built dohc zc with 8:1 compression, suggest turbo for setup.
 

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)

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

holset h1c with 12 cm housing

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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?

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

u'll also need some OC

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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 balls out. It really depends on what your goals are, but even the T3/TO4B can crush 400whp.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

(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 ;D

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

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

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

really? I figured a t3 will be too small? wouldnt a t3 be pushed to its limits to run my set up?

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

One thing you never said was whether this is a daily driver or a street/strip weekend car or ur race car. Theres a local guy near me with a gt-30r on his DOHC ZC and it runs like tits. On the other hand if its ur daily driver, I'd go with a t3 adapter on ur hf manifold and get a small garrett t3

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

Given everything else with the setup you might want to just suck it up and get a decent log or mini-ram, and a T3/T04E. You've got the backbone for a real ass-hander, but, yeah, it takes a few more dollars.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

my bad i did forget to mention the situation.....the car wont be a daily driver but it sure as hell cant be a track car ( it has to be able to be street driven) i have this car and a crx (with a z6, bolt on's) so i will have to put both cars to use. (maybe like 60/40 split....crx 60% of time/ hatch 40%)




yeah that was my plan, get a nice ass turbo mani set up (planned on having my 1st new turbo) and I still havent ruled out buying a mani too ( i might have too)........ its just right now im in a tough spot..... my girl and i are about to split so im gonna move to las vegas (so i can stay with the fam till i get back on my feet) so i need to get the car through the desert from san diego to las vegas (about 400 miles) ... at this point i just wanna make sure i can get the car to las vegas ( dont wanna leave that car in the middle of the desert).


thanks again for your help guys ( i have been trying to research and check e-gay for all the turbos that have been mentioned)

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

Check Tunertoys on the mani, he stocks some of the best at affordable prices.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

yeah that was my next stop (time to hit up craig) i was just on lsd.motorsports looking at his turbos ( i cant afford that right now).....JD(and others): what do you think about this turbo? http://cgi.ebay.com/ebaymotors/T3-T4...spagenameZWDVW



would somethin like that get the job done?

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

ill have to hit up craig (tuner toys) when i see him online.... the cheapest he has listed (which is for a b-series) is a $600+ ram mani (log mani might be best i can afford)

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

No. Even if you're in a tight budget, you're just going to be throwing your money away in the long run buying a Chinese turbo. It may last 50 miles, it might last 5,000, but in the end it's still a high probability of being a losing gamble.


Wait until you can afford a decent turbo. Might want to look into a Holset HY35, going to cost less than a new T3/T04E.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

thanks for the help man ( i had a feeling it was a ching chong snail....I was mostly asking about the size of the turbo) but ill look into the holset turbos...thanks again

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

since im tryin to price all the new parts im looking at... for the waste gate......what spring rate should i get? ... i was thinking a .7 spring (10.2psi) since i can always up the boost (i will need a boost controller) and i figure im gonna need that much psi to power the zc.......chime in guys lmk what ya think

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

Randy is selling a splog in the FS section, you could port the flange and go for the gold.

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

d series 10 lbs turn ya out

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

yeah i was already looking at that mani, but what flange are you talking about? (turbo or w.g)yeh im thinkin 10 will get the job done :y

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

more like 15 bro 8- is low compression in my eyes

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

you should be able to run about 14-15 on pump with that low of a c/r

Mabey even or boost than that

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

well i was thinkin 10 (and run more with a boost controller) but as you guys have said with that low of c/r i prob. should start off with more boost........it took the car maybe an 1/8th-1/4th of a block just to get my speed up :-[

thanks for caring... i didnt think you would :'(





I sent tuner toys (craig) a I.m. on that other site :7 (since he is online there) to see what he can come up with, but this is what im in need of.... turbo, manifold, and wastegate :-\

Re: built dohc zc with 8:1 compression, suggest turbo for setup.
 

anyone have any ideas on where i can find a good price (like a package deal) im also gonna need a wastegate (tial) where can i find a good price on this?


also what do you guys think about a t04 57trim?? hook me up with links(of where to buy) if you can im in a need to hurry up and get my car running