Vixen exhaust woes

[GJL]

I have a 1971 Vixen 2500 and I am fed up with trying to stop it blowing at the manifold to downpipe flange. I have tried different types of gasket, new studs, brass nuts, extra long brass nuts, steel nuts, spring washers, nordlock washers etc. I also welded a braided flexi pipe in after the bend in the downpipe to eliminate some vibration.
I think the problem is that the middle and back boxes take a smack off the tarmac on the poor and undulating road surfaces around here.
I could chop the 4 inch silencers out of the system and replace them with 3 inch round silencers. Or delete one silencer and have a 3 inch diameter silencer at the back in line with the wheels, so hopefully it will be less likely to contact the road than the middle silencer.
Something like this... https://jetex.co.uk/product/round-silencer-box-mic...

I am running on Toyo CF Proxes 185/65/15 tyres. They are good tyres but I could change them for something more akin to the original size as perhaps the lower 65 profile is causing the car to bottom out.

I have set the ride height and stiffness to what is an acceptable level and didn't really want to go any stiffer. I suppose a tyre with a taller profile would have more give and soften the ride slightly so I could adjust the shocks a little too.

Any thoughts or ideas will be appreciated. Thanks in advance.

[Moto]

I see you're running the standard alloy fin wheel. I have these on my Vixen with 195/65 fitted and although some say they're a tad too wide for 5.5J rims, I've had no problem on either the road or track.. They would give you 6mm additional exhaust clearance from the ground compared to 185/65.

Moto

[Monkeythree]

Change the tyres. Going to a bigger profile will not only increase your axle height but will also make the body appear lower (wheel arch clearances) which you can then correct back by increasing the suspension ride height. More tyre sidewall height might also mean you can increase the stiffness of the suspension without sacrificing ride comfort.

[Dollyman1850]

It sounds more to me that you need a better exhaust fabricated.
you shouldn't have clearance issues with a 65 profile tyre. The secret is to utilise oval silencers of about 3 inches with 2 1/4 inch pipework. you need to loose as much silencer between the chassis rails and cross tubes then have some bent pipework into the silencer itself curving around the cross tubes. This will give enough clearance but needs to be done by someone who know what they are doing.



N.

Edited by Dollyman1850 on Wednesday 14th July 00:29

[Moto]

Interesting photo as I've always been worried about whether the Vixen chassis is strong enough to cope with using that type of lift. There doesn't seem much to the outriggers.

Have you strengthened yours somehow or is it just that the body shell gives the required support to them?

Would an older, unrestored chassis be a concern lifting this way?

Moto

[S1Vixen]

I use a similar lift on the S1 Vixen (albeit with a new chassis) and it changed my life. The outriggers are braced to the top tubes which appears to give sufficient support for lifting the car without deflection.

[Dollyman1850]

Moto said:

Interesting photo as I've always been worried about whether the Vixen chassis is strong enough to cope with using that type of lift. There doesn't seem much to the outriggers.

Have you strengthened yours somehow or is it just that the body shell gives the required support to them?

Would an older, unrestored chassis be a concern lifting this way?

Moto

Its bolted to a big eff off placcy bodyshell so not sure what you are worried about disturbing even without not much chance of deflection in such a light car.

Edited by Dollyman1850 on Wednesday 14th July 12:07

[Moto]

Dollyman1850 said:

Its bolted to a big eff off placcy bodyshell so not sure what you are worried about disturbing even without not much chance of deflection in such a light car.

Edited by Dollyman1850 on Wednesday 14th July 12:07

That's good to know. May just find one of those lifts on my Xmas list then.

Moto

[Dollyman1850]

Moto said:

Dollyman1850 said:

Its bolted to a big eff off placcy bodyshell so not sure what you are worried about disturbing even without not much chance of deflection in such a light car.

Edited by Dollyman1850 on Wednesday 14th July 12:07

That's good to know. May just find one of those lifts on my Xmas list then.

Moto

They pay for themselves in a very short space of time.. 2 poster are a bit more versatile for body off etc but if you have limited head room then the 1m scissor lift cannot be beaten.. mine is an Automotech.. the company been around a long time so a safe choice..
N.