iiPancho

I while back I was reading around about guy's who take the head of a different sohc engine and a put a different transmission on put it on their d16y8's.

Would this bring noticable gains?

EDIT: After all i found out i dont have a d16y8 but i i have a y7, so what head and trans could i use to improve?

batallic

the d16y8 is like the best d series besides the d16z6 and jdmd15b, there like the same and the y8 has already has the shortest gears for the d series, more hp?... boost, swap,

batallic

u prolly read the mini me.. using the y8 head on a 1.5 engine block

rick_rabies

do it. its worth it and cheap

TravisCadello

whats the best d series head?

miamiboy91

i think the z6 has the best potential out of the d series i only have cai cheap a$$ headers and full exuast with a rebuilt motor but i kept everything stock i mean everythin and i ran a 14.9 at the track but most of the time i get like a 15.3 so thats my opinion form experience

holsetcivic

if u already have a d16y8 its not really worth doing a head swap. its already vtec. and it already has a close ratio trans. peaple who do d series head swap typically have non vtec blocks and want a little more kick out of there setup. really your only option is the turbo your d16y8 or swap it for a more powerful b16, b18(ls, gsr, type-r), H22, etc.

MonkeyMagic

english?

rick_rabies

hes says go to dohc or turbo. you know that. keep it the way it is, throw cam in it and turbo....youl be japanese in no time

newtron63h

i understand that the D15B starts out with more power but thats because its a jdm engine. the potential output is still lower than a D16, about 7% lower potential output. plus theres the big thing that very few people think about. everyone looks at HP, nobody looks at TORQUE. hondas already are low on torque, why put yourself at more of a disadvantage there?

SOHC_civic_si

No I disagree. A mini-me is not worth it. After you have gotten all your parts needed (complete cylinder head, including VTEC solenoid, complete intake manifold set-up, VTEC ECU, etc., etc.), you will have spent half the amount you could have on a pieced together turbo kit. Save a bit more and have 175-200 hp rather than 115.

SOHC_civic_si

Complete bullsh!t. Post a time slip of you running 14.9 in a bone-stock Z6 with I/H/E, and I will believe you. What did you trap at? 0-60 ft? The only, and I mean ONLY way you could run a 14.9 on a basically stock Z6 is with a shot of nitrous, or a fully stripped interior (and I mean completely stripped).

EG6KILIN

lol........

batallic

z6 it flows the best

trustdestruction

JDM D15B

it's essentially a Z6 head with a slightly more aggressive cam... so you get the head flow of the Z6 and a better cam than the Z6 or Y8.

NightCat

I have a Y8, and its tranny...it sucks.

Mini-me is a giant waste of money if you ask me, the 10hp or whatever difference isnt worth it. I hate my Y8..but Im sure Id hate anything else even more yet...its still way to ****ing slow. needs boost.

as for the cam to be hotter in the Z6, as far as I knew that was bullshit...but I could be mistaken.

miamiboy91

well yea u r ryte i did have my partially gutted i just had my passenger seat and like i said my motor is rebuilt and my v-tech engagement is at 4000 rpm

trustdestruction

So you make phone calls at 4000RPM?



Setting VTEC to 4000RPM is going to hurt performance, you ricer.

and no, partially gutted isn't going to help you enough to do what you said.

newtron63h

i agree with destruction, vtec is designed to give optimal torque(laughable on a handa) down low by using low lift and duration to get the best velocity, and then changes to high lift and duration for better volume in high rpms. setting it to engage at 4000(well before any small honda engine needs more air volume) will hurt your low end torque. this severely hurts the driveability of the engine.

there are 2 ways you can accuartely adjust vtec engagement to optimise power 1) to flow bench the head and find out where the low lift lobe starts dropping the air volume and adjusting vtec to kick in at that point or 2) putting it on a dyno and playing with the vtec.

a stock Z6 redlines at 7200, and vtec kicks in around 6000.......i dont think a 1.6 will need vtec much below that. maybe 5500 but much before that and its a waste. also you need to think about where your gear ratios put the revs in each gear.........if you shift at 7200, and 2nd puts you at 5500, then you just wasted 1500 rpms of vtec(but its not like nitrous or anything that runs out).

remember, TQ x RPM/5252=HP so at 7200, you have no problem making hp even with low torque. but at 5000 you need QUITE a bit more torque to make up the RPM difference and still get HP.

quick example of a torqueless engine.

2.4L Formula 1 V8. about 750hp at 19,000rpm which works out to 207ft/lbs at 19,000. if you cut the rpm in half to 9500, then you have to be making 414ft/lbs to stay at 750hp. theres no way you can get 414ft/lbs out of a 2.4l N/A. so they keep the rpms high and dont really worry about torque. BUT they also dont daily drive those either. low rpm isnt something they think about. 6000 sounds like idle on one of those.

and before anyone says "thats F1, it has nothing to do with a D16".......well engine principles work the same in all 4stroke gas engines.

check out "Renault F1 dyno" on youtube. youll see what i mean.

SOHC_civic_si

Actually? You're probably the biggest moron on H-T. And there is a lot of morons on Honda-Tech.

VTEC NOT V-TECH YOU RETARD, is set at a point within your RPM band when the torque has virtually reached it's max, and by switching to the larger lobe this allows the valves to stay open longer, essentially allowing more air into the engine, which increases power on the top end.

Setting VTEC at 4K is going to make your car run like ****. If you set it at 4K and dyno tuned your car you would see on the graphs a huge dip in power around that point.

And I don't care if all you got is a dash, you're not running a 14.9.

trustdestruction

Further details of second method:
Set VTEC to engage after redline. This will make VTEC not engage at all. Do a dyno run.
Then set VTEC to engage at the lowest possible point, to make VTEC always engaged. Do a dyno run.
Then, take both of your torque curves lay them on top of each other, and wherever they cross is where you would set your VTEC engagement point, or at least right around where they cross.

VTEC engages at a stock setting of 4800RPM on a D16Z6.

newtron63h

gotta say im not sure about 4800. my moms bone stock 93 Si definitely doesnt engage til somewhere around 6.

trustdestruction

Have heard 4800 as a widespread consensus. Then I hooked up an LED to the VTEC wiring to monitor VTEC to make sure it's working and the LED turned on at 4800RPM just like people have said. I'm gonna contact a tuner and ask for their knowledge for sake of argument.

With what instrument are you finding out when your mom's bone stock 93 Si's VTEC engages? Your ears?

newtron63h

ears and seat of the pants. granted vtec engaging on a D is definitely more subtle than on B engines, but its still very definite.

id like to get a dyno sheet on her car just to see what exactly happens. 4 of us at school got to put our cars on the dyno and a early RSX-S was one of them. vtec resulted in about a 20hp and tq increase. along with a very subtle increase in wheel speed.

newtron63h

dont quote me on 6000, its been at least a year since ive driven the car. i could be way off.