Difference between Garrett TI and TII exhaust housing?
Hey gang,
I'm having a turbo rebuilt for me, but my source doesn't have any usable .48 AR TII exhaust housings. He does have an older TI unit, however.
From what I know the older units had less nickel (stamped with M3 instead of M4). I'm not sure if this would make a real world difference for me as I never plan on going above 15psi or officially racing the car.
What I don't know is this: Is there ANY flow difference between the two units? When I asked the shop this question, I never received an email response.
Anybody with knowledge of the differences between these two parts, please chime in!
Re: Difference between Garrett TI and TII exhaust housing?
well..my solution would be to look for the .63 housing..
but if you want a .48 then that's what you want
nickel content is good for engine blocks..but I can say it likely isn't going to mean much in regards to your exhaust housing..
why do I say that ..?
experience,.. experience with GLOWING red turbine and swing valve housings during cool down in my driveway..
about 60 seconds after a good rip up the hill in front of my house..
considering the heat still in the housing as I lifted the hood..that or those housings were very likely see through at the crest of the hill just moments before..
that ^ never caused me any issues..'least not turbo / manifold related ones..
and that would have been the T1 housing / 85 log style turbo set up
Re: Difference between Garrett TI and TII exhaust housing?
Need to do some grinding to get the flange of TI turbine housing to clear the 1 piece or two piece intake manifold.
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Re: Difference between Garrett TI and TII exhaust housing?
Re: Difference between Garrett TI and TII exhaust housing?
Thanks guys! That helps a bunch!
Oh, Johnny, I'm not well versed in different turbo ratios, but it was my understanding that a stock .48 would be the best fit for my application. I'm just looking for a peppy daily and don't want turbo lag even for better top end.
My car only has mildly ported/polished head and manifolds, open 2.5" exhaust, stage III cal, running 15psi max.
I'm all ears though if I misunderstood something, but I figured the .48 would be best for my build.
Re: Difference between Garrett TI and TII exhaust housing?
And for those who are curious, here's an album with some of the build. I'm horrible at remembering to take photos during a project though lol
https://photos.app.goo.gl/gGdRGz9kbrTastqr9
Re: Difference between Garrett TI and TII exhaust housing?
I had a 0.48 on my 2.5 CB last year and it worked well with near zero turbo lag but was maxed out at 4500 or so. I am now running a 0.63 and yes it does have a bit more lag but not too bad. The engine is a fresh build so I have not cranked on it yet over 3500 or so. Maybe next week
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
chromguy
I had a 0.48 on my 2.5 CB last year and it worked well with near zero turbo lag but was maxed out at 4500 or so. I am now running a 0.63 and yes it does have a bit more lag but not too bad. The engine is a fresh build so I have not cranked on it yet over 3500 or so. Maybe next week
What have you done with the valvetrain? If you haven't switched to at least the PT lifters, you'll certainly get some float and lose power at about 4500+. Really, the conical spring mod is needed if you want to spin these engines up.
I had the PT lifters before, and it made a noticeable difference, but the engine would still top out at about 4800-5000rpm. This was better than the 4500 I was getting beforehand.
For this build I did go through with the conical spring mod. We'll see how much freedom it brings me on the top end.
I'm curious to see how your .63 housing does when you can really open it up though!
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
Mudman
What have you done with the valvetrain? If you haven't switched to at least the PT lifters, you'll certainly get some float and lose power at about 4500+. Really, the conical spring mod is needed if you want to spin these engines up.
Yes PT lifters with comp beehives. Also ported head with stock valves (for now, +1 are on the shelf), stock two piece manifold, S60 turbo and 3"SV with 3" exhaust with 2.5 muffler. Forged pistons with 12 thou shaved off the deck to increase compression to approx 8.3:1 IIRC
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
chromguy
Yes PT lifters with comp beehives. Also ported head with stock valves (for now, +1 are on the shelf), stock two piece manifold, S60 turbo and 3"SV with 3" exhaust with 2.5 muffler. Forged pistons with 12 thou shaved off the deck to increase compression to approx 8.3:1 IIRC
Heck yeah man! That sounds like a sweet setup. I'm running the budget version, 3.3l springs and GM retainers with stock keepers and valves. The valves got a 3 angle job though when the shop put it together for me.
My engine isn't set up to be a "heavy breather" so I do believe the .48 housing will be the right match for a daily driver. However, if I find things are still getting choked on the top end, well it's not THAT big of a deal to swap exhaust housings on a fresher turbo 😉
Re: Difference between Garrett TI and TII exhaust housing?
I was happy with the 0.48 as a daily last year but many of our seniors suggested I use the 0.63..Why not?? was my thought. Once I break in the engine, I will see which one I like better. The 555 also has an LSD so that is different as well. No wheel spin for now at 10 psi.
Re: Difference between Garrett TI and TII exhaust housing?
go with the .63 if possible. barely any more lag and breathes better up top.
Brian
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
Aries_Turbo
go with the .63 if possible. barely any more lag and breathes better up top.
Brian
Well the .48 has already been ordered 😅
But honestly, that's fine with me. From the various posts I've dug up, other people with as mild of a build as mine have been happier with the .48
Curious to see how chromguy's setup works for him, but even his build is moving more air than mine.
That being said, I did inquire with Chris at TU to see if he has any of his .63 in stock and if he'd sell me one. You know..as a backup
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
Mudman
Well the .48 has already been ordered 😅
But honestly, that's fine with me. From the various posts I've dug up, other people with as mild of a build as mine have been happier with the .48
Curious to see how chromguy's setup works for him, but even his build is moving more air than mine.
That being said, I did inquire with Chris at TU to see if he has any of his .63 in stock and if he'd sell me one. You know..as a backup
yeah a .48 is nice for a mild torquey street car. i tend to like a little bit laggier, larger turbo because it fries the tires less down low and makes it more docile unless you really want it.
Brian
Re: Difference between Garrett TI and TII exhaust housing?
The turbo is being shipped today, along with a spare Stage I .63 TU brand exhaust housing. If I ever find the .48 to be restrictive, well I have a backup plan.
Re: Difference between Garrett TI and TII exhaust housing?
Well my turbo from TU arrived today, it it looks great! Chris was able to source a TI exhaust housing in pretty much perfect condition. No cracks at all. This one even got a brand new CHRA rather than refurbished. I'll tell ya, never had a turbine shaft seem so..fitted. Spins freely and has ZERO play either direction.
The only thing is my stocker came with a nipple on the compressor outlet for cruise control. This one..not so much.
What should I watch out for if I wanted to drill and tap it for the nipple? Other than just stuffing rags in there, having a vacuum ready, and making sure gravity promotes any shavings to exit the housing, I'm not sure if there are any tips or tricks. Thanks!
(Photos of the turbo added to the Google album linked in earlier post.)
Re: Difference between Garrett TI and TII exhaust housing?
Quote:
Originally Posted by
Mudman
Well my turbo from TU arrived today, it it looks great! Chris was able to source a TI exhaust housing in pretty much perfect condition. No cracks at all. This one even got a brand new CHRA rather than refurbished. I'll tell ya, never had a turbine shaft seem so..fitted. Spins freely and has ZERO play either direction.
The only thing is my stocker came with a nipple on the compressor outlet for cruise control. This one..not so much.
What should I watch out for if I wanted to drill and tap it for the nipple? Other than just stuffing rags in there, having a vacuum ready, and making sure gravity promotes any shavings to exit the housing, I'm not sure if there are any tips or tricks. Thanks!
(Photos of the turbo added to the Google album linked in earlier post.)
There is no reason not to just pull the cover after marking the back side and then doing the drilling and tapping in an area where chips won’t be an issue. Otherwise, just tape off the oil and coolant holes and stuff rags in there.
Re: Difference between Garrett TI and TII exhaust housing?
Well, you were right. Not a big deal taking the compressor housing off. I drilled and tapped the spot, although I wasn't quite able to get the nipple to start threading. So I was gonna run the tap in a little further to open up the top of the hole when I found out somebody clipped my poor mum's Odyssey with a trailer.
Had to go over there and pull her fender away from the tire, bungee the bumper in place, etc 😅
Tomorrow I'm going back over to run the 1/8" NPT tap in a little deeper. Will let ya know how it goes
Re: Difference between Garrett TI and TII exhaust housing?
Quick question,
My SV bolts are pretty buggered up, I'd like to just install fresh ones. Would grade 8 or higher stainless be acceptable? I know they're M8 1.25, just want to make sure whatever I pick up can handle the heat. Thanks guys!
Re: Difference between Garrett TI and TII exhaust housing?
I've used both stainless and high strength metric bolts. Both with about equal results. There is one swingvalve bolt that penetrates the housing, if any are gonna snap off it always seems to be that one. Stainless obviously doesn't corrode like mild steel, but isn't anywhere near as hard as the other style of bolts. IMO, just make sure you use a good high temp antiseize on the bolts, and don't overtighten. Also run a clean sharp tap through the housing threads. Hopefully that was done on your new housing, but better to check it now, while turbo is on bench.
Also run a 18 X 1.5 tap through that o2 sensor bung. They always get lots a debris in the threads. Makes for changing o2 sensors a snap down the road.
Todd