818SR Tire Options to maximize handling when off of the track

[bnr32jason]

Well they were using a 255 in the rear, so a 205 in the front is a bit small still I think. Especially since every picture we've seen that shows the tires close enough to see the size has a 225 front tire. But I haven't seen anything from the most recent track day of course.

205's on the front and 255's in the rear seems like a recipe for gobs of understeer.

[Erik W. Treves]

I would not bank on 205's on these cars giving you understeer.

[Wayne Presley]

I've been asking this for months, no one has answered.

Wayne do you think it would be possible to fit 235's on the front without body modifications?

I would say that you could but don't know if you need bigger unless you go bigger on the rear

[Wayne Presley]

Hi Wayne,

I like the staggered look also. Can you please tell us what tire sizes were used on the 818R up front during the recent testing?

Thanks!

Second test had 225/40/17 on the 818R with 255/35/18 Hossier R6's

[bnr32jason]

I would say that you could but don't know if you need bigger unless you go bigger on the rear

I don't want to run 235's, but if I end up running the factory 5x100 setup, the set of wheels I want is only available in 18x9 in 5x100, so I don't want to run a 225 on a 18x9. I'm still searching for different wheels that I like in smaller sizes, but coming up empty so far.

Thanks for the information!


Also thanks for the tire size information. I knew there was no way they were running a 205 on the 818R.

[apexanimal]

205? Do you have a source for that information? That seems awfully small.

I know the gallery shots shows a 225/40 for both the S and the R. I can't imagine them using such a small tire for track testing.

It's been posted in several threads now... They wanted a 225 but had to go 205 due to availability...

[apexanimal]

I don't want to run 235's, but if I end up running the factory 5x100 setup, the set of wheels I want is only available in 18x9 in 5x100, so I don't want to run a 225 on a 18x9. I'm still searching for different wheels that I like in smaller sizes, but coming up empty so far.

Thanks for the information!


Also thanks for the tire size information. I knew there was no way they were running a 205 on the 818R.

Most of the fastest miata s are on 225s on a 9" wheel with no issues...

They were running a 205 Hoosier r6 on the front on the r during testing

[metalmaker12]

I am running 235/45r17 on the street all around and a staggered set will be coming

[bnr32jason]

It's been posted in several threads now... They wanted a 225 but had to go 205 due to availability...

He just said they were running a 225.

[JeromeS13]

He just said they were running a 225.

Correct, for the second test, not the first round....

[Wayne Presley]

Both cars had a 30mm split on the second round (215/245 S and 225/255 R)

[longislandwrx]

The prices on the RE-11A are much cheaper than their RE-11 counterparts, and not available in very many sizes. Maybe its a promotional initial run? Seems funny. I wish precise wheel well measurements were available... I'd pick up some RE-11s... ridiculous prices right now.

most likely i'll use a 225/40R18 in front and a 255/35R18 in the rear both on 18x9s time will tell how much room there is.

what are everyone's thoughts on running 255s all the way around? It would be nice to rotate tires front to back

[Silvertop]

The prices on the RE-11A are much cheaper than their RE-11 counterparts, and not available in very many sizes. Maybe its a promotional initial run? Seems funny. I wish precise wheel well measurements were available... I'd pick up some RE-11s... ridiculous prices right now.

most likely i'll use a 225/40R18 in front and a 255/35R18 in the rear both on 18x9s time will tell how much room there is.

what are everyone's thoughts on running 255s all the way around? It would be nice to rotate tires front to back

I'd be a little concerned about the effort required to steer the thing at very low speeds, or when parking with 255's on the front. Are you planning on leaving the power steering in place? If you want to be able to rotate tires, you might want to consider 225's on all four corners. How much power are you planning on making?

I'm planning on using the stock 16" wheels, which pretty much means the biggest tire I can run will 225/50-16. My big decision will be whether to run them on all four corners (so I can rotate them), or whether to run 205/55-16 on the front. This may provide better grip balance per some of the discussion above,along with easier slow speed steering. Of course, I'm doing an NA build which will only yield about 200 flywheel horsepower, so I shouldn't need quite as much tire as some.........

[longislandwrx]

My first new tires for my AWD WRX were 225/50R16 RE-01Rs on the stock 05 rims. They were so wonderful, but I was only putting about 260whp through 900mm of tire.

steering will be manual.

power, not sure what RWD driveline loss will be but my current setup should be good for over 325 whp.... I think too much for a 225. I'd rather have a little more safety grip in the back.


I had grippy 225s on my rx7 with manual steering and I don't think it was ever an issue. I would say go for it if I were you.

[Wayne Presley]

Remember that rear tire size isn't based on HP, it affects the handling balance on the car.

[longislandwrx]

Correct, but I need to leverage that vs not exploding the tires every time I hit the gas. Do you think that a pair of 225s could effectively put 330hp to the ground without having to constantly modulate the throttle?

[Wayne Presley]

Correct, but I need to leverage that vs not exploding the tires every time I hit the gas. Do you think that a pair of 225s could effectively put 330hp to the ground without having to constantly modulate the throttle?

Nope, not even close....Here's 338 RWHP put through 235/40-17 Yokohama A048's

[longislandwrx]

confused. not even close to putting down the power? or not being close to too much power for the tire?

[bnr32jason]

He is saying 225's would be too small to handle that much power. The tires in the video were 235mm street legal race tires. So 225mm street performance tires just wouldn't be able to handle the power.

[apexanimal]

Correct, for the second test, not the first round....

Got ya... Didn't see that one...

[Xusia]

He is saying 225's would be too small to handle that much power. The tires in the video were 235mm street legal race tires. So 225mm street performance tires just wouldn't be able to handle the power.

That how I read that too, but in the video the tires seem to handle the power just fine. The way we have interpreted that comment would make more sense if the tires slipped or something. But it didn't look they did, so... ??

[longislandwrx]

That how I read that too, but in the video the tires seem to handle the power just fine. The way we have interpreted that comment would make more sense if the tires slipped or something. But it didn't look they did, so... ??

and there lies my confusion... hooked up pretty well, just a few chirps.

[Wayne Presley]

In the video I had to lift by 6000 rpm in first, 7500 in 2nd due to wheelspin. The 818 Sube power has way more torque that the Elise so wheelspin will be an even bigger problem. If you look at the lap in the blue car, the fast right hander, I get the car sideways on the exit just with a little more throttle pedal and virtually no lag. The turbo Elise on the track you had to give it a little throttle to spool up the turbo then you're able to modulate the power delivery.

[bnr32jason]

You can see subtle cues in the Elise video of the car getting nervous and slightly twitchy at high RPM's and that is on R-compounds.

That's why it's safe to assume that 225's on the rear of a mid-power (250whp+) 818 would be troublesome.

[Xusia]

Hey Wayne, on a side note, I really appreciate you taking the time to answer all our questions and wanted to say thank you. You've been very forthcoming (and patient!!). Sharing your experience with the 818 testing has been super insightful - pure gold, really. And I'm sure I'm not the only one who feels that way!

So again, thank you!

[Silvertop]

Hey Wayne, on a side note, I really appreciate you taking the time to answer all our questions and wanted to say thank you. You've been very forthcoming (and patient!!). Sharing your experience with the 818 testing has been super insightful - pure gold, really. And I'm sure I'm not the only one who feels that way!

So again, thank you!

I'll second that!