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Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 14, 2008 09:54PM

THE SCCA Goodyear race tire distributor in Kansas City - (supporting the SCCA Midwest Division races at the track) tells me that the latest Goodyear slick in the 16 inch wheel size ( 16x7, 16x8, 16x9, 16x10, etc.) is THE best race tire choice this year because of effectiveness and availability.

Questions for the British V8 Forum group: ?????


Can MG B front and rear 4 lug hubs take the strain ? Must the hubs be upgraded ? ($$$$$)

What is the maximum inside wheel offset vs outside wheel offset SIZE necessary on the 16x7 (16x8, 16x9, 16x10) race wheel ?

Is there only one inside (maximum for clearance) wheel offset possible ? Must all the other wheel size increase be on the outside dimension of the wheel?

If more/most of the offset must be on the outside of the wheel - where does the strength of the stock hubs become vulnerable?


Another racing wheel size question for consideration : ???

Can 15 inch tall race wheels (15x7) be used at the front with 16 inch race wheels (16x8, 16x9, 16x10) be used - with effectiveness - at the back ? What are the pros and cons?

Any and all considerations will be much appreciated.

Phillip G


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: V6 Midget
Date: April 15, 2008 08:37AM

Phillip, you know that I'm not any type of expert about the racing stuff, but I'll try to help if I can. I've seen a lot of SCCA racing MGBs both vintage and production and most I've seen still use the original hubs with stronger/longer studs fitted. Kent runs aluminum hubs on his MGA, but I think that's mostly for reduction in unsprung weight rather than strength. You could always give Kent Prather a call and see what he recommends to his customers. The rear axle flange should be up to the job, especially on race axles with their better material and heat treatment.
As far as fitting the larger wheels and tires that problem is the same for a street car as a race car and when you're unsure about fit the best way is to cut a template of the tire profile and fit it in the wheel well, then take measurements and determine what offset wheel you would need to put the tire where you want it and the flange in alignment with your hub or axle. Running flared fenders of course gives you more room to the outside so most likely a positive offset wheel. You don't want too much offset though on the front or your steering effort will suffer. We covered this for street tire selection last month and there was a good diagram posted by Rob, check the thread by Jim Blackwood about the Roadmaster project on the MG board. [forum.britishv8.org]
Running different sized tires and wheels on the front and rear will mean that you have some additional factors to consider when dialing in your sway bar settings and shock settings, but shouldn't be too much to overcome. I don't know what your experience level is, but if you don't have a lot of seat time behind you I'd try to keep things as simple as possible at first to make it easier to set your chassis.
Hope this information helps.


Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 15, 2008 10:17AM

KC Bill,

Thank you very much for your good advice and your ideas for calculating inside wheel clearance. That input is a BIG help.

Kent Prather's alloy hubs must be a big help and an even bigger investment - about $1,000.00 at each wheel. But the unsprung weight gain (loss) is probably worth it. How much do you wan'a spend ? How fast do you wan'no go ?

I'm thinking of 16x8 alloy wheels (first) just at the rear. Expense again. It will change a lot of handling and braking characteristics (top-end speed ?), I'm sure. But the first time onto the track with the RV 8 will present a lot of other teething problems as well - and I will have moved ahead on the rear wheel opening size of the flared fiberglass rear fenders to accommodate the 16x8 wheels. One step at a time.

Hope you can join us at our pit area our first time out.

r'gds,

Phillip G


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: V6 Midget
Date: April 15, 2008 11:09AM

Phillip, do you have to keep the original lug pattern or can you change to a 5 lug pattern as long as you use the original brake rotors and calipers? The reason I ask is that Bill Guzman at Classic Conversions Engineering sells a 5 lug aluminum hub that is pretty reasonably priced. [www.classicconversionseng.com]


rficalora
Rob Ficalora
Willis, TX
(2683 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: rficalora
Date: April 15, 2008 04:15PM

Good advise from Bill Y... but call Bill Guzman & talk with him. When I got a coil over kit from him i was able to specify the lug pattern. Pretty sure he can handle any typical 4 or 5 bolt pattern so even if you have to stick with 4-lug, he can probably set you up. His contact info is at the link above.


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: V6 Midget
Date: April 15, 2008 04:38PM

I'll be looking forward to joining you. Will you be ready by the June regionals at Heartland Park ? I have the Heartland MG regional meet on Saturday, but plan on going over to Topeka on Sunday for the racing.


Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 15, 2008 05:00PM

Bill,

In the SCCA GT 2 class, almost any modification is allowed - anlmost unlimited. The major limitation is ...

Front tires maximum cross section 12.0"
Rear tires maximum cross section 13.75

Phillip G



Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 15, 2008 05:03PM

Bill,

The RV 8 won't be ready in June, but I will be driving with Robert Maupins in his HP (new class) MGB at Heartland Park.

Do look us up and join us.

Phillip G


Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 15, 2008 05:08PM

Bill,

Any modifications to the suspension and brakes are allowed in SCCA GT 2.

I am using a David Headley front coil over suspension on the RV 8. And bigger front brake rotors, with discs in the back.

Phillip G


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: V6 Midget
Date: April 16, 2008 08:29AM

I've got the Heartland MG Regional show on Saturday, but I plan on going over to Topeka on Sunday,, what day to you guys race? I've known Robert for years now, glad to hear he's back racing again after a bad season a couple of years ago.


Phillip G
Phillip Leonard
Kansas City
(395 posts)

Registered:
02/03/2008 04:12PM

Main British Car:
1992 MG RV8 Rover 3.5

Re: MG B V 8 & MG RV 8 SCCA Race car wheels and tires
Posted by: Phillip G
Date: April 16, 2008 10:27PM

Bill,

Robert plans several races this year in his new HP MG B. Lots of improvements have been made on his B and he should be ready for Heartland Park Topeka on June 14/15. I plan to be his crew that weekend. Hope you join us. We can use the help.

Phillip G


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