Urgent help with a BRM Gearbox (2024)

I think I have a BRM CR LSD Box.

What are the "Speed to RPM figures" in the gears on a BRM Box in an F.????

I have put a BRM?? box in my car and the speeds are almost the same as my standard F box in all gears except 5th.

I do not mind having a slow 5th gear if there is a marked difference in the other gears but there is not.

I am going to the Alps in 20 days and a lot of long distance driving against V6 Audi's.

If the box is not the correct Box I have to change it next week.
Can anyone help??

Thank you
Andy

charless wrote:Never mind the ratio - see you on the Stelvio.

Yes.

The thing that pi$$es me off is that I paid for a BRM CR LSD Box (Std box is only £60ish) and paid someone to fit it.
and the person that sold it to me is not answering my messages.

But it will not stop my enjoyment of the trip.

Where are you going to be??

Andy

.

Ralph wrote:Do you have the gearbox type for the new box fitted to your car (e.g. C4BS)?

Ralph.

Quoted by seller:
The label has probably fell off, it's a B6BST same as all 200 BRM boxes.

http://forums.xpowerforums.com/showthread.php?t=42843

Andy

Okay, the final drive ratios are different - BRM box is 3.937 and the MGF is 4.200. The gear ratios are also different. Based on the figures that I have for the gear ratios, what you are experiencing is exactly what I would happen with this gear box.

TBH if all you were after was a limited slip diff for your gearbox I would have gone down the route that I am going. I've sent my gearbox off to Intelligent Tuning in Fllintshire to have a Torsen type B diff fitted. They are sourcing the diff from a 620 Turbo and then fitting it into my gearbox and uprating the bearings to caged ones.

Ralph wrote:Okay, the final drive ratios are different - BRM box is 3.937 and the MGF is 4.200. The gear ratios are also different. Based on the figures that I have for the gear ratios, what you are experiencing is exactly what I would happen with this gear box.

TBH if all you were after was a limited slip diff for your gearbox I would have gone down the route that I am going. I've sent my gearbox off to Intelligent Tuning in Fllintshire to have a Torsen type B diff fitted. They are sourcing the diff from a 620 Turbo and then fitting it into my gearbox and uprating the bearings to caged ones.

Ralph

Yes also I wanted better acceleration in 2, 3 + 4th? gear.

As I have the old Gearbox out at the moment I can look at that route if necessary to get my top speed back again if it is a std non VVC box.

How much is it costing you.?

I am off to the Alps in 3 weeks so it will have to wait till I come back
I am still sorting out my mothers complicated affairs.

also posted the challenge on http://forums.xpowerforums.com/showthread.php?t=42843
Andy.

AndyG wrote:

Ralph wrote:Okay, the final drive ratios are different - BRM box is 3.937 and the MGF is 4.200. The gear ratios are also different. Based on the figures that I have for the gear ratios, what you are experiencing is exactly what I would happen with this gear box.

TBH if all you were after was a limited slip diff for your gearbox I would have gone down the route that I am going. I've sent my gearbox off to Intelligent Tuning in Fllintshire to have a Torsen type B diff fitted. They are sourcing the diff from a 620 Turbo and then fitting it into my gearbox and uprating the bearings to caged ones.

Ralph

Yes also I wanted better acceleration in 2, 3 + 4th? gear.

As I have the old Gearbox out at the moment I can look at that route if necessary to get my top speed back again if it is a std non VVC box.

How much is it costing you.?

I am off to the Alps in 3 weeks so it will have to wait till I come back
I am still sorting out my mothers complicated affairs.

also posted the challenge on http://forums.xpowerforums.com/showthread.php?t=42843
Andy.

My gearbox is also being done at the same time Andy........I will PM you the 'estimate' we were given right now....

Jim

Ralph wrote:TBH if all you were after was a limited slip diff for your gearbox I would have gone down the route that I am going. I've sent my gearbox off to Intelligent Tuning in Fllintshire to have a Torsen type B diff fitted. They are sourcing the diff from a 620 Turbo and then fitting it into my gearbox and uprating the bearings to caged ones.

This sounds very interesting Ralph - how much is this costing you may I ask? Would be interested in doing the same for my F(s)

Rob
Technical Registrar @ Technical@mgfregister.org
http://mgf.ultimatemg.com/

Ralph wrote:Rob, the work is costing just over £300 plus parts.

Thank you Ralph.

For that I might get a special ratio box built in the future.

Sounds to me like you have a Rover 200vi gearbox, which i have. The 1st to 4th gears are close and the 5th is a sort of cruising gear. 4.2 FD.

These don't have a LSD as standard.

Easy to see if it has the LSD by looking in where the driveshafts go, if you can see straight through then you have an LSD (type B) and if it has a shaft going over it, its a standard open diff.

Heres a picture of my 200vi gearbox with a type B LSD i have fitted- not the best picture but you should be able to tell a difference from looking into a standard box.

Gaz.