Legality of crank swaps

[JS154]

How do you figure? There is no build restriction placed on any 3.0L BMW engine in STU. The E36 M3 3.2L engine has to run stock cam lift (not stock cams) this year because the class displacement limit is currently 3L; however, that engine will be allowed to run uncorked next year (@3520# pounds) when we raise the displacement limit to 3.2 liters for 2012...

I believe our plan is to leave that current engine build restriction in Table A for 2012 to accommodate a Spec E36 classing request, so you can build it either way, whichever you prefer. - GA

Correct on wording regarding stock camshaft LIFT.

BMW E36 M3 (95-99) max displ 3200 min weight 3200
Engines are permitted 0.040 overbore, 0.5
point increase in compression.
Engines must use the OEM camshaft lift.

'95 was the 3.0L
'96-99 was the 3.2l


With that table, is there anything stopping someone from dropping a 3.2L S54 into an E36 M3 right now, overboring and bumping compression 0.5?

The only limit is on max displacement it seems, for the E36M3, which is a chassis. Nothing stopping anyone from putting a built S50 (3.0L USDM engine) into an E30 bmw and going nutzo with cams and upping compression and such...that will be 290 at the wheels easy in that case.

If this isn't class creeep I don't know what is. If that's the intent, so be it, but it would be wise then to also do something along the lines like make STL a National class and bump the displacment limit to under 2500cc, to give all the current STU cars. Or perhaps just leave the class alone for a little while. Rules stability is important, lack of rules stability was a huge problem for BMW CR for a number of years and the result was significantly declining participation from 2002-2007.

Increasing the class displacement limit to 3.2L is solving what problem that presently exists? That opens the door to the E46 M3 with the S54 engine and the Acura NSX with the C32B engine, just off the top of my head.

[JS154]

I believe our plan is to leave that current engine build restriction in Table A for 2012 to accommodate a Spec E36 classing request, so you can build it either way, whichever you prefer. - GA

SpecE36 (BMW CR) already fits in STU, stock 2.5-2.8L engines, stock brakes and transmissions at just under 2700# IIRC. A great car for ITR, and a field filler for STU even at it's present weight. with the 1.1 ratio it will become a backmarker in STU.

Well prepped and well driven they turn high 2:13's low 2:14's at the Glen, which is 5-6 seconds/lap off this years STU leaders.

[Greg Amy]

The S54 engine has no business being in STU.

300 whp is NOTHING in STU. With a weight of ~3500# a 3.2L engine can put out somewhere around 385 crank and still be within the class goals (a guesstimate; I don't have the exact numbers).

You guys need to realize that STU ain't no "let's just cobble something together and go racing" kind of class. STU is a "let's compete in World Challenge GTS-caliber cars". If you're not happy competing against a RealTime Racing-quality Acura TSX, or a Stasis-quality Audi A4 turbo AWD, or a BimmerWorld-quality BMW E46 M3, then you are going to be very frustrated and very unhappy in STU.

I'm not trying to be an ass. We most assuredly welcome your participation in STU, but you need to "level-set" your expectations with that mindset.

GA

[Greg Amy]

...is there anything stopping someone from dropping a 3.2L S54 into an E36 M3 right now, overboring and bumping compression 0.5?

Yes, the class does not currently allow 3.2L engines, except as per that table. And, as per the opening philosophy, you cannot take an engine from that table and install it into any other chassis.

However, the class displacement limit will be bumped to 3.2 in 2012 (assuming BoD approval, which I wholly expect) so it will be legal for next year. And if someone does it, jesu kristy I'd love to watch that!

Nothing stopping anyone from putting a built S50 (3.0L USDM engine) into an E30 bmw and going nutzo with cams and upping compression and such...that will be 290 at the wheels easy in that case.

Correct. See above "jesu kristy".

If this isn't class creeep I don't know what is.

It isn't creep. It's the exact philosophy and intent of the class, the kind of thinking and engineering we're encouraging for STU.

This is STU. See post above.

...it would be wise then to also do something along the lines like make STL a National class...

Ah, a man with own heart. Help promote it, send emails to your reps, encourage people to double-dip in STL to get its numbers up.

... and bump the displacment limit to under 2500cc...

Nope, sorry. STL was created for two basic purposes: one, because there was no way to get sub-2L car light enough to make them competitive in STU; and two, to have a lesser prep version a la the current World Challenge Touring.

If it's your contention that 2L-2.5L cars are in the same boat as STL, where they can't get light enough or be allowed enough mods to compete with 3.2L full-tilt-boogie cars, then that's another matter entirely. The resolution for that may be another class, though given STL's difficulties with getting National status I'd not hold out hope for that. But if you can demonstrate that a full-tilt-boogie (ftB) 2.5L car cannot EVER put out as much power-per-cc as a ftB 3.2L car, no matter how much money is tossed at it, then you'd have a leg to stand on. But I've not seen anyone try, so it's hard to gage.

Or perhaps just leave the class alone for a little while.

That's where we are now. We spent a lot of time on the class this year trying to figure in how we were going to merge in WC cars, and how to handle forced induction, and to get a general philosophy hashed out and published so that we have a strong foundation for going forward. I'd like to think we're there (if you think differently, speak up; we're listening). There are NO (none, zip, zero, nada) major changes in the works for STx, the only thing we expect to see going forward are classification and allowance requests.

Increasing the class displacement limit to 3.2L is solving what problem that presently exists?

To discontinue the consistent requests for 3.2L cars as specific allowances, cars that we think fit within the performance goals of the class. The S54 fits within that expectation and is weighted at the same 1.1#/cc as all the other cars.

SpecE36 (BMW CR)...a field filler for STU

I concur. Do not read in those allowances as expectations of competitiveness. They are, for the most part, responses to specific requests for inclusion. "Sure, come play in the pool, but don't expect to win." Same goes for IT cars, Spec Miatas, TDI Cup cars, etc.

GA

[Z3_GoCar]

300 whp is NOTHING in STU. With a weight of ~3500# a 3.2L engine can put out somewhere around 385 crank and still be within the class goals (a guesstimate; I don't have the exact numbers).

You guys need to realize that STU ain't no "let's just cobble something together and go racing" kind of class. STU is a "let's compete in World Challenge GTS-caliber cars". If you're not happy competing against a RealTime Racing-quality Acura TSX, or a Stasis-quality Audi A4 turbo AWD, or a BimmerWorld-quality BMW E46 M3, then you are going to be very frustrated and very unhappy in STU.

I'm not trying to be an ass. We most assuredly welcome your participation in STU, but you need to "level-set" your expectations with that mindset.

GA

Ha, that's only 15/20 hp more than the oe CSL, it's still got at least another half point of compression, intake/exhaust port jobs, removing the remaining cat's and mufflers, and the intake work left to make more than that.

You should have access to the World Challenge VTS horsepower results. The VTS I have doesn't list the hp:

http://www.world-challenge.com/inclu...dc1f09a88ab97c

[Z3_GoCar]

Ha, that's only 15/20 hp more than the oe CSL, it's still got at least another half point of compression, intake/exhaust port jobs, removing the remaining cat's and mufflers, and the intake work left to make more than that.

You should have access to the World Challenge VTS horsepower results. The VTS I have doesn't list the hp:

http://www.world-challenge.com/inclu...dc1f09a88ab97c

Chuck Stickley's already got 400hp from his S-54:

http://forums.bimmerforums.com/forum...t=stickley+s54

[Greg Amy]

Chuck Stickley's already got 400hp from his S-54

The one described as "...over 400whp on a 3.4l stroker s54 that revved out north of 8500. I remember him saying it cost a ton, somewhere near $40k though."? Doesn't sound STU-compliant to me...

All the other non-turbo S54 engines and dyno charts there are indicating 350-ish. At ~3500# sounds like a good STU fit.

[Z3_GoCar]

The one described as "...over 400whp on a 3.4l stroker s54 that revved out north of 8500. I remember him saying it cost a ton, somewhere near $40k though."? Doesn't sound STU-compliant to me...

All the other non-turbo S54 engines and dyno charts there are indicating 350-ish. At ~3500# sounds like a good STU fit.

That's 350 with stock cams, which are open, and without head polish/porting. The right oe cams and it's another 10 hp, without even resorting to pulleys, or overdriving the two dry sump stages, which are prefectly STU legal.

[Greg Amy]

IMO, to me it still sounds within the philosophy and intent of STU...if you disagree, I encourage you to send a letter to the CRB/STAC, we'll definitely discuss it. - GA

[Z3_GoCar]

IMO, to me it still sounds within the philosophy and intent of STU...if you disagree, I encourage you to send a letter to the CRB/STAC, we'll definitely discuss it. - GA

Check this out:

http://store.vacmotorsports.com/vac-...px?Thread=True

15-20hp gain over a CSL air box, that'd put it right at 370-380hp without any internal blueprinting, compression bump, or even underdrive pulleys. I think we've got the motor to have here.

[Mrsideways]

Check this out:

http://store.vacmotorsports.com/vac-...px?Thread=True

15-20hp gain over a CSL air box, that'd put it right at 370-380hp without any internal blueprinting, compression bump, or even underdrive pulleys. I think we've got the motor to have here.

I thought we were gonna try to keep Independent throttle bodies out of STU. I realize they come stock on the S54's but just sayin

[JS154]

The one described as "...over 400whp on a 3.4l stroker s54 that revved out north of 8500. I remember him saying it cost a ton, somewhere near $40k though."? Doesn't sound STU-compliant to me...

All the other non-turbo S54 engines and dyno charts there are indicating 350-ish. At ~3500# sounds like a good STU fit.

The S52 is 3152cc.

The S54 is 3246cc, which makes the whole concern moot. The S54 is too large for STU, even if 3.2L becomes the rule for 2012.

[Z3_GoCar]

The S52 is 3152cc.

The S54 is 3246cc, which makes the whole concern moot. The S54 is too large for STU, even if 3.2L becomes the rule for 2012.

Nope, it's still a 3.2 as per the STCS:

I

.

Weights and Engine Allowances

Minimum weights for cars with normally aspirated piston engines will
be determined by 1.1 lbs/cc displacement for the installed engine (see
following table). Displacement is the factory displacement for the installed
engine. For

the purpose of weight assign ment, engine displacement will
be rounded to the nearest 100cc (e.g., 2150cc = 2200cc and 2149cc

= 2100cc).

[Mrsideways]

The one described as "...over 400whp on a 3.4l stroker s54 that revved out north of 8500. I remember him saying it cost a ton, somewhere near $40k though."? Doesn't sound STU-compliant to me...

All the other non-turbo S54 engines and dyno charts there are indicating 350-ish. At ~3500# sounds like a good STU fit.

The problem is as you get faster weight means less. If you were doing a drag race from 120-150mph would you take the 2000lbs car with 200 hp or the 3500lbs car with 350hp (given they both had the same CoD)? I think the saving grace in all this HP to weight is that a 3500lbs car on 8 inch wide wheels aint gonna stop very well.

[Matt93SE]

Yeah, good luck getting a set of 245/45/17 Hoosiers to last a 30+min race on a 3500lb car with 350hp.

[JoshS]

The T2 Camaros did it, and that was with crappy camber too. But they complained a lot about it.

[JS154]

Nope, it's still a 3.2 as per the STCS:


I

.
Weights and Engine Allowances

Minimum weights for cars with normally aspirated piston engines will

be determined by 1.1 lbs/cc displacement for the installed engine (see

following table). Displacement is the factory displacement for the installed

engine. For

the purpose of weight assign ment, engine displacement will

be rounded to the nearest 100cc (e.g., 2150cc = 2200cc

and 2149cc
= 2100cc).

Correct, but the rule specifially states "for the purposes of weight assignment".

it does not say that calulation is to be used for engine displacement eligibilty.

Reading the proposed rule strictly, "up to 3.2L" = 3200cc.

So the question then is what is the 3.2l cutoff? Is up to 3200 actual cc the ceiling for eligibility, or is 3200 calculated cc the cutoff? If the latter, the limit is really 3.249 litres, not 3.2litres.

The wording also says "displacement is the factory displacement". 3246cc is greater than 3.2l

for example: 5.0l (old old trans am limit) - Ford 302, Chevy 305. "5.0l" engines, but both were under the 5000cc limit.

I guess my point is the actual displacement limit should be clarified, assuming the proposed rule is adopted.

[Z3_GoCar]

My guess is the e-46 generation M3/S-54 is being brought into STU, because STU is being alighned to world challenge GTU, where this generation M3 and some of the pony cars are.

[Greg Amy]

My guess is the e-46 generation M3/S-54 is being brought into STU...

Don't overthink this. The car is NOT "being brought in", it just so happens to have a displacement that meets our stated philosophy for the class. And the philosophy for the class was changed from 3.0 to 3.2L because of the number of requests for exceptions we were getting for 3.2L cars, all of which we approved and expected to be approved going forward.

Nothing more, nothing less. No smoke-filled rooms, no dark ulterior motives to make the world great for Bayerische Motoren Werke.

We have demonstrated the will to exclude cars that exceed the performance expectations of the classes (see STL and Integra ITR and S2000, various Loti products). If you truly believe the performance of any of these engines is far and above the potential of its competitors, then put all your information together with a submission to the CRB. It will be seriously considered, but you better support the request; sending something like "exclude the 2012 M3 because it's too fast" will surely be responded with "we will continue to monitor the performance of the class".

It all starts with a well-written letter. Make your case, support it with relevant data.

GA