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Discussion Starter #1 (Edited)
Some of you may have seen the article in this month's SportsCar where my FS prepped Mustang is compared with a prepped BMW 335i...and the results are surprising, to say the least.

Yeah, both myself and Jason Isley were faster in the Mustang than we were in the BMW, but the times were very close (too close)...I went 53.60 in the Mustang/53.77 in the BMW and Jason went 53.73/53.97.

Before anyone starts thinking that the BMW can really hang with the Ford in FS, or that neither one of us knows how to drive a Mustang, a couple of points need to be made regarding conditions.

Results were skewed a bunch because of conditions, which can be a problem anytime you're trying to take real info from a single data point. First, we ran on BFG R1's (rather than my normal Hoosier A6) and my car was just not happy on them (at all), even after I softened the back and played with pressure, to try and get some grip, it was loose, loose, loose. I could have gone full stiff on the front bar, but by that point I didn't really want to mess with the car too much to find a set up for tires that I'd never run again. Second, there was one long acceleration zone where the Mustang was on the limiter for a prolonged period (but shifting to third wouldn't have worked) and the BMW could keep accelerating, with it's taller gear. I'm sure that was good for at least a couple of tenths. Third, the course surface was not the best in the world, so the BMW's lack of LSD actually helped stabilize the car. And, finally, there weren't any long sweepers, where the Mustang could really shine, with its good balance, camber, stiff(er) springs etc...of course, with the marginal grip provided by the tires/surface, maybe that's just as well. I think, if we ran the two cars against each other on 10 different courses, the Mustang would win every time and the gap would be at least half a second on a 60 second course, on average...but, that's just a wild guess, the data we gathered paints a different picture.

Still, it was a bunch of fun to do the test. The guy's from SportsCar were great, BFG came through with free tires, we got plenty of seat time and the BMW was actually surprisingly fun to drive...the 335i definitely has some serious grunt, probabaly acclerates right with the FRPP Power Pack Mustang.
 

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Maybe i'm misreading something here.... You say it's FS prepped Mustang, but you mention stiffer springs later on. Are you just talking about stiffer springs than the BMW?
 

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Discussion Starter #3
Maybe i'm misreading something here.... You say it's FS prepped Mustang, but you mention stiffer springs later on. Are you just talking about stiffer springs than the BMW?
Yeah, stiffer than the BMW. The FRPP springs in the Shelby are pretty stout. The BMW has surprisingly soft springs, which were good for that day, with the low grip, but resulted in tons of body roll.

Hey, how do you edit thread titles? I wanted to change the title of this thread, but can't seem to do it...
 

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Cool article and thats BA that you got to participate.

BTW, how do you have FRPP spirings on your GT? Is that a Shelby or CS or something else? Not really up on all the hot FS setups.
 

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Hey, how do you edit thread titles? I wanted to change the title of this thread, but can't seem to do it...
You need an ADJUSTABLE edit button. ;) No, I think MFE or the like will hafta do it. It changes on your post, but not on the title in the forum. Weird.
 

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Discussion Starter #6
My Mustang is an '07 Shelby GT, which is delivered with the FRPP FR3 suspension with M-5300-K spring set...stock, oem. :)
 

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I thought the article was overall very good. And appreciate the mentions in it. There were a few mistakes, like the fact that while GT's and Bullitt's get a 34mm bar... the Shelby has a 35mm bar. :) And we can handle a 295 tire though it's a squeeze I prefer it over the 285.

Appreciate Mike not giving away the proprietary setup information I gave him (and freely give any and all my customers).

One thing that surprised me is that it said the BMW was better mid sweeper. I certainly think that's a function of the BFG tires, because I don't sure don't have any issue with push. Anyone looking at vids of me (new one from today on YouTube) can see that understeer isn't generally an issue. :)

None the less it was a cool article, and offers what I'm sure are very accurate opinions based on the control tire.
 

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Discussion Starter #12
Sam, I'm not sure where they got a 34mm front bar, I think I gave them the Shelby's 35mm spec...also, the 285 was the biggest size BFG we could fit, not to be confused with the size (295) I prefer to run.

The comments on the BMW being better steady state wasn't a reflection on the Mustang pushing, but rather on it being loose. Like I said, my car on that surface and with those tires was very, very loose and, as a result, was hard to get to take a set on sweepers. The BMW, with its inherent understeer and lack of LSD, was just more settled in sweepers and easier to drive on the low grip aggregate asphalt we ran on that day. Funny thing, on Hoosiers and any other surface I've run my car on, it is just on rails in sweepers, taking a set and allowing attitude to be dictated by the throttle. I probably could have gone stiffer on the front bar and continued messing with the shocks and tire pressures to dial in more understeer (which that surface and course rewarded), but we ran out of time.
 

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I don't doubt what you told them was correct... just pointing out an inaccuracy in the the article, and something I thought odd which I'll put down to test conditions (most likely tires).

I can buy the BMW is easier to drive fast on a less than great surface. :)
 

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Discussion Starter #14
I don't doubt what you told them was correct... just pointing out an inaccuracy in the the article, and something I thought odd which I'll put down to test conditions (most likely tires).

I can buy the BMW is easier to drive fast on a less than great surface. :)
Yeah, I think the BFG R1 tires were the real issue. Maybe if I had really tried to adjust the set up for those tires, mostly in terms of giving up grip on the front end, it would have settled down.
But, the car is just so good with the set up you've worked with me on and Hoosiers that I really didn't want to get too carried away making changes for the BFG's. Thing is, on Hoosiers and the normal set up, poor grip surfaces don't usually cause any real issues. I've run the car at Golden Gate Fields, which has a surface kind of similar to the surface we did the test on, and the car was very good and a blast to drive.
 

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Read the article in my issue that came in the mail yesterday. I've always wondered why the SCCA allows R-comps in the stock classes? Seems counter-intuitive. Either way a cool article, and now I'm not looking forward to comparing my times with my brother-in-laws 335i X-drive coupe.
 

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Why do they allow R-comps? Because you can't really police tires that well unless you require a spec tire.

ST is a perfect example of how the tire companies are building stickier and trickier tires that meet the letter of the rule if not the spirit of it. R-comps evolved the same way and requiring a treadwear number that isn't standardized (and they are not, 140 from Joe's tire is not the same as 140 from Bob's tire and doesn't have to be), it's laughable to try.

FWIW I LOVE r-comps and don't see the draw to running on street tires (ok, cost... but I want the speed the R's give).
 

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As an outsider I think it is strange that R comps are legal in Stock and SP. But I also see that it is difficult to police anything different. If you specify street tires with a minimum treadwear (like ST) then people would just shave all the tread off. In that case you still aren't really driving a streetable tire. It would be cool to have more competition due to lower cost but I doubt that is going to happen. On a local level though you may see more ST oriented classing in order to promote attendance, it just doesn't translate to a national level. Plus there is a lot invested into the current setup. A lot of people don't want to move away from R comps.
 

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The way the current rules are written the word "Stock" can lead to misunderstanding. From a newbie perspective if you are someone who is coming from a street performance or drag oriented background the word stock is processed as "as it rolled off the line". The stock class really doesn't fit that, it's really more of a "factory prepped" type class and I think that's where much of the contention is. Add in what a lot of people view as "race car tires" with the DOT R-comps. You can see where someone would bring their bone stock Mustang and expect to be more or less even in the F Stock class and get their doors blown off by regulars on "race tires" would get turned off from the sport.
 
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