PDA

View Full Version : Turbo-Bitchin' Thread. Was: What's the target power to weight for STU?



Z3_GoCar
06-11-2012, 10:34 AM
Any one know what this is?

Rabbit07
01-26-2013, 09:17 AM
Any one know what this is?

120 per liter.

Andy Bettencourt
01-26-2013, 09:07 PM
Crank or wheel?

Rabbit07
01-26-2013, 09:22 PM
Crank or wheel?

Yes

Andy Bettencourt
01-26-2013, 09:35 PM
Yes

Riiiiiight....

Greg Amy
01-26-2013, 10:12 PM
Riiiiiight....
Welcome to National...er, Majors racing, dood...

Rabbit07
01-27-2013, 11:12 AM
welcome to national...er, majors racing, dood...

lol!

Terry Hanushek
01-27-2013, 11:20 AM
Crank or wheel?


Yes

Would that be crank for NA cars and wheel for turbos? :D

Terry

Rabbit07
01-27-2013, 12:10 PM
All kidding aside, the "target" , which is just an assumption is crank. ie 2.5 BMW makes roughly 255 WHP. 2.5(120)=300, 300(.85)=255.

Z3_GoCar
01-28-2013, 02:03 AM
Funny, that doesn't jibe with the the target power to weight rato of 9-10lbs/hp because then the car would have to weight 2550lbs to get to 10:1.

The new TIR to weight chart and tire size limits really slowed Hoover down, he just set a new lap record this weekend:

http://www.mylaps.com/results/showlaps.jsp?id=2559440&perclass=0&pos=1

The only option it to go turbo or go home....

Rabbit07
01-28-2013, 09:28 AM
Excuse me but where did you come up with 9-10:1?

Looking at those results I see new TR's in all the classes. The evidence provided would indicate that the track was fast .

Z3_GoCar
01-28-2013, 08:56 PM
Simple math that's in the GCR:


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

Rabbit07
01-29-2013, 09:29 AM
My colleague had the power value as wheel in that calculation.

Chip42
01-29-2013, 11:09 AM
no dog in the hunt, but no, he didn't use whp. he used 120 hp/l which you just stated was the estimated chp/l for STU. you assume a 15% driveline loss and you could just as easily have said 102 whp/l (120*0.85).

weight to wheel hp numbers following Greg's math (which is correct):
120hp/liter x 0.85 x 1 liter/1000cc x cc/1.1# = .093 hp/#, or 10.75 #/hp

And FWIW, 102whp/l is much more in line with STL, I don'thave a clue what one might actually see in STU

Greg Amy
01-29-2013, 11:25 AM
no dog in the hunt, but no, he didn't use whp. he used 120 hp/l....
Be careful: "he" made that post in January of 2011, which may have been prior to "his" inclusion on the STAC. Or damned close, so a newbie.

- Him, who is enjoying this discussion, especially in light of a lot of IT guys Jonesin' to get their category into the National racing program..."be careful what you ask for..."

Chip42
01-29-2013, 11:43 AM
doesn't change the math. what "he" calculated in 2011 matches what the cat killer quoted as expected chp/l. I was simply pointing out that chris' assertion about the math was incorrect based on his earlier posts, dated 2013.

and THIS IT guy might think the options presented by ST look like fun but this IT guy has NO desire to see IT made into a "national" class.

Andy Bettencourt
01-29-2013, 03:27 PM
- Him, who is enjoying this discussion, especially in light of a lot of IT guys Jonesin' to get their category into the National racing program..."be careful what you ask for..."

I think the only reason any of 'us' would want IT in the National program is if it was managed the way it is now...by the Ops Manual. If it was to take the typical 'Prod Style' or now 'ST style' comp adjustments, I don't know anyone who would want the CRB screwing it up.

Z3_GoCar
02-01-2013, 05:48 PM
Granted that there were other records broken that weekend, but not in all classes. But, the STU record was set exactly a year ago by the same car and driver. So, if the reset weight to TIR chart was used, and he still broke the record, it would indicate that the same gap between turbo and naturally aspirated cars at the runoffs still exits as the N/A car's hadn't and anything done to speed them up.

Prof. Chaos
02-05-2013, 07:58 PM
Granted that there were other records broken that weekend, but not in all classes. But, the STU record was set exactly a year ago by the same car and driver. So, if the reset weight to TIR chart was used, and he still broke the record, it would indicate that the same gap between turbo and naturally aspirated cars at the runoffs still exits as the N/A car's hadn't and anything done to speed them up.

A lot of the new lap records that weekend were in new classes, or classes that had been sped up. T1 and T2 are now both faster classes, and T4 and BS didn't exist a year ago. As for STU:

Jan. 22, 2011 Hoover set the STU track at AAA Speedway at 1:53.897
Jan. 22, 2012 he reset the STU record with a 1:50.115
Jan. 27, 2013 he reset it again, at 1:48.792

Looks like those STU turbo car adjustments are working. :017:

jmac36
02-06-2013, 06:52 PM
A lot of the new lap records that weekend were in new classes, or classes that had been sped up. T1 and T2 are now both faster classes, and T4 and BS didn't exist a year ago. As for STU:

Jan. 22, 2011 Hoover set the STU track at AAA Speedway at 1:53.897
Jan. 22, 2012 he reset the STU record with a 1:50.115
Jan. 27, 2013 he reset it again, at 1:48.792

Looks like those STU turbo car adjustments are working. :017:

Gee funny how that worked out, ain't it? Welcome to the world of Super Turbo Under. Hate to say I told ya so, but.......

Z3_GoCar
02-07-2013, 01:53 AM
Gee funny how that worked out, ain't it? Welcome to the world of Super Turbo Under. Hate to say I told ya so, but.......

That's why the Prof left STU and is now rolling EP :023:

jmac36
02-07-2013, 10:24 AM
That's why the Prof left STU and is now rolling EP :023:

Yes , I would say its why a lot of folks are heading to the fine folks at NASA.

Unfortunately, that's not much of an option down here, and the EP boys are not too excited about having a huge sedan run amongst them, so I'm sort of stuck here in the new turbo wonder class.

The irony of this is I have our 2011 mazdaspeed 3 in mothballs, simply because I thought the turbo was no real match for a well prepped atmo car. I may have to get it out and re-evaluate!

Matt93SE
02-07-2013, 11:50 PM
Joe, wasn't it making like 9,000,000lb of torque before you blew the intake manifold off it?

I'll let you buy the 240SX for a steal. turbo is easysauce with SR20, and the car will be equipped with Moton goodness next week...

jmac36
02-12-2013, 01:30 PM
Joe, wasn't it making like 9,000,000lb of torque before you blew the intake manifold off it?

I'll let you buy the 240SX for a steal. turbo is easysauce with SR20, and the car will be equipped with Moton goodness next week...

Matt, you is exactly correct, Kingfish! And that was with a 37 mm restrictor. Tell the fine folks how fast that car is out of the corners.......