Maximum Wheel and Tire Width Fitment Guide for the FD
In 2014 I won the Atlantic Regional Time Attack Championship with my 93 FD stock drive train and 245/45/16 on 8.5 wheels.
This year our track is hosting the National Competition and I wouldn't mind owning that title as well. I have the home court advantage on a very technical 1.6 mile 11 turn short track with many elevation changes and a top speed of about 110 MPH.
I think going to a wider tire would help my chances significantly. The track is not the smoothest and I think a skinny 18 inch would do more harm than good. I have been toying with the idea of a 295/35/17.
The front and rear fenders are rolled and beat out with a BFH so that is not a concern. I am concerned with rubbing on control arms, and when turning, along with not altering the scrub radius so that it changes the turn in of the car more than my current wheels (16x8.5+40 F / 16x8+30 R. Does anyone have a track setup that they have tried. or could provide some insight; it would be appreciated.
I race 18x11 +45 on 295/30-18 Ventus TDs Front and Rear on my stock body FD.
That wheel width is the recommended "optimum" by Hankook looking at their new tire spec chart.
I have rolled/slightly pulled front fenders, rolled rear, Ohlins coilovers, Tripoint swaybar shortened 2" for full steering lock, -2.4deg Front, -1.2deg Rear camber.
If you are the type of driver that drives up the limits and then backs off a hair you will be WAAAAAAAAAAAy faster with this set-up.
If your fenders are as super rolled as you say, I personally would run 18x11.5 +38 with the 295/30-18 Ventus TD as I prefer these soft sidewall tires with a tiny bit of stretch (my 265 TDs on 10.5 wheel felt a little better).
I used Forgestar F14 and they are 22lbs in 18x11 +45 and ~ $1,500 as set.
This year our track is hosting the National Competition and I wouldn't mind owning that title as well. I have the home court advantage on a very technical 1.6 mile 11 turn short track with many elevation changes and a top speed of about 110 MPH.
I think going to a wider tire would help my chances significantly. The track is not the smoothest and I think a skinny 18 inch would do more harm than good. I have been toying with the idea of a 295/35/17.
The front and rear fenders are rolled and beat out with a BFH so that is not a concern. I am concerned with rubbing on control arms, and when turning, along with not altering the scrub radius so that it changes the turn in of the car more than my current wheels (16x8.5+40 F / 16x8+30 R. Does anyone have a track setup that they have tried. or could provide some insight; it would be appreciated.
I race 18x11 +45 on 295/30-18 Ventus TDs Front and Rear on my stock body FD.
That wheel width is the recommended "optimum" by Hankook looking at their new tire spec chart.
I have rolled/slightly pulled front fenders, rolled rear, Ohlins coilovers, Tripoint swaybar shortened 2" for full steering lock, -2.4deg Front, -1.2deg Rear camber.
If you are the type of driver that drives up the limits and then backs off a hair you will be WAAAAAAAAAAAy faster with this set-up.
If your fenders are as super rolled as you say, I personally would run 18x11.5 +38 with the 295/30-18 Ventus TD as I prefer these soft sidewall tires with a tiny bit of stretch (my 265 TDs on 10.5 wheel felt a little better).
I used Forgestar F14 and they are 22lbs in 18x11 +45 and ~ $1,500 as set.
In 2014 I won the Atlantic Regional Time Attack Championship with my 93 FD stock drive train and 245/45/16 on 8.5 wheels.
This year our track is hosting the National Competition and I wouldn't mind owning that title as well. I have the home court advantage on a very technical 1.6 mile 11 turn short track with many elevation changes and a top speed of about 110 MPH.
I think going to a wider tire would help my chances significantly. The track is not the smoothest and I think a skinny 18 inch would do more harm than good. I have been toying with the idea of a 295/35/17.
The front and rear fenders are rolled and beat out with a BFH so that is not a concern. I am concerned with rubbing on control arms, and when turning, along with not altering the scrub radius so that it changes the turn in of the car more than my current wheels (16x8.5+40 F / 16x8+30 R. Does anyone have a track setup that they have tried. or could provide some insight; it would be appreciated.
This year our track is hosting the National Competition and I wouldn't mind owning that title as well. I have the home court advantage on a very technical 1.6 mile 11 turn short track with many elevation changes and a top speed of about 110 MPH.
I think going to a wider tire would help my chances significantly. The track is not the smoothest and I think a skinny 18 inch would do more harm than good. I have been toying with the idea of a 295/35/17.
The front and rear fenders are rolled and beat out with a BFH so that is not a concern. I am concerned with rubbing on control arms, and when turning, along with not altering the scrub radius so that it changes the turn in of the car more than my current wheels (16x8.5+40 F / 16x8+30 R. Does anyone have a track setup that they have tried. or could provide some insight; it would be appreciated.
if you can fit an 11" wide wheel, I would find a tire tread width around 10.5-10.9" wide. this will give you the trapezoidal shape that you want with the tire. when you think about turning, the tires sidewall is already stretched into position and holds the tread in place better than a tread width wider than the tire beads, which can lead to the tires sidewall flexing under load and possibly leading to unpredictable let go of the tire (it just let go).
find a race car that has tread widths wider than wheel widths in racing.
This is for performance, more comfort can be had with wider tires than wheel width as the sidewalls flex over bumps more. its not a huge difference but a difference.
What tires are you running? make/model right now?
traction going forward is different than turning traction.
My philosophy when it comes to handling (turning) is to maximize grip and confidence/predictability. This lends itself to a smaller tire sidewall and slightly stretched sidewalls. this holds the tread in place when turning. the width gains traction as long as you can get it to temp.
straight line traction is about going to a taller tire on a small diameter wheel and lowering the PSI to elongate the contact patch in the forward direction. you run as wide as you can get to temp and gain traction. the more WHP, the wider the tire.
if you are just spinning tires, perhaps your tires aren't to temp? the tires are not a sticky tire, or your tires aren't wide enough and overheat.
its normal for cold tires on cold surfaces to have poor traction. this will be the case with any tire you choose.
traction going forward is different than turning traction.
My philosophy when it comes to handling (turning) is to maximize grip and confidence/predictability. This lends itself to a smaller tire sidewall and slightly stretched sidewalls. this holds the tread in place when turning. the width gains traction as long as you can get it to temp.
straight line traction is about going to a taller tire on a small diameter wheel and lowering the PSI to elongate the contact patch in the forward direction. you run as wide as you can get to temp and gain traction. the more WHP, the wider the tire.
if you are just spinning tires, perhaps your tires aren't to temp? the tires are not a sticky tire, or your tires aren't wide enough and overheat.
its normal for cold tires on cold surfaces to have poor traction. this will be the case with any tire you choose.
I am looking to maximize straight line traction while being able to maintain turning traction. Straight line traction is more important than turning traction for street use for me, and this car will only see a track on rare occasion.
Being a street car, it is rare that any tires I put on will get up to proper temps for great traction. So I guess I am looking more for the best cold traction I can find.
You will always be faced with trade offs. the trade off being longevity vrs. performance (grip). I don't know of a tire that is going to last 50K miles and grip like a beast.
I will only run extreme sports tires on my 7, because I spent a lot on the car, and tires are what makes everything happen between the car and the road. Why would I spend tens of thousands on the car and skimp on the most important mod? that is just me.
If you really look around you can find deals on good tires. I purchased my Kumho XS 265/35/18 new for 600 shipped.
I was more getting at if a all season performance tire will perform better If not driven at the limit? Because of the tires temp. Perhaps a better question would be will an all season tire perform better at a lower temp? I suppose it doesn't matter as I'm in So. cal lol but still an interesting question and it's nice I don't have to store my car for the winter. That must suck.
I was more getting at if a all season performance tire will perform better If not driven at the limit? Because of the tires temp. Perhaps a better question would be will an all season tire perform better at a lower temp? I suppose it doesn't matter as I'm in So. cal lol but still an interesting question and it's nice I don't have to store my car for the winter. That must suck.
some of the extreme sports tires say on the tire not to operate in very cold temps as in 30 and below. When the extreme sport tires are in their operating range, the grip difference is gigantic between the two. It could be a .4G difference in grip which is miles apart.
I know the tests with a Toyo R1R on a miata without sway bars they were peaking at 1.3G, with the sway bars connected he peaked around 1.1G, and I would imagine a all season peaking around .85G or something.
Senior Member
Joined: Sep 2011
Posts: 682
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From: Pawtucket, RI
The Max Performance Michelin Pilot SuperSport (Max Performance Summer) tires on my FD have less grip than the General GMax AS-03 on wife's Mazda3 in even 50F temps. Part of the issue is size. I'm on 275 rears on the FD, they don't really warm up in normal usage.
In normal conditions, the best UHP all-seasons are capable of within 0.05 g of the best Extreme performance tires. (Tire Rack's best average g's for Extreme Perf = 0.97 for ZII Star Spec, UHP all-season best = 0.93 for Pilot Sport A/S3
At 50F or cooler, on the street in normal usage, my money's on the best all-seasons for grip over the best Extreme perf tire.
In normal conditions, the best UHP all-seasons are capable of within 0.05 g of the best Extreme performance tires. (Tire Rack's best average g's for Extreme Perf = 0.97 for ZII Star Spec, UHP all-season best = 0.93 for Pilot Sport A/S3
At 50F or cooler, on the street in normal usage, my money's on the best all-seasons for grip over the best Extreme perf tire.
Im looking into the Federal rsr's that BlueTII runs and they are at an attractive price. THe tread width is only 9.1" for a 255 however. Is that too much of a stretch for a 10" wide wheel? I also like the Dunlop star specs which are at 9.6" tread width but about 300 bucks more a set. decisions, decisions
Federal Tyres - UHP - 595RS-R
Right there-
Federal recommends the use of the 255/40-17 RS-R on an 8.5" to 10" wide wheel.
Right there-
Federal recommends the use of the 255/40-17 RS-R on an 8.5" to 10" wide wheel.
Full Member
Joined: Sep 2014
Posts: 114
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From: Sacramento
Picked up some enkei nt03s 17x9.5 +44. Was thinking +40 for concave but couldn't pass up the deal on these. $800 used but literally brand new. No chips or scratches. Will post some pics after the install. Want to put a small spacer on the back but can't find any hubcentric ones available for the rx7 under 10mm
Federal Tyres - UHP - 595RS-R
Right there-
Federal recommends the use of the 255/40-17 RS-R on an 8.5" to 10" wide wheel.
Right there-
Federal recommends the use of the 255/40-17 RS-R on an 8.5" to 10" wide wheel.
Senior Member
Joined: Sep 2011
Posts: 682
Likes: 4
From: Pawtucket, RI
Personally, for street usage I like for the tire to come closer to covering the total outside wheel width to protect the wheels. I'm running 275/35-18 on 18x9.5 wheels and to me it looks about right. I have to think that 255/40-17 on 17x10 would look a bit stretched, *to me*.
Full Member
Joined: Sep 2014
Posts: 114
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From: Sacramento
Here are the 17x9.5 +44 with 255/40s. Running about a 26.25" height, want to drop the front down just a tad more, 1/2" or so in the front.
One problem I have is the fender line rubbing on full turns. I ordered new fender liners because mine were torn apart when I bought the car and they may be slightly sagging from not being fully mounted anymore. I'm hoping I can mount the new ones higher. If anyone has suggestions on avoiding fender line rubbing I'm all ears.
One problem I have is the fender line rubbing on full turns. I ordered new fender liners because mine were torn apart when I bought the car and they may be slightly sagging from not being fully mounted anymore. I'm hoping I can mount the new ones higher. If anyone has suggestions on avoiding fender line rubbing I'm all ears.
Full Member
Joined: Sep 2014
Posts: 114
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From: Sacramento
Hey, look, someone else with 9.5s up front lol. With your size tire I think we'd be at the same diameter. Do you have fender liners? If so, are you running on those at all. Look good, wish I could have found 18s at a good price.
The only fender liner I have is what covers about midpoint at the top to the rear of the wheel. Not the front liner. Mine were actually ripped to shreds when i bought the car so I just removed them.
Joined: Mar 2001
Posts: 30,807
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From: FL-->NJ/NYC again!
I know from experience I prefer a 255mm tire on a 9.5" front rim and a 265mm tire on a 10" rear rim.
So in my opinion a 255mm is too much of a stretch on a 10. Not a fan. However, my homie (and tuner) John Renna runs that size front and back (with staggered offsets) on his FD Blueberry Farms and he tracks with no safety issues etc.
We actually just spoke about it tonight and he said it's a bit too much stretch for him..... he did it because he had to. He runs +36 offset front and +20 rear and needed the stretch on stock rolled (heavily rolled out back he tells me) fenders.
It comes down to personal preference.
I know from experience I prefer a 255mm tire on a 9.5" front rim and a 265mm tire on a 10" rear rim.
So in my opinion a 255mm is too much of a stretch on a 10. Not a fan. However, my homie (and tuner) John Renna runs that size front and back (with staggered offsets) on his FD Blueberry Farms and he tracks with no safety issues etc.
We actually just spoke about it tonight and he said it's a bit too much stretch for him..... he did it because he had to. He runs +36 offset front and +20 rear and needed the stretch on stock rolled (heavily rolled out back he tells me) fenders.
I know from experience I prefer a 255mm tire on a 9.5" front rim and a 265mm tire on a 10" rear rim.
So in my opinion a 255mm is too much of a stretch on a 10. Not a fan. However, my homie (and tuner) John Renna runs that size front and back (with staggered offsets) on his FD Blueberry Farms and he tracks with no safety issues etc.
We actually just spoke about it tonight and he said it's a bit too much stretch for him..... he did it because he had to. He runs +36 offset front and +20 rear and needed the stretch on stock rolled (heavily rolled out back he tells me) fenders.
widths vary greatly from tire manufacturer to tire manufacturer and from model of tire to model of tire.
One needs to look at the tread width and section widths of tires to gain a good understanding of just how wide the tire is.
for instance a 255/35/18 RE760 sport tire has a tread width of 9.3", yet a yoko AD08R tire has a tread width of 9.9".
.7" difference or 18mm difference.
One needs to look at the tread width and section widths of tires to gain a good understanding of just how wide the tire is.
for instance a 255/35/18 RE760 sport tire has a tread width of 9.3", yet a yoko AD08R tire has a tread width of 9.9".
.7" difference or 18mm difference.
