FS Autocross Setup

5282 Views 42 Replies 3 Participants Last post by Static_LV, Jul 1, 2014

Static_LV

Discussion Starter · Mar 25, 2014

I have been running FS on street tires and plan on sticking around this class for a while. That said, I am looking for ways to improve the overall handling characteristics of my 2011 GT/CS.

The rule changes for 2014 have been interesting and open up some possibilities.
I am currently running the 19x8.5" GT/CS wheels (Heavy) with the Pirelli PZero Neros 255/40R19 (also Heavy).

With the +/-1" rule this year this opens up the possibility of running 18x8.5 wheels and 18" tires. I have been kicking around the options and there are a number of sub 20lb wheels in this category. 18" tires are also several lbs lighter. If I am doing my math right it is possible to drop about 16lbs / wheel by making this switch. That is a lot of unsprung weight. Also all things being equal, a smaller wheel diameter is going to effectively lower the center of gravity for the car by about 1" between the two setups and acceleration will wind up being just a bit quicker, which would be really nice coming out of turns in exchange for a bit of top speed in each gear.
I am not particularly worried about that due to the course setups we have here in the vegas region being oriented to smaller, lighter, slower cars, I have yet to run into a course here where I can top out second.

So my question to all my fellow AutoX fanatics is this. Good idea? Bad idea?
Also do any of you have experience running anything wider than a 255 on an 8.5 rim? I would really like to get some R-S3 275/40R18 squeezed on there but I don't really know if that is feasible or effective with a big heavy beast like this.

-Static

1 - 20 of 43 Posts

straybullitt

· #2 · Mar 26, 2014 (Edited)

I think that is an EXCELLENT idea!
Going to 18's, that is...
I'm not a big fan of a much wider tread than rim width though. The guy that won my class (ESP) last year went up one size to a 255 on an 8 inch rim and it seemed to neither hurt nor helped him.
Remember, the sidewall is just as angled out on the inside of the wheel as the outside. Imagine what the inside looks like during hard cornering!
You don't want the sidewall pulling the tread up off of the racing surface.
I just run the stock size 245/45R17 200 tires on my stock Bullitt and it has been a very competitive setup.

Soccerluvr4

· #3 · Mar 26, 2014

SLA set up and run 315s all around! That's what Brian with the 99 Camaro was running at the Oakland event. But he already has SLA.

straybullitt

· #4 · Mar 26, 2014

Soccerluvr4 said:
SLA set up and run 315s all around! That's what Brian with the 99 Camaro was running at the Oakland event. But he already has SLA.

I think that we'd have to use spacers on the front of our cars to run 315's. Not sure about Static's car.
Here's the thing about Brians car, the difference in times between his ESP illegal Camaro and my stock Bullitt, was about the difference between the R compound tires that he was using and the 200 treadwear tires that I was using.
Either the setup on his car was doing very little to help, OR, he was maybe a little rusty driving the car that he's owned for the last 16 years...

Static_LV

Discussion Starter · #5 · Mar 26, 2014

I would definitely have to run spacers or a really offset wheel to run 315s. I am not even sure if they would fit at all in the front and running a staggered setup would just turn a stock 2011 into a worse push-monster.

I have quite a few pictures of the current 255/40R19s under load on the 8.5 wheels and they do not seem to deform much sidewall wise so keeping that profile on the 18"s would probably be the way to go. I don't have much (any) empirical evidence on the 275s. The sidewall angle and deformation on those is exactly what I was concerned about myself so I will let someone with deeper pockets give that a testing first. On something light like a Miata that probably doesn't matter as much. On my big red sled, I really don't know what the result would be so I am going to err on the side of caution

Time to hurt my credit card and do some shopping

Out of curiosity, why are you running a stock Bullit in ESP? Wouldn't FS or STU be a better class for you?

On a completely different tangent, what, if anything, are you guys using for data logging?
I have been looking at a lot of different options but in the AutoX community it doesn't really seem like data logging is a really hot topic and most of the data loggers seem to be more oriented to circuit racing type stuff.

-Static

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straybullitt

· #6 · Mar 26, 2014

Why do I run in ESP?
Good question! At first, everyone that I knew was in that class and I wanted to race with them. Then, I discovered, that the leader in FS was, usually, a little faster than the leader in ESP, so, I could be more competitive in ESP.
Also, my car is unimpeachable as far as tech goes...:lol:
I like being the underdog with a stock car, I had a great time chasing the leader all last year and got within 10ths of him at the end of the year... My rookie year in autocross.
I considered going into FS this year because, sadly, Bob, the winner last year, isn't able to attend this year. My ego is getting the best of me though and I'm staying in ESP and going to TRY to win the class because it is the last season that we will be racing at this location (Marina).
I'm still chasing the leader of FS... Just doing it from ESP.

I haven't seen any data logging going on either. That doesn't mean that some of these guys aren't doing it though. Im just not SEEING them do it. A lot of sponsored cars and "test mule" cars from various aftermarket manufacturers show up at Marina, so who knows what they're doing?
Haha. The most that I do that could be considered "data logging" , is to put a few little white lines on the side of my tread so I can tell how far my tires are rolling onto the sidewalls.

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Soccerluvr4

· #7 · Mar 26, 2014

straybullitt said:
Why do I run in ESP?

Good question! At first, everyone that I knew was in that class and I wanted to race with them. Then, I discovered, that the leader in FS was, usually, a little faster than the leader in ESP, so, I could be more competitive in ESP.

Also, my car is unimpeachable as far as tech goes...:lol:

I like being the underdog with a stock car, I had a great time chasing the leader all last year and got within 10ths of him at the end of the year... My rookie year in autocross.

I considered going into FS this year because, sadly, Bob, the winner last year, isn't able to attend this year. My ego is getting the best of me though and I'm staying in ESP and going to TRY to win the class because it is the last season that we will be racing at this location (Marina).

I'm still chasing the leader of FS... Just doing it from ESP.

I haven't seen any data logging going on either. That doesn't mean that some of these guys aren't doing it though. Im just not SEEING them do it. A lot of sponsored cars and "test mule" cars from various aftermarket manufacturers show up at Marina, so who knows what they're doing?

Haha. The most that I do that could be considered "data logging" , is to put a few little white lines on the side of my tread so I can tell how far my tires are rolling onto the sidewalls.

Ron, so what class do you think I'll be in with my next mods and 4.10s?

Static_LV

Discussion Starter · #8 · Mar 27, 2014

Interesting, out here I haven't seen anything in FS come close to the ESP numbers. I am currently taking 1st or 2nd in FS and I am usually 4-7 seconds raw off the ESP leaders depending on class. Granted the ESP leaders are running HEAVILY modified setups but in stock trim there is no way I am competing with those guys.

-Static

Soccerluvr4

· #9 · Mar 27, 2014

Static_LV said:
Interesting, out here I haven't seen anything in FS come close to the ESP numbers. I am currently taking 1st or 2nd in FS and I am usually 4-7 seconds raw off the ESP leaders depending on class. Granted the ESP leaders are running HEAVILY modified setups but in stock trim there is no way I am competing with those guys.

-Static

Time to modify!

Static_LV

Discussion Starter · #10 · Mar 27, 2014

That's a never ending road that I'm not going down just yet

. I will do some stock class mods but that's it for a couple seasons.

-Static

Soccerluvr4

· #11 · Mar 27, 2014

Static_LV said:
That's a never ending road that I'm not going down just yet . I will do some stock class mods but that's it for a couple seasons.

-Static

You do have a pretty good starting platform already...... I plan on graduating out of ESP next season.

straybullitt

· #12 · Mar 27, 2014

Soccerluvr4 said:
Ron, so what class do you think I'll be in with my next mods and 4.10s?

Im no expert in the SCCA class structure but if I had to guess, I'd say probably OSP.

straybullitt

· #13 · Mar 27, 2014

Static_LV said:
Interesting, out here I haven't seen anything in FS come close to the ESP numbers. I am currently taking 1st or 2nd in FS and I am usually 4-7 seconds raw off the ESP leaders depending on class. Granted the ESP leaders are running HEAVILY modified setups but in stock trim there is no way I am competing with those guys.

-Static

There are no 5 litre cars that are regulars in ESP up here... THANKFULLY!
The one guy that had a 5.0 wasn't a regular and apparently isn't driving his car this year so isn't in ESP any longer.
Nobody has been so fast that a set of R compounds on my car wont take care of... even the guys that have showed up on R's...

So far, that is...:lol:

And I WILL use the R's if necessary!

The leader in F stock drives a 5.0 and the dude is smooth as silk. We were talking, one day, about modding cars and came to the same conclusion that you did, basically... If someone else can get in your car and turn a three second better lap... the problem is NOT the car.

Static_LV

Discussion Starter · #14 · Mar 27, 2014

Yeah I know I am not yet pushing the envelope of my 5.0 yet but I am pushing the edge of the current tires. I am on 220 tread wear Pirellis. As daily tires they are not bad at all but they are nowhere near the RS3s or r-comps.
The other problem here in Vegas is the heat. When it gets summer hot the Pirellis seem to lose a LOT of lateral grip. I have had a couple of other mustang guys ride along (both ESP both a lot faster than me) and they were surprised at the point I would start to get loose and how much earlier I had to be on the brakes.

I would love to let one of them drive mine next time and see what the outcome is.

-Static

straybullitt

· #15 · Mar 27, 2014

Yeah, the heat must be a killer!
You'll be a LOT happier on the Hankooks or any 140-200 tire. I use Dunlop Dirrezzas.
They don't seem to "grease up" as fast but I've never raced on a 110 degree day.

So where do you guys race in Vegas?

Static_LV

Discussion Starter · #16 · Mar 27, 2014

The daytime events are usually out at the Las Vegas motor speedway. Lately it has been the south bullring parking lot but we have run on others. We also have events out at the old airfield in St George Utah about and hour and a half away. Night time events last year were at the silverton casino not sure if that will be the case or not this year.

Looking at most of the real competitive guys most of them out here are running the Hankooks if they aren't on Hoosiers so I am leaning that way pretty hard. We have a couple of national level drivers here and I am making a grand assumption that they know more than I do as a newb about what works in this environment.

The real killer in the heat is working a corner in the sun and a good wind for a couple hours. Last summer we had a couple corner workers with heat stroke problems. It happens quick out here. People forget to stay really hydrated and that's it.

Where do you guys run up there? I am up there for work pretty regularly and would love to stay the weekend for some track time.

-Static

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straybullitt

· #17 · Mar 27, 2014

This will be the last year for events at Marina. We race at a decommissioned Army airfield. It's on a giant concrete ramp area that was used for parking helicopters. Soccerluvr4 and I have also begun attending SCCA events at the Oakland coliseum in Oakland CA.
The event that I'm REALLY looking forward to, this year in June, is the TireRack/ SCCA Nationals at Crows Landing CA. They set up about a 90 second course on these GIANT ex-Naval airbase runways and I understand that speeds get into the 100+mph range. It should be a BLAST!!!

Static_LV

Discussion Starter · #18 · Mar 27, 2014

That sounds like fun. I am seriously thinking about San Diego in a couple weeks.

-Static

Soccerluvr4

· #19 · Mar 27, 2014

straybullitt said:
This will be the last year for events at Marina. We race at a decommissioned Army airfield. It's on a giant concrete ramp area that was used for parking helicopters. Soccerluvr4 and I have also begun attending SCCA events at the Oakland coliseum in Oakland CA.

The event that I'm REALLY looking forward to, this year in June, is the TireRack/ SCCA Nationals at Crows Landing CA. They set up about a 90 second course on these GIANT ex-Naval airbase runways and I understand that speeds get into the 100+mph range. It should be a BLAST!!!

Looking forward to that one also!!! Gears probably would hurt me a bit since I'll be in 4th at 100.

straybullitt

· #20 · Mar 27, 2014

Static_LV said:
That sounds like fun. I am seriously thinking about San Diego in a couple weeks.

-Static

It's totally addictive!

We'll all have to meet up one of these days and wear out an expensive set of tires together! :thumb:

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