Building e30 to IT spec for DSP autox?

[Jean]

A SM E30 is a car that only has to be 2300lbs with a 2.5l or 2340 with a 2.7l. Consider this. DSP and ESP are VERY close to exactly the same speed. There isn't a decent ESP car around that doesn't put close to or over 300hp to the wheels and well more torque than that. Fully prepped ESP 4th gen f-body should weigh around 3300lbs, and fully prepped DSP E30 should be around 2600 maybe a little less.

Remember they are already equal in speed on course. Now double the HP (at least with turbocharging) of the E30 and drop another 300lbs off the car too, and you'll see how a SM E30 should be just as competitive with any other SM car..............

I am going to read the 2007 rulebook again, I saw the weight vs. engine displacement paragraphs but somehow didn't see this limitations if you are staying NA. If what you just posted true, then I am going in a completely wrong direction with my goal of putting m30b35 into my 84 318i sm car....

[joshh]

I don't think it is.
I think that for now the surface at KMP tends to reward lighter smaller cars or cars with alot of traction (AWD) because of the lack of grip vs seasoned concrete.

Some folks seem to think that the current top E30 is much stronger power wise than other E30's. Maybe others just need to build a MAX S/P engine. I have heard from a VERY reputable source that the current DSP champ car isn't a maxed out S/P car by any means. I'm guessing Mike Shields doesn't ever visit this site.

Completely maxed to the limit of the rules, (which is what the cars should be for comparitive purposes) the E36 is DEFINATELY the better car.....

Now in SM the cars are much, much more equalized. And FWIW everyone talks about crappy rear suspension on the E30's but most shortcoming are fixable and/or nonexistant with the spring rates, and ride height used on a S/P or SM car.

Someone is pulling your leg. The top DSP cars are almost or are maxed out for SP rules. Having data acquisition systems and all. If you read through the rules for DSP, there really isn't all that much to do, it's just the cost of the parts. Even my Integra is about 75% there. Other than the 275's of course.

[xLibelle]

DSP e30 winning equation:
-start with early model 2-door and euro bumpers.
-no tar in trunk, stripped otherwise lightweight battery there tho.
-late model non-is interior, driver & passenger seats replaced with light weight race, manual windows.
-smaller steering wheel, extended shifter with shorter throw.
-radio and AC delete, no ABS, manual rack, NO options, no sunroof, nothing.
-m20b25 engine bored out to spec, parts bin balanced internals.
-custom plenum to ITB's with EL straight pipe exhaust.
-port matching and expansion up to 1 inch in and out of the head.
-stand alone programable ecu, larger injectors, direct coil spark, timing sprocket
-50% LSD, i think quaife is legal
-m3 aluminum arms with fully adjustable cam & cas.
-choice springs & shocks & sways
-stock rotors with sticky pads (maybe a slight upgrade but keep weight down)
-aluminum 15x9 with 275 all around, body modified to house them (max 2" each side)
-get thin mod

did i miss anything?
everything else like acq systems is a part of planning or just extra weight.

[JGood]

did i miss anything?
everything else like acq systems is a part of planning or just extra weight.

You forgot to mention that you should leave the antenna in the down position to lower the center of gravity.

:)


EDIT: When I bought my new quarter panel from BMW, it didn't have an antenna hole... Maybe there is an allowed antenna removal for a update/backdate? Shit, this could get the e30 back on the charts!

[DSP74]

DSP e30 winning equation:
-start with early model 2-door and euro bumpers.
-no tar in trunk, stripped otherwise lightweight battery there tho.
-late model non-is interior, driver & passenger seats replaced with light weight race, manual windows.
-smaller steering wheel, extended shifter with shorter throw.
-radio and AC delete, no ABS, manual rack, NO options, no sunroof, nothing.
-m20b25 engine bored out to spec, parts bin balanced internals.
-custom plenum to ITB's with EL straight pipe exhaust.
-port matching and expansion up to 1 inch in and out of the head.
-stand alone programable ecu, larger injectors, direct coil spark, timing sprocket
-50% LSD, i think quaife is legal
-m3 aluminum arms with fully adjustable cam & cas.
-choice springs & shocks & sways
-stock rotors with sticky pads (maybe a slight upgrade but keep weight down)
-aluminum 15x9 with 275 all around, body modified to house them (max 2" each side)
-get thin mod

did i miss anything?
everything else like acq systems is a part of planning or just extra weight.

You got the idea yeah, but I'll go through it anyhow because I'm bored.
-Two door-yes but I'd stick to plastic bumpers. So I'd opt for a low optioned 88 since plastic bumpers can be bolted right up without body modifications.
-a good fitting drivers seat and a kart passenger seat with upolstery (if this is still legal)
-I'd keep the stockish size wheel IMO. And a smaller wheel with manual steering would be unmanageable by me, and I'm a stout guy....good god that would be brutal.
-No AC, radio/speakers, a sunroof car with it removed (lighter and more practical a find), KEEP THE ABS
-right on with the engine.
-no way would I lose the stock intake for ITB's. The engine lacks torque as it is. KEEP the long runner intake.
-I used to be on the fence here. ECU mods were very expensive for little gain. Since I've changed positions a bit. I say go with megasquirt, and stock distributer ignition setup with add on MSD ignition.....
-I'd go with a 10" wheel.
-M3 arms are not legal...

[Elephant]

Is a roll cage really a hinderance? I don't autocross and know little about it really but these chassis (and the design) are well over 20 years old and suspension efficiency suffers....at least on the track it makes a huge difference, transforms the car into something almost completely different. I dunno the rules well enough but it seems like it would be helpful.

[DSP74]

I think what you would gain in chassis stiffness would be far outweighed by the extra weight. In a track car that has a cage usually has more open rules that allow removal of things that are able to offset the weight of the cage. In most autox classes you don't have those allowances.

[rwh11385]

DSP e30 winning equation:
-start with early model 2-door and euro bumpers.
-no tar in trunk, stripped otherwise lightweight battery there tho.
-late model non-is interior, driver & passenger seats replaced with light weight race, manual windows.
-smaller steering wheel, extended shifter with shorter throw.
-radio and AC delete, no ABS, manual rack, NO options, no sunroof, nothing.
-m20b25 engine bored out to spec, parts bin balanced internals.
-custom plenum to ITB's with EL straight pipe exhaust.
-port matching and expansion up to 1 inch in and out of the head.
-stand alone programable ecu, larger injectors, direct coil spark, timing sprocket
-50% LSD, i think quaife is legal
-m3 aluminum arms with fully adjustable cam & cas.
-choice springs & shocks & sways
-stock rotors with sticky pads (maybe a slight upgrade but keep weight down)
-aluminum 15x9 with 275 all around, body modified to house them (max 2" each side)
-get thin mod

did i miss anything?
everything else like acq systems is a part of planning or just extra weight.

what rulebook are you reading?

[DSP74]

actually everything on his list was legal except the M3 arms.

[rwh11385]

actually everything on his list was legal except the M3 arms.

really? what rulebook are you reading then as well?

"O. Sunroof-equipped cars may be converted to a solid-roof configuration
provided a model without a sunroof is listed on the same
line in Appendix A."

What 325i had a no sunroof option? 16V 3 series is a different line.

M3s are not in the same line so are illegal as you mentioned with control arms
What 325i had manual windows in the US?
ABS rule in SP: "ABS braking systems may be disabled, but not removed"
If you want to go manual rack, that's a Euro option IIRC and then that's SM territory

[DSP74]

I'd have to double check but I thought all sunroof cars could be converted. Maybe I read that in a fastrack....or maybe that's SM.
Manual rack yeah probably not but I automatically discounted that as maniacal. It doesn't have to be JUST a 325I. Any e30 L6, is on the same line. There were budget model 325's with manual windows. There is a 325E just down the road with manual windows a guy wants $100 for and it has a good body. But the interior is ratty and blue, and the exterior is white.....no good to me.

[rwh11385]

The bold quote is directly from the SP rule section.

Is the 325e local a US model? Do you have records of it being sold with manual windows? More important than finding one example is the proof you'd need to show it existed and is on the same line so you can backdate. SCCA = PITA

[DSP74]

actually burden of proof is on the protester....No I don't have proof it's a US model but with sales lit, it shouldn't be that hard. Again, the burden of proof isn't on the protestee.

[DSP74]

To clarify the things I mentioned were legal on the list was the list I revised. The ABS cannot be removed nor should it be.....

I stand corrected on teh wording, but am not willing to give up on a non-sunroof car availability.....I'm betting some cheapie 325's didn't have them. All you'd need is a sales brocure listing the sunroof as an option.............

[Elephant]

I think what you would gain in chassis stiffness would be far outweighed by the extra weight. In a track car that has a cage usually has more open rules that allow removal of things that are able to offset the weight of the cage. In most autox classes you don't have those allowances.

Do you have to meet a minimum weight for the class? If so, is it not possible to remove enough weight to make up for the cage? Even a basic cage with some well placed gussets will GREATLY improve the chassis stiffness of an E30. This in turn will greatly improve the efficiency of the suspension. It will allow you to run an overall softer set up but still achieve the same "feel and response" as running a much stiffer set up.

One benefit to this is that your straightline and quick transition cornering will improve while maintaining or even improving your high load cornering.

Cheers.