Guys

The SOHC is going into my 89 CRX Si in a week or two and a friend is offering to sell me his y8 manifold for pretty cheap. He is trying to convince me it flows quite a bit more/more power/etc but is it really worth it?

 

what exactly is "pretty cheap"?

 

here are my thoughts on the y8 manifold..

at a first glance, you will notice the HUGE bulbous plenum, absent on the z6. upon closer inspection, in addition to the plenum being wider, the runners come out the back instead of directly 90 degrees down like on a z6, meaning it has longer runners.. longer runners + bigger plenum = ? it sounds like a manifold designed to try and flow better than previous ones, although short runners and big plenum is actually type r characteristics.

Then, i think about this... the Y8 has more advanced ECU tuning, better intake manifold, a stock 4-2-1 header, and it only makes 2 more hp?

I'd like to see some dyno graphs comparing the two.. (note the VTEC crossover differnces in z6/y8...)

 

i did the swap abou t 3 weeks ago
IMO its worthed and u can actually feel a diff on trotle response since theres more volume of air available.. and its more felt on both low and bc of more air and top end bc of more air flow...
heres a few pic for you to look at..
compare the Z6 and the Y8 manifolds.....
heres the Z6 manifold
the Y8 manifold
and the final result

 

Most of that was done to beat emission standards. I have never seen a syno on this but I have been told that a Y8 running OBD0/1 Setups make more hp than a z6

 

LOnger runners will result in a more broad power bnand and torque at lower RPM.

 

posted by eg6ajk - here

http://www.hadamotorsport.com/...x.htm

lots of dyno graphs...hard to tell if z6/y8 manifold differences are exactly correct because of tests being done months apart. interesting though!

i believe in general...
longer runners make more low/mid rpm torque and power.
shorter runners make more high rpm power.

 

the y8 manifold is bigger

 

Cheap is 25 bucks

So I can run an OBD 0 on this and TPS will be cool?

 

Yeah thats a good deal.. Just make sure you get the 5sp mani and not the Auto.....

 

Yep, its off a 5 speed

Im just trying to go as CHEAP as possible.

I got a 100k D16Z6 COMPLETE swap w/neuspeed bushings on the linkage, MSD ignition, chikara header, and some other misc stuff all for 300 bucks


I am then trading someone the Z6 tranny, P28, linkage, and manifold for them to do the swap, and on top of that he is gonna give me a Fields AFC-VTEC controller along with a wiring harness that was made in japan especially for plugging the controller into the Si ecu

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tw1n Turb0 Z &raquo;</TD></TR><TR><TD CLASS="quote">Cheap is 25 bucks</TD></TR></TABLE>

damn, thats real cheap...

 

It's worth it if you're paying no more than $100 for the Y8 I/M. I too noticed a little more throttle response and mid-high end power with it. Not a very big difference, but a difference nonetheless.

Keep in mind that there are other reasons why the Y8 motor has only 2 more peak HP than the Z6. It's mostly due to the intake port design. Remember that peak HP isn't everything though...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1CiViC1 &raquo;</TD></TR><TR><TD CLASS="quote">

damn, thats real cheap...</TD></TR></TABLE>

not really
the one s i got on my car wich is the one on the picture i got it for free

 

Dude, I paid $100 for mine! Looks like I got screwed... But at least it did come with everything (fuel rail, all sensors, t/b, injectors, etc).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">

not really
the one s i got on my car wich is the one on the picture i got it for free</TD></TR></TABLE>

naw, 25 is cheap. you on the other hand fuckn scored

 

Well from what I'm seeing I'll need to do the OBD I conversion to go with the Y8 mani.

IntegraXSi mentioned running an OBD 0 y8 setup.....How is this achieved effectively?

 

from here - https://honda-tech.com/zerothread?id=573612



sorry for the shitty pic...my wonderful scanner turns everything into garbage.

this is a 96-98 d16y8 intake manifold with a 90-91 b18a1 throttlebody, a 99-00 civic si intake in a 88-91 civic/crx. IAT wires have to be extended around a foot or so...IACV wires might have to be extended a few inches also, check to make sure first. TPS plugs right in...stock MAP is used. can use stock obd0 IAT, but have to mount somewhere in intake...or rubber boot for aftermarket intake if you dont like cutting nonreplaceable things. or obd2 IAT can be used with correct plug and will fit in intake as shown. i used a reducer in the line to the dashpot on the TB...cause one plug is big and one is small.

note: i had to use the stock d16a6 throttle cable "crank doohicky thing" instead of the b18a1 disk...because it set the throttle cable at a wierd angle. i also used a 86-87 d15a3 (civic/crx si) throttle cable bracket...cause the upside down d16y8 one didnt fit right for me. also...my y8 manifold didnt come with a IACV so i used one from a 98 f22** accord. if you dont run coolant to it one from a 89 mpfi accord will work if flipped backwards. all injector gaskets are from d16a6, fuel rail is d16y8 and fuel line is d16y8 (but stock will work if aligned right).

the fast idle thermo valve is unplugged from the harness and not used at all on the y8 manifold...it will not throw a CEL.

make sure to check TPS voltage...it will hold idle, i promise.

 

One reason the Y8 makes less top end power is the assymetricle intake ports. The manifold/header were probably added to make up the ports.

-Dustin

 

If you are Putting a Y8 manifold on a Z6 engine does everything from the Z6 line up? injectors/rail/sensors/etc.??? I'm considering this swap on my existing D16Z6.

~Vince