I built my dohc zc for boost so I wanted to run lower compression (so when i wanna up the boost), but i made a huge mistake when selecting the (srp)pistons!!! i thought my new compression would be 8.8:1 but thats becaused i made a mistake when i used the compression calculator, I ended up with a 8:1 compression!!!!...so now im not sure on what turbo would be a good fit for the car?


setup:

-dohc zc/ si trans.(6 puck act clutch)
-eagle rods, srp pistons
-delta regrind cams, kms valves,springs,retainers....i cant remember(brand name of) my cam gear's
-new oem gaskets/seals and belts (cant remember brand of) bearings
-chipped pr4 ecu (xenocron base map), dsm blue top injectors
-2.5 inch cat back exhaust and turbo piping
-7 inch jrc intercooler, "greddy type" bov

right now i only have an hf manifold (would like to still use this for the time being, with a turbo with the right power) and i was gonna use a saab t3 turbo but im thinking that might be too small with my compression ---- up ( i had a t25 on my zc when it was stock and that was too small)


with all the info above....what turbo would you reccomend to make up for the way low compression ( i dont wanna get new pistons, so im thinking more boost would work)

 

holset h1c with 12 cm housing

 

any chance i can run that with an hf mani?(for temp. fix.... i need to get my car out of state)


anyone else reccomend a turbo to help with my low compression?

 

u'll also need some OC

 

Do you mean hight compression; or should I say compared to people who run vitaras. Your fine with the compression. Yes h1c will fit on a hf mani with a adapter plate; but there is a nice splog in the f/s section.

 

Genuine Garrett T3/T4. Any of the stage 1 turbine variants. T3/TO4B would be great. T3/TO4E if you'll be revving out high, or even T3/TO4S (comes with stage 3 turbine) if you're going ***** out. It really depends on what your goals are, but even the T3/TO4B can crush 400whp.

 

Low CR won't make a big difference in turbo selection, you just have to crank the boost controller a bit more to make the same power as a higher CR setup, BUT you are a lot more detonation resistant which is a great thing with a 75mm bore.

What DOES make a difference is cam selection vs CR. The Crower stage 2 turbo cam is GOD at 9-10:1 CR, but at 7.8:1 CR is too much cam and causes a power loss (car had other issues, so I might be wrong about that). I know that running big all motard cams that work on 2.0 B-series freaking suck on B16 and cause issues, and am transferring that concept onto D-series.

All part of my grand unified theory about why stock Z6 cam and 7.8:1 CR Vitara setups do not suck and make great power, a stock cam that is not bad per se but is slightly restrictive works better with low CR. When I have conclusive proof I'll talk more about the subject. :P


If you are dealing with Delta 272's then you should be fine. If bigger you may still be fine, Delta won't stick you with a cam that sucks for boost, but you will *definitely* have to play with your cam gears to get them to work really well.

 

IDK about the cam. With a friends build we want from a crower stage 2 n/a cam, to a stock cam, and then to a crower stage 2 turbo cam. All this on a vitara y8. The n/a stage 2 cam made it feel slower then a n/a d15. The stock cam woke it up a good amount. The crower stage 2 turbo cam help the most, it was geting full boost at a lower rpm, and just felt more peppy all around. BTW all three cams where run on a base map; the same base map. Maybe with individual tuning one of the other ones may or may have not done better. All I know is that on the same untuned map the turbo cam was the best one. BTW the setup made about 230hp at 9psi.

 

(damn i used to be on hmt allmost daily, since its been so long... i feel like a noob )

well when i started the build (back in school) my goal was to be over 250 whp, but ---- came up and now i just need the have the car drivable (from san diego to las vegas) so i dont have to leave my broken down civic in the middle of the desert .

Im looking for a turbo that will power the car(engine setup) without out being pushed to its limits(maxed out) (i.e. I want the car to drive fine(not feel like a snail) and then still have power to pull....when i wanna go faster) but i dont need to hit 300whp all the time


as for my cams, I ordered the combo set up 272/260 (guy from delta reccomended this for my set up) this is a lil section about my cams (from the zcr):

260 Profile
Advertise Duration: Int=260 / Exh=260
Duration @ .050: Int=NA / Exh=NA
Lobe Separation: NA
Gross lift: 400/400
272 Profile
Advertise Duration: Int=272 / Exh=272
Duration @ .050: Int=NA / Exh=NA
Lobe Separation: NA
Gross lift: 425/425
the 'tech guy' said that the 260 was designed to be just a stock replacement without having too many aftermarket bolt-ons, where the 272 works better with modifications.
also the 260 out-accelerates the 272 till ~3500rpm where the 272 out-performs.

and I hear ya about messing with the cam gears.... that was a problem just to get the engine idling right.


we all know this is hmt (so i probaly dont have to say this, but....) but i need a turbo that wont cost more then my build.


thanks for all the much needed help guys

 

Well ----, just get a 14b or a T3 then. Look to spend $100>.