Side exit exhausts - what are the rules?
Discussion
With the coming of the new TVR and also the old McLaren SLR, I'm thinking of putting a side exit exhaust that exits forward of the doors on my new project. I was always under the impression that they weren't acceptable for UK use but obviously the new TVR contradicts that.
What are the rules for where the exhaust exits?
What are the rules for where the exhaust exits?
fatbutt said:
With the coming of the new TVR and also the old McLaren SLR, I'm thinking of putting a side exit exhaust that exits forward of the doors on my new project. I was always under the impression that they weren't acceptable for UK use but obviously the new TVR contradicts that.
What are the rules for where the exhaust exits?
I don't know the rules.What are the rules for where the exhaust exits?
Obviously a lot kitcars, 7-types, cobra copies,etc have side exit exhausts just in front of the rear wheels. New builds need to meet SVA/IVA rules on projected radius etc, my pre-SVA car does not so far as I know, certainly never had issues with it at MOT.
I know of fwd race cars/autotest cars etc, which have the exhaust just in front for the front wheels, including some with an MOT, but again do not know the rules here.
Daniel
I don't know the rules, but I've seen roadgoing cars with exhausts exiting in all sorts of strange places. I don't recall ever seeing any that terminate underneath the floorpan (they all extend to the edge) and there may be a regulation about that. I expect there will be some general restrictions about exposed sharp/hot edges too.
GreenV8S said:
I don't know the rules, but I've seen roadgoing cars with exhausts exiting in all sorts of strange places. I don't recall ever seeing any that terminate underneath the floorpan (they all extend to the edge)
But if you look at various vans and commercials, the exhaust often does exit somewhere way under there.The basic rules are simple... You can't risk any gas ingress - so it has to be aft of any opening side windows - and you can't risk barbecuing pedestrians.
This is an interesting read: https://www.ukpoliceonline.co.uk/index.php?/topic/...
Seem to be as long as its below noise levels and gas emissions you're ok.
The point about not exiting on the passenger side is weird as lots of cars exit on the passenger side, just not near the front wheel and usually at around a 45 degree angle. I'm guessing that exiting behind the front wheel on either side is okay as long as the pipework ahead of the exit point is angled such that the exiting gas is not perpendicular to the side of the car.
Seem to be as long as its below noise levels and gas emissions you're ok.
The point about not exiting on the passenger side is weird as lots of cars exit on the passenger side, just not near the front wheel and usually at around a 45 degree angle. I'm guessing that exiting behind the front wheel on either side is okay as long as the pipework ahead of the exit point is angled such that the exiting gas is not perpendicular to the side of the car.
There are no specific rules as far as the IVA test goes, which is a fairly good guide. The original draft of it would have banned sidepipes, but they saw sense and changed it before it came in to effect. A quick look through the manual doesn't specify where they can exit; the usual things about no sharp edges and not being positioned so that fuel etc could leak onto them. So as long as it's not pumping gas into the cabin, it should be fine.
fatbutt said:
This is an interesting read: https://www.ukpoliceonline.co.uk/index.php?/topic/...
Seem to be as long as its below noise levels and gas emissions you're ok.
The point about not exiting on the passenger side is weird as lots of cars exit on the passenger side, just not near the front wheel and usually at around a 45 degree angle. I'm guessing that exiting behind the front wheel on either side is okay as long as the pipework ahead of the exit point is angled such that the exiting gas is not perpendicular to the side of the car.
Don't think there are any requirements about the angle. My car has twin sidepipes which have a 90 degree bend at the very tip, as do many others.Seem to be as long as its below noise levels and gas emissions you're ok.
The point about not exiting on the passenger side is weird as lots of cars exit on the passenger side, just not near the front wheel and usually at around a 45 degree angle. I'm guessing that exiting behind the front wheel on either side is okay as long as the pipework ahead of the exit point is angled such that the exiting gas is not perpendicular to the side of the car.
CrutyRammers said:
There are no specific rules as far as the IVA test goes, which is a fairly good guide. The original draft of it would have banned sidepipes, but they saw sense and changed it before it came in to effect. A quick look through the manual doesn't specify where they can exit; the usual things about no sharp edges and not being positioned so that fuel etc could leak onto them. So as long as it's not pumping gas into the cabin, it should be fine.
Cheers 
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