T66 Or Gt42 ?

[menphus]

hi all

i was wondering if anyone knew the diffrence between a t66 and a gt42? and which would be best suited for a street driven rb30.

They are both wet journal bearing.

all info is appreciated.

thanks. jvc

[R31Nismoid]

depends what spec mate, post the full details of each your looking at.

Considering the GT42 can be ordered with any range of wheels and housings (as i bet a t66 can also) then its virtually a case of how long is the piece of string in this case as the question is too general

[MattSR]

Yep, a GT42 is a much newer generation wheel in any case - look at the GT series and forget the old paddel wheel shitters

[The Dan]

The T66 is only rated at 700hp whereas the GT42R is rated at 800+...

T66 = old crap GT42R = new + improved design and twin ball bearing cartridge.

Also beware of cheap Chinese copies as many of these are circulating Ebay at the moment and are very very poor quality.

EDIT-R31Nismoid-you are not a trader, nor is FI a for sale section

[discopotato03]

JVC the GT42/GT42R use either

94mm 56T (70.3mm inducer) compressor , max flow ~84lbs at ~ 22lbs boost

102mm 53T compressor , max flow ~ 95lbs at ~ 33lbs boost .

Compressor type for both is BCI-18 or GT series .

Turbine for both is 82mm 84T UHP or GT series .

The once Garrett T66 , rights were sold to Turbonetics , is

91mm 52T (65.5mm inducer) with max flow ~70lbs at ~ 25lbs boost .

I think these normally use TO4P trim (74mm 76T) turbines .

Garretts answer to the T66 was I think the TO4R compressor which is 84mm 63T and good for ~ 75lbs flow at ~ 26lbs boost .

The TO4R is said to be better spooling (lower boost threshold) than any of the above and judging by its major diametre and trim size it seems logical . The fact that its compact enough to fit in a TO4S compressor cover is a bonus . It is used in HKS's (rebadged Garrett) TO4R and TO4Z with TO4 P trim turbines and in bush bearing form just about any turbine practical ie T350 (75.5mm 70 or 76T) , TO4 O (74mm 69T) , TO4 P , TO4 GTQ (79mm 70T) , TO4 GTS (81.3mm 85T) and probably 82mm UHP turbine from the GT42 .

The Americans really like this TO4R compressor up to about 750-780 Hp as its efficient at low and high pressure ratios and not prone to surge . If you go searching for it they sometimes call it the GT67 wheel - they like to call compressors by their inducer diametre (66.7 = 67) for some strange reason .

There are some ball bearing alternatives to the TO4Z using it ie GT3567R and GT4067R which obviously use GT35 or GT40 BB UHP turbines in their native turbine housings .

Cheers A .

[MattSR]

Ash, whats the diff between the Garrett/HKS TO4Z and TO4R then? is it the same turbo, one with a sleeve cartridge and the other with a BB cartridge?