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 gasket ???

dsmless

Well-known member
Joined
Jun 12, 2008
Messages
224
Location
tucson,az
My turbo inlet gasket gave out today (blew out on the sides). Its a thin metal one, dont recall the brand as it came with my turbo, but its toast. I want to know what type of gasket you all run, Im split between a copper one like from here click, or a stainless one like this click

Let me know what you think, my setup is a mitsu flanged DNP tubular manifold and a gt30r series turbo with the FP turbine housing
 

I have the stainless steel one, three years daily driving still holding strong.
 

Jason G.

Well-known member
Joined
Oct 7, 2003
Messages
3,279
Location
Anderson, SC
I've read about the SS 7cm gaskets expanding and jacking up the threads on bolts, ymmv.
FP sells the good 7cm gasket.
 

JNR

Well-known member
Joined
Apr 23, 2004
Messages
9,798
Location
ca
I bought a SS gasket from RRE, iirc and one thing I noticed is it was larger than the one I replaced (the opening) even though they are both supposed to be the same...Not complaining though, as it gave me a good excuse to open up the manifold and turbine housing, but I mention this so you check the new one against the old one in case it's smaller than what you're replacing (will act as a restrictor plate).

I'd prefer copper given a choice, for better sealing, but didn't have any issues with the old SS one or don't anticipate problems with the new one, either.
 

dsmless

Well-known member
Joined
Jun 12, 2008
Messages
224
Location
tucson,az
Im planning on running about 28 psi on e85, you think this will be an issue for a ss gasket? People with a ss gasket, how much psi of boost are you running? Anyone runing a copper gasket?
 

JNR

Well-known member
Joined
Apr 23, 2004
Messages
9,798
Location
ca
I was running ~24 psi myself, but that # is sort of irrevelant being this is the seal between the exhaust and turbine wheel and not the compressor wheel. There will be some resistance from the wheel of course, but doubt it's enough to be overly concerned in that respect. This is assuming your flanges are flat though, since a thick (for a gasket) SS plate won't conform enough to anything that is not true, within reason.

For good measure, I trued my flanges so they are both as flat as possible so I won't be relying on the gasket in that respect. I didn't have issues before that I know of, but since it was apart may as well do things right.
 

mitsuturbo

Well-known member
Joined
Jun 2, 2008
Messages
3,537
Location
Near Seattle, Washington
The copper one from ffwd is supposed to be the shit, from what i understand. I put one on my setup, but i haven't run it yet. We'll see.
 

toybreaker

Well-known member
Joined
Apr 30, 2006
Messages
3,553
Location
Colorado
It's worth noting that the pressure on the exhaust side of things (prior to the turbine wheel) is going to be significantly higher than your "boost" pressure as measured in the intake.

... and I do mean significantly ...

It's not unusual to see back pressure numbers that are twice as high (if not higher!) pre turbine than you're seeing on your boost gauge.

That's not a guess, either, I've personally measured it (back in the day) when I was having sealing issues on a Lotus.

This phenomenon got my attention and taught me all about the difference between a time-sert and a heli-coil when anchoring a stud in an aluminum head.





Curtis also knows a "bit" about this as well.

Somebody send him a link to this thread and see if he'll chime in. /ubbthreads/images/graemlins/smile.gif

The man knows a "few" things about sealing things.

I could write a "book", and then some (/ubbthreads/images/graemlins/rofl.gif) about this topic, but Curtis knows this topic as well, if not better than me.



... let me apologize in advance for his spellun and/or grahmmer though /ubbthreads/images/graemlins/fawkd.gif





I gotta go, work beckons. /ubbthreads/images/graemlins/frown.gif
 

Barnes

Well-known member
Joined
Feb 9, 2003
Messages
6,249
Location
Richland, WA
Quoting JNR:
I was running ~24 psi myself, but that # is sort of irrevelant being this is the seal between the exhaust and turbine wheel and not the compressor wheel. There will be some resistance from the wheel of course, but doubt it's enough to be overly concerned in that respect.



This is not true. With a free flowing exhaust sytem (manifold, turbine housing, o2 housing,exhaust, and correct turbine wheel & A/R) you should be running approximately a 1:1 pressure ratio between your exhaust manifold pressure and your intake manifold pressure. So if you are running 25psi, your manifold->turbine housing will encoutner 25psi AT LEAST. In systems with higher restrictions this pressure can be higher.
 

jepherz

Staff member
Joined
Aug 8, 2004
Messages
7,875
Location
KC, Missouri
I've run several of the copper gaskets and never had any luck. They'd always basically melt and blow out the sides. This was always with brand new 2g turbo/manifold bolts too. Switched back to the OEM style with 7 cm opening for an evo3 turbo and my problems went away. I wouldn't run copper again.

The issues I had were running the car hard for several days at road courses.

A friend had the same problems with the copper gasket with a 35r mated to a mitsu exhaust housing. I believe he had issues with OEM gaskets as well, but those didn't typically melt and tear apart in the same way.
 
Last edited:

dsmless

Well-known member
Joined
Jun 12, 2008
Messages
224
Location
tucson,az
damn, thanks for the good comments, so I'm torn between a ss or a copper one, the thing is I already got both of them here so I'm really undecided here
 

JNR

Well-known member
Joined
Apr 23, 2004
Messages
9,798
Location
ca
Just curious how thick are the copper gaskets for the manifold-to-turbo? Are they multi, like the gasket for the exhaust manifold-to-head?

Wonder how a copper (or ?) o-ring would perform, if you had a groove in either flange...be sort of a PITA to put that groove in there though, being you couldn't throw it on a lathe for the most part, but if you had a nice mill...
 

mitsuturbo

Well-known member
Joined
Jun 2, 2008
Messages
3,537
Location
Near Seattle, Washington
I've just read a bunch of reviews/experiences on tooners, and it seems like everyone who's run a stock 7cm gasket from Mitsu has had good luck with it. Some of the guys running the SCE/FFWD copper gasket have reported blowouts, while others have reported good results.

While i've seen burned out stock type gaskets, i believe they've all been VERY old and well used. It's probably a good idea to go with the 7cm one from mitsu.
 

JNR

Well-known member
Joined
Apr 23, 2004
Messages
9,798
Location
ca
Yeah, sounds like you can't go wrong with the oem...My question for the ones that get messed up is how good were the flanges to begin with and are they properly installed (torqued/sequence)...just seems odd that you'd have issues if it was a quality material, had two flats and it was held down per specs.
 

mitsuturbo

Well-known member
Joined
Jun 2, 2008
Messages
3,537
Location
Near Seattle, Washington
I agree. I ran the same thick, flat, stainless one many times on different setups. No issues, even with re-using it. I think i used it with my evo3, my 60-1, and my 3052. I see posts where some have had them break. One even dropped material into an E3 turbine and chopped it up. I still have mine somewhere, i think. I just figured the copper one would be an improvement. If i'd have researched it more, and given it more thought, i would have just bought the mitsu 7cm gasket.
 

dmj

Well-known member
Joined
Feb 2, 2008
Messages
673
Location
orlando FL
Go oem. I used the stainless gasket torqued to factory specs and it stretched into an oval shape and snapped one of the bolts.I went back to oem and never had a problem.
 

Latest posts

Top