher horsepower cars in
both ST and STS. If cars need to be down-classed in the future, then
competitors may have to remove LSDs.

Limited Slip Differentials – Option #2:
Modify 14.10.K to apply the existing STR/STX/STU LSD allowance to all ST
classes.
Note: This would minimize the LSD-removal impact of any future downclassing
of cars, at the expense of an immediate upgrade for most
current ST/STS competitors. Street Touring is premised as a bolt on
category and aftermarket diff installation is not generally bolt on. LSDs
are not available for many of the newer target ST cars which may hurt
diversity. May require moving some cars to different classes than those
listed in the above proposal to compensate for the addition of an LSD


I believe as of the Oct issue, Option #2 has been choosen but I'm just not sure yet. So if the LSD option #2 is good, I could actually get a LSD (hello OS Giken!) and heck that alone might make it worth it to go after God's Chariots (ST Civics) again. A Metric Mechanic ST-legal refreshed motor would go a long way as well. Who ever said autoxing at a National level was cheap!?! :D

Good luck with your build and I'll be following your progress.

[JeremyE30autox]

Then your good!

[race2win]

Solid mounts on the transmission are not allowed in stx

Correct...I did not install solid mounts, they are OEM rubber replacements ;) The lighting in that picture does make them appear metallic, here is a pic of them next to the old ones...

[JeremyE30autox]

Solid mounts on the transmission are not allowed in stx

[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!

[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.

[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]

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

[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...

[SoloSol]

Sell me that amp!