Turbo Gaskets - SORTED With Part Numbers

[peterguk]

When i removed the turbos from my 3000 mile M400 engine, i found both turbine outlet gaskets split. One came out in 3 pieces They were the cheap, thin, pressed out steel shim type available on ebay for about £1 each.

Having fitted dozens of OEM compression type turbine gaskets to MR2s, and knowing Nissan have never had a problem with their compression type gaskets, these are what i wanted. There is also a theory that compression type gaskets are better at retaining the torqued bolts. Hmmm, turbine bolts coming loose on Nobles? Cheap shim type gaskets? Common link i wonder?

So i ordered 2 sets from my local Nissan dealer. Turbine inlet, no problem. Turbine outlet, 1 stud is 1.5mm off centre.

So i phoned around - was advised by one Noble "specialist" to file out the hole . No thank you.

After many phone calls and emails, i now have the answer:

There are two almost identical turbine housings. They differ depending on the centre housing:

1st)"T" series, i.e. T25 and T28 fits journal bearing centre housings (4 bolt fixing).

2nd) "GT" series, fits ball bearing centre housings (6 bolt fixing). The turbine housings are essentially identical - except for the 4 or 6 bolt fixing, and the outlet flange stud 1.5mm off centre.

So, Nissan part numbers:

Turbine inlet (all) 14415-17M00

Turbine outlet (T25 and T28) 14445-26E00
Turbine outlet (GT25, GT28) 14445-79E00

This is substantiated by Phil Brett's decats not fitting my T28s. His decats were designed for his GT25s. So although he has 25s, he has the GT centre housing, requiring a 6 bolt fixing turbine housing, thus his are the 2nd type.

[ThatPhilBrettGuy]

Thanks for this Peter. I know there were lots of people moving away from gaskets, as it was thought to be one of the causes of the turbo's undoing and in the odd case, falling off! Perhaps it was always budget gaskets being the issue.

[Iaing01]

I've just had all my turbo gaskets replaced by petersmiths, i hope they last :-o as I think they're pukka noble parts.

Iain

[ThatPhilBrettGuy]

Iaing01 said:

..pukka noble parts....

That seems to be coming a oxymoron in some areas.