Official E30 DSP Thread.

[E30 Racer]

18's with 265/30/18 street tires with a flared E30 would look good on the street too, should I decide to keep the car on 15's for competition.

Will it look nice? You bet. But the turning radius and ride quality will suck. Also, keep in mind 285s are over $300 each, and one of the reasons Alex is so fast is frequent tire replacement.

Good luck. See you at the Toledo Pro or Peru NT?

[joshh]

Speaking of Alex and 285's vs 275's. I read a report that Patrick's Subaru beat him by 8 seconds???? This can't be right. Can someone or Alex explain what really happened?

[alex]

Speaking of Alex and 285's vs 275's. I read a report that Patrick's Subaru beat him by 8 seconds???? This can't be right. Can someone or Alex explain what really happened?

Huh? Wanna share the source?

[DSP74]

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[alex]

Alex what kind of usefull life are you seeing out of the Hoosier 285's? How about how many runs before they are DEAD?

I don't know. I sell them after 20-30 runs, sometimes sooner.

The set I sold to Tom Bleh in 2006 for his E36 is still on the car after many events on various surfaces.

[DSP74]

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[joshh]

Huh? Wanna share the source?

Never mind. You were driving an M5 on street tires. My mix up. Sorry.
I knew there had to be something wrong with that...and I had my sites mixed up.

[alex]

Never mind. You were driving an M5 on street tires. My mix up. Sorry.
I knew there had to be something wrong with that...and I had my sites mixed up.

http://sccaforums.com/forums/5/284627/ShowThread.aspx

[alex]

To put into perspective however, how many local events do you run. I know several fast guys do not run many local events.....And keeping fresh tires at big events is obviously much more important.

Last season I ran a lot of evens with Boston BMWCCA. Same lot as used for Devens National Tour. Judging from the tire wear I could probably run close to 100 events on that lot and still have some tires left.

Best way to tell is to do a side by side test.

Quit wasting your time on the boards and go drive some, will ya?

[rsafier]

Will it look nice? You bet. But the turning radius and ride quality will suck.

Yeah driving the big wheels was a MAJOR adjustment. It took me 2-3 T&T events before I figured out how to make the car turn in anything slightly tight. And grid is really very annoying if its packed, lots multipoint moves because you can't turn much without slamming into your inner fenders (I could get 1 turn on a 2.7 turn rack before I hit).
I wouldn't want to run anything nearly that wide on the street.

I still have the Porsche 18x10 setup if you wanna try it out for cheap this season. hint...hint...nudge...nudge.... I need to get rid of this stuff so I can reclaim some garage space.

[Fair!]

Speaking of Alex and 285's vs 275's. I read a report that Patrick's Subaru beat him by 8 seconds???? This can't be right. Can someone or Alex explain what really happened?

Yea, Pat won SMOD by a lot... in a DSP Subaru AWD car with no power... he looked unusually fast. The Surface at the TMS Bus Lot used at the recent Ft. Worth 2008 SCCA National Tour (link to pics) is super slick so AWD cars had a big advantage, plus it was cold as hell. 2 driver cars had a distinct advantage, as did heats running later in the day when it warmed up from 48° in earliest the morning runs. I ran early and with no co-driver, which hurt my times... running 315mm rear tires in a 2475 pound car doesn't get any heat in the tires! :( Still, the two competitors in my class using an AWD Subaru STi on 235mm wide slicks were still way off, time-wise, so the "narrower is better" tire theory didn't help them. ;)



As for lack of turning radius... well, just make sure you allow for enough turning angle on the wheel set-up you run. Our E36 has a stock rack (well, the faster Z3 rack) and with 17x10s and 275/40/17s or 18x10s and 285/30/18s up front we've managed to keep the tires from rubbing at full lock and kept every bit the steering angle inherent in the BMW rack. So our turning radius should be close to stock... other than the track width that is added (minimized to about 2 millimeters of clearance everywhere!). Took a lot of checking, cutting, hammering, rolling and flare work to get that, of course.

That's not an E30, which is a lot more cramped up front...

[DSP74]

Wow!!

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[GotCone?]

but how are you guys addressing the lack of toe/camber adjustment in the rear? going lower for DSP to me this seems like the biggest limitation. Can't do slotted eccentrics on the subframe or anything... only offset bushings which don't do a whole lot. excessive rear toe out IMHO is a rather large limitation for the car.

I also strongly feel the 275-15 Hoosier on a 15x10 is the best route. With the right spring rates, and perhaps some fender trimming, one can get the car quite low, with great gearing and be fast. I wouldn't be surprised of some of the E36 DSP guys don't at least try for the 15's. I know I'll be test fitting a set on my E30 from a friends CSP miata (w/ spacers of course) just to see how well it will work. But I'm not bothering w/ competiting in DSP w/ the E30... it's being built for track use.


Fair... when you say Pat's car has 'no power' can you elaborate? I've seen his dyno plot and have a very similar one (minus a few ft. lbs... darn cat) from the STS 2.5 RS I've campaigned in. Just curious what your definition of 'no power' is.

I've also had the chance to drive Pat's DSP RS in '07 in rage and it's blisteringly quick. It was at the Subaru Challenge in Kansas City. :D my first time in his car and ever on r-comps, but I've driven a many Subaru's in my day.

[DSP74]

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[rsafier]

I had a low car on big tires and the camber was fine, about 2* perhaps 2.5* negitive in the rear. You have enough tire the lessened traction isn't a big deal and helps even out the wear some. I had zero adjustment in the rear, I don't true eccentric bolts, at least on my Vettes they would get out of wack very quickly after a couple autocross events even torqued to crazy high numbers.