CO_VaporGT_09

I'm looking into the Time Trials (TTB) group for NASA, and trying to divy up my points appropriately. Of course, the cosmetic ducktail spoiler is costing +4 and not adding anything, but I'll address that if I ever become competitive locally. Planning on starting next season (doing rollbar and race seats next winter, I hope).

Question is:

I'm looking at doing a 265 width tire (only +1 point) instead of a 275 (+4 points) and see most of the track or race tires (ie Yoko Advan, Hankook Ventus RS-3) come in a 265/35-18, with an overall diameter of about 25.5" or so.

I know this is the standard diameter on the FR500S or C variants, but wondering if anyone has had trouble with this small a diameter tire on the stock ABS circuitry? Obviously it'll give a bit of torque multiplication compared to my 275/35-20 street setup or my current 275/40-18 track NT05s, but I'm worried it might have an effect on the electronics.

Any need to flash with the SCT3 to tell the ECU this (outside of the speedo and odometer readings being a bit off)??

If it's an issue, I'm sure I can find a way to get the 275/35 (not much of a change there) or 275/40s instead.

Thanks!

CO_VaporGT_09

Nada?

Oh well, I did find this thread by Vorshlag (see their name on BMWs all the time at NASA events) all about developing the 2011 GT for TTB (probably TTA soon) and SCCA STX:

http://www.vorshlag.com/forums/showthread.php?t=7806

They carry the AST coilovers (Strano does as well) and seem to be developing some parts of their own. Their C/C plates look nice but pricey.

They have a nice demonstration of changing out the front LCA bushings, which I'm hoping to do later this summer.

06GT

Only issues we've had with ABS have been due to running DTC60s or DTC70s up front and getting on the pedal way too hard. Gotta ease into those pads because the initial bite is nuts, especially with track tires.

In summary: driver mod is again the best mod.

CO_VaporGT_09

Drew

When will you get the new Boss? Keeping the 06 as well?

Reading through that Vorschlag thread, seems like they discovered the same thing when they switched to the DTC60 all around and used it for autocross (then wised up and got some HP+ instead). They said the ABS went into 'ice mode' and basically wouldn't slow the car much at all. I was wondering if that was maybe due to the too short tire diameter, but sounds like not.

Good to know, thanks!

They also had on that thread wheel fitment info with weights, the same Enkei's as here:

https://themustangsource.com/f722/se...ensors-494572/

They look like a pretty good price for a fairly lightweight and decent looking wheel.

Have you done any paid driver schools? We have a group called FAASST, and then Pettiford's Go4It school locally as well. I'm just not sure if I'd get much from it, for the cost, compared to just more seat time.

06GT

Josh:

Boss is slated for Q4 delivery but I'm hoping it shows up sooner so I can start putting it on the track! The '06 will be up for sale once I get a VIN notification for the Boss.

Vorshlag has a lot more info on their experiences w/ the car on Corner-Carvers, Terry posts under SN "Fair" there. After talking to him a bit on that forum it sounds like their "ice mode" issues were primarily due to mismatch of pad compounds bedded into the rotor, plus getting overzealous w/ pedal application. http://www.corner-carvers.com/forums...ad.php?t=44217 (Brake ordeal is on the last few pages, but it is an interesting build to follow). There is also a good tip on Hoosier 255 tires for points benefit...apparently the section width is almost identical to a 275! The downside is the tire OD is REALLY small by comparison.

IMO, HP+ is good enough for beginners only on the open track. They could work well for auto-x since there will be less energy transferred to the brakes during a short run, and the moderate initial bite won't freak out the ABS as much--meaning they can jump on the pedal harder if they like. For open track there is way too much heat energy for them to deal with once you really get going quick. Their max operating temp is only 750*F, same as Hawk's HPS line. For the DTC60s and 70s, you need to "breathe" onto the pedal. The ABS in our race car went out last year so I spent most of the season learning to drive without it. It's definitely not a bad thing, driving without it will teach you a lot.

Yeah they work well on our cars as I understand it. A guy on BossMustangsOnline runs them on his Boss and likes them so far. Avoid the TPMS for track wheels, waste of money.

Not yet, but Bondurant is right in my backyard, and our local org has a discount rate with them. I'm planning on doing an extra day at the Miller School when the Boss event is held, so that should be good. It's not going to be cheap, however.
In general, my opinion is that you just want to get as much seat time as possible. Try and find a more experienced driver to ride with you or watch your runs--because more seat time practicing bad habits isn't going to help you go faster! I'm actually a certified instructor with our organization here in AZ, took my first students this past weekend. That was interesting...

06GT

Also to get back to the root of your question I've run 275/35/18s and 255/45/17s (really short!) without issue.

Fair

Just poking around on this forum (I'm looking for a Mustang forum to be a supporting vendor on), see this thread, and I'm mentioned here?? That's weird... but cool.



Yea, I think the ABS issues were a pad compound mis-match (at the Pro Solo event shown above). I'm running DTC 60s all around for track use now (we swap dedicated sets of bedded rotors/pads between track and autocross/street) with no issue. Just did a track day last weekend and they worked great. DTC's are NOT a good pad for the street and should not be used for that... loud, tons of dust, don't work cold. The Hawk HP+ is indeed the better dual-use street/track or street/autocross brake pad compound.



Tire diameter shouldn't effect the ABS. I have been trending towards ever taller tires, for street, autocross, and track use. This is mostly due to gearing advantages for autocross (lengthening 2nd gear on my 3.31 geared car well into the mid 70mph range with the taller tires), but also for increased sidewall height. The taller sidewall has less "tire spring rate" than the 30 and 35 series rubber, and rides better, too. Seemed to work fine at the track with the 40 series - no weird deformation of the tire carcass, and with some tire pressure changes it had near perfect scrub on the edges.



Getting something nearly as tall as the 27.1" tall stock rubber (255/40/19) is tough, but the 275/40/18 Bridgestone RE-11 we are running now is pretty close (26.6"), and has a good deal more grip than the various 265/35/18 tires we've tried in the past year (Hankook, Toyo), the 265/40/18 (Yokohama) and even the 275/35/18 (Dunlop). That might seem crazy to try all of those street tire models, but the car is built around an SCCA "ST" class, which limits us to 140+ treadwear.



Having a ball in this 5.0, and the last track event in it was the most fun I've had behind the wheel in years. It was funny - I drove my E46 330 BMW (about 230 whp) on 285 Hoosier R6s in the morning - which was faster in every corner - but had a LOT more fun in the Mustang on 275 street rubber (420+ whp). An extra 200 hp will do that I guess.

So... what Mustang forum is the place to be to talk about S197 Mustang suspension tech? Or does such a place even exist? Corner-Carvers is pretty tech-centric, but also fairly intolerant to new folks, so... ???

06GT

Blast from the past...

I love this site, but the Autocross/Road Racing subforum here is pretty much a ghost town.

There is generally some active discussion going on at www.s197forum.com, despite it being a drag-centric site. They have an active corner-carving subforum with a lot of people with varying levels of experience. Also don't forget to visit the BOSS302 forum here as well as www.bossmustangsonline.com .