Turbo Preference for 4age

[Megz]

Hey Guys, i searched this forum and the old but couldn't find out much on which turbo would be better.
I am going turbo with my 4age 16v Ke25. I plan to leave block standard for now and just run low boost. Nothing ridiculous... I was thinking about either going the t25 small ca18 trubo or go the Rb20 Turbo(forgot the model). I have heard that a rb20 turbo flows better, but not sure which to chose. I have been offered a rb20 turbo in excellent order for a good price, but not sure,. Does anyone have any advice on which one would be better for my application??
Cheers
Michael

[feral4mr2]

i run a t25 from a ca18det and recomend it for your 4age. i use a stock 4age, but cheated and used a 1mm metal headgasket (off my old 4agze) combined with a cheap compisite headgasket to lower my c/r as i use a 4agze ECU and electronics etc. and cannot tune it. if i had tuneable aftermarket engine management i would of left the engine 9.4:1 c/r.
i run 12psi when ever i'm in it, the t25 on mine spools @ ~2700rpm and full boost by ~4000rpm til redline. keeping the c/r higher might help spool up a little earlier, not to mention should have more torque and better fuel economy.

what engine management are you going to use?

[finney]

well i know of a certain 4AGTE that has put out 169fwkw with a td04.... but then again a good manifold will also produce good figures. i believe yellorolla was responsible for this particular manifold.. but then again if i'm wrong feel free to correct me as i've had a fair bit to drink today

[Dom-AE71]

Mike!

Your better off using a T25g off a early model SR20 as apposed to the CA18 due to the fact the CA18 T25 is ceramic and the SR20 T25g is steel turbine.

My mate with his swift has a T25g bolted onto it and it starts spooling up VERY early.

P.S word on the street is theres a motor in your garage with a T25g already bolted onto it

[feral4mr2]

but then again a good manifold will also produce good figures.

a log style manifold is capable of producing ~350hp (depending on the other stuff bolted on as well), so you dont 'really' need anything fancy. different styles of manifold can effect spool up of the turbo.

CA18 T25 is ceramic

hrrmm.. i'm sure both my ca18det t25's are steel wheeled.

what a/r's are the t25g?

[AE86slut]

I've got a T25G-size turbo sitting around that would probably be better than anything mentioned so far. It's brand new, and is yours for $700 if you want it.

PM me for details if you're interested.

Cheers,

Jeremy.

[myne]

Say you wanted a turbo that'd spool at about 3500-4000 rpm and provide a solid 25psi to redline, what would you use?

[Megz]

Okcheers for the advice guys. At the moment i am just working out things for the project. Anyone else have anything to say?
Michael

[4agte]

Say you wanted a turbo that'd spool at about 3500-4000 rpm and provide a solid 25psi to redline, what would you use?

a gt 2535 or 2540

[45aken]

yeah mate the T25 seems to be the go, or if you have the money you can the the ball bearing GT25. BTW your old sprinter is going through a fair transformation in my workshop as we speak

[adamaw11]

but cheated and used a 1mm metal headgasket (off my old 4agze) combined with a cheap compisite headgasket to lower my c/r

Any idea of how much that would have dropped the compression by?
thats probably a good simple solution in many cases.

[45aken]

you can work it out 'fairly' simply, (trusty engineering) i think it readuces it to around the high 8's (guess)

[myne]

How do you think a T28 would respond on a 4age?
Anyone done it?
Pro's and cons of it?

[Megz]

4SAKEN-So my old sprinter is still around?? Hows it looking? If you got any pics it would be much appreciated!
Yeah i am starting to go towards t25g. but we'll see wat happens
Cheers
Michael

[Megz]

Also i will be only looking for around 7psi for now, then when a solid block gets built i will upgrade turbo.
Michael