Question on stock SR20 turbo questions

[Matt300ZXT]

Oops, forgive the redundancy of my thread title lol

I'm looking for basic info on the specs of the various SR20 turbos. The best I can gather the S14 SR20 turbo is a GT28R where as the S15 turbo is the GT28RS? I'm mostly looking for a basic primer on what turbos (and whether journal bearing or ball bearing) came on the various S chassis SR20 motors.

The reason being is I'm looking to upgrade the turbos on my 300ZXTT from wimpy T22s to better flowing T25s or T28s. If I can find a place that rebuilds SR20 turbos and get fresh ones with a T25 housing versus buying JWT Sport 500s for example with bored out T22 housings for roughly the same price, then I'd rather buy the turbo with the larger housing.

I know a lot of turbo shops that upgrade Z32 turbos bore out the stock T22 housing for T25 wheels or even T28 wheels but they aren't as efficient since a big wheel is stuffed in a small housing and they aren't matched so to speak. However, I would take a shot in the dark and guess that a T25 housing bored out for a T28 wheel would be more efficient than the T22 housing bored out for the T28 wheel. I have found one shop that sells the early SR20 turbos rebuilt for $500, or for extra they can bore it out and install the T28 wheel. I have emailed them to see if they use new CHRAs or just rebuild the original CHRA which I'm planning on steering clear if it's not a new CHRA.

Anyways, some info you guys could pass along would be greatly appreciated since soooooooooooooo many people on here use SR20s, or fantasize about using an SR20.

[Sinfix_15]

[Matt300ZXT]

Um, what? Appears to be a setup for a single turbo but not interested in going that route. I don't want to have to change a bunch of stuff on the car just to accommodate a turbo upgrade. That's why I'm interested in info on using slightly larger SR turbos on the VG.

[91LudeSiT]

I would also like to know since I'm interested in running an sr20 turbo on my Miata.

[WillTheBeast]

I've heard of people using the twin T25 set up for the 300zx off an S13 sr20, i'd say go that route since you can purchase a used T25 for $120-$150 and buy a rebuild kit for like $90 is necessary. Also i feel like if you used the T28 you'd have to use black magic to squeeze them in so that they're not awkwardly angled or smashed against something, but thats just a guess since im not that familiar with the 300zx powerplant.

[carguy07]

I'm not an SR expert, but I do know that all the t25's are journal bearing. The t28's (I think) are all ball bearing. The s15 turbo is the most sought after one, but I believe the automatic cars and some random ones came with the s14 style turbo. I also doubt you will get a new CHRA for $500, the cheapest option on ATP is $728.

I've had gpop shop rebuild a t25 before and it was well worth it. It worked just like new and they didn't use a new CHRA. Maybe the 300zx is more picky than an SR, but I would trust a reputable shop to reuse one.