Rear box on a Sprint, is stainless best?

[pereirac]

The rear box on my Sprint is about 20 years old but being stainless it looks in pretty good condition from the outside.
On a long drive with the hood up the noise is pretty intrusive and gets quite 'wearing' (I am trying to convince TOH to drive from the UK to Geneva in October for a classic car rally).

I would be interested to know what other owners think about the various exhausts around.
Is it likely that the baffles in my SS one have 'died' after 20+ years?
Should I replace it with a shiny new SS box or a mild steel one?

Any suggestions welcome

Thanks

Carl

[Hamish Coutts]

Caarl,

I think it very likely that the baffles have gone awol a long time ago.

Paul Matty or Susan Miller can provide a replacement. When I got a new back box on my +2 it was much quieter. If you do go for a new one, make sure the tailpipe protrudes beyond the back bumper. That will make it quieter (shock waves from the exhaust are carried past the bumper so don't resonate through it, causing more noise).

I took TOH on a week long tour of the Highlands - made sure there was always something in the boot (e.g. walking jackets, small luggage) to stop any resonation there.
Worked a treat! She never commented once on exhaust noise except to say she liked the sound of the tickover!

Hamish.

[pereirac]

Hamish,

Thanks for the suggestion, Susan seems to favour mild steel boxes. Did you fit a stainless one?

Carl

[stuartgb100]

Carl,

I fitted an ss box from Susan Miller to my Sprint about 6 mths ago. I'm more than happy with it........... pleasant noise, but not too racy!!

Racy is fine, but not on long journeys.

Think PO had cut the intermediate pipe wrongly, because no matter what alignmrnt, the exhaust hangs low. Have now a new ss intermedite pipe from Susan.

This is over long both front and rear........will cut to get the correct alignment and (as Hamish correctly says) make sure the tailpipe clears the rear skirt.

HTH.

Regards,
Stuart.

[bill308]

Years ago when I last painted my S2, I remember having to strip a lot of tar like undercoating from the rear bottom panel. I now think this material was put on to dampen panel vibrations. When I next paint the car, I will likey restore the undercoating or try something else.

Bill

[Hamish Coutts]

Carl,

From what I can make out a full stainless system (manifold to rear pipe) makes a much sharper or harsher noise than an equivalent mild steel one. The same applies when only a silencer is fitted.

I fitted a stainless centre pipe and silencer to my +2. Yes there is a bit of exhaust noise inside the car but not too much. I have done a few journeys >4 hours and didn't find exhaust noise a problem. Mind you, the boot was fairly full and there was the usual clutter caused by a motoring holiday, on the back seats. I also had to turn the sat nav up fairly loud to hear it clearly.

I am thinking on trying a wee 'cherry bomb' silencer just upstream from the silencer to see what effect that has.

Regards,

Hamish.

[fatboyoz]

Carl,
Can't comment on s.s. as my car is off the road and haven't fitted the new system. I have heard of a product called aluminized steel. Mild steel is coated with aluminium for longevity and you don't get the boomy sound.
Perhaps from a supplier in the States.
Regards Colin.

[mac5777]

Carl,
I have a 67 elan coupe and used an original designed stainless box. I have also heard that the mild steel is the quietest. After 2000 miles it is starting to get a little racey when backing off only. Otherwise it sounds great around town and when getting on the webers. Highway driving is still OK even with the window down. At 65 mph with tires and gearing I run at 3400 rpm.
Bill, I used a product made in San Jose, CA. that is called Sound solutions, go to Quiet car. They sell a paint that with three coats will reduce the sound level by 20 DBs. I painted the interior, doors, roof and the boot areas and it really works. Even with a stainless box I could easily hear the radio if I had one.
Sarto

[richardcox_lotus]

I have just replaced my Sprint rear box/silencer with a stainless one, from Miles Wilkins - it includes the heat-shieldy bit above the actual Silencer. When I first drove the car back home with hood up, it seemed noiser than my previous Steel one. Now driving topless (Summer's here !), I think it's a bit louder, but not too bad.

Mid you, my wife insists she can hear me coming home from 3 miles away

[pereirac]

I have just discovered after a lot of phoning around that nobody makes mild steel boxes any more (even Susan Miller can't get them..) so it looks like the question is pretty academic now, unless somebody out there has one hiding in a corner??

Thanks

Carl