200tw tires for Track use

[GTIfan99]

Stock.

View attachment 252893

Stock height and rubbing? Ouch.

Maybe because you're on 18's?

 

[DerHase]

There's something to be said about running a taller sidewall for more speed up top too. Autox for sure is better with a shorter tire but for tracking I prefer a taller tire

Taller tires will basically never make you faster, unless you're talking about spinning off the line. Or if you're RPM limited in upper gears (or for autocross, second gear).

Even then we're talking a 1.2% difference. So it'll feel like a 2-3hp/wtq difference at the very most(in favor of the smaller tire). For all practical purposes you'd basically never notice a difference from that alone.

What would be noticeable is that, combined with added drag and weight (1lb per tire), plus you can't fit a 10in wide wheel on a GTI (easily) so it'll be pinched a bit on the wheel. A shorter tire would feel quicker because you can run through all the gears quicker. If this weren't the case... nobody who drag races would be putting in 4.10/4.56/4.88 gears vs normally stock 3.42 or 3.73s on most domestic stuff.

Strut cars wear tires stupid no matter what you do, but having a very mild stretch helps wear the outer edges just a little bit less stupid. If you follow Andy Hollis's testing and some of the forums he's on (including the forum that shall not be named) he talks about wheel width being more important than tire width for track. For autocross - more tire is usually better, and more wheel is usually better regardless of if one or the other is limited. I know that when I started putting my 205 RT660s on 15x8in wheels on my Mazda2, my tire wear and overall grip/feel was WAY better than it ever was on a 7.5in wheel FWIW.

If I were autocrossing (and wanted to be competitive) I'd probably make a 255 fit, but unless we were able to fit at least a 9.5in wide wheels, I'm not going to bother.

Stock height and rubbing? Ouch.

Maybe because you're on 18's?

Those are 17x9 Apex wheels with 245/40R17s.

My "build" thread is only a couple pages long in my sig. You can check it out to see what I had to do to fit everything.

Some time tomorrow I'll get some measurements for you since they're off the car to be flipped on the wheels. (Getting tire machines in my garage is one of the best things I impulse bought when the pandemic started... LOL).

 

[krs]

I didn’t realize the GTI an R were that different on the rear end to where rubbing is a concern.

How much of that is attributed to rim width? I’m on 8.5” wide and I was surprised the 255’s fit with no issues, including at full turn on the front. I am lowered, but not slammed.

 

[scrllock]

I didn’t realize the GTI an R were that different on the rear end to where rubbing is a concern.

How much of that is attributed to rim width? I’m on 8.5” wide and I was surprised the 255’s fit with no issues, including at full turn on the front. I am lowered, but not slammed.

You can fit a 255 with the right tire and offset, 9" wheels shouldn't be a problem. 660s are just that wide.

Taller tires will basically never make you faster, unless you're talking about spinning off the line. Or if you're RPM limited in upper gears (or for autocross, second gear).

Even then we're talking a 1.2% difference. So it'll feel like a 2-3hp/wtq difference at the very most(in favor of the smaller tire). For all practical purposes you'd basically never notice a difference from that alone.

A taller tire can be the difference between having to shift up into 4th or 5th (and then downshift twice vs once). And you have less spring rate, more contact area, everything else being equal (comparing a 245/35 to a 245/40 for example). I'd say the difference is there, but probably minute enough that personally I'd rather err in favor of comfort (and thus taller profile), if they're street tires.

 

[DerHase]

245/40R17 RT660 mounted on a 17x9 ET42 Apex SM-10.

(the level/floor is touching tire only, not the rim)

259mm (10-3/16") wide overall.
173mm (6-13/16") hub mounting surface to inside sidewall (basically like backspacing is measured but to the edge of the sidewall)

The tires have 4 days at VIR on them, and due to the tread profile(tiny bit rounded on the edges), I wouldn't take the following measurement as 100% accurate, but the actual treadwidth comes out to at least 245mm (9-5/8"), may look more like 250mm (9-27/32") if they were brand new.

For science!

You can fit a 255 with the right tire and offset, 9" wheels shouldn't be a problem. 660s are just that wide.



A taller tire can be the difference between having to shift up into 4th or 5th (and then downshift twice vs once). And you have less spring rate, more contact area, everything else being equal (comparing a 245/35 to a 245/40 for example). I'd say the difference is there, but probably minute enough that personally I'd rather err in favor of comfort (and thus taller profile), if they're street tires.

It's a 1.2mph diff at 100mph(245/40 vs 255/40 R17s). It's a 4mm (3/16in roughly) difference in sidewall height.

I'd agree going for the taller option for an 18in wheel(esp for a street driven car), but for 17s I'd go for the shorter tire as it'll still have much more sidewall than any remotely equivalent usable 18in tire.

I'm going to stick to a 17in wheel for as long as I can Partially because I'm a cheapass, partially because it lets me get stupid on curbs

 

[Salami]

It's a 1.2mph diff at 100mph(245/40 vs 255/40 R17s). It's a 4mm (3/16in roughly) difference in sidewall height.

Except he is comparing different aspect ratios, not section widths.

245/35R18 vs 245/45R18 in his example.

12.25mm sidewall height difference and 3.9mph speed difference at 100mph.

 

[scrllock]

Except he is comparing different aspect ratios, not section widths.

245/35R18 vs 245/45R18 in his example.

12.25mm sidewall height difference and 3.9mph speed difference at 100mph.

yeah section tread width is a different story. the increased weight is almost always worth the extra width if you can fit it, as long as you're taking corners. I'd be running a 255/35 instead of my 245/40 if they had been in stock.

 

[krs]

So today was my second day in the RT660’s. I was told these would get better after one full heat cycle, and I’d say I agree.

I definitely like these better than I did the v730’s after a few days. I’m not all that great and articulating descriptions, but it seems the tires just didn’t slide as much, and held the grip better.

However there is one tire that seems to be chunking out already at the seam across the tread. I emailed tirerack to get their take.

 

[jmblur]

So today was my second day in the RT660’s. I was told these would get better after one full heat cycle, and I’d say I agree.

I definitely like these better than I did the v730’s after a few days. I’m not all that great and articulating descriptions, but it seems the tires just didn’t slide as much, and held the grip better.

However there is one tire that seems to be chunking out already at the seam across the tread. I emailed tirerack to get their take.
View attachment 252966

Weird wear, seems like potential mfg defect.

 

[GTIfan99]

So today was my second day in the RT660’s. I was told these would get better after one full heat cycle, and I’d say I agree.

I definitely like these better than I did the v730’s after a few days. I’m not all that great and articulating descriptions, but it seems the tires just didn’t slide as much, and held the grip better.

However there is one tire that seems to be chunking out already at the seam across the tread. I emailed tirerack to get their take.
View attachment 252966

Definitely a defect.

 

[bfury5]

So today was my second day in the RT660’s. I was told these would get better after one full heat cycle, and I’d say I agree.

I definitely like these better than I did the v730’s after a few days. I’m not all that great and articulating descriptions, but it seems the tires just didn’t slide as much, and held the grip better.

However there is one tire that seems to be chunking out already at the seam across the tread. I emailed tirerack to get their take.
View attachment 252966

I've seen this in a LOT of 660s, consensus seems to be just send it and the mark will wear itself away. If TR will give you a new tire though, that's obviously preferable

 

[bfury5]

I don't like creating spring rate with the rear tire pressure, unless I have to.

From my experience, once you get over mid 40 psi in the rear, the rear starts to have a line that if crossed, you get snap oversteer. Under mid 40's, it's more progressive.

I used to run pretty low in the rear in STH trim. Rear didn't need the artificial spring rate, and lower PSI have the tire a lot of slip angle tolerance

I'm thinking about going 245 40 17 RT660 next to get a tire that's likely as wide as my 255 V730, but with a shorter sidewall.

There's a noticed difference in acceleration with shorter tires.

I ran 245/40-17 for about 2 years, it was great especially on a manual car. I've never seen limiter in 2nd on an autocross course, so the extra acceleration everywhere was worth whatever small mph loss there is

 

[GTIfan99]

I used to run pretty low in the rear in STH trim. Rear didn't need the artificial spring rate, and lower PSI have the tire a lot of slip angle tolerance

I ran 245/40-17 for about 2 years, it was great especially on a manual car. I've never seen limiter in 2nd on an autocross course, so the extra acceleration everywhere was worth whatever small mph loss there is

I've only shifted to 3rd once. Our clubs speeds seem to slowly go up in 3 year cycles, then we have an incident, and back to tight slaloms and lower speeds.

 

[mrmatto]

I've only shifted to 3rd once. Our clubs speeds seem to slowly go up in 3 year cycles, then we have an incident, and back to tight slaloms and lower speeds.

Where are we in the cycle this season?

 

[Autobahn]

Picture of my 255/35/18 V730’s after one event, top tire is the front which has around -2.3 camber. Looks like I could use some more camber dailed into my plates.

The bottom tire is the rear, camber looks fine at around -2.2. I got some good heat into them and they still felt manageable.

They took about 1.5 laps before I felt confident to start pushing.

Initial testing seems to be around 1.5 - 2.0 seconds slower than the RE71R at Auto Club Speedway Roval though I would like to get some more use before full judgment. Faster lap times shifted to my 4/5th lap compared to my 2/3rd with the RE71R. The car tends to heat soak a bit more before getting up to speed for a hot lap.

I like the stiffness of the sidewalls, I think I can run less than 35 psi hot with the right camber up front for a bit more grip. Steering response wasn’t bad too.

Overall good price point and can handle the heat for a small sacrifice in lap times.