STU Target Weight/WHP Ratio

[anthony1k]

I seem to remember reading that the '09 WC Realtime Acuras were putting out around 285 WHP. At 2750 lbs this puts them at around 9.6 lbs/WHP. Is this a good target number for STU? Any guesses of where about the top 3 at the runoffs were?

[Matt93SE]

Sounds like a good target to me. if you can keep up with the winners, you're doing good..

[anthony1k]

Sounds like a good target to me. if you can keep up with the winners, you're doing good..

I'm actually trying to get a sense whether or not this is a good number. WC teams typically do not broadcast HP numbers.

[Chip42]

my napkin math has it at 9-10#/hp. supposedly they are using "power numbers" in STO - something like HP*Tq/2. maybe the same in STU, so classifications might see more hp/# in the lower displacements and less in the higher. as it is, they need time for the class to developed and then for data to be collected. it's kind of a big "?"

build one. I am.

[Greg Amy]

Since STU is an engine-centric class, there's not a direct horsepower-to-weight target, it's a displacement-to-weight target. The target range in STU - just a target, mind you, not an end-all, be-all guaranteed goal - is 120hp/liter.

Since the STCS-published minimum weight is 1.1 pounds per cc displacement, one can thus infer:

120hp/liter x 1 liter/1000cc x cc/1.1# = .109 hp/#, or 9.17 #/hp

PLEASE NOTE: "Target range". Not a guaranteed end result.

Also don't forget that the RealTime-prepped WC car now has to add 5% to its weight.

GA

[23racer]

With the new rules, my car will be running very close to 9.9 lbs per whp. If that is the target the additional 5% really is working and I don't need to loose as much weight this winter, .

The buzz seems to have died down, so the new rules must be close to acceptable for everyone. Great job!

Eric

[Knestis]

Since STU is an engine-centric class, there's not a direct horsepower-to-weight target, it's a displacement-to-weight target. The target range in STU - just a target, mind you, not an end-all, be-all guaranteed goal - is 120hp/liter.

Since the STCS-published minimum weight is 1.1 pounds per cc displacement, one can thus infer:

120hp/liter x 1 liter/1000cc x cc/1.1# = .109 hp/#, or 9.17 #/hp ...

OH SNAP!

Hyabusa 1300cc engine + Suzuki Swift = 1430-pound winnar...??

:026:

K

[Greg Amy]

Hyabusa 1300cc engine + Suzuki Swift = 1430-pound winnar...??

Bring it!

[kipv]

I still have no idea why we would create such a list of "off the chart exceptions" in STU. Why would a 3.2 liter BMW built to STU specs only weigh 3200 lbs. A 3 liter "ANYTHING ELSE" would weigh 3300lbs. I wont even begin to address the inconsistency suggested by the ridiculously low Detroit Iron weights listed.

[Matt93SE]

Also keep in mind that those super-light cars have severely limited engines. i.e. lower compression and stock cam lift vs. 12:1 compression and 0.600" cam lift that everything else gets.

But yeah, it almost seems like STU is a run-what-you-brung-free-for-all with seemingly every car on the planet allowed to run in the class in some level of prep. I'm sure this is making it incredibly hard to police the class from a tech standpoint as well.

Welcome to New-Production, not Super Touring.

[benspeed]

I still have no idea why we would create such a list of "off the chart exceptions" in STU. Why would a 3.2 liter BMW built to STU specs only weigh 3200 lbs. A 3 liter "ANYTHING ELSE" would weigh 3300lbs. I wont even begin to address the inconsistency suggested by the ridiculously low Detroit Iron weights listed.

I'm with you on that - doesn't seem right....

[kipv]

STO (over 3 liters) should run in STO to STO rules.

[Chip42]

I'm with you on that - doesn't seem right....

I could see these making sense AFTER an envelope had been defined or a car built to the rules as written came up as a serious under/over. but to just willy nilly chuck them upon the class, and in such disorganized, redundant, and unneeded way, they add confusion about the class in general. bad move by the STAC on that one.

similarly - some american V6s or S52 M3s might make sense in the class as they would be woefully slow in STO (assuming this is true and that anyone cared). but again - an envelope needs to exist so that people can see the alt classification as fitting in or not.

3.0L, factory crank, head, intake, TB. country of origin and where it was sold are irrelevant. play ball. let the field sort itself out THEN start applying controls.