Proposed Solo Class STP(ony)

[boardkat]

PS Dennis I really hope you run STP, you're car is already the closes and minor changes away from giving the feedback they need.

see above
not a fan of provisional classes, especially absent any local/regional talent. that said, i expect that ryan (otis) and james (paulson) will be prepping their '16 GT and camaro in 2017 for STP - i'll reconsider it then.

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[SteveW]

I submitted my comments in support of the creation of the class. I just don't have enough experience with these cars to comment with any value on the wheel width debate, though. It seems plenty of brain power has already weighed in on that matter and it is still sitting at 10" today for the S550.

 

[Simmons-Racing]

I went to a dyno day today. The car Only has a cat back and a Lethal/ Lund 93 tune.

Made 416whp

Simmons

 

[Grintch]

And

Dear STAC, you're dumb and I'm right! maybe I should do it in call caps.

I keed, I keed.

Seriously though, I don't see any reason to handicap the wheels. See the FS testing at nationals. See that no other class uses suspension design to determine wheel width. See that IRS guys are still willing to accept the 285 tires against the 315 for solid axle guys until the class shakes out.

What data is the AC using to decide that this handicap is required?

Why haven't pony cars been popular in ST? They are heavy and can't run enough tire legally to get their power down. So STP "fixes" that by allowing IRS cars to run the same 285 tire as in STU WITH A NARROWER WHEEL. Thanks a lot.

My letter suggested a max of 305 & 11" for IRS and 325 & 12" for live axel cars.

 

[Whiskey11]

And

Why haven't pony cars been popular in ST? They are heavy and can't run enough tire legally to get their power down. So STP "fixes" that by allowing IRS cars to run the same 285 tire as in STU WITH A NARROWER WHEEL. Thanks a lot.

My letter suggested a max of 305 & 11" for IRS and 325 & 12" for live axel cars.

I'm not sure I know of any live axle car that can fit a 325 (let alone a tire that is this width and competitive in ST) under the stock contoured fenders. The S197's would swallow a 335 out back with minimal inboard room but not up front without flares. With the absence of a competitive 325 (and options in the 335 range) and the fender contour restriction, this would put us at 305x11 for IRS and 315x12 for live axle cars. I can see why what you suggest isn't drawing any weight with the STAC.

Frankly, I'm hoping for more tire but I suspect that it just wont happen before next year.

Also, FWIW, I think the S550 puts down power really well on 275's. It is very sensitive to how quickly you jump on the throttle and wasn't as forgiving as my S197 was on 285's but when you roll onto the throttle right these cars put power down almost a little too well given the massive power difference. I can only imagine what BoardKat's car was like on 315 wide Hoo$ier A7s... probably downright silly coming out of a corner.

 

[boardkat]

I can only imagine what BoardKat's car was like on 315 wide Hoo$ier A7s... probably downright silly coming out of a corner.

it's awesome

i did have my tuner soften the driver demand table though - the stock throttle mapping sucks, which is probably part of the problem you described jumping on the gas.

as a side note, i'm still putting power down really well on 315/18x11 rival s. and that's with 450+ RWHP and stiff-ish rear springs (1600lbs). color me impressed!

 

[Whiskey11]

it's awesome

i did have my tuner soften the driver demand table though - the stock throttle mapping sucks, which is probably part of the problem you described jumping on the gas.

as a side note, i'm still putting power down really well on 315/18x11 rival s. and that's with 450+ RWHP and stiff-ish rear springs (1600lbs). color me impressed!

<grabs hot pink marker> Where would you like to be colored?

 

[z3papa]

And

Why haven't pony cars been popular in ST? They are heavy and can't run enough tire legally to get their power down. So STP "fixes" that by allowing IRS cars to run the same 285 tire as in STU WITH A NARROWER WHEEL. Thanks a lot.

My letter suggested a max of 305 & 11" for IRS and 325 & 12" for live axel cars.

I'm still scratching my head to figure out if you can fit or if there exists a 12" wide wheel which could fit the live axle cars, and have never heard of a 325mm tire by any manufacturer. It's like you are proposing surreal allowances for live axle cars to support higher wheel/tire widths for IRS. For clarity, I recommended higher width's of wheel/tire for other reasons but can't wrap my head around the proposal for reasons you're giving.

 

[dontlifttoshift]

325-30/19 is the factory rear size for the C6 Z06. They are available, but not in typical autoX brands.

 

[BmacIL]

it's awesome

i did have my tuner soften the driver demand table though - the stock throttle mapping sucks, which is probably part of the problem you described jumping on the gas.

as a side note, i'm still putting power down really well on 315/18x11 rival s. and that's with 450+ RWHP and stiff-ish rear springs (1600lbs). color me impressed!

Finally, someone who gets it :clap2:. The stock table is pretty aggressive and track mode is basically an on-off switch. I laugh with all these people getting the Pedalmax.

 

[SteveW]

Hey guys, couple questions I'd like to toss up as I ponder a setup for this class:

1. with 20" Bridgestones in the works for late next season is a 20x10" wheel/tire setup a reasonable thing to look at? (should yield mid-60s 2nd gear speeds)

2. would the BMR rear toe-links be legal? You can do a camber kit, which might include an arm. The toe adjuster does affect camber but obviously, the upper arm is the primary camber adjustment component so not sure how leaving the OEM upper arm in place and installing the aftermarket "turnbuckle" style lower link as a camber kit looks.

3. can we get rid of that sound tube coming off the intake snorkel?

Saw a big discussion about wheel rates on a different forum thread so I started looking into what might be typical in ST* but not getting too far. Here's what I know so wanted to see more thoughts on this:

Soft end of the spectrum: Trophy winning BMW STX car - 369 lbs fr/222 lbs rear wheel rates

Stiff end of the spectrum (Boardkat) - 645ish lbs fr/384 lbs rear

Factory GT PP - 152ish lbs fr/174 lbs rear

If you add 20% to the BMW rates as a SWAG for the 20% higher weight of the S550 then you might look at 480 lb springs front and 1100 lb springs for the rear. Boardkat has run with 700 fr/1600 rear but thinks even stiffer would be better. Yikes and so confused!

 

[DickR]

Hey guys, couple questions I'd like to toss up as I ponder a setup for this class:

1. with 20" Bridgestones in the works for late next season is a 20x10" wheel/tire setup a reasonable thing to look at? (should yield mid-60s 2nd gear speeds)

2. would the BMR rear toe-links be legal? You can do a camber kit, which might include an arm. The toe adjuster does affect camber but obviously, the upper arm is the primary camber adjustment component so not sure how leaving the OEM upper arm in place and installing the aftermarket "turnbuckle" style lower link as a camber kit looks.

3. can we get rid of that sound tube coming off the intake snorkel?

Saw a big discussion about wheel rates on a different forum thread so I started looking into what might be typical in ST* but not getting too far. Here's what I know so wanted to see more thoughts on this:

Soft end of the spectrum: Trophy winning BMW STX car - 369 lbs fr/222 lbs rear wheel rates

Stiff end of the spectrum (Boardkat) - 645ish lbs fr/384 lbs rear

Factory GT PP - 152ish lbs fr/174 lbs rear

If you add 20% to the BMW rates as a SWAG for the 20% higher weight of the S550 then you might look at 480 lb springs front and 1100 lb springs for the rear. Boardkat has run with 700 fr/1600 rear but thinks even stiffer would be better. Yikes and so confused!

Steve - I suggest that you call Sam Strano. He has a pretty good handle on how to set up a wide range of cars including pony cars and is already working with Chris. Based on a brief conversation Sunday at an autox Sam may not recommend springs as stiff as some other guys do. (I'm sticking with FS but love to keep track of this stuff).

FYI: Sam can get/sell parts from pretty much every vendor. Don't think that just because a part doesn't show up on his web site that he cannot sell it. His prices are competitive even without considering the expert advice that is included for autocrossing and other applications.

 

[dontlifttoshift]

We talked briefly about the 20" 'stone in the FS thread. It looks like about 63 mph would be top speed. In STP where you get power mods to offset the rotating weight and you can lower the car to offset the diameter, it might be worth it if buying wheels anyways.

 

[Grintch]

Saw a big discussion about wheel rates on a different forum thread so I started looking into what might be typical in ST* but not getting too far. Here's what I know so wanted to see more thoughts on this:

Soft end of the spectrum: Trophy winning BMW STX car - 369 lbs fr/222 lbs rear wheel rates

Stiff end of the spectrum (Boardkat) - 645ish lbs fr/384 lbs rear

Factory GT PP - 152ish lbs fr/174 lbs rear

If you add 20% to the BMW rates as a SWAG for the 20% higher weight of the S550 then you might look at 480 lb springs front and 1100 lb springs for the rear. Boardkat has run with 700 fr/1600 rear but thinks even stiffer would be better. Yikes and so confused!

Are those wheel rates or spring rates? It's a huge difference.

 

[SteveW]

Are those wheel rates or spring rates? It's a huge difference.

The last paragraph was taking about spring rates for the S550. The first part was wheel rates so I could compare between setups of the two examples I mentioned. Hope this clears it up.

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