Two different turbo options!
 

I have a T25 off a CA18 silvia and i have a stocker off a TT Supra......just wondering which would be more effecient to put on the miata. thay are both stock off turbo cars, but the CA18 turbo IS off a 1.8 while the Supra turbo is off that big ol' 3.0, iregardless of the fact that it only runs off 3 of the pistons

You've gotta give us the specs on the turbo's. Look on the turbine housing and tell us the A/R's. I think the CA18det T25 is a .48/.49 and start making boost before 2000rpms and are at full boost by 3500rpms. They'lll support up to about 230hp with full engine management.
I have no idea what the Toyota is, but it's probably some funky KKK KO3 or another application specific unit.

A better question, since the turbo is essentially the cheap part of the build if you're buying used, is what manifold and DP are you using. The CA18det T25 uses a standard T2 turbine inlet/outlet and you can find a mani/dp everywhere. I can almost guarantee you that the Supra turbo is some funky flange on both ends of the turbine and you're gonna have to have something custom made to get it to fit.

Post some specs and some pics and we can help more.

i didnt want to buy a mani until i decided which one to use. im just gonna use the nissan one, most likely. the supra one wont give me enough pros to make up for the cons

Hitachi CT20 (might be the CT12, I can't recall 1j from 2j and the differences in the US and JDM cars anymore) if I remember correctly with something like a .36 on both sides for the A/R.... Probably to much hassle especially if you have the T25 handy.

Between the two, the Nissan one sounds like the better choice. Don't forget to port the wastegate hole.

I'm pretty sure the ca18det t25 is smaller than the sr20 one. I'd look for one of those instead.

Most CA18det's came with a .48/.49
Most SR20det's came with a .80/.64
The CHRA'a are identical.

yah, that's what I meant by smaller....

I had a sr20 t25 on my ka24de s13, made 200hp at the wheels on 7lbs of boost. It was a good turbo and would make a good street turbo for the miata 1.6 or 1.8. I think the ca18 t25 is kinda small and since there is a pretty good supply of sr20 t25s you might as well get that.

Most twin turbo set-ups (oem at least) utilize really small turbos, I'd shy away from any turbo from a tt car (whether it be nissan, mitsubishi or toyota).

Good luck... :bigtu:

well the supra one is probably a ct20 which are CRAP...big time lag and really bad compressor surge problems with these.......
and the ca18 will be a small t25 which limits your HP big time.....

Id sell both for whatever you can get for them and get a SR20 T25 or a T3 S60

+1

Go with the SR20. The supra's CT26's aren't ideal for a miata. I wouldn't recommend going with that. I just bought a T25 off an SR20 this past friday. I couldn't be happier.

Yea get an sr20 t25, Im running the A/R .80 Trim,

nobodys gonna actually buy a CA T25 if its not worth anything, and its just what i have here.....im like most people here and working on a budget

Ahh the 4 cylinder RB:bigtu: ... careful when looking at CA18 turbos.. remember that the motor is from 88-89 (18ish years) so that could have some miles on it. But for aplication wise it spools fast and good low end due to only for 1.8L so should be ok. But most upgrade to a s15 t28 so that shows no one wants it.

find somebody who wants to turbo their motorcycle, they might buy it...

The Ct26 was from the MKIII Supra and the MR2, he has the smaller CT-whatever from a TT. But regardless, use the T25. It costs you nothing and if you are unhappy with it you can get the SR20 T25 that everyone is pushing.

Oh I missed the part he mentioned TT's.