Gt67

[aquickv6]

What is the difference between the TE45a and the GT67?

 

[Taffy]

The 45a has a 66mm older style Garrett compressor wheel. The GT67 uses the newer technology 67mm wheel. Although the 67mm wheel has been around for a while.

The 66mm whell will make more power than the 67 above roughly 24 psig. The 66mm wheels seems to be very efficient up to 30+ psig. The 67mm wheel seems to be very efficient up to 24 psig. The 67 will make more power than the 66 at lower boost pressures.

I recommend the 67 for those with ported heads and a good sized cam, and the 66 (45a) for those that have unported heads and small cam. You can run the 66 to high boost, which effectively forces more air into the engine.

 

[aquickv6]

Very good explanation. Thank you!

 

[JZ 97 SS 1500]

Originally posted by Taffy


The 66mm whell will make more power than the 67 above roughly 24 psig. The 66mm wheels seems to be very efficient up to 30+ psig. The 67mm wheel seems to be very efficient up to 24 psig. The 67 will make more power than the 66 at lower boost pressures.

Eh?? The 66 and 67 are almost identical up to about 60 lbs/min. The 67 will pull away at higher boost, lbs/min levels. On the units that we have tested, 690rwhp was max with the T66 at 27psi, then boost was falling off. With the 67, we were able to hold 30psi before falling off and made 760rwhp. This was on a 2JZ, boost pressure will differ, but the max airflow of the turbos will not differ no matter the engine its on.

 

[Taffy]

Originally posted by JZ 97 SS 1500
Eh?? The 66 and 67 are almost identical up to about 60 lbs/min. The 67 will pull away at higher boost, lbs/min levels. On the units that we have tested, 690rwhp was max with the T66 at 27psi, then boost was falling off. With the 67, we were able to hold 30psi before falling off and made 760rwhp. This was on a 2JZ, boost pressure will differ, but the max airflow of the turbos will not differ no matter the engine its on.

That is very interesting. There have been more than a few big name Buick guys that have run the GT67 and have shown that the 67 was not able to keep up with the 45a (66mm compressor wheel) at higher boost levels.

Red Armstrong was one of them. There have been a few guys on this board that have said that they were not able to get the 67 to make power at the higher boost levels like a 45a would.

On the T66 that you had the boost falling off, did you have a big enough exhaust side? I was talking to Sean over at RB Motoring, and they were having a problem with one of their Skylines at high boost. They were running a P trim exuast wheel on a T66. The upgraded the exhaust side to a Q trim and viola, they were able to get the boost levels that they wanted.

Boost can be limited by the exhaust flow, no matter how high of a pressure ratio the compressor wheel is efficient at.

I have more than a few customers that have the 45a turbo and are running well above 30 psig without the boost falling off. The higher we crank the boost on the 45a, the more power we make.

Maybe when you guys tested the turbos, you had other problems??

All the info that I have given is from what my customers running the 45a and the GT67 have told me, and what I have been told by very reputable people in the turbo world that are running these turbos on the Turbo Regal.

The 67mm wheel that was on the 2JZ, I am guessing it was a TO4R? If so, the exhaust sides of the HKS TO4Rs are HUGE in comparison to what the average (or ANY Buick guy for that matter) would run.

Jose - Do you have a compressor map of the GT67 wheel? I have looked high and low, but I will be damned if I can get my hands on a map.

 

[Taffy]

When we finally get the dyno installed, I will be sure to test the 66 vs the 67 with a LOT of parameters being datalogged for comparison.

 

[Taffy]

Originally posted by JZ 97 SS 1500
Eh?? The 66 and 67 are almost identical up to about 60 lbs/min. The 67 will pull away at higher boost, lbs/min levels. On the units that we have tested, 690rwhp was max with the T66 at 27psi, then boost was falling off. With the 67, we were able to hold 30psi before falling off and made 760rwhp. This was on a 2JZ, boost pressure will differ, but the max airflow of the turbos will not differ no matter the engine its on.

Not being able to edit sucks.

Anyways, the compressor map for the T-66 shows that the 66mm wheel "should" make boost up to a 3.6:1 pressure ratio. If the map is correct, you guys should have been able to get more than 27 psig out of the 66 on the 2JZ, unless the turbo is WAY off the map on the lbs/min.

I am going to bet on the fact that the exhaust on the T66 you guys ran on the 2JZ was not adequate.

What exhaust were you running on the 2JZ when the T66 fell off at 27 psig?

There is a guy out this way that has a 45a on a BONE STOCK LC2 and is blowing upwards of 32 psig with a P trim exhaust with no problems!

 

[JZ 97 SS 1500]

That is with 4" DP and 4" catback, thats more then adequate. They are making upwards of 1100+rwhp with the 4" catbacks

Jose

 

[lazaris]

Originally posted by Taffy
Not being able to edit sucks.

Anyways, the compressor map for the T-66 shows that the 66mm wheel "should" make boost up to a 3.6:1 pressure ratio. If the map is correct, you guys should have been able to get more than 27 psig out of the 66 on the 2JZ, unless the turbo is WAY off the map on the lbs/min.

I am going to bet on the fact that the exhaust on the T66 you guys ran on the 2JZ was not adequate.

What exhaust were you running on the 2JZ when the T66 fell off at 27 psig?

There is a guy out this way that has a 45a on a BONE STOCK LC2 and is blowing upwards of 32 psig with a P trim exhaust with no problems!

As point of refrence if you have a bone stock LC2 the turbo make more total boost than a bigger inch motor. So it depends on what you have when comparing turbos.

 

[Taffy]

Originally posted by JZ 97 SS 1500
That is with 4" DP and 4" catback, thats more then adequate. They are making upwards of 1100+rwhp with the 4" catbacks

Jose

I was talking about the exhaust housing and exhaust wheel with the T66. I think that is what was holding you back.

One thing that I forgot to mention, the T66 that Turbonetics sells uses a different wheel than the TE45a. John has changed the compressor wheels a few times in the 45a. Everytime he changes them, the turbo gets better.

 

[c&cgn]

I had this very conversation with Chopper from Limit in Vegas this weekend. His thoughts agree with what Taffy is saying. Basically their research and real world experience has shown them that the GT67mm wheel is slightly more efficient than the 66mm wheel at lower boost levels, up to approx 24 psi. From there the 67mm starts to fall off and the 66mm keeps going strong thru to the 28 - 30psi range. This is based on using the same exhaust wheel and housing for both of these comprssor wheels.

Chopper said they have actually "downgraded" a few Buick guys from the 67mm wheel to the 66mm in the TE45A with better results.

 

[JZ 97 SS 1500]

Both turbos were .81 A/R and p-trims. Same motor as well...

 

[Taffy]

Originally posted by JZ 97 SS 1500
Both turbos were .81 A/R and p-trims. Same motor as well...

That is really weird. I have not even a clue as to why you are having the exact opposite results that we are.

 

[boostedLC2]

Originally posted by Taffy

Anyways, the compressor map for the T-66 shows that the 66mm wheel "should" make boost up to a 3.6:1 pressure ratio.

There is a guy out this way that has a 45a on a BONE STOCK LC2 and is blowing upwards of 32 psig with a P trim exhaust with no problems! [/B]

I'm another one of those guys and I've had good success with the 45a at 30+ lbs. I heard the same story about Red at the Nationals which led me to choose the 45a over the 67 since I needed to run high boost with the stock motor.

Jim

 

[Doug Jacobson]

Ok fellas, I have a few questions on this too. I have a 67 p trim with an .82 housing. After being at the track yesterday I'm kinda disapointed at the power it makes. My MPH is pretty lousy for the size of this turbo I feel. At 25-26 psi I'm geting 125 mph. I have stock heads ported by me (doubt they flow too good) ported intake and a frontmount. I have no other issues with my car that I can find but increasing the boost above 24-25 psi doesn't make it go any faster.

I also have a Turbonetics T-66 here with an .63 housing on it. I think it is a P trim too. Would it be benificial to swap exh. housings and try this Turbonetics turbo? If I can squeeze more boost in this thing and not be getting it too hot i know I can make more power, just don't know if the 66/.82 is the right combo or not. I know my car needs boost to get good numbers, I ran an TE-52 to 32 psi to 10.80's at 123 mph, now with a 67mm turbo I get 10.70's at 125 mph(*), I think I should be better than that.

* With the turbo change came a TH400, frontmount and 75pph injector chage too

 

[supergn6]

i know that turbo 400 ate up 25hp 2-3 mph