Name this Precision turbo?

[MNwe4]

Ok, so I currently have this turbo on my car and was told by a performance shop owner that it is a PT-68 GTQ, but from what I'm seeing on Precision's website, the numbers aren't matching up. Here's the markings that I can see on the turbo itself:

Compressor housing:
A/R .70
M24
EC-1

Turbine housing:
A/R .63
Says "precision"

Please help my properly identify this thing. Thanks.

 

[bison]

That covers a lot of possibilities. Has the S cover. Measure the wheels

 

[RUQWKNF]

Bison is correct.
We need the engraved numbers on the compressor cover discharge. The intercooler hose, when in stalled on the turbo, typically covers up the engraved info. The only other way to tell without taking the compressor cover and turbine housing off and measuring the wheels, would be to remove the compressor cover backing plate clamps, 1 at a time and look for these CNC cut letters/numbers.
CCS _ _

And on the turbine housing, if it's a 3-bolt Buick, you can unbolt your downpipe and look for the turbine housing CNC cut part number.
Which would look like this,
THB_-_ _ (Or, THB3-76)

Hope this helps.

Patrick

 

[TTnewB]

Pics couldn't hurt either! If you do take the covers off please becarefull of the comp. wheel it doesn't take much to bend or chip a blade. Also depending on how long the turbo has been on the car, it could give you trouble getting that thing off. If you need to take the t housing off.

Good luck
TTnewB

 

[MNwe4]

Thanks for the replies guys. Seems like a little much work for me right now just to satisfy my curiosity. I've only had my car up here in MN for a few months and the driving season is already coming to a close in a month or two . Based on the info I've given, is there any possibility it could be a PT-68 with a GTQ trim? Maybe over the winter when it's just sitting I'll yank it out and find out for sure.

 

[bison]

Thanks for the replies guys. Seems like a little much work for me right now just to satisfy my curiosity. I've only had my car up here in MN for a few months and the driving season is already coming to a close in a month or two . Based on the info I've given, is there any possibility it could be a PT-68 with a GTQ trim? Maybe over the winter when it's just sitting I'll yank it out and find out for sure.

If you pop off the downpipe and the housing says THB3-80 it is most likely a 67 or 70 GTQ. The turbine will protrude from the housing into the dp if a GTQ. Im guessing no since most who ordered a GTQ ordered with a .85 exhaust housing. Most likely a 6776. Also the journal GTQ really needs a 4000 stall to spool really well. The 6776 is ok with a 3200 but a 3400 is ideal. If you have less than a 3600 stall and the turbo spools well you most definitely dont have a GTQ even with a .63.

 

[MNwe4]

Pics of Turbo!!!

Hey guys, I'm a moron, sorry. I have nice pics of the turbo before it was installed.

On the exhaust housing I do see a THB3-80, the 80 looks engraved.

Looks like the compressor housing says 6780s. Now it can be identified, right?

Thanks for the help!!! This board is awesome.

 

[bison]

67 GTQ .63 a/r

 

[MNwe4]

Thanks! So....what stall do you recommend? I supposedly have a 3400 stall Yank converter in the car. I have confirmed it's a new Yank and there's a sticker on it that says PY-3400, which obviously signifies a 3400 stall, but I can't build any boost on the line. I realize stock brakes aren't that great, but still, I got nothin. It's actin more like my old 2800. Yank does offer a standard 2850 for Buicks. Maybe they labeled it 3400, but never modified it? What do you recommend?

 

[bison]

You have low 10 second/high 9 capable parts. Id suggest a 9.5" PTC. Contact Dusty Bradford on here for one.

 

[MNwe4]

Thank you so much. Looks like I have good stuff, but it's just not syncing up. I'll send him a message.

 

[forcefed3.8's]

I would look for preturbo exhaust leaks, and check the AFR during spool up. I have no problems footbraking a 76GTQ with a .85 exhaust housing with a 3000 stall Vigilante. It is sluggish driving, but building boost on the line is no worse than my old TE63 P trim .63 housing. The car went 1.52 60' off 7psi and the headers were leaking around the ports from porting them.
An RJC boost controller helps alot too. Around town spool up is like night and day.
I am not saying more stall won't help, I am just saying you shouldn't be having spool up issues. I am looking to switch to a PTC and add a brake over the winter so I can run some local heads up racing.

 

[bison]

I would look for preturbo exhaust leaks, and check the AFR during spool up. I have no problems footbraking a 76GTQ with a .85 exhaust housing with a 3000 stall Vigilante. It is sluggish driving, but building boost on the line is no worse than my old TE63 P trim .63 housing. The car went 1.52 60' off 7psi and the headers were leaking around the ports from porting them.
An RJC boost controller helps alot too. Around town spool up is like night and day.
I am not saying more stall won't help, I am just saying you shouldn't be having spool up issues. I am looking to switch to a PTC and add a brake over the winter so I can run some local heads up racing.

You have a lot more engine than he does. TSM was running a 3800 stall to get a journal GTQ to spool quick. He needs a 3800 to have really good spool up. Any less without N2O and it will suck on the street.

 

[Dusty Bradford]

Thanks! So....what stall do you recommend? I supposedly have a 3400 stall Yank converter in the car. I have confirmed it's a new Yank and there's a sticker on it that says PY-3400, which obviously signifies a 3400 stall, but I can't build any boost on the line. I realize stock brakes aren't that great, but still, I got nothin. It's actin more like my old 2800. Yank does offer a standard 2850 for Buicks. Maybe they labeled it 3400, but never modified it? What do you recommend?

Before you pull anything out, do this stall test.

Footbrake the car until you see 0-1# on the boost gauge and get an rpm reading. This will give us an idea of what the converter is doing.

A 67mm should come up with anything in the 3000-3200 range.

 

[forcefed3.8's]

He has less turbo though. There are no less than 6 cars up here running 0 pumps spooling 66 or 76 GTQ's. There are only 2 of us not running 231's. The TSS cars (234 cubes and a 66GTQ) are monsters on the street. Alot of us are switching to PTC's, but before those came out, the 5 disc Vigilante was the best way.

 

[bison]

He has less turbo though. There are no less than 6 cars up here running 0 pumps spooling 66 or 76 GTQ's. There are only 2 of us not running 231's. The TSS cars (234 cubes and a 66GTQ) are monsters on the street. Alot of us are switching to PTC's, but before those came out, the 5 disc Vigilante was the best way.

Without electronic control you will have a hard time controlling it when it comes on. With a higher stall its easier to peddle the car on the street.

 

[MNwe4]

Before you pull anything out, do this stall test.

Footbrake the car until you see 0-1# on the boost gauge and get an rpm reading. This will give us an idea of what the converter is doing.

A 67mm should come up with anything in the 3000-3200 range.

Good idea. I have done this before. At 0-1psi it starts slipping the tires around 2800 rpm. I have spoken to Yank and they confirmed it is a Pro Yank 3400 stall. Question, would the tranny being slightly over filled cause any problems like this? I know it's not low, but may be a little high.

Also, when I stab it while cruising it does take longer than expected for the boost to come on. Others have commented on it and spectators even say they can see the lag. That it's like "night and day" or "a completely different car" once it gets rolling.

Thanks again for the support guys. You've all been a big help.

 

[Dusty Bradford]

Good idea. I have done this before. At 0-1psi it starts slipping the tires around 2800 rpm. I have spoken to Yank and they confirmed it is a Pro Yank 3400 stall. Question, would the tranny being slightly over filled cause any problems like this? I know it's not low, but may be a little high.

Also, when I stab it while cruising it does take longer than expected for the boost to come on. Others have commented on it and spectators even say they can see the lag. That it's like "night and day" or "a completely different car" once it gets rolling.

Thanks again for the support guys. You've all been a big help.

It may make near 3400 rpm at 5# of boost. This is where some converters are rated. Bottom line though is it's too tight for your combo. Some cars can get away with spooling a 67DBB with a 2800. The combo and yours being standard journal bearing is obviously calling for another 400 rpm or so. Something looser down low but tight up top like my 9.5 could really make a difference.

 

[MNwe4]

Sounds good. When I'm ready to swap converters, I know who to contact. Also, just found that my right rear brake cylinder is leaking, so I may not be getting all of the holding power on the line that I need. We'll see if that helps and I'll go from there. Thanks for all of the great support guys!!!