UK & J-Spec Tubby Differences

[Scott]

Are there any differences between the fitment of the UK and Jspec turbos? I have a pair of turbos for sale that came from a J-Spec. Now I know there are differences in the UK assembly but are there differences in the turbo fitment? Basically, can you swap JSpec turbo's with UK spec? turbo's?

 

Cheers

[Wez]

You will also need a manifold and downpipe

[Scott]

You will also need a manifold and downpipe

 

Ahh that's what I thought.

 

So the turbo's can't be swapped over individually, it has to be as a, to 1st downpipe, assembly?

 

Cheers

[Branners]

and they are considerably different turbos so the spool would be fairly odd on them in sequential mode.

[Scott]

and they are considerably different turbos so the spool would be fairly odd on them in sequential mode.

 

Sorry I worded that wrong, I meant swapping the turbos as a pair but seperate from the manifold etc. As in using a UK spec manifold with JSpec turbos.

 

While I am here, I did a search but couldn't find a definitive answer on turbo models.

 

Any ideas what they are?

 

J-Spec Ceramic Pre-VVTi -

J-Spec Ceramic Post-VVTi -

UK Spec -

 

I have read that the J-Spec are definitely CT20 and that they are also, definitely, CT12a lol.

[Chris Wilson]

UK / US spec turbos are 4 bolt fitment to the manifold, J-Spec are 3 bolt. Some UK cars came with ceramic turbine wheels in the 4 bolt housings. There was much fiddling about with these things during the life of the cars, far more than most people realise.