DOUGLAP1

But of course. Corner Weights set in March 2013 by Franz Blam Racing:

LF = 652 lb / RF = 648 lb
LR = 817 lb / RR = 819 lb

Oh, I forgot to add my modifications include a full FabSpeed exhaust with headers, single cats, and muffler. The cats are 200 cell, and ST class does allow 100 cell cats, so perhaps that is one area where I am not prepared to the limit.

I don't remember running against a vette that was not on A6's, but it sure would be fun to try. Typically a well prepared Z06 with a very good driver on A6's (with me also on A6's) will be faster than me by 1 - 1.5 seconds on a 90 second course (we run some big courses around here). I did take FTD over a Z06 early this year, but he claimed his A6's weren't fresh.

burglar

Spotted on Bookface:

Street Touring
#14254 RWD Wheel Width Limit Proposal
Change the following language in 14.4 WHEELS:
STU - 11”
Change the following language in 14.3 TIRES:
STU (2WD, Mid-Engine, Rear-Engine) - 255mm
STU (2WD, Other) - 285mm
STU (AWD) - 255mm

If this is not a ruse / troll it has to mean something good for P-cars, right?

burglar

http://cdn.growassets.net/user_files...pdf?1434725484

cut/paste:

Street Touring
#14254 RWD Wheel Width Limit Proposal

The STAC and SEB are working together to ensure we carry out a clear, strong vision for Street Touring, and STU as described below.

The Street Touring category of vehicle modifications is meant to fit between the current Street and Street Prepared categories. This category provides a natural competition outlet for auto enthusiasts using affordable sports cars and sedans equipped with common suspension and engine modifications compatible with street use.

The Street Touring Ultimate class is meant to be the fastest class in the Street Touring category. It should provide members with competition in affordable high performance cars.

It is important that we continue to provide our membership with a category that offers good balanced competition, that is inclusive of different car types, and that respects the work that it took to grow into the strong class we see today. STU has also seen recent enthusiasm in the form of increased requests for expanded car classing and additional allowances that would enable fair and expanded classing.

In order to capitalize on this growth and enthusiasm, the STAC presents the following proposals for feedback to point STU in the direction of increased stability, increased performance, and increased opportunities for classing with
simplified allowances.

Change the following language in 14.4 WHEELS:
STU - unlimited 11”
Change the following language in 14.3 TIRES:
STU (2WD, Mid-Engine, Rear-Engine) - 255mm
STU (2WD, Other) - 285mm
STU (AWD) - 255mm

The STAC is considering allowing some mid-engined cars, such as the Porsche Boxster, into STU. Per the above proposal, these cars would be limited to the same tire size as AWD cars. After collecting data to review the performance
potential of ST mid-engined cars, allowances could be adjusted, and/or the cars could be moved if appropriate.

Note: The STAC and SEB believe the new wheel restriction will improve parity between cars that have more room for extra-wide wheels and those that do not. This also directly addresses cost escalation issues that have been expressed as a barrier to entry. The STAC has queried many STU competitors and found none running wheels wider than 11” so this proposal should hopefully not be a takeback.

sjfehr

Good news for owners of older Boxsters, but I have a feeling this is going to be very restrictive and few people will take advantage of it. Note: no mention of Caymans. And it also comes 8 years too late: I was more interested in running my 986S in STU when that was the only way to run street tires with a reasponable index. Better news now would be a proposal for a new SST like was propsed for STP that would give a home for newer Boxsters, Caymans and 911s with coil-overs and camber.

I ran 285s on my 986S in Stock, so 255 is a step backwards. I wonder if 255s on wide rims would be faster than stuffed 285s? Camber would certainly bring a big improvement.

burglar

Oh sure, finally get traction on ST Porsches and you complain about it.

cretinx

STU Boxsters excite me but frankly with those limitations I can't imagine them being much fun . . . .

Joe Ricard

Yep rules as written will keep Old Boxster owners from even considering it. Not to mention they probably don't AX anyway. If they are a car enthusiast the super clean Boxster will have been upgraded to wider wheels from a Boxster S or 996.

SCCA membership is due to expire end of this month. Now sit more on the edge of jumping ship.

sjfehr

One of the SEB members posted to another forum that they don't have any preconceived notions right now and are looking for feedback. So, if you have feedback, write a letter!

Personally, considering how quick STU is already, I think 986 through 981S could all fit the competitive balance of STU, depending on what the new STU looks like. With the creation of STP, I think there's a very good opportunity here to build a better (read: less course-dependent) mix of cars between STU and STP. The tire allowances can change if the quicker cars no longer have to be restricted so deeply for parity's sake. Mid-engine and AWD might be a very good mix for the new STU. I'd really like to see the tire allowance go away completely if it were possible to do so without even worse unintended consequences.

edfishjr

Like sjfehr says, they are looking for feedback. Boxster/Cayman/911… what would fit and why. The 255mm for rear/mid engine is a proposal.

My first reaction is that a 986 non-S could not be competitive in today's STU. I think it would have to be an S or maybe even a Gen1 Cayman S and the tire width would have to be 265 (to get enough rear traction… I understand they may not fit on the front) but I haven't run any numbers yet.

Lugod's STU Corvette dyno'ed at 380HP/390TQ on a Dynapack. I don't know if that is wheel or related back to the flywheel, but I think it is at the wheels. Borg has stated his goal is 400TQ for his build. It is true that these numbers are created only at high RPM in these motors with intake/exhaust and tune. The torque curve is no longer flat. But, Lugod's got to 360 lb-ft by 2700 RPM.

the other thing to take into account: the new tires put down power better. This will change the previous calculation when it comes to high-power vs. low-power on street tires by favoring the high-power car.

sjfehr

Would the whole 996 family fit well here, too? I think it would. I'm also not a fan of artificially limiting tire width for the sake of parity, especially when it's smaller than stock. Personally, I'd like to see cars at least be able to run OEM width; if we're giving handicaps, let the slower cars run artificially wider instead of limiting the fast ones. If we take the other slow heavy front-engine RWD cars and move them to STP, there's no need to limit tire so badly for AWD. I think we should raise the tire limit across the board - 285 for mid-engine/rear-engine/AWD and 315 for front-engine/RWD. Maybe even give tire width based on an Appendix A list where lower powered (or heavier) cars get more tire. 4000lb S4 should be allowed to run wider tire than a 2900lb STI.

What power gains would we expect to see from Porsches in STU trim?

ToSi

Yep, great news.. might not be perfect, but it's a start.

PS - which other forum?

The STP idea in the same Fastrack is another example of silly popularity based classing.. If approved, it will mean ~6 ST classes that still don't have a place for everything that can run in stock/street. How is this better than just taking away a few of the less streetable allowances from SP (cut up fenders, plastic bushings, full stand alone EFI) & running on 200tw tires, making ST a sort of SP-lite & returning it to its original vision?

edfishjr

I'm working a spreadsheet to predict performance in STU. I need some data from you guys. My plan is to publish the results here first, let you guys chew it up, then put it into a letter.

1. What is the biggest front tire width that fits on 04 BoxsterS, 07 CaymanS, 09 Cayman and 04 996C2? Can they all fit 255? 265? Or is the limit less? (These are the cars I'm putting into the calculations to start with.)

2. Porsche folks often complain that using Porsches curb weights is not realistic for US delivered cars. Here are the curb weights. Can anyone say what the real lowest weight of a US delivered version might be? The 996 number seems particularly low.

04 986 Boxster S 2911
07 Cayman S 2998
09 Cayman 2992
996 2959

sjfehr

Every single car was sold with at least 200lbs of worthless crap Though the seat allowance helps considerably there. I think the weight on the 09 Cayman/S will need to be higher to account for the weight of PDK and LSD. Do you want to model for PASM or for MCS?

The biggest tires I tried to fit on my '04 986S were 245/35-18 V710s on 987 wheels, but I recall people talking about stuffing 285s in the front. I may be thinking 987, though. With larger wheels and spacers, I bet 265 would fit without issue. I'm running 255/35-18 on my 987.2 Boxster S and there's quite a bit of room for spacers and wider rubber. Same for the 285/35-18 in the rear.

edfishjr

I want to model for lightest starting weight before STU mods. I'm assuming that springs are changed, both seats, intake, exhaust, tuning done to the max, 2-piece brake rotors with aluminum hats, sub-10b battery, custom lighter wheels, LSD added, etc. But, I need good base weights to start from. I don't need to get the actual race weight for every car, I just need to get reasonable comparisons.

IIRC the 285 in front? question was for GT3s... I didn't know if it applied to other cars.

sjfehr

It just occurred to me that I actually saved exactly the quotes you're looking for in my tire info .txt because they seemed like very useful information to keep for reference. I got the impression at nats last year that 996 GT3s can only fit 245 up front.

Summary:

Alan Pozner: "285s fit on the front of 987s (and 997s) just fine in stock form."

John Vitamvas: "Dave Hedderick had 285s on the front of his dad's 986S at the 2008 Nationals."

internet tough guy (not sure real name?): "Rad had 285s all around on his '08 Cayman S in AS that won AS this year at Nats. I've been running 275F 285R most of this year but will be going to 285F for next year. They actually fit better than the 275s "