zx2gotboost

this isnt really Honda/acura related, but you guys here on honda-tech are very wise,
I am having a Big debate with another member about cams with turbo.
See I purchased an intake cam by "web cams" Specs : 227*@.50/.400 High REV Intake cam
I was wanting to know what would be the BEST exhaust cam to go with my intake cam?
The cam I was looking at has the specs of: 216*@.50/.398 High Torque exhaust cam.

Now heres the tricky part, these are for <U>Turbo</U>

Heres some specs about the motor/mods I am using:

Motor 2.0 DOHC
9.6 compression
RPM range I want power in 3200-7100 RPMS I want it up High!
How well does head flow Soon to be ported
Stock intake mannifold? Ported STOCK intake manny
n/a or F/I F/I or course
Power Goal Since thses bottom ends are weak, illl settle for 250+WHP
1999 Ford ZX2 Focus
Mods:

T25 sr20det turbo 7-10 psi
Fidaza light wieght flywheel
Spec 2 clutch
SCT chip (VCT set at 0* when in boost)
70mm maf
42# injectors
Ported throttle body
Under drive pulley
2.5" exhaust, no cat, no res, apexi turbo muffler
Weight reduction

Now when it come to cams, im a totoal NOOB,
Now I need you guyses wise opinions, facts on my cam set up, Do you think my cams are TOO aggressive/Big for my turbo application?
You think I should go with Stock/Mild cams?
Or do you think How I am setting them up is perfect or will be ok?

My car is not daily driven, its weekend driven,
My goal is to win a few races/ get good dyno result/ great 1/4 mile times
So my thing is : Street/Race

Now post away based on the ifomation I have gave you. If I left out anything let me know


Modified by zx2gotboost at 3:48 PM 1/9/2006

zx2gotboost

no one smart enoguh huh?

Scott_Tucker

What are the seat-to-seat durations? The durations @ .050" are useless without them. It should be on the cam card that came with your cam. What is the compression ratio? Did you CC the the heads, etc to get the <u>exact</u> compression ratio?

How come Web Cams isn't helping you out on this?

beepy

Duration is good to know, but without IVO, IVC, EVO, and EVC, who knows how it will perform. There might be exhaust gas reversion problems with using a long duration intake cam with a shorter duration exhaust cam... But again there is no way to know without the opening and closing angles.

Do you have Desktop Dyno? Stick in the engine and turbo specs and have the iterator figure out the best cam specs for you.

zx2gotboost

^ say that in english please?

zx2gotboost

9.6 compression

Joseph Davis

7100 isn't high rpms.

There's "traditional" setups where you try to maximize cylinder filling, and turbo cam rule of thumb starts dictating a minimum LSA of 116 degress or somesuch to prevent significant valve overlap.

The high RPM setups could care less about maximizing cylinder filling, and just run more rpms at a lower average combustion pressure, and make more power... much more power... but it can end up being a narrow peaky powerband if you haven't chosen your parts correctly. These setups run really well with NA style cams.

So, yeah, why isn't Web cams helping you? I've seen nothing but good out of their products.

zx2gotboost

there official site http://www.webcamshafts.com doesnt have an email addy, Guess ill call/fax them....

zx2gotboost

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">And two high rev cams have a LSA of 114. A high rev and a high tq have an LSA of 112. Both setups will work for boost just fine.</TD></TR></TABLE>

zx2gotboost

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">I think you are going WAYYYYYYYYYY to big on your cams for turbo and kind of big even for NA unless you are at about 11.5 Compression

Foor boost my opinion is about 210-213 Duration @.050 and about .395 to .415 lift

The 227 Dur @.050 you have is more for and engine that has 12 to 14 to 1 compression and is going to run it from 3500 to about 9000RPM that wont work well with turbo

Tom</TD></TR></TABLE>

zx2gotboost

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">The best thing i can say is you will need to test them and see for your self what cams do

I big to bigger cam will ALWAYS lag more in the lower RPM 2000 to 32-3500 this with a turbo also with some lag creates big issues for street driving , Now if your building a 280 to 300hp turbo engine and squeezing all you can than a slightly bigger cam will get you a little more if you dont care how it makes power in the low end

I dont like big cams with Turbo engine and street use

Cams are give and take if they give you more power on top they take away from the bottom that is a given

You need a cam for turbo that is good for bottom end and good midrange the turbo will take care of the top end

I still have the stock factory cams in my cars and im now making WELL over 550HP with them </TD></TR></TABLE>

zx2gotboost

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">And since you're so ******* brilliant Tom, would you please, oh pretty please explain to me why an Integra GS-R on 5~6lbs of boost will put down 230+whp when it's a little 1.8L with 10.0:1 c/r. I mean.. we've got a big bad 2.0 with 9.6:1 c/r. And the Integra GS-R cams by your standards are HORRIBLE for boost (236*/.423 intake, 224*/.378 exhaust), ya? Pretty please Tom, do tell. You know EVERYTHING.</TD></TR></TABLE>

Scott_Tucker

Probably your best bet would be to go with stock cams. You don't want much more overlap than stock because with a turbo or blower the pressure in the intake manifold/combustion chamber can force fresh air/fuel mixture straight out the exhaust valve. The only thing you might want that is different is slightly higher lift because under boost the heads will flow more than when they are naturally aspirated.

Joseph Davis

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AutoEng2002Si &raquo;</TD></TR><TR><TD CLASS="quote">Probably your best bet would be to go with stock cams. You don't want much more overlap than stock because with a turbo or blower the pressure in the intake manifold/combustion chamber can force fresh air/fuel mixture straight out the exhaust valve. </TD></TR></TABLE>

No, that's with a blower, where you as good as have no exhaust pressure (comparatively). Turbos typically have higher exhaust pressures and blow through doesn't happen. Although, when it does, it's a good thing: the very first puff of intake charge gets superheated by the intake valveface... blowing that right out the exhaust and drawing in good cold intake charge is what you want.

I've gotten 1200 rpms quicker spool by lowering VTEC on D16Z6 to 4000 rpms. GSR, SC61, open 3" downpipe makes best power/spool with VTEC at or about 4000 rpms as well. Funny how the big NA cam profiles do better, huh?

zx2gotboost

Thanx for everyones help! I am going to stick with the Agressive cams I juts bought, and have a MEAN Top end!