hi,i've got a tdo5h 16g on my 93 plate import impreza at the moment but i am looking to upgrade,my question is i have found a place that can surply me with either a 18g,or 20g outter housing and compresser wheel,is it a case of the old 16g outter casing unbolting and bolting the new one on,cheers.

 

 

Dont think its quite as easy.

I was looking to get the kit to upgrade my 18G to 20G. Spoke to the various tuners and all said it would be better to sell the 18G and buy a 20G rather than paying for the conversion.

It can be done but its debateable as to whether its worth the money over buying the appropriate turbo in the first place.

HTH

 

to be honest i was told that all the exhaust/wastegate housings were the same on the td05 and the compresser housing and wheel are what makes it a 16g,18g,20g,remove the old 16g housing undo the 12 sided small nut,remove the old wheel and then refit the new wheel and housing??

 

yeah but im sure it needs rebalanced after??????

 

But the 20g looks very different to the 16g.

I know little about turbos, but have seen a few

 

yes,i was thinking that but isnt the turbo made up from two halfs,wastegate housing and compresser housing with a spindle that runs through the middle which runs either on a bronze bush or roller bearings with the wastegate/wheel at one end and the compresser wheel on the other,as i'm a mechanic by trade and can get the parts (compresser housing and wheel )for under £200 didnt really want to shell out £600 plus for a complete new turbo if i can mod the one i have,

 

The Turbo center needs opening out as the recess the 16g wheel sits in isn't big enough for the 18g and 20g wheels. Then as its in peices anyway the bearings and seals will need replacing. The cost of the parts, machining and rebuild kit plus a spare td05 to work on if needed dont come to much less than a pre configured 18g or 20g turbo.

 

the 20g looks different due to its bigger compresser housing i belive,really after some views on this so any ideas are welcome,cheers

 

when you say the center of the turbo needs to be opened out do you mean in the exhaust housing section as i thought the bigger compresser wheel sits in the bigger compresser housing

 

have heard back from the place that is selling them and they say that it is a direct replacment fit and the only thing that has to be done extra is the balancing of the new compresser wheel,sound about right to anyone.

 

to support the 20g on an early wrx you will also need the following at a minimum:
full decat
bigger tmic/fmic
induction kit (if fmic fitted)
at least an sti '754' gearbox (and rear diff if different from your own)
uprated clutch
550cc injectors minimum
adjustable fuel reg
walbro 255lph fuel pump
bigger MAF/MAF housing
various silicone hose for inlet
ecu that can be remapped
new dump valve

To make full use of the potential of the 20g the following will be required too:
sti3/4 heads
headers/up-pipe
boost controller
bigger brakes!

Also might be needed:
need short engine when original lets go!

Done all this the last 4 years on my gradual change up to 20g on an sti2 (basically a wrx)

 

Not much then?

 

Bruce is correct, the 18/20G wheel is not a direct fit into a Subaru TD05 without machining work.

Andy

 

I would question Coulty's list.
Forget the brakes, you just go faster with the stock ones on....

That list sure looks familiar, but would add you need a good mapper (he is in Scotland..) and Vmax + a full dose of NF booster.

DropShots Day

Do you feel your 20g is a bit 'dated' now?
Graham

 

I don't !

I have the choice of virtually everything out there and I chose a 20G for my 2.5 Spec C.
It is primarily my road car so I didn't want to be hanging around waiting for boost !
Don't kid yourself that you need more than 380bhp and more importantly 430lbft torque for a very fast road car, its the immediate access to that torque that makes a car a pleasure to drive

Andy

 

have got most of that list,

 

have been looking into this abit more today,my car is mostly set up for acceleration and not for top speed etc due to the close ratio box it has in it,my next question is would i be better staying with my 16g and having that rebuilt due to the bigger turbos having more lag due to there size,my car at the moment is very quick through the gears and i dont really want to lose that,perhaps i'm thinking abit overkill with a 18g or 20g,my 16g is also the 90degree inlet one so i would have to mod that too.

 

Interesting Andy, especially the torque.
Everyone seems 'MD321T' crazy.

Graham
ps: Bought a H&S sport cat. Just waiting for it.

 

looks like its going to be a 18g then i think

 

yes yes its all good

 

was told today by a seller of these 18g wheels that they come already balanced??so i'm guessing its the wheel that is balanced itself, and not the wheel to the spindle it sits on??was told its a bolt on part after the centre housing has been machined out and theres no need to have it balanced once it is all built up???is this right as it does make sense i surpose that its the wheel that has to be balanced.bit like balancing a car wheel?

 

Both impellers and spindle need balancing to each other. Once balanced the compressor impeller is marked with relation to the spindle + exhaust impeller so that when the turbo is put together, the compresser impeller sits back precisely in that position. Hope that make's sense.

 

now i see,thanks for that.anyone have a idea of the cost of this balancing????

 

 

Give Graham Goode a call. I know they have a balancing machine. My brother did a University project on turbos and they helped him out with balancing them.
I too was looking at buying a 20g housing and impeller to fit onto my stock 16g. After you consider all the costs involved, was alot more feasible to buy a 20g off the shelf and sell the 16g. I now have a 20g built by Andy F.

 

Just buy an 18g or 20g and sell your 16g,. not worth all the hassle and will prob cost you as much fitting, balancing, machining etc......

 

i can get the machining of the housing done for free,i can build it up myself,the only thing i cant do is balance it,think for what i have worked out there is about £250 to £300 saving,but yes there is a fair bit of hassle,most likley save some cash up and exchange my old one and some cash and have one from andy f.