The Authoritative Galant VR-4 Resource

Join the best E39A 1991-1992 Mitsubishi Galant VR-4 community and document your GVR4 journey.

  • Software Upgraded - Reset Your Password to Login
    In order to log in after the forum software change, you need to reset your password. If you don't have access to the email address you used to register your GVR4.org account, you won't be able to reset your password. In that case, follow the instructions here to regain access to the forum.

turbo help

ExplicitCC

Well-known member
Joined
Feb 23, 2014
Messages
49
Location
Lake elsinore, CA
What up guys, I'm building #901 and came across a 20g but the o2 side is smaller than my EvoIII 16g, is there a reason why? Should I change it or leave it? 20g the one on the left
 

fuel

Well-known member
Joined
Feb 23, 2009
Messages
2,164
Location
Toronto, ON, Canada
do you know for sure if they are both TD05H turbine wheels? I would be measuring before swapping housings. How about the entry size, are they mis-matched too?
 

prove_it

Well-known member
Joined
Jul 3, 2008
Messages
4,201
Location
Sioux Falls, SD
That has to be a Tdoh5 housing. By the looks of it too, I'd swear its a 6cm housing. Pics of the turbine inlet, and other side of the scroll please.
 

mikus

Well-known member
Joined
Jan 11, 2007
Messages
2,763
Location
Aurora IL
^+1 looks like a 6cm housing on left, triangular footprint on mating surface vs. rounded on 7cm.
 

ExplicitCC

Well-known member
Joined
Feb 23, 2014
Messages
49
Location
Lake elsinore, CA
Here are some more pics


 
Last edited:

fuel

Well-known member
Joined
Feb 23, 2009
Messages
2,164
Location
Toronto, ON, Canada
yes that's a 6cm2 ex housing on the 20G I'm sure. I would be swapping over the EvoIII 8cm2 housing over.
 

slugsgomoo

Well-known member
Joined
Oct 16, 2003
Messages
3,745
Location
Tacoma, WA
I don't know how that knock off housing flows. A real evo3 housing is definitely bigger than what's on the 20g, but even the real ones require significant porting.

It's pretty easy to tell given the shape of the turbine->o2 flange that the hotside isn't MHI. The fact that the "TURBOCHARGER" badge is on the front means "definitely not a real Evo3"


I'd also note that the MHI Evo3 B16g came with a 7cm^2 hotside, not 8cm^2.
 
Last edited:

biglady112

Well-known member
Joined
Sep 30, 2005
Messages
1,255
Location
Commerce City, Co
Neither turbo is a 20g. They have a 2.75" inlet and are down firing turbos that do not use a j-pipe.
 

CutlassJim

Well-known member
Joined
Jul 17, 2006
Messages
1,694
Location
Manchester, NH
I would agree that neither is a "real" 20G but they jam 20G compressor wheels into factory appearing housings and call them bastard 20G's. That large of a compressor wheel with the small turbine side to help spool is a recipe for poor performance though. Ever see anyone run record breaking times with one?
 

Jesus_Negros

Well-known member
Joined
Jan 7, 2012
Messages
2,338
Location
USA
The last sentence is very misleading and has nothing to do with a "recipe for bad performance".
 

tektic

Well-known member
Joined
Dec 19, 2012
Messages
1,497
Location
ronkonkoma, ny
Quoting CutlassJim:
I would agree that neither is a "real" 20G but they jam 20G compressor wheels into factory appearing housings and call them bastard 20G's. That large of a compressor wheel with the small turbine side to help spool is a recipe for poor performance though. Ever see anyone run record breaking times with one?



a bastard 20g It's not necessarily bad performer.. compared with an evo 3 16g It adds extra flow but some extra lag comes with it. It's just a different turbo. your car will produce more power but slightly higher in the rpm range. I've had at least 2 different people tell me this was the their favorite turbo they had.

As for the Chinese casting it is like evo 3 casting with the fire ring notch ported out to start. The waste gate flapper is a 34mm but doesn't seem to work as smoothly as the mhi. I was able to get it to stick open if i moved it back and forth with my hand, however with exhaust gasses flowing this may not be possible. the waste gate area still needs to be ported on the units I have seen. The metal doesnt contain as much nickle as the mhi casting so its not as hard and more prone to rust. It's not nearly the same quality of the mhi but if your careful porting and installing it It can work just as well. I striped out the threads of one of the bolt holes way too easily. an this was the reason I didn't use it with my small 16g.
 
Last edited:

fuel

Well-known member
Joined
Feb 23, 2009
Messages
2,164
Location
Toronto, ON, Canada
I have exactly that 'bastard' 20G turbo on my Galant, replacing the factory big 16G. I used a Kinugawa turbo 20G compressor wheel and cover combo (has the same part number of the Evo III housing but is clearly a knock-off, but not many would know) and the turbine was clipped/back-cut 7 degrees to help with keeping up with the extra flow. I also swapped on an Evo III exhaust manifold and high-flow O2 housing at the same time but kept the rest of the exhaust stock (cat deleted though). I noticed a huge improvement of power mid and top end and the increase of lag was minimal. I did find due to the extra air flow I was hitting boost cut much earlier at around 16psi now.

IMG_3834.jpg


IMG_4121.jpg


IMG_4125.jpg


IMG_4127.jpg
 
Support Vendors who Support the GVR-4 Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications RixRacing RockAuto RTM Racing STM Tuned

Recent Classifieds Listings

Top