Tips on Properly Aligning Cat-EBPV-Exhaust

[Vanya]

Hi All,

 

So in an attempt to get a more spirited exhaust note out of my SE I switched out the stock system for the SJ Super Sports Stainless exhaust (will post a comparison at some point, but the difference was mild to say the least).

 

Upon switching I've however not been able to manage to seal all the gaps at the EBPV - neither towards the cat nor the exhaust. With the engine running there's substantial blowing from the gaps.

Considering the state of the system before I dremelled off the old bolts holding the flanges together (rust-city) I suspect rust was doing most of the sealing.

 

Does anyone have any advice on what to do? I've heard there are different sealants one can apply (I've even heard copper paste mentioned as a viable alternative). I've also thought about loosening up the cat entirely at the turbo end, aligning best I can at the EBPV and then dealing with the turbo. But having a leak at the cat end feels better than a leaking turbo outlet....

 

The SJ-sports exhaust flange doesn't seem to have an compatible angle to successfully seal off against the EBPV.

 

As a last resort I could tear out the EBPV and fit a shiny new spacer but I'm sure I'm doing somethingwrong and would like to learn what it is.

 

Thanks for any advice.

 

P.S. I removed the EBPV and cleaned up the mating surfaces to eliminate rust buildup. It didn't work as hoped.

 

 

[philip600]

Hi Vanya,

Did you use any exhaust paste on the joints ?

I've removed my EBPV but when I fitted my new cat bypass pipe & sports box last year a smear of exhaust paste on the flange joints ensured a good seal ( be careful what you use sealing the joints before the CAT as some can harm them )

I had my back box off again recently to remove my gearbox but again I used exhaust paste on the joint & this has sealed fine.

Phil.

[Vanya]

Hi Phil,

 

Nah I mounted the whole lot bone-dry. I had read about exhaust pastes but I got the impression that the general consensus was that "if you have to use paste, you're mounting it wrong" and that the paste simply breaks down and starts leaking anyway. Could be a lot of BS though.

 

I'll pick up a tube this weekend and give it a shot. The CAT-Turbo joint is mounted dry and doesn't leak at all.

 

Thanks again for the tip!

[dodge1979]

I have previously fitted the sj back box and sports cat (no,longer running with) my basic verdict is this. The flanges dont line up with the same supplied ebv spacer because theyre different. Basic quality. Or not... Assemble all together, but jyst finger tight on all bolts, including mounts to the frame that mounts to the gearbox, and adjust, fiddle, tighten throughout the system start to finish several times..you will get there..

[rocket63]

Yup. I have to echo Gerts comments. I have a twin exit Larini and it was the devils own job to line it up. I had to loosen, adjust all mounting points. I concentrated on mating the EBPV with the cat and exhaust down-pipe first, then concentrated on the rest. You might have to use a little persuasion or be prepared to modify some of the mounting points.

[qwerty123]

You do know what that piece of junk was fitted for? It's for (US) Californian emissions or somesuch. Have you considered ripping it out and fitting a spacer, plugging the vacuum and strapping up the throttle jacking rubbish out the way (or removing it as well)

 

Its all excess crap really.

 

I think SJ do an alloy spacer iirc, didn't cost a lot afaik

[Vanya]

I've considered tearing it out to be honest and fitting the spacer - but at that point I kinda start thinking of just getting a De-Cat pipe which extends past the EBPV anyway.

 

Thus far I've however bought some flange sealant for exhaust systems. I'll see how I get on with it. Otherwise as many have suggested, bye-bye EBPV!

 

Thanks for the tips everyone.

[andydclements]

If you are still struggling when you've tied the exhaust cement, consider getting a wire exhaust ring. There aren't any designed to fit but given the diameter you'll probably be able to find one. They are normally hollow conical with a flat base so you'll be able to get the cone to go into the flange of the exhaust and the EBPV will then press into the flat base of the ring.

 

Personally I'd go with removing the EBPV and blanking off the vacuum pipe that control it.

[qwerty123]

there's a de cat pipe on ebay at the mo

 

http://www.ebay.co.uk/itm/NEW-LOTUS-ESPRIT-S4-STAINLESS-STEEL-DE-CAT-PIPE-LINK-PIPE-/280758535728?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item415e834630

 

although they are quite good (Cybox) a bit of exhaust putty might still be needed.

 

It will make the car a little noisier but release a bit of 'GO' as well

;-)

Edited June 2, 2013 by qwerty123

[dodge1979]

Not all decats remove the need for the spacer, some require it still...and to be honest if you have to use exhaust paste to seal theb there is something wrong... The jointing faces shouldnt need it on this car..if it was a tube sliding into another ok..but we dont have that

[Vanya]

Well the exhaust paste did the trick - killed the "leak" immediately. I could have tried undoing the cat at the turbo end to better align the remaining components but somehow I just don't think it would have worked - the adjoining surfaces of the EBPV and the SJ Exhaust don't seem to mesh too well together.

 

Thanks for the tips everyone!

[dodge1979]

Im using the sj spacer, and no the faces dont match your right, however by correctly adjusting everything I have no leaks..and no paste used. Paste will eventually crack, crumble etc..

[Vanya]

I think the paste might have cracked after my last outing hehe - I'll check again and try to align with the cat loosened up at the turbo. If that doesn't work then I'll tear out the whole rotten system and fit a new cat and spacer pipe.

[Vanya]

A quick update:

 

I've removed the EBPV (will put it up for sale if theres any poor sod who wants it) and replaced it with a spacer while blanking off the hose. I still couldn't align things properly. Even by more or less removing the cat there wasn't a way to get the damned thing to join the spacer at even a relatively decent angle.

 

After some fiddling I've got it mounted with paste and the exhaust bracket slightly at an angle nearest the cat.

 

I think I'll look into a wire exhaust ring next...

[dodge1979]

Just a small note...there are two types of decat..the difference being whether they need a spacer or not..ie one is longer than the other..I have a short one with spacer on mine and a friend has a longer version with no spacer. .he struggled Originally trying to get the spacer to fit until realising it lined up better without...

[rocket63]

[Zolder]

Our (genuine) Lotus Sport exhaust does away with the ebpv/spacer, and bolts straight to the cat. so much easier to fit. 

Edited July 25, 2013 by Zolder