SCCA F-Street Setup. What's Everyone Done so Far?

[Whiskey11]

Likely exactly the same bar then.

I'd personally start on medium front bar, but everyone is really fond of the stiff front bar. I just noticed that it pushed more in big sweepers and didn't help much else. Maybe the MR shocks are the difference from everyone running normal shocks on the 15-17 GTs.

Honestly, having tested all three settings on the BMR 35mm front bar, I wouldn't put it beyond the softest setting. Just enough bar to put the bias slightly into understeer territory, but not enough that you can't correct with throttle application. My co-driver and I have ran all three bar settings and the car just gets insanely pushy with the bar above the softest setting and requires a silly aggressive amount of throttle application to get the car to rotate at all...

I guess the caveat to this is that I'm also running more than factory rear camber... at -2.2º out back, I think I'm the highest for rear camber in the FS S550 Mustang field. That might also explain my liking of the bar in the softest setting since the rear tires are sitting flatter to the pavement while cornering:

Still not as flat as I'd like, but tire wear is way more even across the back tires than the front tires...

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[DocWalt]

FWIW my opinion is coming from the thought that the GT350 bar is similar in rate, though a bit stiffer, to the PP front bar with the silly tight bushings.

I have tried all three settings as well as the drilled factory bar and soft or medium is where I will go unless it's a narrow runway course (one of my local sites is ALL transitional stuff). I figure soft or medium is as far as you'd ever want to go on a GT with its slightly softer setup all around.

I only have about -1.0 rear camber and -1.8 front, FWIW. Slight toe out up front and slight toe in rear.

In other words, I'd start on medium and see if it's pushy or not and then try soft.

 

[jpaulson]

I agree that it won't take a lot of bar. I have been running a drilled front bar on my '16 and '18. New hole is 1.5 inches from OEM hole center to center. Just ever so slightly tight but easily fixed with the right pedal as Cris describes. Would not want any more bar than that to be honest.

BTW. The new gearing on the 18 is veeeeerrrrryyyy nice!

 

[Whiskey11]

BTW. The new gearing on the 18 is veeeeerrrrryyyy nice!

Yeah, I'll be following the results very closely to see how the 18's are doing. Zero to 60 MPH times are identical, but not ever having to shift would also be nice... those few instances in which going beyond 60 is a thing (as has happened a few times) might offset the identical 0-60 times on an autocross course... If the 2015 launched with a 7500 RPM red line, it'd be even less concerned about the 2018 cars, but since they didn't, well, there isn't much of an advantage to them!

Here is to hoping a Mustang can wrangle the F-Street National Championship from the Bimmers and Camaros...

 

[DickR]

I agree that it won't take a lot of bar. I have been running a drilled front bar on my '16 and '18. New hole is 1.5 inches from OEM hole center to center. Just ever so slightly tight but easily fixed with the right pedal as Cris describes. Would not want any more bar than that to be honest.

BTW. The new gearing on the 18 is veeeeerrrrryyyy nice!

Regarding the front bar note that at least on the 18 the bar bushing is bonded to the bar and clamped by the brackets such the the bushing has to flex for the bar to twist and for it to allow the bar to "rotate" under straight line "dive" or "lift" conditions. Basically the same as many oem control arm bushing which add to wheel rate based on their twist resistance. Therefore changing to an aftermarket bar which has bushings which allow the bar to easily rotate will have several "hard to compare/measure" differences compared to the OEM setup. Also, as I learned the hard way today when removing my front bar the oem 18 bushing brackets are two pieces of metal which are essentially riveted together (normal U-bracket and a flat plate under the bushing. The "rivet" has to be forced apart. I used a hammer to drive increasingly large screw drivers between the metal pieces. Then I used the same method to separate the U-bracket from the rubber bushing. This was necessary in order to get the bar out of the car. It was a VERY long day using hand tools and jack stands but the new 35 mm Whiteline bar and Whiteline links are installed.

Note that the Whiteline 35 mm bar I got from Sam Strano now has teflon cloth lined bushings. No grease needed or recommended! Sam now sells Whiteline links for the front bar.

Note that Whiteline bars use collars instead of welded rings so you control placement. A little more work but potential positive.

 

[DickR]

FYI the gearing in the 10 speed is also very very very nice! 3rd gear is almost identical to second in the new manual and the short 1st and 2nd are GREAT for Pro Solo launches. Shifts are FAST in competition situations. It does take a bit of "school of hard knocks" learning to use the paddles correctly and avoid an extra shift and/or holding the upshift paddle a little too long and putting the trans in automatic.

 

[DickR]

FYI here is a picture of the front bar bracket with the remains of the "rivet" which holds the upper U and the lower plate together.

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[Norm Peterson]

Regarding the front bar note that at least on the 18 the bar bushing is bonded to the bar and clamped by the brackets such the the bushing has to flex for the bar to twist and for it to allow the bar to "rotate" under straight line "dive" or "lift" conditions. Basically the same as many oem control arm bushing which add to wheel rate based on their twist resistance.

I thought that was the case, thanks for confirming it. Basically, this bar arrangement is being intentionally used for more than just roll resistance, though I'm not quite sure why.


Norm

 

[k4show]

Would BMR CB005 cradle lockouts be helpful for autox? I think they'd be legal in CAM-C but not in STP. Any thoughts?

 

[SteveW]

Would BMR CB005 cradle lockouts be helpful for autox? I think they'd be legal in CAM-C but not in STP. Any thoughts?

I have a set on my car for CAMC and is a large part of locking down movement in the rear subframe, helping to make the rear end more predictable and easier to control.

 

[DickR]

FYI for left foot brakers.

Be sure to turn off Advance Trac or you may experience loss of power if you even touch the brake pedal enough to light the brake lights when you are applying power.

The cars have a safety function called brake over throttle that cuts power at speeds over 10 mph if brakes and throttle are applied simultaneously. This function is disabled when Advance Trac is off.

 

[DocWalt]

Good to know. I've started LFB recently thanks to my STS adventures, I was wondering how it would go in the Mustang.

 

[DickR]

Good to know. I've started LFB recently thanks to my STS adventures, I was wondering how it would go in the Mustang.

Mark had two issues on his last challenge run. One was probably going to full automatic due to a long paddle hold. The other was hopefully neglecting to turn Advance Trac off after changing to Track mode. The DL1 data tends to support both possibilities. Hopefully Advance Trac didn't turn itself ON.

 

[DocWalt]

Mark had two issues on his last challenge run. One was probably going to full automatic due to a long paddle hold. The other was hopefully neglecting to turn Advance Trac off after changing to Track mode. The DL1 data tends to support both possibilities. Hopefully Advance Trac didn't turn itself off.

I've done testing at an event recently with the dyno mode plug disconnected... Works great. AdvanceTrac turned itself on during my first run and I wasn't risking it doing it again.

I did get some weird dinging noises towards the end of one of my runs, but no message on the screens and no codes. Whatever.

 

[DickR]

FYI picture of my 2018 at the NJ SCCA Pro Solo with a FAST co-driver at the wheel. The terrain of the lot may be exaggerating the lean angle but you can see part of the motivation for a bigger front bar. The other part was the car was loser than even my co-driver liked.

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