Vixen - brakes and suspension rebuild - guidance and advice
Discussion
My Vixen nut & bolt rebuild is making good progress - thanks again to everyone who contributed advice on the engine.
Body / chassis are apart and the body is stripped and ready to be worked on. I am now focused on the chassis (which is in very good condition) and the brakes/ suspension set up. Someone has already worked on the car. It has upgraded front brakes and rear ARB and looks to be in good condition.
I plan to go with the 2.3 Duratec (adding lightness) and, subject to finding a good builder, am aiming for 250bhp, so need brakes and suspension to match. This is a fast road car with occasional track and will be using regular tyres. With this in mind:
Brakes – I have vented front disc with Wilwood four pot, so think this is good enough. I have researched two other high performance Vixens and understand that the owners decided to keep the rear drums. With correct bias I am told this is sufficient. Any views or advice on this?
Wishbones – my wishbones look to be in good condition. I plan to dismantle and blast clean to check for cracks but if OK plan to keep. I understand that there are race wishbones available but am told these are unnecessary on a fast road car. Anyone care to correct me?
Shocks – I would prefer to have height adjustable. Any guidance between Gaz, Protech, Avo etc. Is it easy to get advice from the suppliers on correct spring and shock rates? The engine and gearbox should be a little lighter than stock so the calculations should be easy (I hope!). Or do I forget trying to figure it out and go directly to Adrian? Any views?
Rear axle – I know that I need new bearings and new quill shafts but have some confusing advice (for me at least!) on the LSD. On set of advice is to rebuild the LSD with Quaife LSD and a new Quaife CWP, with the second bit of advice being to swap over to a Sierra 7” LSD. I would prefer to build with Quaife components as I am not in UK and sourcing a Sierra LSD may not be easy. Can anyone guide me on this, better to rebuild or just swap out?
I do know that some people have been swapping the rear set up for the 2500M set up with rear discs. Is this clearly better, it seems that some of the Vixen racers did not swap over. Are there any side benefits, such as being able to fit wider rear wheels?
Many thanks as ever.
Nigel.
Body / chassis are apart and the body is stripped and ready to be worked on. I am now focused on the chassis (which is in very good condition) and the brakes/ suspension set up. Someone has already worked on the car. It has upgraded front brakes and rear ARB and looks to be in good condition.
I plan to go with the 2.3 Duratec (adding lightness) and, subject to finding a good builder, am aiming for 250bhp, so need brakes and suspension to match. This is a fast road car with occasional track and will be using regular tyres. With this in mind:
Brakes – I have vented front disc with Wilwood four pot, so think this is good enough. I have researched two other high performance Vixens and understand that the owners decided to keep the rear drums. With correct bias I am told this is sufficient. Any views or advice on this?
Wishbones – my wishbones look to be in good condition. I plan to dismantle and blast clean to check for cracks but if OK plan to keep. I understand that there are race wishbones available but am told these are unnecessary on a fast road car. Anyone care to correct me?
Shocks – I would prefer to have height adjustable. Any guidance between Gaz, Protech, Avo etc. Is it easy to get advice from the suppliers on correct spring and shock rates? The engine and gearbox should be a little lighter than stock so the calculations should be easy (I hope!). Or do I forget trying to figure it out and go directly to Adrian? Any views?
Rear axle – I know that I need new bearings and new quill shafts but have some confusing advice (for me at least!) on the LSD. On set of advice is to rebuild the LSD with Quaife LSD and a new Quaife CWP, with the second bit of advice being to swap over to a Sierra 7” LSD. I would prefer to build with Quaife components as I am not in UK and sourcing a Sierra LSD may not be easy. Can anyone guide me on this, better to rebuild or just swap out?
I do know that some people have been swapping the rear set up for the 2500M set up with rear discs. Is this clearly better, it seems that some of the Vixen racers did not swap over. Are there any side benefits, such as being able to fit wider rear wheels?
Many thanks as ever.
Nigel.
nigeljones said:
My Vixen nut & bolt rebuild is making good progress - thanks again to everyone who contributed advice on the engine.
Body / chassis are apart and the body is stripped and ready to be worked on. I am now focused on the chassis (which is in very good condition) and the brakes/ suspension set up. Someone has already worked on the car. It has upgraded front brakes and rear ARB and looks to be in good condition.
I plan to go with the 2.3 Duratec (adding lightness) and, subject to finding a good builder, am aiming for 250bhp, so need brakes and suspension to match. This is a fast road car with occasional track and will be using regular tyres. With this in mind:
Brakes – I have vented front disc with Wilwood four pot, so think this is good enough. I have researched two other high performance Vixens and understand that the owners decided to keep the rear drums. With correct bias I am told this is sufficient. Any views or advice on this?
OK on Brakes as is.
Wishbones – my wishbones look to be in good condition. I plan to dismantle and blast clean to check for cracks but if OK plan to keep. I understand that there are race wishbones available but am told these are unnecessary on a fast road car. Anyone care to correct me?
Your wishbones appear to be fairly new from the photos BUT! If any trace of pock marks I would replace them. I have seen perfectly good looking lower front wishbones shear in 2 places when racing.
Shocks – I would prefer to have height adjustable. Any guidance between Gaz, Protech, Avo etc. Is it easy to get advice from the suppliers on correct spring and shock rates? The engine and gearbox should be a little lighter than stock so the calculations should be easy (I hope!). Or do I forget trying to figure it out and go directly to Adrian? Any views?
I like Protechs, My dads car has Avo's..some will advise that Olihns cannot be beaten. My view is that as long as you pick a reasonable quality shock you will not notice any difference
Rear axle – I know that I need new bearings and new quill shafts but have some confusing advice (for me at least!) on the LSD. On set of advice is to rebuild the LSD with Quaife LSD and a new Quaife CWP, with the second bit of advice being to swap over to a Sierra 7” LSD. I would prefer to build with Quaife components as I am not in UK and sourcing a Sierra LSD may not be easy. Can anyone guide me on this, better to rebuild or just swap out?
I don't think your rear axle is up to 250 hp for any length of time.
if you are keeping your std uprights then you should buy brand new quills and also throw the crush tubes away and run them with machined solid spacers. they need careful setting up though.
I do know that some people have been swapping the rear set up for the 2500M set up with rear discs. Is this clearly better, it seems that some of the Vixen racers did not swap over. Are there any side benefits, such as being able to fit wider rear wheels?
You will get 7" wide wheels under vixen std arches. The limiting factor is the lower pivot bar. You can piggy back the dampers and shorten the pivot rods to get in wider rear wheels..This is an involved task though so my first question is do you need too?
2500 M uses a TR6 diff. why swap weak for not so weak but still not as good as it can be? Again your solutions are dictated by how original you want your car. Rebuilding a srd or TR6 diff will cost you upwards of £1500 if you are fully stripping, replacing all the bearings, CWP etc and replacing the diff unit. A 4HU which was an original fitment for a griffith is a very heavy unit but won't upset any purists. Again though you would need a full re-build and to alter the ramp angles to get the best from it.
I used a cosworth because principally i am a skinflint...It is non original but very cheap to source, is newish so if purchased from the correct car won't need a re-build, Is proven for outputs up to and over 400hp, doubtless their will be other jap based LSD diffs which you could source locally that would do the same job...What about a late MX5 rear end??
As a seperate note. regarding rear anti roll bar. if not designed properly this may be inducing understeer and pushing on at the front. my advice would be to run the car then disconnect and compare before changing anything too wildly.
Many thanks as ever.
Nigel.
Body / chassis are apart and the body is stripped and ready to be worked on. I am now focused on the chassis (which is in very good condition) and the brakes/ suspension set up. Someone has already worked on the car. It has upgraded front brakes and rear ARB and looks to be in good condition.
I plan to go with the 2.3 Duratec (adding lightness) and, subject to finding a good builder, am aiming for 250bhp, so need brakes and suspension to match. This is a fast road car with occasional track and will be using regular tyres. With this in mind:
Brakes – I have vented front disc with Wilwood four pot, so think this is good enough. I have researched two other high performance Vixens and understand that the owners decided to keep the rear drums. With correct bias I am told this is sufficient. Any views or advice on this?
OK on Brakes as is.
Wishbones – my wishbones look to be in good condition. I plan to dismantle and blast clean to check for cracks but if OK plan to keep. I understand that there are race wishbones available but am told these are unnecessary on a fast road car. Anyone care to correct me?
Your wishbones appear to be fairly new from the photos BUT! If any trace of pock marks I would replace them. I have seen perfectly good looking lower front wishbones shear in 2 places when racing.
Shocks – I would prefer to have height adjustable. Any guidance between Gaz, Protech, Avo etc. Is it easy to get advice from the suppliers on correct spring and shock rates? The engine and gearbox should be a little lighter than stock so the calculations should be easy (I hope!). Or do I forget trying to figure it out and go directly to Adrian? Any views?
I like Protechs, My dads car has Avo's..some will advise that Olihns cannot be beaten. My view is that as long as you pick a reasonable quality shock you will not notice any difference
Rear axle – I know that I need new bearings and new quill shafts but have some confusing advice (for me at least!) on the LSD. On set of advice is to rebuild the LSD with Quaife LSD and a new Quaife CWP, with the second bit of advice being to swap over to a Sierra 7” LSD. I would prefer to build with Quaife components as I am not in UK and sourcing a Sierra LSD may not be easy. Can anyone guide me on this, better to rebuild or just swap out?
I don't think your rear axle is up to 250 hp for any length of time.
if you are keeping your std uprights then you should buy brand new quills and also throw the crush tubes away and run them with machined solid spacers. they need careful setting up though.
I do know that some people have been swapping the rear set up for the 2500M set up with rear discs. Is this clearly better, it seems that some of the Vixen racers did not swap over. Are there any side benefits, such as being able to fit wider rear wheels?
You will get 7" wide wheels under vixen std arches. The limiting factor is the lower pivot bar. You can piggy back the dampers and shorten the pivot rods to get in wider rear wheels..This is an involved task though so my first question is do you need too?
2500 M uses a TR6 diff. why swap weak for not so weak but still not as good as it can be? Again your solutions are dictated by how original you want your car. Rebuilding a srd or TR6 diff will cost you upwards of £1500 if you are fully stripping, replacing all the bearings, CWP etc and replacing the diff unit. A 4HU which was an original fitment for a griffith is a very heavy unit but won't upset any purists. Again though you would need a full re-build and to alter the ramp angles to get the best from it.
I used a cosworth because principally i am a skinflint...It is non original but very cheap to source, is newish so if purchased from the correct car won't need a re-build, Is proven for outputs up to and over 400hp, doubtless their will be other jap based LSD diffs which you could source locally that would do the same job...What about a late MX5 rear end??
As a seperate note. regarding rear anti roll bar. if not designed properly this may be inducing understeer and pushing on at the front. my advice would be to run the car then disconnect and compare before changing anything too wildly.
Many thanks as ever.
Nigel.
Edited by heightswitch on Monday 20th February 07:26
Thanks for the quick answers. Could I clarify a few points:
Shocks / springs – got it on the brands. Do I trust the manufacturers to guide me on springs and shock rates or will I need to know before I order?
Rear axle – to clarify I planned to get new quills (David Gerald best?) and can follow your advice on machined solid spacers (but do I have machined up here or can I buy off the shelf?). If I do this will it survive?
Wheels – I thought the standard wheels are 7” (I have 195 / 60 tyres right now) – will this work with this much power and weight of car? Or just learn to drive better! It sounds like I may be keep the standard wheels….
LSD – to clarify, you concur with the advice to buy the 7” Sierra Cosworth LSD? I guess I then need to modify the diff carrier? If I rebuild the TR6 unit is it meaningfully lighter? I like lightness.
ARB advice – got it – custom bar was installed by PO but so far everything I have seen suggests he really knew what he was doing (but will check!)
Thanks
Nigel
Shocks / springs – got it on the brands. Do I trust the manufacturers to guide me on springs and shock rates or will I need to know before I order?
Rear axle – to clarify I planned to get new quills (David Gerald best?) and can follow your advice on machined solid spacers (but do I have machined up here or can I buy off the shelf?). If I do this will it survive?
Wheels – I thought the standard wheels are 7” (I have 195 / 60 tyres right now) – will this work with this much power and weight of car? Or just learn to drive better! It sounds like I may be keep the standard wheels….
LSD – to clarify, you concur with the advice to buy the 7” Sierra Cosworth LSD? I guess I then need to modify the diff carrier? If I rebuild the TR6 unit is it meaningfully lighter? I like lightness.
ARB advice – got it – custom bar was installed by PO but so far everything I have seen suggests he really knew what he was doing (but will check!)
Thanks
Nigel
nigeljones said:
Thanks for the quick answers. Could I clarify a few points:
Shocks / springs – got it on the brands. Do I trust the manufacturers to guide me on springs and shock rates or will I need to know before I order?
protech will supply nice shocks for you or you could just go to Steve reid or Adrian who will supply you with a package. Diff uses of your car will need different spring rates? 200lb all round will be a good starting point for a fast road car.
Rear axle – to clarify I planned to get new quills (David Gerald best?) and can follow your advice on machined solid spacers (but do I have machined up here or can I buy off the shelf?). If I do this will it survive?
The machining of solid spacers differs for each car. It is an engineering process you have to follow to set the correct preload for the wheel bearings. if you do not know how then I would advise you let a specialist do it for you.
Wheels – I thought the standard wheels are 7” (I have 195 / 60 tyres right now) – will this work with this much power and weight of car? Or just learn to drive better! It sounds like I may be keep the standard wheels….
Std wheels are 5.5" you can run 6", TR6 fitment 6" wheels run too close to std pivot rod. again you need to know what you are doing and build the car then fit the car up as you go to ensure clearances.
LSD – to clarify, you concur with the advice to buy the 7” Sierra Cosworth LSD? I guess I then need to modify the diff carrier? If I rebuild the TR6 unit is it meaningfully lighter? I like lightness.
I would go for the 7.5" ford unit with 100mm flanges as fitted to granadas and scorpios, It is stronger again than the 7" unit. To fit this though you will need to make an entirely new diff carrier top and bottom.
ARB advice – got it – custom bar was installed by PO but so far everything I have seen suggests he really knew what he was doing (but will check!)
if the guy that built the car new what he was doing and you are not going to change the fundamental weight of the engine up front then why risk spoiling what you already have?
Thanks
Nigel
If you look back at your previous posts you will see a picture of a chassis fitted with a cosworth diff.Shocks / springs – got it on the brands. Do I trust the manufacturers to guide me on springs and shock rates or will I need to know before I order?
protech will supply nice shocks for you or you could just go to Steve reid or Adrian who will supply you with a package. Diff uses of your car will need different spring rates? 200lb all round will be a good starting point for a fast road car.
Rear axle – to clarify I planned to get new quills (David Gerald best?) and can follow your advice on machined solid spacers (but do I have machined up here or can I buy off the shelf?). If I do this will it survive?
The machining of solid spacers differs for each car. It is an engineering process you have to follow to set the correct preload for the wheel bearings. if you do not know how then I would advise you let a specialist do it for you.
Wheels – I thought the standard wheels are 7” (I have 195 / 60 tyres right now) – will this work with this much power and weight of car? Or just learn to drive better! It sounds like I may be keep the standard wheels….
Std wheels are 5.5" you can run 6", TR6 fitment 6" wheels run too close to std pivot rod. again you need to know what you are doing and build the car then fit the car up as you go to ensure clearances.
LSD – to clarify, you concur with the advice to buy the 7” Sierra Cosworth LSD? I guess I then need to modify the diff carrier? If I rebuild the TR6 unit is it meaningfully lighter? I like lightness.
I would go for the 7.5" ford unit with 100mm flanges as fitted to granadas and scorpios, It is stronger again than the 7" unit. To fit this though you will need to make an entirely new diff carrier top and bottom.
ARB advice – got it – custom bar was installed by PO but so far everything I have seen suggests he really knew what he was doing (but will check!)
if the guy that built the car new what he was doing and you are not going to change the fundamental weight of the engine up front then why risk spoiling what you already have?
Thanks
Nigel
Got it on shocks / springs. Plan to get help on the solid spacers.
Sierra 7.5" LSD, OK better start doing some searching for a unit. You mentioned there was an example of the diff carrier in my earlier post .... I checked but could only see your Zetec engine on a 2500M chassis, but there are no pics of the Sierra LSD. Did you mean another post perhaps? Unfortunately the search engine is on the blink again. Did I miss something
Thanks.
Sierra 7.5" LSD, OK better start doing some searching for a unit. You mentioned there was an example of the diff carrier in my earlier post .... I checked but could only see your Zetec engine on a 2500M chassis, but there are no pics of the Sierra LSD. Did you mean another post perhaps? Unfortunately the search engine is on the blink again. Did I miss something
Thanks.
heightswitch said:
[ 200lb all round will be a good starting point for a fast road car.
Not doubting your years of experience and knowledge with these cars but that sounds surprisingly soft?Something around 375F / 350R seems to be popular for the S series cars, maybe a bit bigger lump of engine up front but not hugely different?
phillpot said:
Not doubting your years of experience and knowledge with these cars but that sounds surprisingly soft?
Something around 375F / 350R seems to be popular for the S series cars, maybe a bit bigger lump of engine up front but not hugely different?
You could run 600lb front 400 rear like my other car!!Something around 375F / 350R seems to be popular for the S series cars, maybe a bit bigger lump of engine up front but not hugely different?
Or 800 front 400 rear like another mates M racer with essex engine
or you could build a nice road car with 200lb alround.
Actually if you are light and travel alone most of the time 180 - 90 lb might be even better??
nigeljones said:
Got it on shocks / springs. Plan to get help on the solid spacers.
Sierra 7.5" LSD, OK better start doing some searching for a unit. You mentioned there was an example of the diff carrier in my earlier post .... I checked but could only see your Zetec engine on a 2500M chassis, but there are no pics of the Sierra LSD. Did you mean another post perhaps? Unfortunately the search engine is on the blink again. Did I miss something
Thanks.
its a vixen chassis!Sierra 7.5" LSD, OK better start doing some searching for a unit. You mentioned there was an example of the diff carrier in my earlier post .... I checked but could only see your Zetec engine on a 2500M chassis, but there are no pics of the Sierra LSD. Did you mean another post perhaps? Unfortunately the search engine is on the blink again. Did I miss something
Thanks.
N
In case it helps, when I got a new chassis for my Vixen from DG, they offered to make it with the 'M' series carrier brackets, so that I could change diffs and carriers easily.
It's actualy pretty simple, if you want to mod you existing chassis the same way... it needs two
extra tubes, and rewelding of the 'cross' stiffening tubes to suit.
Also on the web there is a kit to adapt a very strong Nissan (? I think) diff to TR6 mounts. Yes, I know purists all wince at this, but it may be cheaper than a 4HU ??
It's actualy pretty simple, if you want to mod you existing chassis the same way... it needs two
extra tubes, and rewelding of the 'cross' stiffening tubes to suit.
Also on the web there is a kit to adapt a very strong Nissan (? I think) diff to TR6 mounts. Yes, I know purists all wince at this, but it may be cheaper than a 4HU ??
Neil,
Many thanks for those fabrication pictures, very clear, much appreciated.
In the post above AndyP mentions the Nissan LSD conversion which I think is this - http://www.goodparts.com/shop/index.php?categoryID...
You were clear in your advice that the Sierra LSD is the cheapest solution. I would need to source one from the UK which is possible but slightly trickier. Do you have any views on whether the Nissan route is better? Obviously I would save the fabrication costs and judging by the pictures the Nissan unit looks to be lighter. Any views?
Thanks all for the guidance on the shocks, springs and LSD, anyone care to guide me on the rear brakes question? As mentioned, research suggests some think that rear drums are sufficient whereas others opt for rear disc conversion. Anyone have any views?
Thanks
Nigel
Many thanks for those fabrication pictures, very clear, much appreciated.
In the post above AndyP mentions the Nissan LSD conversion which I think is this - http://www.goodparts.com/shop/index.php?categoryID...
You were clear in your advice that the Sierra LSD is the cheapest solution. I would need to source one from the UK which is possible but slightly trickier. Do you have any views on whether the Nissan route is better? Obviously I would save the fabrication costs and judging by the pictures the Nissan unit looks to be lighter. Any views?
Thanks all for the guidance on the shocks, springs and LSD, anyone care to guide me on the rear brakes question? As mentioned, research suggests some think that rear drums are sufficient whereas others opt for rear disc conversion. Anyone have any views?
Thanks
Nigel
Whatever works for you Nigel.
certainly their are lots of drift cars running around with the nissan unit.
I chose cosworth because there are lots of them over here and it cost me £75 to buy.
The driveshafts were made up for me by Drivelink UK, again local to me. The shafts are UJ, nothing special.
http://www.commercial-propshafts.co.uk/the-company...
N.
certainly their are lots of drift cars running around with the nissan unit.
I chose cosworth because there are lots of them over here and it cost me £75 to buy.
The driveshafts were made up for me by Drivelink UK, again local to me. The shafts are UJ, nothing special.
http://www.commercial-propshafts.co.uk/the-company...
N.
Edited by heightswitch on Tuesday 21st February 06:45
wow, at that price I will find someone to source one for me.Gassing Station | TVR Classics | Top of Page | What's New | My Stuff