Primary turbos & stuff

[Marky]

Rando question - (and someone\'s bound to have measurements) - can the guts of a secondary - any of them - fit into the housings (mainly the exhaust housing) of a primary (again, any of them)?

Main reason I ask being not having to faff about with the wastegate situation. Using the secondary front cover wouldn\'t be the end of the world - there\'s room to rotate it and I can always get creative with WG actuator mounting.

(Thinking out loud - could an early 92-93 RS secondary with WG be used and would it be an improvement over the VFwhatever I have on my rev A BH?)

I can\'t imagine it will create much of a difference in spool going to what is a marginally larger unit... as it is I\'m getting full boost by 2500rpm so not terribly concerned if that gets pushed out a bit more. More looking forwards to a simple (ish) bolt-on upgrade to have on hand for if/when my current one grenades itself or starts eating oil, i figure why replace when you can upgrade

I\'m not wanting mega HP, more just getting a little bit more out of it - I\'d be happy to trade off a slightly slower spool for running slightly less boost to get the same result.

And yes I know option B is collect parts and convert to single turbo - to be blunt I genuinely just get a laugh out of the way the thing drives now, it\'s 90% of the reason I bought it over a legnum or wrx wagon in the first place. (The other 10% was the cupholders, they\'re just awesome)

[funkytown]

some useful stuff in here, telemekas has posted some real good stuff on TT turbo\'s in the past.

http://www.clubsub.org.nz/forum/index.php/topic,4776.0.html

[Andy_Mac]

that cupholder fully blew my mind the first time i used it ay, from pics i could never work out what it was when closed.

i can safely say that cup holder was atleast 90% of the reason why i got mine..

[Joker]

pretty sure they are the same turbo just with diff inlet/exhaust side (internet conjecture)

re: 18/19 perhaps the other combo\'s too

[Marky]

Holy crap

Copied, pasted and edited everything useful from that thread into a nice tidy thing

Then got "You cannot post in this thread"

thanks forum you d!ck haha

I\'ll do it again later - short version as I read things is that simple bolt on win = VF27 in older exhaust housing, VF31 from rev d in same = best bolt on win with sweet f-all machining involved

They are all slightly different but my understanding from what I\'ve found is the later model turbos would be capable of much (well, some) more if given the larger housings the earlier one came with, at the expense of slightly slower spool - sounds right (same theory as with evo 456789 turbos, people mix & match housings for different results)

[telemekas]

The different series turbos (not cars) cannot be mixed "directly" without some machining or spacers being used.

If the series has the same turbine wheel and CHRA ie Ball bearing then the prim<-->secondary can occur.

Series 1

VF14 -//-> to any primary (with maching can be made fit to any primary turbo as it has the 5700 turbine wheel)

VF17,VF19,VF21 <--->VF13,VF16,VF18,VF20

Series 2

VF27 -//-> to any primary (with machining then best fit to a VF25 or VF26 as these use the same 6200 turbine wheel)

Series 3

VF32 <-->VF31 (with maching then can be made fit to any primary turbo as it has the 4700 turbine wheel))

[Marky]

Ok - thankyou! I was hoping you\'d reply.

So in my case - best bet would be to source another VF26/27 pair as I have now, and have the 27 put into 26

Would this thread here be along the right path? (edit - albiet with sourcing a P16 housing, not reusing the slightly smaller P14 as he has?)

http://www.subyclub.com/index.php/topic/5276-diy-convert-your-tt-primary-turbo-to-ball-bearing/

I wouldn\'t be DIY\'ing it like this guy has but gets the point across. Did find it interesting re: both primary and secondary wheels having the same measurements though

[telemekas]

If you are going to use a VF27 then you will be restricted to a P12 or P14 from the respective primarys VF25/26.

The 6200 turbine is cut back design and is smaller inducer/exducer size 39.1/34.9mm.

The P16 housings which use the 5700 wheel (46/35.4mm) will be too large.

The guy from subyclub has done a good conversion.

If you want to use a P16 then the one to use is a VF32 (2nd) or VF31(prim) both BB and same wheel sets.

[Marky]

Thankyou - makes things much easier, it\'s quite hard to sort things out with so many different options available!

I think best bet for me (in terms of bang for buck) looks like that might be the best proposition for me then, trying to acquire the parts for a frankenstein 32/31 P16 would be a pain and doesn\'t look like much real benefit for the extra cost involved.