BTR Diff into GKN earlier chassis

[ProjectChimaera]

Hi I have a 98 Chim 4.0 with a BTR diff. I'm replacing the chassis with a refurbished one from a 95 car.
The mountings on the chassis are different and look like they will need modifying?

Any advice from anyone who has completed this change would be much appreciated.

I've made some templates for reworking the existing side brackets but would be interested to hear of other experiences or better solutions before I get cutting and welding.

[N7GTX]

BTR mounting brackets are available from TVR parts and dealers

http://tvr-parts.com/tvr-parts/part-details/tvr-r0...
http://tvr-parts.com/tvr-parts/part-details/tvr-r0...
http://tvr-parts.com/tvr-parts/part-details/tvr-r0...

Edited by N7GTX on Tuesday 6th September 18:26

[carsy]

You will also get what you want from RT Racing.

[ProjectChimaera]

N7GTX said:

BTR mounting brackets are available from TVR parts and dealers

http://tvr-parts.com/tvr-parts/part-details/tvr-r0...
http://tvr-parts.com/tvr-parts/part-details/tvr-r0...
http://tvr-parts.com/tvr-parts/part-details/tvr-r0...

Edited by N7GTX on Tuesday 6th September 18:26

Thanks Ian but they are the same as the ones originally fitted to my BTR diff and don't fit the earlier chassis that I'm now using that had brackets for an earlier diff arrangement. I'm wondering if anyone has actually manuafactured some conversion brackets?

[Engineer1949]

R T racing are the boys for that same rear just need brackets

john

[ProjectChimaera]

Engineer1949 said:

R T racing are the boys for that same rear just need brackets

john

Hi John, do the GKN ones fit the BTR front diff flange? Are the dimensions the same as the BTR ones?
Cheers
Adi

[SILICONEKID345HP]

TVR CENTRAL.

[N7GTX]

Central do this bracket conversion.

http://www.centraltvr.com/product/Bracket-set/

[ProjectChimaera]

N7GTX said:

Central do this bracket conversion.

http://www.centraltvr.com/product/Bracket-set/

My word that's expensive!

[carsy]

Very.

[N7GTX]

Yes, so probably best to give RT Racing, Sheffield a call.

http://www.rtracing.co.uk/content/tvr-servicing-sh...

[chimyellow]

When I did my conversion from a GKN to a BTR on an early chassis I fabricated an offset rear bracket.
For the front I used later brackets and welded new mounting points to the chassis to take them.

I also had to bend the hand brake and brake line brackets slightly to get it all to fit.
I kept the original drive shafts.

The car has done well over 5000 miles since including time on a track and is all working normally.

The biggest issue is clearence to remove and replace the oil filler (but this might be tight on the later chassis anyway)

[ProjectChimaera]

Thanks to all for the advice, Richard at RT Racing has shipped two new hybrid front diff mounting brackets that I hope will be the solution.
Will post some pics when installed.

[chimyellow]

You will need an offset rear mounting as well as the centre line of the differential mounting bolts on the BTR is offset to one side compared to the GKN.
This offset is taken into account on the later chassis by the inverted V in the rear of the later chassis not joining the top chassis rail in the centre.

[chimyellow]

This is the bracket that I made up to fit the later differential into the earlier chassis.
It shows the amount of offset required.

[OleVix]

Why do people make the conversion? Knackered GKN?

My GKN is in good condition, but I'm soon to send more power through it, thinking 5,4 V8D engine... will it handle it?

[portzi]

chimyellow said:

This is the bracket that I made up to fit the later differential into the earlier chassis.
It shows the amount of offset required.

Which one are you fitting the TVR special top one, or the well crafted bottom one ?

[N7GTX]

OleVix said:

Why do people make the conversion? Knackered GKN?

My GKN is in good condition, but I'm soon to send more power through it, thinking 5,4 V8D engine... will it handle it?

I asked Dom at Powers this very question only 3 months ago thinking that the BTR would be stronger and better. He said the GKN was perfectly okay so saved myself a £1,000. No issues so far.

[ProjectChimaera]

It's not about changing the diff on this one or about preference it's about changing the chassis and making my existing diff fit an earlier chassis with different mountings.! Slightly backward scenario but necessary none the less.

Not sure about the offset rear mounting yet, mine seems central on both the old and new chassis so I need to get the tape measure out and see.

[ProjectChimaera]

It's not about changing the diff on this one or about preference it's about changing the chassis and making my existing diff fit an earlier chassis with different mountings.! Slightly backward scenario but necessary none the less.

Not sure about the offset rear mounting yet, mine seems central on both the old and new chassis so I need to get the tape measure out and see.