Diff bracing

[Catsuma]

Does anyone happen to have a photo or two of how the Caterham diff bracing struts are supposed to fit on an SV chassis?

Thanks

[Johno]

Would be interested in this too, as considering these, was going to have some braces made up by Mog , but they've gone a bit quiet, so considering the Caterham items.

They should fit from the diff bolts on the rear casing to the harness mounting points.

I think JeffC on here fitted these to his CSR after diff case issues, perhaps a search will show up the pic.

Found it. . . . http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by Johno on Saturday 29th September 20:42

[JeffC]

indeed I did, I forgot to post that I also thought they amplified the racket from the diff closer to your lug holes! the diff was considerably noisier after It was rebuilt and I refitted it, I even sent it back to R&R to get them to check it, it was that bad, sold the car shortly after that as the attraction for using it on the road wore off but on reflection I keep thinking those braces might have transferred the noise??!!

[WillieLocost]

Jeff, was your bracing rose jointed or solid at the ends? I'm guessing so, and suspect braces using a rubber bush at the ends would resolve the noise transfer.

May be worth investigating for those considering getting some fabricated.

[nigelpugh7]

Catsuma said:

Does anyone happen to have a photo or two of how the Caterham diff bracing struts are supposed to fit on an SV chassis?

Thanks

Not sure if these help, they were from my first S3 R500 build, dont know how they compare to the SV version though:

[Johno]

So they are bushed at the diff end with standard suspension rubber bushes ... But not at the chassis rail end I do 't think.

Noise not really an issue for me as it's solely for the track, but can understand how it could transmit more noise/vibration even with the rubber bushes.

[mickrick]

Well the rubber bushes defeat the object don't they.
What's the point of bracing something, then using rubber bushes to alow it to flex.
IMO the diff needs bracing to the top of the suspension turrets, as there's nothing bracing the bar across the back of the seats which the Caterham ones bolt to.
I'd also use a rose joint at one end, threaded into a sleve with a LH external thread on the sleeve, so they can be adjusted to take out slack after they've been fitted.
As for the noise http://www.demon-tweeks.co.uk/motorsport/ear-plugs...

[WillieLocost]

I assume you'd also replace the main diff mounting bushes with solid brass or alloy to complete the conversion? =P

The rubber suspension bushes will only really absorb a bit of vibration...they're not very flexy (Hence they're used in the main diff mounts).

[mic]

I can't see the point in doing anything other than fitting the CC diff struts, they do the job.

[mickrick]

WillieLocost said:

I assume you'd also replace the main diff mounting bushes with solid brass or alloy to complete the conversion? =P

The rubber suspension bushes will only really absorb a bit of vibration...they're not very flexy (Hence they're used in the main diff mounts).

They still flex. that's why folks go to so much trouble on race cars to use rose joints. The rubber flexes enough to change the suspension geometry.
They're only used in production cars because of cost, and I suspect Caterham also use them because it alows a bit of tolerance for the diff bolts to be rogered in, because the diff mounts don't line up perfectly.

[sfaulds]

mickrick said:

Well the rubber bushes defeat the object don't they.
What's the point of bracing something, then using rubber bushes to alow it to flex.
IMO the diff needs bracing to the top of the suspension turrets, as there's nothing bracing the bar across the back of the seats which the Caterham ones bolt to.
I'd also use a rose joint at one end, threaded into a sleve with a LH external thread on the sleeve, so they can be adjusted to take out slack after they've been fitted.
As for the noise http://www.demon-tweeks.co.uk/motorsport/ear-plugs...

Sounds like you've got a couple of diagonals and a bulkhead missing if there's nothing bracing the harness bar.

The diff isn't solidly mounted into the chassis, so solidly mounting the back of it strikes me as a bad idea. The Caterham braces work.

[JeffC]

WillieLocost said:

Jeff, was your bracing rose jointed or solid at the ends? I'm guessing so, and suspect braces using a rubber bush at the ends would resolve the noise transfer.

my bracing was supplied from the factory, it wasnt rose jointed, that car was mainly a road car and it ruined it once I had the diff rebuilt with the bracing on, you would struggle to believe how bad it was .

my DR400 S3 doesnt run them and I wont be fitting them if I can help it, I use it a fair bit on track on slicks but obviously doesnt have the power of the Csr260 and touch wood so far its fine .

[mickrick]

sfaulds said:

mickrick said:

Well the rubber bushes defeat the object don't they.
What's the point of bracing something, then using rubber bushes to alow it to flex.
IMO the diff needs bracing to the top of the suspension turrets, as there's nothing bracing the bar across the back of the seats which the Caterham ones bolt to.
I'd also use a rose joint at one end, threaded into a sleve with a LH external thread on the sleeve, so they can be adjusted to take out slack after they've been fitted.
As for the noise http://www.demon-tweeks.co.uk/motorsport/ear-plugs...

Sounds like you've got a couple of diagonals and a bulkhead missing if there's nothing bracing the harness bar.

The diff isn't solidly mounted into the chassis, so solidly mounting the back of it strikes me as a bad idea. The Caterham braces work.

Oh er.. you're right, sorry ! I stand down. Ignore me.

[sam919]

Catsuma said:

Does anyone happen to have a photo or two of how the Caterham diff bracing struts are supposed to fit on an SV chassis?

Thanks

Are you fitting these to over come a problem that's occurred, higher torque from engine and potential failure of casing, or just as a matter of course?

Im not sure of the SV chassis but, we had a number of problems with a 7" diff on a CSR200, the top mountings on the casing were failing. I made some plates similar to these below:


www.csr7.com/photos/20071128-CSR-diff-plates1

www.csr7.com/photos/20071128-CSR-diff-plates2


These gave the casing around each mounting hole (where the failures had been), more strength as you can imagine.

As for a strut type bracing, i used 'Stauff' blocks/ pipe clamps with a female rose joint attached to the flat cover plate - done by drilling through the plate and through one of the clamp sides, using an allen bolt for the fixing - fixed to the chassis either side of the diff, take your pick, again not sure of pick up points on an SV chassis the CSR has a lot of tubular parts that can be used. I used a pick up point each side of the upper diff casing at the rear as one of the above photos suggests, to attach another two female rose joints- one each side,measured the distance in between and added 50mm/ 25 mm per end, i used threaded bar in between the joints with lock nuts. Ok not as nice as a powder coated tube, but it works. Then bolted it all together, it can be done without going through the boot floor.

A third method is to use one of these brackets,but you need some way of mounting it to the chassis, its pretty close on a CSR to a chassis section to the rear and wouldnt be all that difficult to fabricate something to mount it on:

http://www.ebay.co.uk/itm/GGR1071-Cosworth-Group-A...

Apologies i dont have any photos of the finished work on the CSR but if you take your time both strut and brackets fit in nicely.

Edited by sam919 on Monday 1st October 06:42