Is there a knack to sealing exhaust slip joints?
Turbo Mini Forums

It's the joint between the mirage manifold and the play mini exhaust. I will check for a miss match between ID OD but I struggle to get a good seal. I use the putty type exhaust paste but some people recommend RVT? I use a decent quality exhaust clamp which I put on the furtherest end of the slotted pipe, I take it that's the right place to put it?

Thanks guys!

I always use firegum

Silicone sealer

What clamp you using?

Mikalor clamps are working well for me.

RTV does work well on exhausts as long it's the high temp stuff.

I use to use the cheap U bolt type clamp but I am using the Mikalor type now. I might try silicone sealant next time and see. I'm tuning using a wideband and I'm a bit nervous about leaks. I really like the idea of putting in a flex joint, I have a gearbox mounted bracket on the turbo downpipe but I think that might make things want to flex at that first join.

A small amount of almost any sealer will work as long as the smaller diameter pipe is inserted past the slots that allow the larger diameter to me clamped up AND that both pipes are aligned correctly.

All too often a small mis-alignment gives problems.

I know of one regular contributor on here who uses ordinary bathroom silicone sealer instead of a manifold to head gasket and has no problems with 200bhp+

Personally I would be very wary of any silicone based sealer unless it is specifically marked as safe for use on systems with catalytic convertors.
Silicone is one of the primary killers of wideband LSUs - and catalytic convertors, which is what normally get mentioned on the tube/tin.

Remember a few years ago in the southeast hundreds of widebands were destroyed by fuel from certain supermarkets and the problem was traced back to a refinery in Essex (that supplied the supermarkets) where several unleaded petrol storage tanks had got contaminated with a silicone additive that shouild only be used with diesel.

Schrödinger's cat - so which one am I ???

Thanks for all the help everyone, food for thought. Good point Rod about the wideband compatibility.

I use firegum sealant as well and always been fine. How tight is the joint?

generally if it's leaking it's a bad fit, simple as that really.

I exit my turbos then about 12" back into a slip joint on each. I leave this unclamped due to lpcation, and to allow movement in the joint.
Even unclamped there are no leaks as it is a nice snug fit.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I reckon it's a combination of a lose fit plus a bit of engine movement causing the downpipe to move making it worse.

True, slip joints will not like any sort of engine movement, mine's bolted in solid.

Definitely get a flexi of some sort in there, whether flexi or balljoint style.

it's very hard to get a mini engine to stop moving !

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Only put sealant on the male part of the joint. That way, you'll never push the excess into the exhaust, so less chance of causing problems with the cat or sensors.