What turbo can i use? FOR COMMENT ONLY
Turbo Mini Forums

There isn?t a great deal of option with regards to "easily" switching the standard MG Metro T3 turbo.

MG Metro Turbocharger
Model No. TBO342
Part No. 466564-0002
Turbine Trim - 69 Turbine A/R 0.25
Compressor Trim - 40 Compressor A/R 0.42

Don?t forget the turbo fitted to the MG Montego & Maestro is basically the same fitment, and just uses a different boost solenoid to raise a higher boost pressure as standard. Although I don?t know anyone out there that has actually used one of these so can?t comment on their suitability with the metro engine

Another suitable turbo charger that appears to work, and is a direct replacement, is the T3 Turbo fitted to the escort rs turbo. 2 variants are available, the first fitted to the series 1 is cooled purely by the lubrication oil (as per the metro item), while the series 2 is water cooled for better longevity. See details below

Escort RS Turbo Series 1
Model No. TBO345
Part No. 466644-0001
Turbine A/R 0.36

Escort RS Turbo Series 2
Model No. TBO355
Part No. 466944-0001
Turbine A/R 0.36

The advantage these turbo's seem to offer is in the slightly larger A/R in the turbine housing causing a shift in when peak boost is reached, in this case higher up the rpm range. Incidentally the original metro turbine housing (A/R 0.25) is no longer available and most recons will come with the A/R 0.36 effectively giving you a turbo identical to the Escort RS Turbo.

Hybrid T3?s are commonly available and allow for a more robust (360 deg thrust bearings etc) turbo that can handle more boost, and flow more air efficiently. The original T3 turbo has been proven over the quarter mile and on the track by the true turbo mini owners out there, and has seen some large power figures indeed! Infact the larger T3 turbo is potentially more suited to the track car where revs are kept high allowing it to remain on boost much more of the time!

With some additional work it is possible to fit other turbo?s to your A-series engine, there is a slight trend at the minute to adapt a T2 flanged turbocharger to the original cast exhaust manifold using an adaptor plate which seems to work very well, and has been proven by other people on this site especially on the quarter mile, with the lower inertia compared to the T3 it can spool up very quickly. It must also be realized that by sticking a smaller turbo on the car it will mean the boost will come in sooner but will also tail off sooner compared to a bigger turbo.. There are variations of course with the T2 series of turbo?s , starting with the T2 (Renault 5 GT Turbo & Nissan Bluebird) where the phase 1 wasn't water cooled, while the later phase 2 was water cooled, which leads to T25?s (typical rover tomcat/820 turbo which is what R5 tuners spec as stage 3 turbo & s12 nissan silvia) and T28 (typical s13 & s14 nissan 200sx turbo). It must be realized that just because a turbo can fit, doesn?t make it the right choice!!!!!!! There are lots of variables in a turbocharger that allows it to be tailored in the design phase of an engine, so don?t be surprised that by sticking a turbo off a 2litre car in your 1.3litre mini it will be a bit slow to spool up. Some further part numbers are listed below

Renault 5 GT Turbo Phase 1
Model No. TB02??
Part No.
Turbine A/R 0.??

Renault 5 GT Turbo Phase 2
Model No. TB0235
Part No. 465367-0001
Turbine Trim - 58 Turbine A/R 0.35
Compressor Trim - 49 Compressor A/R 0.48

Nissan Bluebird (1.8L)
Model No. TBO210
Part No. 466370-0019
Turbine A/R 0.63

Nissan 200sx (1.8L)
Model No. TB2525
Part No. 465795-0003
Turbine A/R 0.64

Rover T-Series Turbo (2.0L)
Model No. TB2555
Part No. 465199-0003
Turbine Trim - 64 Turbine A/R 0.49
Compressor Trim - 60 Compressor A/R 0.48

Nissan 200sx (2.0L)
Model No. TB2815
Part No. 471104-0001
Turbine A/R 0.??

People may also of heard about ball bearing turbos, a lot of these have come about through modifying the Garrett T-Series of turbocharger, all of this must be realized as being based on old compressor/turbine technology.

In the mid to late 90?s Garrett released a new series of turbo charger depicted by the GT prefix, this utilized upto date technology in its design creating turbo?s that flow more air efficiently and are more robust (handle more boost!). Don?t believe the hype that all of these turbo?s are ball bearing cartridges, only the turbo?s with the R suffix carry this arrangement. Note that there has been a slight shift also in the applicability in the range in which Garrett Turbo works for example (according to garrett catalogue)

GT12 Turbo can flow enough air for 50-130bhp and suits 0.4l to 1.2l
GT15 Turbo can flow enough air for 100-220bhp and suits 1.0l to 1.6l
GT20 Turbo can flow enough air for 140-260bhp and suits 1.4l to 2.0l
GT22 Turbo can flow enough air for 160-280bhp and suits 1.7l to 2.2l
GT25R Turbo can flow enough air for 170-250bhp and suits 1.4l to 2.2l
GT28R Turbo can flow enough air for 200-280bhp and suits 1.6l to 2.5l
GT28RS Turbo can flow enough air for 250-320bhp and suits 1.8l to 2.7l
GT30R can flow enough air for 350-500bhp and suits 2.0l to 3.0l
GT32 can flow enough air for 200-420bhp and suits 2.0l to 2.7l

The list does go on but anything else is severely verging on the large side!!

A large selection of GT designation turbo?s are available using the T2 flange, and also the T3 flange. So there is scope out there to allow a change of turbo but there will need to be work done to allow the exhaust downpipe to be connected to the turbo exhaust elbow. Although this has been made easier with the increasingly available V-Band connection which allow 2 pieces of prepared pipe to clamped with an almost jubilee clip type arrangement, but perfects a gas tight seal (originally created for sealing reactor vessels!!)

It would be good to see the recent developments in turbochargers etc to start coming through to the turbo mini scene, so that the results can be witnessed.

An alternative to the metro cast manifold is to have a custom set of manifolds constructed in either stainless steel or mild steel of some designation.

A motorsport company called ?mirage motorsport? (web address http://freespace.virgin.net/richj.barnett/index2.htm & tel no 01953 888936) manufacture stainless steel exhaust manifolds that come with a T2 sized flange. The kit was designed to be fitted with a T2 turbocharger from a Renault 5 GT Turbo, or indeed T25 sized turbo. Although the aforementioned GT Turbo unit would make a more obvious choice due to its similar engine capacity compared to the metro.

These mirage motorsport manifolds also mean there is no need to chop the bulkhead to fit the turbocharger with it being smaller, and a more compact arrangement. This may appeal to people who do not wish to cut there bulkhead. The kit comes complete with an exhaust elbow to fit the T2/T25 (additional work is likely to be required to fit T25 size of compressor housings) series of turbocharger and a 2 ?? downpipe. The kit is not a complete bolt on coversion, and does require some small brackets to be made up, and moving of the waste gate actuator to the hot side of the turbo, along with re-phasing of the waste gate lever due to its close proximity of the bulkhead. Nic (aka greypride) is currently putting the finishing touches to a guide on fitting the mirage kit.

Hopefully this will answer a few questions to anyone new to the turbo mini scene.

Note this is my first pass at writing something in-depth(ish) for the site, and would appreciate any constructive feedback

Edited by dan on 3rd Jun, 2005.

Hi Dan

That seems a really good guide. Only comment I have got is maybe put on some contact details for mirage eg website link?

yeah looking good dan, maybe also some pictures of the different flanges/sizes of the flanges might be a plan.

Good overview.
Escort RST turbocharger could also be considered a 'hybrid' (ie good upgrade) when used on a metro manifold - and probably easier to locate than a monty/maestro unit.

The exhaust housing is a different A/R if ive got it right, creates more top end but means the old girl spools up a bit slower.
they can be used to very good effect however

comments fed back in guys,

i've got details of the bolting arrangement for T2's and T3's but i'm unsure of the size of the port, anyone got any ideas?

Not sure on the port size, but I'd quote the (approx) bolt spacing, so someone can tell at a glance if they're looking at a T2 or a T3 (easy if you know, not easy if you've not seen either!)

Somet else worth mentioning is that fitting the T2 using the mirage kit still needs fabrication skills to make an actuator bracket, and plumbing for the cooling.
Modding a metro manifold to take a T2 is even more work, needing a pillar drill, taps, stainless studding and a die grinder.

Finally (so it's a usefull reference) include the pitch and thread of the unions used on the T2, and T3 range...
The T2 uses 7/16" x 18tpi and 1/2" x 21tpi or something like that (i've got the exact pitch written down somewhere, but know nothing about the T3 stuff). Also mention that Iain can supply new hoses and the correct unions of you decide to go this way!

Excellent work Dan, How are you going to work this? I'd have thought you'd get it to the point that nothing more gets added, then sticky and lock it and delete all these messages to avoid confusion?

Edited by TurboDave16V on 16th Dec, 2004.

yep your right it needs to locked down at some point, I am sure Alex can sort this

i think i might be able to delete the messages but i'll check first

when i get back to work next week, i'll talk to iain (once i've checked out his new car) and try and get the thread details, and also do some quick drawings etc for the flanges but i might stick them in another topic perhaps?

cheers

Yeah it can have the responses deleted, and then sticky and lock it, Iain did it to the bit i wrote the other day on how to use the forum.

I'll do it as soon as the thread is 'finished' :)

Very very good

Top marks for that man!

Alex

AlexF

I found this part-list (PDF-file):

http://www.turboworld.nl/turboworld/pagina...45Catalogus.pdf

http://www.minifreunde.at

this is also a particular good reference site, i guess these ought to be posted in the website link section

http://www.turbomaster.info/eng/

Does anyone know what the Compressor A/R is for the Escort RST T3's??

Pretty sure it's a 0.42 or 0.47 - ie not much bigger. I recall it is a 50 trim however.

check out the link to this catalogue for a/r details on T3's

http://www.melett.com/pdfs/Garrett/Garrett%20T3.pdf

Does anyone have a similar guide for non Garrett turbos? ie KKK / IHI

http://mini.twisted-design.net/blog/

i don't know of any in particular

try the catalogue section of the link below

http://www.melett.com/index.php

hey dan where can i get a 0.36 a/r t3 housing for my t3 turbo?

do u have any source that has used ones?

sam

i know that turbo technics will sell you a fully re-conned T3 with the .36 exhaust for £290+vat....no idea on used ones though other than ebay or rst owners clubs etc...

Edited by Nick on 8th Mar, 2006.