Hi all,
I have been scouring the FI area reading the various turbo vs super threads, etc and i am just torn on which way to go. I have had 2 S2k's and am currently driving an E46 M3. I am, however looking to get rid of the M3 and move back into an S2k. I am mainly looking at the 02-03 area as i prefer the AP1's. My goals for the S2k engine wise are not major, i am just looking to get similar performance from the S2k as the M3. So basically i'd like to be in the 300-350 whp bracket. Lately i've been leaning towards the turbo setup as it seems to produce a more smooth power line and better torque and low end power. My only concern is reliability. I like the SC kits for their outstanding relability ratings, however a turbo system would be really nice. I also like the upgradeability of the turbo systems if i decide to go for more power in the future. Basically i would like to know how reliability of a basic turbo system putting down 300-350WHP on stock internals would compare to an SC sytem doing the same.
I have also read about the GT30 vs GT35 turbos and i'm wondering which would be superior. I am leaning towards a GT30 right now as i like the fact that it spools faster and creates more power down low. Just wondering where the gt30 tops out hp wise and if i am limiting myself alot going with the smaller turbo.

 

as long as you get your turbo kit installed AND TUNED properly, reliability shouldn't really be an issue. Turbo reliability on the S has come a long way.

If you are looking at only ~350 whp, you don't even need to worry about a thicker headgasket. That is as long as you don't plan on raising the boost much down the line. Even if you are, you can just get the headgasket installed at that time.

As far as turbo choice is concerened. A GT35 isn't much slower than a GT30 when it comes to spooling, however if you aren't looking for very high HP numbers, the GT30 is still a very good choice. From what I have seen the GT30 maxes out around ~450 whp, which is still way more than enough for street driving.

Let us know if you have any other questions...

 

Go turbo!

As Kirk said "reliability is all in the tune".

Grab yourself a inline pro kit, inline pro headgasket, exhaust, and clutch.

Or.. If moneys no object, drop it off with Cody and he can give you 350whp with just under 10psi.

 

Thanks for your reply. Yeah, 350 whp is what i'm looking to run right now. I know i would never wanna go higher than 450whp, but 400 might be in the future whenever i decided to install the thicker headgasket.

 

in that case the GT30 will be more than enough for you...

 

I don't want to thread jack, but I have some similar questions and I don't want to start a new thread.

Is it really worth it to go with a GT series ball bearing turbo when running such low boost? I would think that the spool advatnage over a journal bearing turbo is really most apparent at boost more than the 10 psi we are talking for stock motor setups. The BB turbos cost more and can't be rebuilt. Doesn't seem like its worth it...but then again, trying to justify mods never works

Which trim T3/T4 do the GT30 and GT35 equal? 50 and 60 respectively? Thanks.

 

Will this be your daily driver?

 

quicker spooling isn't the only benefit of ball bearing turbos.

I've seen some people suggest that ball bearing turbos aren't worth it, but I personally do not agree with that.

Yes the ball bearing turbos require extra effort to install, but they are better products than the older style journal bearing turbos. Especially for a street driven car.

Besides quicker spool, another benefit of ball bearing turbos is that they are water cooled. You don't have to worry as much about seizing up your turbo after running it hard. The oil doesn't cool it down, all it does is lubricate. The coolant is what keeps the turbo cool and therefore you don't have to wait as long for it to cool off before safely shutting the car off.

Also, ball bearing turbos are made for a longer life span. Journal bearing turbos have a life span and need to be rebuilt after some use, especially harsh usage. Ball bearing turbos are meant to last "for the life of the car or engine." (as i read somewhere).

 

I should also note that the S2000 that I don't even have yet will be somwhat daily driven. I'm looking at a couple AP1's right now and probably not even going to go FI for at least a year. My daily driver is my Audi A4 with GT28RS. I'll probably end up splitting the duty with these cars but since the Audi already has 120k miles, I'll likely put more miles on that. I doubt I'll do much track driving with the S2000, but I'm sure it will see some autoX, road course and strip from time so time since it will be a fun car to have. I almost think I should go SC. I'll have to find one locally and see how I like it.

 

Well the s2k will probably more or less be my daily driver in the summer months (live in canada) and in winter i'll be driving the ridgeline or something. I used to be set on goin with the comptech kit but after seeing the dyno charts on those compared to the turbo ones, i'm just hooked on turbo. We'll see what happens. The inline pro kit is kinda what i'm thinking of going with and i'm thinking the gt30 will do my just fine for my application.