T25 vs T25... Which One Do I Choose??

Dale69

Tuner
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Location
Mackay, Nth Qld
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Charade G102 1,3l
okay turbo guys couple of questions to rack the brains.
I have just bought 2 different Garrett Turbos, both T25's, and am wondering which one to use as all the a/r numbers are double dutch to me.
Quick rundown, will be going on a 1.6L Daihatsu motor running about 8:1 compression, auto, used as a daily driver but with regular 1/4 mile duties, hoping for about 160whp but more is good ;)
First one has .48 turbine and .42 compressor, standard off a 90's Nissan 300zx 3.0L v6 twin turbo, Second has .64 turbine and .80 compressor, standard off S13 Nissan Silvia SR20 2.0L, both are in very good usable condition.Will be looking at around 7-10 psi for daily and up to 16psi or so for race duties.
my main question is would one be suited to the task better than the other in the long run? would the smaller one spool earlier and run out of puff higher or? or could i make a swap of turbines and or compressors to make something better?
thanks guys :D
 
Off the top of my head it seems that the 300ZX would be the better choice as it was feeding app 1500cc and it should be a tad more responsive.
 
A 300zx turbo will give you more power than you need so it is the best bet of the two.

But..................
You need to understand that it is an old turbo design (came out in the eighties)

As such a modern turbo using todays technology will be soooooooooo much more efficient and spool up way quicker for the same power.

Buying the turbo isnt the end of the cost - you need a decent manifold to get the best results along with a decent ecu and an uprated fuel system.

With that in mind doing it properly will cost a fair amount a so the extra cost of a new generation turbo could seem worthwhile
 
what would happen if i was to put the .80 compressor housing onto the .42 impeller? both have the same size impeller and compressor wheels so would be easy swap.
Just asking for space reasons, and i know nothing about turbos, as the .80 housing is about 2 inch diameter smaller than the .42 housing and only have approximately 10 inch between block and radiator. also both have the same size compressor outlet, 38mm,only difference is 2 bolt and other is three bolt mounting points
 
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A 300zx turbo will give you more power than you need so it is the best bet of the two.

But..................
You need to understand that it is an old turbo design (came out in the eighties)

As such a modern turbo using todays technology will be soooooooooo much more efficient and spool up way quicker for the same power.

Buying the turbo isnt the end of the cost - you need a decent manifold to get the best results along with a decent ecu and an uprated fuel system.

With that in mind doing it properly will cost a fair amount a so the extra cost of a new generation turbo could seem worthwhile

yep, will be doing all that, taking my time and doing the research at the moment so i can do it right first go :), hoping to have it on the road by the end of this year and will have the 1.6 motor built by the end of next year :)
 
what would happen if i was to put the .80 compressor housing onto the .42 impeller? both have the same size impeller and compressor wheels so would be easy swap.
Just asking for space reasons, and i know nothing about turbos, as the .80 housing is about 2 inch diameter smaller than the .42 housing and only have approximately 10 inch between block and radiator. also both have the same size compressor outlet, 38mm,only difference is 2 bolt and other is three bolt mounting points
Understand first that I'm working off of your stats and general operating theory.
I would not try what you're considering. The engine has an 8:1 compression ratio, which a bit low for a small-displacement gasoline engine, so there should be decent crankcase pressure to work off of. If the compressed gases, like it sounds, will be flowing into a smaller chamber, then the dynamic pressure will be upped even more, and that could be too much of a good thing. Given the compression ratio and the size, the engine probably needs more airflow, not higher internal pressure.
 
hola como estas, tengo un motor nissan qd32t dentro de una chevrolet k5 blazer 1982, cuenta con una caja de 5 velocidades de nissan patrol y61 y juego de diferenciales de 4.88, llanta 33 "rin 15, mi motor es turbo y cuenta con bomba de inyeccion mecanica de nissan td27 de alta presion, quiero mejorar el rendimiento de mi motor y poder sacar muchisomos mas caballos de fuerza, me gustaria por favor que me indicaran que kit me recomiendan o que turbo, o modificaciones me recomiendan para aumentar la potencia de mi motor, muchisimas gracias, espero su respuesta
 

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