My turbo matching and the issues

[renxun]

here i had few turbo that i had tried b4 beside the stock twin turbo on my 1jz-gte.

ar50 compressor wheel 57mm inducer , ar70 hotside t3 flanged wid 2 3/8inch turbine ...
-power doesnt rush in wild... it will just come and pull to redline. nothing impressive.

then had tis t70 which i tink its a hybrid.. not sure though .... i bought it used... this is whole lot better compare to the previous ar50 much more power at the top end but it is fairly laggy

the hybrid of compressor a/r 70 , 48mm inducer (to4e fin) wid the hotside of a/r 58, t4 twin scroll and turbine size of 2 1/4inch ... this thing is fun .. it came in early, builds up extremely fast , and the car goes torque and wild up to 6300rpm when the powerband came back down. i love this one... then wid the love of this turbo i felt i need something more at the top end... and dun wanna loose the responsive behavior of it... heard of the gt3540 n gain lots of positive reviews of it.... got it installed ....
- 1st gear is nothing.... 2nd gear it feels nothing at first and it rushed in on 4300rpm all the way to red line... but the behaviour is not as mad as my hybrid... at 1.5bar it only out run my hybrid on the top end of 3rd gear and on 4th it pulled much more... thats with a 0.82 hotside....

im unsatisfied.... as i thought it might be the front inducer which is not big enough to make my car felt as torqey as before. so i go for another hybrid of to4z spec but its on journal bearings and i purposely choose the a/r70 hot side but had it machined to fit in the 2.5inch turbine wheel. the turbine wheel same size as gt3540 and i thought that wid a smaller turbine housing and bigger front inducer i could get the behaviour like my previous hybrid, but at a much higher differant state of level. however i was WRONG. my car doesnt came as it should... it builds 0.2bar on 3k rpm.. then coming in at 4000rpm and it rushes wild on 5000rpm onwards. i was very very dissapointed that i almost gave up trying...

then i was tinking to give a very last shot....which is to find another smaller rear housing... might wanna use a ar58 or the ar64... why 64? i was tinking that wid the 66.7mm inducer it will fairly make some big amount of spooling wid the smaller a/r and i was worried about it restricting my flow over the top end... however it might also be as lag as the normal ar64 or 63 they came in wid turbine size of 2 1/4 inch or the 2 3/8inch size so with my turbine size of 2.5inch it had already meant to slow down a notch and wid the ar 64 i guess it wont help...

so i might as well go for the a/r 58 t4 twin scroll instead... i compared b4. the 58 doesnt look small at all ... its just as big as my ar70... and i was tinking it would be best since all this while my front comp housing is maintained at a/r70 and wid d fairly big turbine wheel of 2.5" it should be slower than the previous 2 1/4 inch so i guess it should be ok and it should flow ok if i dun go above 25psi and big amount of rpm.... im not looking for massive rpm but at the shift point of somewhere 6.3-6.5k rpm......

any idea? sorry my sentence might confuse some of you but please bear with me. thanks

[turbo4agte]

With your results so far I think you should go with a small 60-1 which is the .70 a/r compressor, .63 a/r exhaust. I also dont know if any company makes a ball bearing 60-1, but that would help out.

I dont think a twin scroll would help with spool unless you have a twin scroll manifold with properly split cylinders.

[renxun]

yess im currently using a twin scroll manifold.

for a 60-1 i guess you are reffering to t04s.

[Smokey228]

Im currently wondering what single i should go, when i plan to go that route...

I, at first, looked at the gt3540 with the .82 rear, but decided against cause it did seem laggy option. I then was looking at the 3040 with the .82 rear, virtually same size rear wheels, but the 35 is slightly more aggresive.

I have heard good things about the 3040 with the .82 rear on the 1jz. But am still doing some research into is as i want to start spooling as quickly as possible and full boost of at least 18psi by around 3500-3700rpm...

There were a few threads about this, i think i mighta even started one a while back...
This one
this one
this one

Cheers,
Jase

[renxun]

i had bought a brand new ar58 turbine housing and had it machined from the original size of 2 1/4" to 2.5" and see how it will perform by then .. i really had no choice as i dont have much technical knowledge nor understanding on how to read the compressor curve vs turbine speed. so i guess trial and error is the only way to go... (the only expensive way)

[The Real Roadrunner]

or buy the right turbo for your purpose in the first place?

don't stuff around with bush style turbos with old technology as it WILL cost you more money in the long run.

don't listen to anybody that talks about GT2835/ 3040/ 3540 either unless they are talking about genuine HKS products as chances are they dont know what they are talking about.

if you want Garrett products then your choices are basicly a GT3076r or GT3582r or bigger with the rear housings tailored to suit your needs.

what power are you chasing and at what rpm do you want it to hit full boost?

i think ive answered these questions way to many times so far and always come to the same conclusion all the info will be in the threads linked by smokey.

list your mods and what you require and ill let you know your options.

cheers
linden