Turbo & Intake Upgrades

[SMZ300zxTT]

I have JWT 530 turbos with HKS intercoolers and hard pipes with HKS SSQV blow off valves. (On a side note: Yeah the driveablility is terrible and I ordered recirculation fittings to use for now.) Apparently the size of the intake and exhaust need to be opened up to get the most performance and response with the turbos. I wanted to be able to do 500hp on pump gas. I got with Greg from Speciality Z and he is saying the JWT 700 would be my ticket to make that with the breather modifications. So when you add up all the parts the price tag is right around the $6,xxx figure. I assume I can get substantially better performance with the 530s and the breather mods alone. Of course if I invest in a pair of Mike Smith manifolds I might as well replace the turbos also. Part of me says go all in or go home while another part of me says to try the breather mods on the JWT 530 turbo and see how I like it. I can always go back in and upgrade the turbos at a later date...

Here is my struggle and I would like some input:
Keep the 530s and do Ashspec intake & SMICs, SZ 3" downpipes, 3" to 2.5" test pipes and don't replace manifolds - basically just do the easy stuff.
Keep the 530s and do Ashspec intake & SMICs, SZ 3" downpipes, 3" to 2.5" test pipes along with Mike Smith manifold replacement - pull more performance without breaking the bank.
Replace everything, the manifolds are going to be replaced, what is a extra couple thousand? JWT 700 turbos, Ashspec SMICs & intake, SZ 3" downpipes & 3" to 2.5 testpipes and Mike Smith manifolds. - going all out.

This is what I'm considering and want to hear from other Z owners with experience with these modifications.

[twinturbozxtacy]

if you want 500 on pump gas and greg told you what to upgrade to get you there i dont see what the question is? the 500s will have a way better response no doubt, but fall far from 500 on pump gas. imo they are enough, i had 500s and they were great, nice and peppy, i got the gt28s now with the msp manis etc... laggy. so it depends on how you want your car to respond. straight line or twisties.

[SMZ300zxTT]

I was worried about lag. I was told the 700's spooled up like the 500's with the breather mods. I'd think any turbo larger might not have as good of a response. Really most of the roads around here are straight but I'm not trying to break any speed records either out on public roads. Really the 530s will probably work well enough. It's more of a weekend, fair day driver. Not so much a track day vehicle. The car seems laggy with the factory sized intake and exhaust. I think I'd be happy if I can get more bottom end power out of the vehicle. Hopefully I can do the breather mods and get the low end power and response I'm looking for.

[NolimitZ32]

In my experience the GT2860RS is the best all around turbo for the VG30DETT. I get full spool to 1 bar (14.7 psi) at around 3400rpm, I'm running SS tubular manis and 3" TBE, NO intake breather mods. If that's laggy than I don't know what not laggy would be.

[SMZ300zxTT]

I am not sure the difference between the JWT 700 and the "Disco Potato"/GT2860R. I read that it used the same CHRA. I don't know if it is the same turbo and has a different name or housing or what. I'll have to do more research. So when it comes to picking a turbo I read that you want to pick the smallest one that will accomplish what you want it to do. Anyway, I've read a lot of good things about the GT2860RS.

[NolimitZ32]

The GT2860R/RS is basically the same turbo. I should add a caveat, I run HKS 2530s which is a slightly altered version of the standard GT2860 for slightly faster spool. Generally you do want the smallest turbo which will achieve what you want however you want it to be within the operation range of the turbo, if you constantly peak a turbo you will greatly decrease its life. Its a fair jump from the 530/550 to the 675/700 but its all you have to chose from unless you want to do a full custom setup, in which case I'd say have a look at twinscrolls (not sure how it would work on 3 cylinders though).

Check out this site for lots of info on turbo sizing info and other useful stuff. http://ztechz.net/