[Static_LV]

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.

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[Static_LV]

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.

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[Static_LV]

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.

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[Static_LV]

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.

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[Static_LV]

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.

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[Static_LV]

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.

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[Static_LV]

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

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[Static_LV]

Addictive doesn't even begin to describe it, but yeah I need to find a tire sponsor riki-tik.

Running on a bigger track has a lot of appeal for our platforms. Being able to take advantage of some acceleration out of turns and on the odd straight is really where the I could see my car come into its own.

-Static

 

[Static_LV]

Nice, sounds like your weekend plans are coming together

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[Static_LV]

I know what you mean about the tight courses. Even worse, the guys on the track team are all running little FWDs On the good side this means that some of the corners that they make tricky for them are a blast to trail brake into with just enough momentum to rotate clean and get right back on the gas as soon as the line starts to open back up. The bad side is some of their favorites like the decreasing distance slaloms just suck when it gets down to 2 car lengths and the car they are measuring off is a Civic EK hatch that I can put comfortably in my trunk or backpack.

I was watching some of Sam Strano's videos of his FS runs last year and I would love to run on some of the courses he was on. Its like they were made for the 5.0.

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[Static_LV]

I have only been on one course so far which could be considered a "long straight" but even at that I never hit the rev limiter in 2nd. I would love to actually hit third sometime
After getting burned the first time I encountered a decreasing distance slolam, I make sure to pace those things off every time I do a course walk. It seems like a little thing but you can definitely tell the people who aren't ready for it (they are the ones with the last cone in the slolam stuck under their car) Increasing distance setups are interesting too, same track but backwards in the afternoon runs. If you are tricky, you can come out of them faster than you went in, if not you wind up sideways coming out of the series and completely screw your time for that run, don't ask me how I know.

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[Static_LV]

Well, after a couple months of waiting for my new wheels and tires to come in, I finally got to run them last weekend and what a difference! I am still trying to find the new traction limits and it is going to take a while to go through the data that I was able to collect from the last event but the difference is night and day. This last event was out in Utah on an old airport with 3 different surfaces, asphalt, flat smooth concrete, and heavily grooved concrete. The new tires performed very well on all surfaces and the lighter unsprung weight definitely helped minimize lateral shift on high g transitions between surfaces. This was a bigger track than I have run in the past and it was nice to be able to use 3rd gear for once. All in all, very happy with the new wheels and tires. Will update throughout the season with further experiences.

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[Static_LV]

Ah sorry, I thought I posted what I ordered up above. I went with the Enkei Racing PF01 18x8.5 and Hankook RS-3 v2 200TW in 255/35R18. It's kind of an odd setup and they look tiny on the car but it does have the advantage of lowering the CG by over an inch without changing any suspension components or ride height.

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[Static_LV]

Sucks to hear about the series cancellation, it sucks to do mods getting prepped for something only to have the rug pulled out at the last second.
One the good side, it sounds like you are well on the way to ESP greatness. What new car are you building?

We were racing in St. George at the old airport. I am digging the new setup, and I am definitely the weak link in the equation so it is time to do some data analysis to figure out what I can do better.

Here are a couple of links to the final run of the day for me on day 2.

Inside view with with telemetry and reference lap overlay

https://www.youtube.com/watch?v=C1aTY7Ztz78

Outside view

https://www.youtube.com/watch?v=NnF6VCVAwXI


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[Static_LV]

I am using an application called Harry's Lap Timer. The OBDII data is being collected with a PLIX OBDII wireless transmitter. GPS and GeForce data are from the iPhone internal sensors.

The info is better than nothing but it is far from good. The sampling rate are not nearly fast enough to really get a full data set for analysis but on the good side major mistakes I make do show up in the analytics. It's hard to see in the video but the series right before the slalom on the back side I have a major hesitation which puts me off the line for a good slalom entry which in turn screws up my break point and downshift point for the hairpin.

I lose almost a second there vs my reference lap and then go on to make it up and then some on the last third after the hairpin.

The nice thing is that I can see the things I need to work on for my driver mod but it isn't really sophisticated enough to do more than rudimentary car setup analysis. That does remind me, I really need to find a set of scales like badly.

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[Static_LV]

The video without telemetry was taken with a GoPro. Supposedly there is a way to integrate that with the app and pull in the GoPro video but I haven't messed around with that.
I have mainly been using the GoPro to see things like tire deflection and suspension motion.
I am kind of worried that it is going to get destroyed one of these days shoving it in wheel wells and such but it is nice to be able to see what is going on under load.

-Static

 

[Static_LV]

I find that duct tape works pretty well if you have a semi decent mounting surface.

-Static


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