Legality of crank swaps

[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

[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.

[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).

[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.

[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.