Regarding the Garret T66, how does it compare in size size and CFM against the T78/88 series from Greddy? What turbine footprint is the Greddy based on, Mitsubishi, Garret or IHI?

Alright, I've found out that the Greddy turbos are based on the Mitsubishi series. Anyone have any insight on how they compare to the Garrett units?

Lyn found this info for me, so I'll share it with all of you.

TS04, T-61, T-64, T-66, T-70, T-72 and the T-76 all belong to one family of Turbos
made by Turbonetics called the Competition T-Series! They are all based on
Garrett turbos.
Also in the Turbonetics family of competition turbos there is the Thumper Series!
The T-88, T-91, T-100 all fall under this series from Turbonetics. Basicaly in all of
the above turbos the # represent the size of the compressor wheel in millimeters
and thus the compressor performance. The higher the # the greater the air flow
capability!. Roughly the TSO4 is capable of 550hp and the T-100 is capable of
1600hp!
The Greddy T-78 and T-88 are another series made by Mitsubishi turbos of Japan!
The #'s on these turbos don't represent the size of the compressor wheel but
actually the performance output of the turbo. So then the T-88 flows more than
the T-78. In comparison with the Turbonetics turbos the Greddy T-78 would be
close to the T-66 and the Greddy T-88 to the T-76.
GReddy T78 has a TD-07
compressor and a TD-08 exhaust turbine. GReddy T88 has a TD-08 compressor
and a TD-08 exhaust turbine. T78 has a 67mm compressor wheel, not sure about
the T88. The T88 turbo is definitly smaller than a garrett based T76, it's slightly
smaller than a T72... I'd say it's around the size of a T70.




The T-88 Greddy might me smaller in compressor size in comparison to a Garrett
T-76 but it's not in compressor performance. For one the Garrett based turbos are
6 blade compressor wheels and the Greddy are 8 blade ones! You just can't
compare them based on the inducer size only!
When you rate turbo performance it's not just by the size or by what the
compressor is capable of producing but also you have to take the turbine side
into consideration.
It's obvious that a T-76 match with a T-3 turbine section would not operate at it's
maximum HP capability like as if it was match with a Q-trim turbine section.
One of the reasons why the Greddy T-88 turbo is capable of supporting a little
extra HP over the T-76 is because of the turbine section. The turbine section of a
T-88 would swallow the Q-trim Garett based turbos for breakfast!
As for the HKS turbos they are all based on Garrett designs.
The TO4S is just a 60-1 with a P-trim turbine section.. The only T04R I saw from
them was a 60-1 compressor section machined to fit either a 66 or 70 mm
compressor wheel or what is known here as the 66-1 or 70-1 with a clipped
P-trim turbine wheel. I have seen the old T-51R but not the Kai or modified latest
versions. The one I saw someone had already machined the compressor to fit a
76mm compressor wheel! The turbine section was a Q-Trim!
As for the new T-51's available from Garrett they come in various compressor and
turbine trims. I saw one trim that was very interesting . It had a 10 blade
clipped turbine wheel vs. the regular 11 blade design and was much bigger than
the Q-trim or even the turbine section of the Greddy T-88!

Originally posted by Big Boost
TS04, T-61, T-64, T-66, T-70, T-72 and the T-76 all belong to one family of Turbos made by Turbonetics called the Competition T-Series! They are all based on Garrett turbos.

Basicaly in all of the above turbos the # represent the size of the compressor wheel in millimeters and thus the compressor performance. The higher the # the greater the air flow



The numbers roughly correspond to the inducer diamter of the compressor wheels. The air flow will roughtly go with the inducer diamter squared. So, a T76 should flow about (76/64)^2 = 1.41 times as much as a T64.

Now, there's more to it than that. The T64 has a 3.670" diameter exducer, while the T76 has a 4.03" diameter exducer. Notice that the largers diameter turbine that Turbonetics has is the 'Q' trim T-04 turbine (which is 3.111" inducer diameter). So, as you go from a T64 to a T76 compressor wheel, you stay with the same sized turbine wheel. BAD. This drives up turbine-compressor diameter mismatch and screws up turbine efficinecy.


GReddy T78 has a TD-07 compressor and a TD-08 exhaust
turbine. GReddy T88 has a TD-08 compressor and a TD-08 exhaust turbine.


This doesn't make sense. Mitsubishi's naming convention is something like: TD05-16G. This is a TD-05 turbine with a 16G compressor. AFAIK, there is no such thing as a TD-07 compressor. TD-07 turbine, yes, but the compressor designation should be something like 14b, 16G, 20G, 25G, 32G, etc.


T78 has a 67mm compressor wheel, not sure about the T88. The T88 turbo is definitly smaller than a garrett based T76, it's slightly
smaller than a T72... I'd say it's around the size of a T70.


Good luck finding this information. I have yet to see a catelog that lists the wheel inducer and exducer dimensions for Mitsubishi's product line. I have yet to see a full listing of the trims and A/R's that are available for their turbines and compressors.

This is why I don't recommend any Mitsubishi turbos to people: there are no reliable maps available, and even the most basic aero specifications of the turbochargers are not available. You are left to use something because someone else tried it and it worked. You are not given enough information to make sure it works for yourself.




The T-88 Greddy might me smaller in compressor size in comparison to a Garrett
T-76 but it's not in compressor performance. For one the Garrett based turbos are
6 blade compressor wheels and the Greddy are 8 blade ones! You just can't
compare them based on the inducer size only!
When you rate turbo performance it's not just by the size or by what the
compressor is capable of producing but also you have to take the turbine side
into consideration.
It's obvious that a T-76 match with a T-3 turbine section would not operate at it's
maximum HP capability like as if it was match with a Q-trim turbine section.
One of the reasons why the Greddy T-88 turbo is capable of supporting a little
extra HP over the T-76 is because of the turbine section. The turbine section of a
T-88 would swallow the Q-trim Garett based turbos for breakfast!
As for the HKS turbos they are all based on Garrett designs.
The TO4S is just a 60-1 with a P-trim turbine section.. The only T04R I saw from
them was a 60-1 compressor section machined to fit either a 66 or 70 mm
compressor wheel or what is known here as the 66-1 or 70-1 with a clipped
P-trim turbine wheel. I have seen the old T-51R but not the Kai or modified latest
versions. The one I saw someone had already machined the compressor to fit a
76mm compressor wheel! The turbine section was a Q-Trim!
As for the new T-51's available from Garrett they come in various compressor and
turbine trims. I saw one trim that was very interesting . It had a 10 blade
clipped turbine wheel vs. the regular 11 blade design and was much bigger than
the Q-trim or even the turbine section of the Greddy T-88! [/B][/QUOTE]

big boost, i applaud your research and information given. i have indeed learned something new!!!

thanks
jimmy
1996 200sx gti-r motor

Rob, what can you tell me about the T66 Garrett unit and how much HP it can support? More specifically, the T66 Compressor big shaft with a combined with a .69 Q trim turbine.....
Thanks.

Originally posted by Big Boost
Rob, what can you tell me about the T66 Garrett unit and how much HP it can support?

The compressor should support about 700 hp. You'll probably need NOS to spool it, though.

I'm not really sure what turbine would go well with that... Probably the big Q trim T-04

Thanks for your reply Rob.
Now, I have a question for you. Let's say we try to defy all logical reasoning for a minute.

Would a higher compression engine, say 10:1 substantially reduce lag coupled with an equal length stainless steel manifold that is Swain Tech coated (White lightning). My thinking is that a coated system from manifold, to turbine housing, and downpipe would retain a higher percentage of radiant heat to propel the turbine blade thus reducing lag. I know I'm limiting myself to lower boost levels with higher compression, but would this work?

Other key mods, Swain Tech coated pistons, full ported & polished head, polished combustion chamber, 720lb ECU program.

Originally posted by Big Boost

Would a higher compression engine, say 10:1 substantially reduce lag coupled with an equal length stainless steel manifold that is Swain Tech coated (White lightning).


The higher compression will reduce it, but I wouldn't do it. Lag isn't so bad. You loose way more from the increase in compression than you gain. The tuned tubular manifold with the swain coating is a good idea, especially coupled with a divided turbine housing. Ball bearings are a win-win situation, too.

Rob