4200/GS exhaust system pictures

MAF260 · Sep 9, 2013

I'm trying to remember - am I right in thinking that some cars had 2 cats after the manifolds and others had 4?

safrane · Sep 9, 2013

If I recall correctly Pat had the exhaust done in Cardif

Grinzzz · Sep 9, 2013

Prospeed was it? Rings a bell but cant be certain. I've no idea how it sounds!

2b1ask1 · Sep 9, 2013

MAF260 said:
I'm trying to remember - am I right in thinking that some cars had 2 cats after the manifolds and others had 4?

I think they all have all got pre-cats haven't they? There seem to be two types though one vertical and one type laid flat immediately at right angles to the manifold. SO restrictive though.

Chrisbassett · Sep 9, 2013

Maser Sod said:
No you are correct - it's explicitly what I asked for as I wanted to free up the airflow as much as possible.

This is close to what I'd like to have, was this a Prospeed design? I'm tempted to wander over there next month when I go to Llandow, if not before, have a chat about what can be done.

MAF260 · Sep 9, 2013

Would be good to get an idea of the cost of this for comparison.

richard_masa_4200 · Sep 10, 2013

I did get rid of the primary cats and am running new sports cats only. You also have to remember that there are 2 types of exhaust designs. One has the primary cats in the manifold and then a 2 bolt flange to the next section, the other has a 4 bolt flange after the manifold and then the primary cats.

Chrisbassett · Sep 10, 2013

Had mine up on the ramp for the MOT and managed to sneak in and take a photo...

Looks like I have a twin thin pipe going over the steering rack hump, then fairly straight from there to the middle section with a cat in there for good measure. So it looks like I just need the middle sorting and some valves at the back to see if I can bump up the db's

And a shot from the front showing the mini pipes.

Parisien · Sep 10, 2013

......go straight for the straight throughs............

P

MAF260 · Sep 10, 2013

Interesting, Chris. Somebody's already sorted the most restrictive part of the exhaust and a different version to the other 2 shown on here. Seems like this is easily sorted without having to resort to Larini parts and prices.

MAF260 · Sep 10, 2013

richard_masa_4200 said:
I did get rid of the primary cats and am running new sports cats only. You also have to remember that there are 2 types of exhaust designs. One has the primary cats in the manifold and then a 2 bolt flange to the next section, the other has a 4 bolt flange after the manifold and then the primary cats.

I wonder when the design was changed - from the pics on this thread it seems the earlier cars have the primary cats fitted after the exhaust manifold, which can be easily(!) removed. Later cars appear to have the weird exhaust manifold with the bulbous primary cat built in.

Chrisbassett · Sep 10, 2013

Parisien said:
......go straight for the straight throughs............

P

If I didn't live in sleepy hollows, and this wasn't my daily drive then I would...but my average journey would probably start with the local mums throwing stuff at me as I turn their sleeping darling into a screaming ball of hatred, being pulled as I leave the gate for noise pollution and anti-social/terrorist behaviour, then startling the pensioners wandering on the Heath as squirrels have heart attacks with each backfire and fall from the branches onto their heads...

I think a valve is a small price to pay to avoid that (or a less extreme version of it anyway!)

Chrisbassett · Sep 10, 2013

MAF260 said:
Interesting, Chris. Somebody's already sorted the most restrictive part of the exhaust and a different version to the other 2 shown on here. Seems like this is easily sorted without having to resort to Larini parts and prices.

Indeed, it seems there is more than one way to skin this particular cat.

..oops, pun not intended. Sorry.

Have no idea where this was done, but it looks like its a bit hacked together, and not as pretty as some...but it looks like a nice solution to the steering rack issue, maybe the air-flow is better than the flat box section - no idea, but nice to think so ; )

mjheathcote · Sep 10, 2013

MAF260 said:
I wonder when the design was changed - from the pics on this thread it seems the earlier cars have the primary cats fitted after the exhaust manifold, which can be easily(!) removed. Later cars appear to have the weird exhaust manifold with the bulbous primary cat built in.

I know the US export cars all have the primary cats built into the manifolds, and it appears that later UK GS's and maybe 4200 have them too, rather than the 'Euro headers' with the separate cats.
I think they ran out of Euro headers and decided to use up the US export/rest of world headers at the end of GS/4200 production run. Typical Italian!

MAF260 · Sep 10, 2013

Hmmmm.....wondering if its worth getting hold of some non-cat manifolds and playing around with them. The only option for the cars with the cat built into the manifolds at the moment is Larini and the cost will be significant.

Chrisbassett · Sep 10, 2013

MAF260 said:
Hmmmm.....wondering if its worth getting hold of some non-cat manifolds and playing around with them. The only option for the cars with the cat built into the manifolds at the moment is Larini and the cost will be significant.

Just found an excellent write up about 4200/GS exhausts over at the dark side...google for "maserati 4200 sports cat gordon norris" and you will get a PDF with lots of detail. A must read for anyone vaguely interested in all this.

mjheathcote · Sep 10, 2013

MAF260 said:
Hmmmm.....wondering if its worth getting hold of some non-cat manifolds and playing around with them. The only option for the cars with the cat built into the manifolds at the moment is Larini and the cost will be significant.

So you have the 'US headers' then Mark?
Reading the US forums the problem appears to be these are vulnerable to impact damage, and then the loose bits inside the cats are then very near to be 'sucked up' into the engine causing fatal engine damage. Not sure how anything can be sucked up when the gases go the other way though!
I think the new larini manifolds are more aimed to replace these, rather than the euro headers.

MAF260 · Sep 10, 2013

Great find, Chris.

Heres the link:
http://www.maseratilife.com/forums/...ing-usa-header-euro-maserati_4200_exhaust.pdf

MAF260 · Sep 10, 2013

mjheathcote said:
So you have the 'US headers' then Mark?
Reading the US forums the problem appears to be these are vulnerable to impact damage, and then the loose bits inside the cats are then very near to be 'sucked up' into the engine causing fatal engine damage. Not sure how anything can be sucked up when the gases go the other way though!
I think the new larini manifolds are more aimed to replace these, rather than the euro headers.

I don't know, so will have to investigate. I suspect that I have the US headers as it's a GS.

mjheathcote · Sep 10, 2013

MAF260 said:
I don't know, so will have to investigate. I suspect that I have the US headers as it's a GS.

Easy to tell, get on your hands and knees!

4200/GS exhaust system pictures

Member

Member

New Member

Special case

Member

Member

Junior Member

Member

Moderator

Member

Member

Member

Member

Centenary Club

Member

Member

Centenary Club

Member

Member

Centenary Club