Spacers and Track width
 

What's everyone thoughts on Track days and Spacers?

IMO the "theory" behind it sounds great, but response/feedback/drawbacks from experienced (track day) regulars would be awesome.

The idea atm is to buy RPF1s 17 x 8 +45 (because its affordable and it fits over the AP Racing Endurance)
Wrap them in sticky A050s or Z221 - 235 40 17
Then slap some 20 or 25mm spacers

****
My aim is to push out as much I can from these cars without putting down large sums of money.
****

Cheers

The theory is simple: Don't.

What suspension deficiency are you trying to address with spacers? I ran 17x8" +44 without issues. 235/40-17 tires, too.

-alex

high speed sweepers without dancing

The lack of information in your reply doesn't help.
Would you care to elaborate? What is your car doing that you don't like? What do you mean by "high speed" and "dancing"?

Track - Winton Motor Raceway
Turn 5 to 6
130km/h give or take 5km/h (AD08Rs - 32PSI Hot) - high speed sweeper is just the name given to it
Dances - as in tail is in and out and I have to do micro corrections through it

I have 7 clicks down from the front and 5 from the rear because I like the over steer characteristics, I'm well aware this plays a factor in how it "dances" but the current settings suits the track

Experience level of the track - 5 with the 86
**I've driven a 34 GTR (400kg heavier) with less development time going through that same turn more stable and faster (yes I know these are 2 completely different cars)

Car Mods (in short)
UEL Headers (4 to 1) & Overpipe 2.5'
OFT Stage 2 UEL E85
Perrin Oil Cooler

Shockworks Coilovers (6f / 5r) - camber 3.4 front - 2.7 rear
Cusco Front Sway 20mm
Cusco Rear Sway 16mm
Cusco Rear Lateral Link - Lower Control Arms
Cusco Rear Lateral Link - Toe Arms
Cusco 4.556 Final Gears + Solid Pinion Spacer

Volk Racing TE37SL 18 x 9.5 +45
Yokohama Advan Neova AD08R - 255 35 18

Essex AP Racing Endurance Competition Brake Kit
Project Mu RC09 Club Racer (F1102) - Front / Rear

I was actually more interested in the results/feedback of no spaces to spaces transition rather then "what my car doing that you don't like" hence why I tried not to mention it in my original post

I've added more information in the above comment

The most popular fitment with the track guys seems to be a 17x9 wrapped in 245/45..17x8 with a 20mm spacer will have more poke than just a 17x9 if im not mistaken and I read somewhere that more poke creates more turbulence which in turn slows down the car.

I actually want 17 x 9 +35 RPF1 with no spacers to start off with, I tried asking the forum but never got an answer.
http://www.ft86club.com/forums/showthread.php?t=72989
* I am under the impression they would clear the spokes (because the sprint kit does) and the barrel (because they fit under the 17 x 8 +45) but this is theoretical, a solid image of an Endurance Kit or template behind a set of RPF1s 17 x 9 +35 would be awesome

RPF1 17 x 8 +45 was the on the official Essex fitment page
http://www.ft86club.com/forums/showthread.php?t=64282

Poke should be almost identical, the difference wouldn't be enough to disturb me.

17x9 et 35 RPF1s clear the AP calipers by a narrow margin, but they clear. Just get those and 245/40/17 tires and call it a day.

I had one of my mates check the endurance kit template behind his rpf1 17 x 9 +35, he said they do not clear the barrels

There are MUCH better ways to correct that than through increasing track width. Plus, 40mm of extra width probably isn't going to do anything for stability.

I would consider damper adjustments, camber/toe settings or a diffuser before resorting to spacers to correct instability.

While I agree that the OP should change the fundamentals in his setup first if he has a handling condition he doesn't like, I fundamentally and strongly disagree with this. In fact, the formula for Static Stability Factor uses track width as one of the inputs (the other being CG height).

There's a reason every major racing series has very strict limits on track width with big penalties for going over.

Isn't SSF a measure of rollover risk? I think OP is referring to high speed oversteer.

OP, if you like the car's balance in low speed corners and only want to increase high speed stability, I would think a rear diffuser (and possibly a wing) would be the way to do it.

You're missing my point, which is that saying extra track width won't help stability contravenes basic physics. It probably won't fix the OP's problem but this is an error of fact.