Wheel choices for wide (gulf) flares?

I understand Superformance makes the MK1 GT40 with 3 rear clips. From the photo posted earlier showing 12 cars at Olthoff, none of the Mk1s have the gulf flares. I am wondering if anyone here has ordered one with gulf flares and what was decided for rim and tire sizes.

Thanks
 
The Gulf cars would have worn BRM-style wheels; I'm not sure but I believe they were on the order of 12x15 or 13x15 in the rear? (FWIW Gr4 racing Panteras were equipped with 14x15 wheels in the 1970s).

I have yet to see any photographs of Superformance's three different body options for the Mk 1 car; the only Mk 1 body style I have seen so far on Superformance cars has been the middle, intermediate width. Perhaps the narrow and wide (Gulf) bodies are still works-in-progress?

Tire choice will be somewhat problematic for the Gulf-style wheels; 345/35-15 is the only tire size available in the appropriate width, but that size is a bit short compared to the original sizes used on the Gulf cars. It may prove to be quite acceptable, however, particularly as the ultra-tall sidewalls featured on '60s bias-ply racing tires are no longer in vogue in this radial age. Fortunately front tires in the 225/50-15 range are widely available, and would be a good match, height-wise. 245/50 might work too, although availability is quite limited.

The medium-width bodies use 8x15 front and 10X15 rear wheels (or thereabouts), typically with taller tires, i.e. 235/60 front combined with 295/50 rear. Other than Avons, there are few 'good' street tires available in these sizes, although there are plenty of H- and S-rated tires which will at least keep the wheel rims off the ground. :)
 

Sandy

Gulf GT40
Lifetime Supporter
With the Gulf wide flares on the RCR I have fitted 14x15" rears rims. They will not fit the 345x15's I think, the tires are a tick small for 14" rims, but might be close as I think the Pirelli specs shoes 13.5" for them so may stretch. They are close to $500 for a tire, which is more then Avons (which are not street legal even groved, But I'll be giving them a shot). I have the 27.0x14x15 sized on the rears. I think BillD has a similar set up except he went with the 26x15x15's. The choices for 15" are lean for us. 17" are much better but might not look right for some. Fronts are not a huge problem. Also you might check out some of the vintage Goodyear bluestreak tires, they have some in 15" that are a little narrow but might also work. One other note is check tire diameter, they vary by a couple of inches in various brands/models. It may impact your gearing.

Overview :: Sasco Sports is a good spot for the racing tires and of course The Tire Rack - Your performance experts for tires and wheels for the rest.

HTH

Sandy
 
Greetings! This is my first post and am preparing myself for delivery of a Mk I from Olthoff Racing sometime in June! While that seems an eternity from now, there's lot's to decide on very soon, like color, engine, etc. I'm looking to build a GT40 that resembles as much as possible the cars competing at Le Mans, etc. (though not a 1075 clone). For example, I'll probably shy away from rondels – or at least rondels with numbers – but I will install the rondel lights on both flanks and aft on the engine lid. They're built by Lucas, I believe, so they'll either not work, or will simply set the car on fire which should add to the drama of the car.

One area that is important to me is wheel and tire size. My intention is to stay with the original 15" diameter so the car looks period correct (though I'd dearly like the choice of tires that are available in 17"). Several dealers are beginning to carry the period-looking CR6ZZ tires that come in 295/50R15, 275/55R15, and 245/60R15. The former and latter might be ideal choices, and my understanding is that they're very sticky and not bad in the wet. Anyone have experience with these? Are there better choices?

As to BRM-style wheels, all I've been able to find are 8x15 and 10x15 in size (which are also standard from SPF). The Le Mans cars had 11x15 wheels, if memory serves. Anyone know where to find these or wider 15" wheels?

Okay, enough for now. Thanks and I'll look forward to participating often on this and other threads. Only five more months!
 
if memory serves, Bill had his BRM's widened to accept the big AVONS. I have the wide fender option on my CAV and the deep dish BRMs,using BF goodrich tires and I also have a set of BRMs with Goodyear non dot eagles for track use. I will check on the sizes for you.
 

Sandy

Gulf GT40
Lifetime Supporter
Yes, Fran at RCR did widen both BillD's and my rears (wheels I should say). They welded in a section to make them 14" for the rears.

Sandy
 
Widended from 15x10 to 15x14

wheels%20004.jpg


Painted Lamborghini Ishtar Orange
paintedwheels003.jpg


Fitted with AVON 15.0/26-15 historic tread race tires (non-DOT)
wheelsandtires%20004.jpg


Bill D
 
Jonathan
The Gulf cars as Sandy stated had 15 X 14 wide rears. and 15 X 10 wide fronts. Backspacing was 5.75" , if your track is identical to original (56") you will need a rear deck to clear approx 72.5" or more to be safe. As usual Bill has put up a super shot of what it should look like!
Cheers
Phil
 
kepetersen said:
As to BRM-style wheels, all I've been able to find are 8x15 and 10x15 in size (which are also standard from SPF). The Le Mans cars had 11x15 wheels, if memory serves. Anyone know where to find these or wider 15" wheels?

I don't know about in the USA, but I know that in the UK there are several manufacturers making "BRM" wheels, and they advertise that they will make them in whatever size you want, both diameter and width. Here is but one example I found with about 30 seconds of Googling (at dial-up speed no less!)

http://www.imagewheels.co.uk/pages/wheels_cast.html
 
We do not advise anyone to split a cast alloy rim and weld in a fabricated spacer, as it is just not good practice. Any metallurgist with light metal experience can confirm this. It would be far safer to machine off the outer rim portion and then, by using commercially available spun rim sections create a "three piece rim" which is what most road race cars use today. The wheels from Image are a good solution as well.
 
Regarding our "wide body rear clam", we are working on it together with Safir. It will be as original and we have orders for a few already. Wheels will probably be sourced from outside at this time unless demand justifies the tool up costs. AS a futher matter of interest we can supply the BRM,s in 17inch as well as "cobra"type halibrands in the same size with the 6 hole drive pin layout and spacing.
 
Bill D.:

I checked out your GT build website -- very impressive! Regarding your choice of Avon vintage racing tires, what percentage of your driving will be on the street? In my case, I suspect that about 90% of my driving will be road use, with 10% or less on the track. I understand that many racing tires are intended to last only a few hundred miles and are less resistant to road hazards. Is that the case with vintage tires of the sort you've selected? I'd love to run tires like you're using and hope they may be a reasonable option that would also allow the wider wheels like you've selected. Any others out there with experience with vintage racing tires (e.g., Goodyear) for street use? Are there potential liability issues here, too?

Thanks!

Kim
 

Keith

Moderator
Hi-Tech Auto said:
We do not advise anyone to split a cast alloy rim and weld in a fabricated spacer, as it is just not good practice. Any metallurgist with light metal experience can confirm this. It would be far safer to machine off the outer rim portion and then, by using commercially available spun rim sections create a "three piece rim" which is what most road race cars use today. The wheels from Image are a good solution as well.

So you are saying that the RCR widened wheels (or any other wheels widened in this manner by other suppliers) are not good for the road?

I think most people realise that for track use this would not be an ideal solution (although we used to do it all the time before there were many dedicated wheel manufacturers) plus we were working in steel. For road use, surely this approach would be fine if the welding was top drawer? :confused:
 

Keith

Moderator
Well those guys certainly look like they know what they're talking about. I guess it's all a question of who does the work......

You pays yer money - yer takes yer choice......:)
 
Kim,

"Are there any liability issues" you ask regarding these race tyres on the street.

Well yes there are, and the major one is that you could destroy your car if you are not very careful. There is no doubting that these post historic tyres look the business and i congratulate the builders on doing great work on their cars, but i plead with you or any body intending to use them on the road, even very carefully, to be ultra cautious.

I doubt that many have ever raced or used these tyres before and therefore may have let "the look" be overiding knowledge.

They probably will leak air.
They will tramline you.
The tyres walls are very thin and will damage easily.
They will need to be heated up to work properly.
They will only have so many heat cyles before they go off.
They will pick up every amount of grit when hot.
ETC, ETC..........
And God help you in the wet with some of them !!!!!!!!

They are not road legal and if you have any misdemeanours on the road you could be in a lot of trouble with the police or insurance company.

Regards,

Graham @ GTA.
 
I appreciate all the info and responses. Personally, I'd sacrifice authenticity for a set of 17x13 BRMs.
 
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