Turbos and cats

[ERIKM400]

Gentlemen,

Can I please call upon the collective Nobility knowledge database for some advice?

I recently had my turbos (M400 Garrett GT28) refurbished but when they came back I was informed that both the compressor housings (exhaust side) have some small cracks around the wastegates.
They also told me that they are unable to replace the housings because these are extremely difficult to find.
I did some searching myself and although compressor housings for the GT28 are not hard to find at all, the problem seems to be that in my turbos the compressor housing is attached to the rest of the turbo with 4 bolts while all the replacement housings I found are six bolt.
Does anyone know where I can find the correct compressor housings?
I have already contacted Universal Turbos in the UK but have not got an answer yet.
It would be quite stupid (and a waste of money) if I had to buy a completely new set of turbos because I can not find a (rather cheap) replacement part.

Another problem is that my catalytic converters are tattered and I need some new ones.
Before anyone suggests "go full decat": there is no way the car will pass MOT in Belgium without cats.
I contacted some companies but the cats on the Noble M400 are quite small (93mm diameter, 170mm length) and they all told me they do not have cats of this size which are able to cope with a 425bhp 3.0 V6 twin turbo, even after explaining there are two of them in parallel.
Has anyone replaced their cats with aftermarket ones?
I would prefer some free flowing sports cats that will still allow the car to pass MOT.

Thanks,

Erik

[StreetDragster]

My bcs exhaust has high flow cats in it, maybe give them a call and see if they can post you some out?

[Rob_W]

For CATS look at Magnaflow who do suitable units

[Jarcy]

My very recent Hayward and Scott system included sports cats. I've got over 400 bhp. I'm sure they'd supply just the cats, as they're separate from the rest of the system. I also got them ceramic coated for good measure.
https://www.haywardandscott.com/

[TuxMan]

I would have thought Universal Turbo's would have been your best bet .

[Blu3R]

The problem is M400 turbos are not GTs, they're T28s which is probably why you can't find what you need. The housings will be difficult to find but not impossible as they were used on plenty of Japanese cars like Nissans. Keep looking, something will turn up.

[ERIKM400]

Blu3R said:

The problem is M400 turbos are not GTs, they're T28s which is probably why you can't find what you need. The housings will be difficult to find but not impossible as they were used on plenty of Japanese cars like Nissans. Keep looking, something will turn up.

Update:
Yesterday I spoke with Graham Page at Universal Turbos, the man who designed and produced the Noble M12 - M4OO turbos together with Lee Noble, who was very kind and helpful.
He told me the turbochargers on the M400 are NOT standard Garrett turbos but were made specific for our cars using parts from different types of Garrett turbos.
The compressor (exhaust) side is indeed from a T28, the intake side is from a T3.
He confirmed that the T28 housings are extremely difficult to find (new ones that is).
If the turbos fail, he suggests replacing them with Garrett GT2554R types, which are smaller but more efficient then the current turbos. They are however not a direct bolt on replacement but need some adaptations to fit the car (which of course they can provide at Universal Turbos).
For someone looking for more power he suggests the GT2860R.

He also advised fitting a 1,5mm restrictor in the oil feed lines for the turbos because apparently with the standard lines the turbos get too much oil which causes the seals to start leaking -> smoking engine.
Thought this info might be worth sharing.

The good news is that he took a look at the pictures of the cracks in the housing I sent him and he assured me that (for now) I can just keep using my current turbos.
Worst case scenario is that the cracks get worse and I lose boost.

Erik

[macky17]

Getting mine rebuilt at Jetstream later this month - now I'm worried I'll have a similar issue. Good to know there is a whole new turbo available which will do the job if the worst happens.

My car has been smoking slightly for a while at cold idle. I'm also getting a siren noise at -0.3 bar boost which I'm guessing is the compressor wheel. What symptoms did you have to tell you yours were in need of work?

[ERIKM400]

macky17 said:

Getting mine rebuilt at Jetstream later this month - now I'm worried I'll have a similar issue. Good to know there is a whole new turbo available which will do the job if the worst happens.

My car has been smoking slightly for a while at cold idle. I'm also getting a siren noise at -0.3 bar boost which I'm guessing is the compressor wheel. What symptoms did you have to tell you yours were in need of work?

I did not have any signs of turbo problems.
My exhaust manifolds were cracked and to replace them the turbochargers had to come out.
I then decided this would be a good oportunity to have the turbos checked and refurbished and that's how we found the cracks.
Same story with the cats.

Here's a picture of what the cracks look like:

[StreetDragster]

ERIKM400 said:

Update:
Yesterday I spoke with Graham Page at Universal Turbos, the man who designed and produced the Noble M12 - M4OO turbos together with Lee Noble, who was very kind and helpful.
He told me the turbochargers on the M400 are NOT standard Garrett turbos but were made specific for our cars using parts from different types of Garrett turbos.
The compressor (exhaust) side is indeed from a T28, the intake side is from a T3.
He confirmed that the T28 housings are extremely difficult to find (new ones that is).
If the turbos fail, he suggests replacing them with Garrett GT2554R types, which are smaller but more efficient then the current turbos. They are however not a direct bolt on replacement but need some adaptations to fit the car (which of course they can provide at Universal Turbos).
For someone looking for more power he suggests the GT2860R.

He also advised fitting a 1,5mm restrictor in the oil feed lines for the turbos because apparently with the standard lines the turbos get too much oil which causes the seals to start leaking -> smoking engine.
Thought this info might be worth sharing.

The good news is that he took a look at the pictures of the cracks in the housing I sent him and he assured me that (for now) I can just keep using my current turbos.
Worst case scenario is that the cracks get worse and I lose boost.

Erik

Great info, thanks for sharing that

Matt

[SwankBaton]

From experience driving with the siren noise is going to increase your cost of a rebuild. Started with smoking on idle, should have sorted it earlier really!

[macky17]

Siren came first and at the time I thought it was a boost leak. We live and learn...

[SwankBaton]

Same here! New compressor wheel and machined housing on top of the service items in the end. Fun fitting the front one as well.

[Exploded]

If you need a housing, you might have luck with MJM turbos.
They built my uncle's Lotus Esprit T28 turbos.

http://www.mjmturbo.com/

[macky17]

Was at Jetstream this morning; they have serviceable housings on the shelf up there and said this isn't a problem at all.

[AMG Merc]

ERIKM400 said:

Here's a picture of what the cracks look like:

Erik, i hope you don't mind me asking but were you born with three hands? Very useful if so