4200 manifolds

[2b1ask1]

Picking up on the tread by Beau regarding de-catting, I propose to remove the biggest breathing obstacle on the 4200 and that is the stupid, nay very stupid restrictions in the manifolds and front section and fully liberate the horses currently being gelded by folds, bends and restrictions in the stock setup!

Does anyone have a pair of stock manifolds currently not in use that could be borrowed to make a pair of jigs to? They would be returned undamaged in just a couple of weeks once the jigs were made and the header plates CAD modelled for laser cutting.

With proper jigs it should be reasonable to make a set of forum manifolds and naturally a complementary set of front pipes (for that matter if you have front pipes, could they also be borrowed for the same reason), available with no pre-cats and xxx cell cats, no cats or dummy cats, the latter being my preferred option.

It has been rumoured that the stock manifolds are double skin, can anyone confirm this?

 

[2b1ask1]

I should add; any of the 4200 models would be suitable.

 

[Parisien]

I believe you are right Newton, can be troublesome because of that fabrication

P

 

[BennyD]

IMO, the front pipes and cats on 4200s are sh!te. Too many obstacles and restrictions for a smooth gas flow. Get rid of them and the engine comes alive and starts producing more power. Well mine did!

 

[CatmanV2]

How will it get past MOT / Lambda issues, Newton? I was never clear on this.

C

 

[BennyD]

Get some 200 cell sports cats in. That way you get good gas flow and it'll pass the MOT.

 

[CatmanV2]

Get some 200 cell sports cats in. That way you get good gas flow and it'll pass the MOT.

Sure, but how does that square with 'dummy' cats.

C

 

[Chrisbassett]

Are both types of manifold the same as far as connections further on are concerned? I know there are manifolds with and without cats built in, especially on GS's

 

[BennyD]

Dummy cats have the cat cans in position but have no cats inside. You will need an on-side tester to pass it but I don't think they can anymore as everything is computerised. 200 cell cats operate as per the originals with no ECU issues but allow better gas flow. That's what I have on mine.

 

[CatmanV2]

Thanks, Benny. That makes it clear

C

 

[mjheathcote]

Yah I think sports cats are the answer, too much trouble at MOT time, and the friendly MOT tester is getter harder!

 

[Tim82]

Do what i did mate, gut out the pre cats and move the sensors from those cats to your main cats further back. 2 less restrictions which allow it to rev more freely without decatting, meaning no dramas with MOT plus you've halved the restriction. Viola

 

[VEDE]

Picking up on the tread by Beau regarding de-catting, I propose to remove the biggest breathing obstacle on the 4200 and that is the stupid, nay very stupid restrictions in the manifolds and front section and fully liberate the horses currently being gelded by folds, bends and restrictions in the stock setup!

Does anyone have a pair of stock manifolds currently not in use that could be borrowed to make a pair of jigs to? They would be returned undamaged in just a couple of weeks once the jigs were made and the header plates CAD modelled for laser cutting.

With proper jigs it should be reasonable to make a set of forum manifolds and naturally a complementary set of front pipes (for that matter if you have front pipes, could they also be borrowed for the same reason), available with no pre-cats and xxx cell cats, no cats or dummy cats, the latter being my preferred option.

It has been rumoured that the stock manifolds are double skin, can anyone confirm this?

Mate I've seen some 4200 manifolds floating around ebay recently.. might be able to pick them up cheap?

 

[conaero]

Newton, yes the manifolds are double skinned and rattle like **** on cars 5 years old and over when could and under load.

A snip at £2k each plus fitting for some of Italy's finest PIG IRON!

 

[Chrisbassett]

Newton, this is a good place to find some more info on the manifolds, and the exhaust in general...

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

 

[CatmanV2]

Newton, yes the manifolds are double skinned and rattle like **** on cars 5 years old and over when could and under load.

A snip at £2k each plus fitting for some of Italy's finest PIG IRON!

Mine don't rattle....

<touches wood, crosses fingers>

C

 

[BennyD]

Mine don't either. Perhaps I've blown the inner skin out the back.

 

[conaero]

Mine don't either. Perhaps I've blown the inner skin out the back.

Now that would figure!

 

[2b1ask1]

As far as I can see from the limited photos on fleabay etc of the two types the top mounts and linking pipework are common and the bottom flange appears to be in the same location meaning if I'm right that all front exhaust sections are the same.

Prices on fleabay are prohibitive for getting an experimental set at least at present. I may chance an indy beaker next year if I don't get any joy any other way. The US type with the vertical pre-cat type setup appear to have a much better pipework arrangement than the EU type ones. The US ones would lend themselves to a much simpler 'modification' as opposed to replacement; picking up a single large bore pipe directly off the collector and linking to the OEM flange in a series of suitable bore pipe bends.

The EU type meet the bottom flange at the worst possible angle creating all sorts of restrictions and gas swirling!

 

[Chrisbassett]

Newton, check that doc I linked to, the manifold and front sections are both different depending on which parts bin was being raided when the car was built - eu manifolds only go with eu front exhausts, us with us.