Turbo... y7 vs y8
 

Yes. I searched and really couldn't find what I was looking for. A friend boosted his car and he has told me there is more compression in y8 then y7. Is this true and how much? Is it caused by VTEC? Also, he said you could run a thicker gasket to lower compression. Has anyone done this? He then began to tell me how his boosted y7 head ran better then y8 head (lost to SRT-4 with y8 then won with a y7 head). I was curious if anyone has ever heard of this or knows anything about it. Thanks.


JP

Re: Turbo... y7 vs y8
 

i would take the y8 over the y7, and no vtec has nothing to do with compression, and stock compression is fine on both those motors

Re: Turbo... y7 vs y8
 

Unless you are getting them both at the same price, I'd just get a y7 since you are going FI anyway. The vtec isn't going to make a big enough difference to you for the average price difference you are likely to pay. Just my opinion.

Re: Turbo... y7 vs y8
 

It's just a stock engine in a 98 coupe ex. So hence the d16y8 (VTEC head). Thanks guys.


JP

Re: Turbo... y7 vs y8
 

That's what I was going to lurk on next. If VTEC makes much more of a difference when turbo'ing. I have a d16a6 and I plan on a mini me turbo, but sometimes I wonder if it would be more pain than pleasure.

Re: Turbo... y7 vs y8
 

yeah, now u gotta tune 2 maps instead of just one... added weight in the valvetrain... but it'd be pretty sweet to get a big turbo and have vtec spool it lol... u got nitrous to get her spinnin and vtec to spool her up ;)

Re: Turbo... y7 vs y8
 

I'm also looking for opinions on this. Straight a6 turbo or mini me turbo? Wondering the benefits or hp gains of going with either the z6 or y8 heads. Also looking for opinions on intake manifold choices. a6,y8,z6 for boost? How about stock vtec head vs. a6 head with a turbo cam. Which would be best for boost? Anybody got any experience?

Re: Turbo... y7 vs y8
 

i'd say the biggest benefit of running the mini-me setup is that you can get a lot higher compression from the combo. that'll gain u a lot more torque, but the downside to that is shortened engine life and being more prone to problems like detonation and lifting head gaskets. i'd never run more than 11:1 compression on a f/i street car. call me a ----- but that's about as much as i'd ever wanna risk running (unless of course you can get it on a dyno and tune it RELIABLY to run that much compression. make sure to retard that ignition timing though)

Re: Turbo... y7 vs y8
 

For a stock motor with a stock bottom end, don't raise the compression with a vtec head. The limiting power will not be your stock nonvtec head it will be your stock bottom end. Don't waste money on the mini-me. Blahblahblah, you're complaining about extra weight and tuning two maps? You're kidding right because that's just stupid. And sohc vtec is going to spool up a turbo like 100 RPM faster than a nonvtec head, nonvtec owns bitches.

Re: Turbo... y7 vs y8
 

If the turbo is properly sized, it should already be spooled before vtec comes on. If you need vtec to help spool your turbo in anything other than 1st gear, your turbo is too big, or you only use it to drag race. Even if the turbo hasn't finished spooling before vtec engages, it should be most of the way there, and I doubt whether vtec is really going to make that much difference with the remaining 2psi.

Re: Turbo... y7 vs y8
 

www.sohcturbo.com, check out zerodaze's setup. 230whp on a b7/y8 combo. weight is not a big deal at all, its such a low amount it doesn't even really matter. my problem is with tuning the crossover and matching both maps. and for my setup, the 14b is gonna be fully spooled by 3500rpm, vtec kicking in at 4800 doesn't do ---- to spool it. u'd have to have like a t4 or bigger or be running a shitload of boost before vtec is actually helping spool the turbo. lots of turbo people change the vtec crossover down to 4200 because it makes a smoother transition, but saying vtec will spool it sounds ridiculous to me.

Re: Turbo... y7 vs y8
 

one of the best D-series F/I setup to me is a z6 block with low compression pistons and a y8 head be cause of its great combustion chamber design and it has 4 quench zones instead of 2 like the 96 and under heads

Re: Turbo... y7 vs y8
 

Everyone is talking about sohc vtec like it's nitrous or something. Mad Vtak doesn't come in sohcs.

Re: Turbo... y7 vs y8
 

My motor will be built and compression would be about 10:1 with a vtec head or 9:1 with an a6 head. So in my case the limiting power will not be the bottom end. I'm looking for a better flowing head or whichever head makes the most power. I know the y8 has the best combustion chamber design but not the best ports. I know vtec isn't gonna ad a ton of horsepower and I'm not gonna do a mini-me just so I can say I have VTEC. I don't give a ---- if I have VTEC or not. I just want the best head combo for boost. Do any of you guys have opinions on an intake mani choice for boost, y8,z6,a6. I know that y8 has the biggest plenum with the most volume but I don't know if it will make the most power.

Re: Turbo... y7 vs y8
 

Use the y8 intake mainfold, leave the a6 head on and turn up the boost.

Re: Turbo... y7 vs y8
 

i would rather have the z6 intake manifold over the y8 yes the y8 has the bigger pendulem but with F/I its about air volicity and how much you can sqeeze into the combution chamber the z6 has the strighter runners and i would seriously go with the y8 head you will get a more complete buning and will reduce the likleyhood of dentonation by increasing the turblance of the air/fuel mixture as the piston comes to TDC,it squishes the a/f mixture towards the sparkplug and away from the end zones of the combustion chamber.......your best be is going to be going with the y8 yea its going to raise the compression but over all it's the better head and go with the z6 intake manifold its going to give you 4% more volicity over the y8 or y7

Re: Turbo... y7 vs y8
 

I heard there was something about the ports in the y8 head that wasn't good. Do you know anything about this? I agree on the combustion chamber. And is the z6 intake mani bigger than the a6? Any pics?

Re: Turbo... y7 vs y8
 

the z6 head flows better than the y8 head, but the y8 mani is better than the z6 manifold. the y8 intake manifold is like an ITR manifold for d-series motors. even though a sohc vtack doesnt make power. look at it this way a non vtec d16 stock has what 106 hp? and the z6 has 125. somewhere within that area there. im sure you'll see some gains from a y8 compared to its nonvtec counterpart. you dont see the high hp d series with no vtec. vtec is always gonna be better than non vtack 8)

Re: Turbo... y7 vs y8
 

dude if you read anything its always going to tell you that the y8 head it better because of its combustion chamber try read somemore before you go giving bad advice

Re: Turbo... y7 vs y8
 

are you talking to me? the combustion chamber. the only thing the y8 head will do is bump up the compression more. read read read go compare a y8 and a z6 head and tell me what you find out :-*

Re: Turbo... y7 vs y8
 

for a daily driver that is all you have to do + turbo.

If you want a race car then go B.

The difference between one engine and the other after it is turboed is not worth the extra money

Re: Turbo... y7 vs y8
 

So I should turbo WITH the y8 head? Gotcha. Should I use any spacing gaskets or not? Or else just leave it alone? Thanks.


JP

Re: Turbo... y7 vs y8
 

If you are just going to run 6-8 psi like on the afc hack, you are fine like that. If you are planning to run around 10-12 psi going with uberdata and making the car obd1 you are fine. If you want to run higher boost you could get a thicker gasket, but again if it's just a daily and you just want a little more, leave it stock, just add turbo.

Re: Turbo... y7 vs y8
 

Nice. Thanks man. I was planning on 7-8psi daily driving. Not to get flamed at and all, but I'm looking at a greddy kit. It is all new and reliable. Sorry guys. I'm DIY, but not hardcore. I textbook/reading know turbo stuff, but mechanically - nope. My Dad doesn't know much about turbos anyway. Plus the boost and whp (about 200whp) I want to make I've been told can be done through the greddy kit. From there Uberdata, and larger turbo when I learn more and can expierment and get the basics down through a kit. I'm young (17) I have time to learn and be back with my own HMT thread for you all! So why is the 92-95 kit so much cheaper than the 96-00 kit? And will the 92-95 work on my EK (98 coupe EX)? Thanks again fellas!


JP

Re: Turbo... y7 vs y8
 

If you're young, you should be too poor to afford a kit over a homemade setup. This is homemadeturbo, we can't condone you buying a kit. Don't waste your money on a vtec head, the bottom end is stock and the head is not the limiting factor like I said.

Re: Turbo... y7 vs y8
 

I'm not too poor. I have the money. I worked for the past couple summers and have another (God-willing) summer job this upcoming summer. Yes HMT is cheaper, but for me its more difficult to do even w/ reading and all. I'm not set in stone so I could still go HMT. BTW, the engine is stock, no hybrid. Stock d16y8 in a 98 ex coupe.


JP

Re: Turbo... y7 vs y8
 

i'm not a fan of the greddy kit at all. if u do get it, at least make sure to get an intercooler, the kit doesn't even come with one, and its one of the most important pieces on any turbo honda, since it helps prevent detonation (the biggest cause of blown engines in turbocharged hondas). any will work, i'm using an eclipse SMIC i got for $50. but then u gotta reroute charge piping, so thats more money you're gonna have to dish out. homemade setup will be a lot more reliable and powerful than the greddy kit, provided u use quality parts, maybe a new turbo, and don't skimp on the important stuff.

Re: Turbo... y7 vs y8
 

I would HMT but isn't there alot of fabrication work? I have pretty decent junkyards around here, and I read some stuff on here to make my own and if ANYONE had a d16y8 walk-through w/ pics or if anyone did it to that year PLEASE let me know. See I need instructions and all that stuff so if I could find someone I could talk to or have a walk-through to follow it would make my HMT easier. The fab. work isn't cool on account I don't weld and I have some freinds that weld, but I DEFINITELY wouldn't trust their welds. The cost of HMT rocks though. I could literarlly make 2 or 1 good one with quality stuff or 1 and blow up my motor ::). But, still. I know exactly what my problem is now. It's not the money, the labor, the hassle, I don't have confidence I know how to do it and manage my own boosted car. I think I need to study more. Anyway, if ANYONE has a boosted d16y8 let me know. I would like to see some pics and some people's set-ups for my motor. Thanks once again guys!


JP

Re: Turbo... y7 vs y8
 

i say its a good idea to study up, regardless of if you're gonna use a kit or make your own setup. its a good idea to at least know whats going on in the engine compartment, whether u made it yourself or bought all the parts in a kit. that way when something happens down the road you'll at least have a general idea of what's going on.