Widest Tires

Suspension, including wheel, tire and brake.
Post Reply
MR_X
Posts: 3
Joined: 04 Jul 2009 09:50

Widest Tires

Post by MR_X » 04 Jul 2009 10:09

I'm new to this forum and 510s. I've wanted one since I was 16 (granted, I'm only 26 now), and have finally decided to start seriously looking for one. My intent for the car will be a fun weekend warrior, at both autocross and a few trackdays here and there.

In my research of this build, I'm trying to figure out the widest tires I will be able to fit for autocross.

What is the widest tires that can be fit under:
stock body lines?
bubble flares?
box flares?

The tires sizes I'm most currious about are:
225/50-13 (21.9" OD, 9.4" section width, 8.5" tread width) - Probably mounted on a 13"x8" wheel
255/40-13 (20.9" OD, 10.5" section width, 9.5" tread width) - Probably mounted on a 13"x9" wheel
275/35-15 (23" OD, 10.8" section width, 10.1" tread width) - Probably mounted on a 15"x10" wheel

Anyone else out there autox? What's your wheel & tire setup?

User avatar
bertvorgon
Supporter
Posts: 10363
Joined: 04 Aug 2003 20:45
Location: White Rock, B.C. Canada

Re: Widest Tires

Post by bertvorgon » 04 Jul 2009 19:00

I have run the equivelent race tire, by Goodyear, 20" X 9.5 x 13, on my 13 x 7" front and 13 x8" rear Panasports. That was a full 9.5" of rubber on the road. Those were the cantelever tires made for the B-sedan/Gt catagories. I ran those for hillclimb/solo/road race. Those are Specialty's flares. With my 4:625 rear end, made for WICKED acceleration.
Attachments
keithcar.jpg
20" x 9.5" x 13" Goodyears Cantelever
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

MR_X
Posts: 3
Joined: 04 Jul 2009 09:50

Re: Widest Tires

Post by MR_X » 05 Jul 2009 06:53

Good looking car, that's just what I'm looking for! I figured the small OD of the tire would help with fitment. How would you say youre flares compared to the BRE bubble flares? Do your custom flares add more clearance?

Did you ever try wider wheels on the front or the rear? I think a 13"x9" would make better use of the tires, maybe even a 9.5" wide wheel. Do you think those would still fit?

Anyone else have any input about the larger 275/35-15 tires? Is this OD too large for bubble flares? Anyone try anything this crazy?

How about you box flare guys, surely someone has to have some massive tires under those?

User avatar
bertvorgon
Supporter
Posts: 10363
Joined: 04 Aug 2003 20:45
Location: White Rock, B.C. Canada

Re: Widest Tires

Post by bertvorgon » 05 Jul 2009 07:35

This is a picture with my 15" x 7" with 205's on there, at 23" tall. As you can see, anything at 23" pretty much fills the flare, given that I have them speced out with a wheel spacer a tad, for increased track. The front, on my car, I did try a 23" tall race tire once, and the cross section was so wide that I would have to trim the airdam, on the leading edge. This is all with 1 to 1.5 degrees of negative camber.

Should you try to put an even wider tire on there, getting the camber correct will be very important, as otherwise there will be no point, if actual traction and stick are what you are after. You have to consider what suspension travel you want also, as getting the car reasonably low, with almost zero camber, even gets flares to the point of rubbing. Now, I have no experience with the BRE bubbles, so someone else can jump in.

You can see that with the side shot, the 23" tall fills everything quite well, and I think I have my 1/2" spacer on the front.

I know there are some people on this site with very wide tires, but, I do not know how well that actually works from a pure racing standpoint, specially Solo use. You want to get some heat into the tires, I can speak from experience, that getting really wide takes TIME to heat the tires, which in most solo use, you do not have. Sometimes it is better to really load the tire well. Depending on castor you run at the front, it can be VERY HARD to turn the car at slower speeds, at it does not get any easier with wide tires. I speak from years of solo use on that point.

A bunch of us that used to battle in Solo did find that the best comprimise between getting the CG low, and best stick, with great suspension travel, was with those 20" tall tires. You will want to run a very stiff ant-roll setup, so you can maximize the rubber contact area, other wise again, no point in trying to stuff the widest rubber under there, other than looks.
Attachments
IMG_0617.JPG
clearance to rear flare
IMG_0614.JPG
23" tall with 1/2" spacers ( approx)
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

User avatar
bertvorgon
Supporter
Posts: 10363
Joined: 04 Aug 2003 20:45
Location: White Rock, B.C. Canada

Re: Widest Tires

Post by bertvorgon » 05 Jul 2009 07:53

here is a picture of the actual BRE car and it's flare's, which are a lot "wider" in the opening.

and another 510 with basically the BRE style, with either 20 or 21" tall Goodyears. This car did not handle well!
Attachments
BRE1.JPG
old album pictures 027.jpg
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

User avatar
rnorrish
Moderator
Posts: 4022
Joined: 23 Jun 2003 12:49
Location: BC : CANADA
Contact:

Re: Widest Tires

Post by rnorrish » 05 Jul 2009 11:52

Keith,
Do you know, off the top of your head, what size slicks Specialty runs on the Miata and Malcolm's 510?
We've run them now too on our 510, and can't remember...
they're 15" slicks, and a bit bigger than the 13's.
richard norrish
'68 'goon resto / '71 ice racer / '72 'goon project / '70 4-door rust pile / '67 520 project
----------------------------------------------------------------------
shardik wrote: My swap will be made of solid gold and it will run on puppy farts.

User avatar
dp61
Posts: 193
Joined: 30 Oct 2004 19:38
Location: Vancouver, BC

Re: Widest Tires

Post by dp61 » 05 Jul 2009 15:18

Hey Keith

Just wondering if you have any idea when the photo of the orange 510 above was taken...and was that at Landsdown or Orchard Park? Probably the oldest photo I've seen of my car! Surprised you thought it never handled well it did run a 2:13 at Knox with an inexperienced driver and a much smaller engine at the time...but it has always run the full Nissan Comp Suspension since '72.

Cheers,
Dave
Last edited by dp61 on 05 Jul 2009 17:21, edited 1 time in total.

User avatar
bertvorgon
Supporter
Posts: 10363
Joined: 04 Aug 2003 20:45
Location: White Rock, B.C. Canada

Re: Widest Tires

Post by bertvorgon » 05 Jul 2009 16:03

Hey cool, no offence meant! We were all experts :( ....That was at Orchard Mall in Vernon, and I can't remember if that was for the Canadian National Solo, that was held there one year, or a regional slalom. ! I thought you had some problems that day, but, so did I ! would say this was either 1977 or 1978. Does that Jive with you? I can look in my Log book. which should tell me for sure. The air box that is on the car there, is now in Calgary, 510Trevor has it.
13's are good for Knox for sure!

Here is a picture of my car, at that same event, with Roger's MGB. We used to battle hammer and tong, drove me crazy. In the fall, if this is the correct year, is when my 510 got written off, on the Squamish Highway.
Attachments
scan0001_800x534.jpg
another picture from that day
VERNON, B.C. SLALOM.jpg
Vernon, B.C. slalom
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

User avatar
dp61
Posts: 193
Joined: 30 Oct 2004 19:38
Location: Vancouver, BC

Re: Widest Tires

Post by dp61 » 05 Jul 2009 17:20

Thanks for the info Keith

I've been waiting for the re-match (lol).... been thinking of joining you guys on one of your cruises (Run beyond Hope or Octoberfast) but seems the dates never jive with my schedule, although with your turbo set-up I'm afraid now all I'd see if your taillights...

Getting back to the original post I believe the car ran 13x8 wheels with 235/50/13 tires under the bre flares, but there did seem to be enough room to tuck something just a little bigger under there. It's been a real issue getting current street tires to fill out the flares though and while they are available they are very expensive.

D

User avatar
bertvorgon
Supporter
Posts: 10363
Joined: 04 Aug 2003 20:45
Location: White Rock, B.C. Canada

Re: Widest Tires

Post by bertvorgon » 05 Jul 2009 18:24

So as not to hijack this thread too badly......,

http://www.the510realm.com/viewtopic.ph ... 77#p128877

Follow this link if you want to read about one of the Vernon weekends.

For any of you non local people, Vernon is a small town in south western central B.C., and when we would hit there, on Friday nights, was about as close as you could get to "AMERICAN GRAFFITI", just the CDN version. Glad I experienced it, as that time period is history now, gone with the A & W drive-in's, the DOG & SUDS. The crusing and nights drags were just a hoot. Gary in his Lotus Europa would go up against some huge American car, and just clean it's clock. The "SOLO CIRCUS", as we called ourselves, had a blast busting the local talent, with some of our faster cars.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

MR_X
Posts: 3
Joined: 04 Jul 2009 09:50

Re: Widest Tires

Post by MR_X » 06 Jul 2009 20:26

Based on those pictures, it doesn't look like 23" OD tires are going to work well in wide tire sizes.

I was helping a friend this weekend test fit some of the 275/35-15s on his '86 Corolla, and he was coming from 255/40-13s. Just comparing the two tires together, the 275 was only about 1/8" - 1/4", if even, wider than the 255. Both were mounted on 8" wide wheels. Were going to borrow another friends 275s mounted on a 10.5" wheel, and another friends 255s mounted on a 10.5" wheel and compare the differences. Basically, we're thinking with a proper sized wheel the difference in width will be pretty minimal.

The benifits of the 255s would be:
Better gearing
Lighter weight
Easier clearance
Lower ride height
Cheaper wheels and tires

If I ever get to the point where I feel I need that extra 1/10th, maybe then I'd look into the 275s.

Thanks for all the help!

Post Reply