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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - wheel, gearing and MPH Calculator

Since the selection of a tire size,gearbox and rearend resulting in the "right" ratios is such an important decision, I generated a couple of formulas in an Excel Spreadsheet to show speed in gear at any specified RPM based on all of the variables which you can plug in.

Here is the spreadsheet link, it may take a little while to load. First, you input your tire and rim size (eg 185/55 r 14) and it will compute the tire diameter. It then automatically picks up this diameter to plug into the MPH calculator. I already put in the ratios for the T-5s behind the 3.4 V^ Camaro and the V8 Camaros of the late 80s-early 90s. I also selected a few rpm points (2800 cruise and 5000 redline) as well as rear end ratios. The first set of V6 and V8 T5 results is based on the stock MGB rear axle. The second batch is based on the Camaro axle.

Feel free to play with it. All the numbers in blue can be altered to play "what if".


http://mysite.verizon.net/vze2mtva/mgbgtrestoration/id3.html

Funky observation, low profile 16 inchers can be the same height or shorter than standard profile 14 inchers. Neat.

BTW the tire diameter formula comes from Tirerack and the speed at rpm math comes form a Porsche speed book.

Regards,


Brian C.
72 BGT

Brian Corrigan

I bought one from a Hot Rod shop. I picked the lowest one they had & chopped it down further until it stands about 1" high. I can send a pix if you like. Barrie E.
Barrie Egerton

Sorry wrong thread BE
Barrie Egerton

Brian!

Thanks for the link! Interesting figures! As I have yet to see my GT on the road, I punched in the numbers and...VOILA!

Again..thanks!

rick
rick ingram

FWIW another calculator at http://pw1.netcom.com/~sgalaba/tiresize.htm#ustirecompare
Paul Hunt

this is what I like to use. It lets you alter many parameters about your car and it already has mgb and hundreds of other cars preloaded. download the dos version at bottom.

http://www.cartestsoftware.com/cartest4.5/
joaquin

Paul & Joaquin,

Neat sites, both of them. I suppose I could jazz mine up a little with the graphs of speed in gear v. rpm. I just got bored at work and had a few minutes to play with wondering about the gearing and rear end possibilities in my never ending GT conversion. I suppose I could come up with a better interface.


Rick,

Glad to be of help.

Regards all,

Brian C.
Brian Corrigan

This thread was discussed between 11/11/2004 and 12/11/2004

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