SE / S2 exhaust change ?

[Avonvilla]

Does anyone know if an full SE system will fit an S2 and vice versa ? with no messing ? S2 system has no main cat. Thanks

[ailwyn]

I am far from an expert, but as I understand it you cannot "straight" fit an SE exhaust onto an S2.

I believe there are two main reasons for this:
1. There is an O2 sensor which needs to be "plugged" into the exhaust.
2. There needs to be at least 1 CAT (main or pre-cat) in order to pass emissions tests (assuming they are applicable to you)

Should I have got the wrong end of the stick, anyone who knows more about it can feel free to correct me.

Ailwyn

[Nige]

Sounds right to me.

[ailwyn]

Ah... so I have been paying attention

[Monty]

The O2 sensor is on the back end of the Turbo, so that doesn`t effect the system. Think Avonvilla knows about the cat but wanted know would the SE fit the S2, which i think it would but need to check the mounting points.

[ailwyn]

Ok, a question then springs to mind - why does the stiffy/wanger need the O2 sensor attached for S2s? Not being funny, just don't know.

I took the original post as full exhaust, i.e. including downpipe. but didn't realise that the O2 sensor is attached to the turbo...... or have I got completely the wrong end of the stick now?

Ailwyn

[Enright]

I also believe that the two are "mainly" incompatible.

There are 4 sections:
Downpipe
Front section
Centre section
Backbox

The mountings should be in the same place, and the backbox is probably the same, but the join between the centre and front section is in a different place (or so SJ Sportscars told me), and the downpipe is obviously totally different because of the cat.

The best thing to do would be to try to get the Lotus part numbers for each section. I may have them in a Paul Matty catalogue at home. If so I'll try to post them later, unless someone else beats me to it.

Edit: actually here's a better idea - Dans has recently posted that he's having a new exhaust fitted tomorrow. He bought it from SJ's, so should still have the bill to hand with all of the part numbers for either SE or S2 on (SE I think).
If someone asks nicely perhaps he could post them in this thread...?

[Gazza]

Sinclaires of London have fitted quite a few Janspeed SS exhausts that are made for the SE to S2 Elans. It fits straight onto the downpipe leaving the pre-cat in place, but removes the main cat as it's a straight through exhaust as the SE's don't have cats.

I was going to have this done, but went the custom route but nchase had it done. The only thing Sinclaires had to do was put the squish in.

As far as I'm aware the only difference is the downpipe which has the pre-cat in for the S2's.

Gazza.

[Monty]

Yep would imagine the only differance in the system is the o2 sensor, maincat and the pre-cat has it`s honey comb in place, so in theory it should fit The part were the O2 sensor is not normally changed when having an exhaust done as this is a big cost and a lot is involved in fitting.

Think Avonvilla started this thread up because he was thinking of a group buy and needed to know if the mounting parts were the same

ps the SE has the hole still for fitting an O2 sensor.

[Enright]

Think Avonvilla started this thread up because he was thinking of a group buy and needed to know if the mounting parts were the same.

Disagree - I reckon he started this thread because we had previously been talking offline about a possible exchange of systems.

He has a noisy 2 1/4" stainless system for an S2 and wants a nice quiet standard bore one.
I have a nice quiet standard bore one (also stainless) but would like to beef it up a bit.

However I'm SURE we can't just do a straight swap because the centre section is definitely a different part number, which makes the front section different too.

Unfortunately I don't have the numbers to hand (apart from S2 middle which is A100S6023F) so need someone else's input.

Whether a swap is possible or not will at least be good reference info for anyone else who needs it in future.

[Gazza]

Enright

I'm sure if you swap exhausts from the pre-cat back, they will both start in the same place and finish in the same place regardless of part numbers.

I did a lot of research into SE/S2 exhausts as I wanted to lose my main cat, especially talking to Sinclaires and the people who had the Janspeed done.

Gazza.

[Gazza]

The middle section part numbers would be different on a SE and S2 because the S2 has a main cat in it.

Hope this helps

Gazza.

[Avonvilla]

LOL no answers for a month and then all these in one day

Ok the reason i wanted to know was because i am thinking of using a virtually stock SE system from Enright on my S2 from the precat back, i have no main cat so basically i just wanted to know if it fits and if the mounting points are the same.

I believe the O2 sensor is on the top by the turbo so this is not an issue as it will not be replaced with a normal exhaust. Also as Monty says it is on the SE too but is just plugged.

The cat needed in my case will be the precat and this piece is identcal SE to S2 except ones full of crap !

Montys spot on with what i was asking.

The parts are differant in look and length but if your going to change the lot from the precat back then they take the same routes so i now believe they are interchangeable as a complete exhaust but not as bits.

I think there is some confusion on what the downpipe is, as far as i am concearned it is the first piece of the exhaust AFTER the precat housing, the precat is a seperate piece and as stated above basically the same on both cars.

Biggest problem now is the logistical knightmare of trying to do a swap with Enright and the no doubt many unforeseen problems that will arise from it.........................not to mention locations !

[Gazza]

Avonvilla

I got myself confused, as long as you change exhausts from the triangular fitting you should be o.k. (see picture)
Above this is the pre-cat which like you said is the same , but got crap in for the S2's, and below this is the downpipe.

Seeing as you are swapping a 2 1/4" custom exhaust with no main cat and not an S2 exhaust for a standard SE there should be no problem.

Gazza

[Avonvilla]

Gazza, is that your system ? the haywood & scott one ? your using the precat still is it full or do you have another cat ?

[Gazza]

Avonvilla

This is not my system, just one of many pictures I took off this site to take to Haywood & Scott so they could see what I wanted.

Mine is a 2.5" from the pre-cat back, removing the main cat and fitting a flexible pipe. The pre-cat is still in place to get it through MOT's.

Like I said before you should not have any problems swapping. I spoke to Janspeed when changing mine and they only make SS exhausts from the pre-cat back for the SE (with no cats). I have seen 3 S2's with this exhaust, some from underneath. The only reason I didn't go for it was I didn't like the look of the tailpipe.

Gazza

[Monty]

Hey Gazza,

How are u finding u`r 2 1/2" exhaust? are u getting more boost? has it effected the way the boost comes in?

Cheers
Jay

[Gazza]

Monty

I'm well pleased with the exhaust, it boosts to just over 0.5 which it did not before. This was mainly due to the knackered main cat and squish . SS 2.5" exhaust cost me the same as it would have to replace the main cat with an original part.

The car now seems as fast as my old SE.

Gazza.