UndergroundTuning

im about to install a Sohc d15b, im making it a jdm mini me(JDM d15b vtec head, jdm d15b non vtec block) how much power will this engine make? i used to have a Sohc ZC with a milled si head, that thing made wicked power, will my new D15b make more than the zc? im an all motor guy, let me know what yall think

soodominican

aren't they the same ****? and wouldn't it be hella expensive to get even 200whp from a single cam?

93formula

the jdm d15b vtec makes 130-ish hp, so if you take a jdm d15b vtec head and put it on a jdm d15 block you are essentially making a jdm d15b vtec engine, so your hp level should be 130ish, on a sohc zc your looking at 100ish hp, so yeah you will feel some improvment.

K2e2vin

Not really; the D15B VTEC has different pistons. More, with tuning, is possible on a P08 head on a D15B2 block; although you'd probably start running into issues with a higher-lift aftermarket cam.

As far as the exact power, you'd have to dyno it. Ballpark figures would be 90whp-110whp assuming everything is good.

93formula

yeah but the pistons increase compression a bit, he is still using a vtec head power will be similar to a vtec engine rather then a non vtec engine his power will be closer to a d15b vtec since he is essentially putting together a d15bvtec rather then a sohc zc.

K2e2vin

VTEC doesn't mean anything if the cam profiles are similar.

If you directly compare a D15B VTEC to a SOHC ZC, the SOHC ZC would actually be the better choice since it has a tad bit more torque(they're rated at about the same HP).

93formula

the sohc zc is essentially a d16a6 100hp, the d15bvtec is similar to a d16z6 130hp, what are you talking about!!??

K2e2vin

The SOHC ZC cam is retarded or advanced a couple of degrees, probably different maps too; the SOHC ZC is rated 130hp.

Whoops, I stand corrected with the HP level; it's actually around 120. I was thinking DOHC.

Even then, the SOHC ZC would still be a better choice since it has much more potential(no replacement for displacement); along with more readily available parts.

93formula

D15B
VTEC
Found in:
1991-1999 Honda Civic VTi EG4
Displacement : 1493 cm3
Bore and Stroke : 75 mm X 84.5 mm
Compression : 9.6:1
Power : 130 hp @ 6800 rpm & 102 ft·lbf @ 5200 rpm
Valvetrain : SOHC VTEC
Fuel Control : OBD-1 MPFI

D16Z6
VTEC
Found in:
1992-1995 Honda Civic EX/Si, Del Sol Si,
Displacement : 1590 cm3
Bore and Stroke : 75 mm X 90 mm
Compression : 9.4:1
Power : 125 hp @ 6600 rpm & 106 ft·lbf @ 5200 rpm
VTEC Switchover 4800 rpm
Valvetrain : SOHC VTEC
Fuel Control : OBD-1 MPFI


D16A6
Found in:
1988-1991 Honda Civic Si, CRX Si, Civic Wagon RT4WD
1988-1995 Honda Civic Shuttle RT4WD (UK/Europe/Asia/AU/NZ)
Displacement : 1590 cm3
Bore and Stroke : 75 mm X 90 mm
Compression : 9.6:1
Power : 108 hp @ 6000 rpm & 100 ft·lbf @ 5000 rpm
Valvetrain : SOHC
Fuel Control : OBD-0 MPFI


sohc zc:
http://crxcommunity.com/viewtopic.ph...928b99d00fd5fe



if the sohc zc was rated at 130hp locals would be swapping them vs d15b vtecs....


if you read the link the cam of a sohc zc is identical to that of a d16a6, with 5.5 degrees of lift more, minor difference considering the age of the engines now, so unless your arguing the d16a6 makes similar power to that of a d16z6.....

93formula

theres more to it then just displacement, the rod/stroke ratio etc, the jdm d15b vtec is actually a pretty good engine, and its the displacement is negligible. and the fact that the d15b makes more hp with a smaller engine with a wilder cam says something, revs higher as well, bigger area under the curve....

K2e2vin

The r/s ratio between the two does not much that much of a difference until you start revving beyong stock rev limits and get into wild cams(ie, around 8000rpm, etc.).

Yes, a smaller engine having to rev higher does tell you something; it doesn't make as much torque. The A6/ZC is more than capable of revving to 7200rpm, the same as the D15B. Only problem is, stock, they're choking at those rpm. The Z6/DOHC ZC have similar short-blocks as the SOHC ZC/A6 and have the same redline as the D15B also.

I have a D15B VTEC btw, and have driven plenty of Z6 and A6 powered cars. The added displacement of the D16 does help; may not be noticeable, but any time you could get more torque; the better. I guess you could say the D15s are peaky compared to D16s with the same or similar heads.

As far as the SOHC ZC cam specs; search for it on D-series.org or OCO. It's the same as the A6 but timed differently. This is verified by a reputable name(I'll let you figure that out).

If you're swapping the D15B in for "130hp", you're an idiot. A D16Z6 or Y8 would be a better choice; only reason is to go with a D15B VTEC is lower miles. It should be noted that the D15B VTEC realistically dynos about the same numbers as the A6(with the A6 having more torque), and less than the Z6/Y8s.

93formula

this argument is getting off topic.....

K2e2vin

Not really; if anything it's still about SOHC ZC vs. D15B VTEC, the OT. :D

As far as that setup goes; should perform about just as well as a SOHC ZC; maybe a tad more HP(especially with tuning) but wouldn't be noticeable much if at all. For potential, there's definitely more with the ZC block. If you plan on building it, a 1.6l block would be the better route as building the 1.5l would actually cost more(mainly due to the rods) and more displacement on the D16's end.

At this point though, it's really negligible and you wouldn't really know what's better until you dyno both setups.

Tyson

93formula, whered you get that info? the compression ratio's are all wrong.

D15B VTEC
9.3 CR

D16Z6 VTEC
9.2 CR

D16A6
9.1 CR

and quite frankly, k2kevin is far from off topic.

93formula

the op asked which made more power the d15b vtec or the sohc zc its been answered ill try and find the link i grabbed the info from..

he used to have a sohc zc with a si head so one is to assume its a a6 head, so with the parts he has, a d15b vtec head and d15b bottom end his end result is or should be similar to that of a jdm d15b vtec. he is not asking if he sould use a 1.6 block etc, he was asking what hp should he be looking at.

93formula

d series info and specs:

http://www.jdmchat.com/showthread.php?t=1368

and its a sticky on a forum so im assuming its correct....

digitally_remastered

sohc zc all the way. much better powerband all around, not just after "vtec" kicks in. its to over rated. ive drove many b16/d16/b18/b20 with and without vtec. i like the feel of a smooth power band from start to finish over vtec kicking in at 5500 rpm. i want the power when i put my foot down!

thats why im building a sohc zc non-vtec for boost.

relo

wow i cant belive this whole thing is over a 100cc. i find i personaly like the stock motors over the mini me motors i have had over heating issuses with the mini me probably because the customers were too cheap to get the block and head checked. i am for the efficiency of the smaller motor just because it makes great hp and is a good all around motor. and every customer i have installed one for has been more than happy i put one in a crx last week and it pulled like a cut bastard to me it felt like a stock ls swap, it was nice .so i hope this has helped the orginal reason for this post so happy new year

93formula

just because it feels faster or is smoother doesnt mean its faster. personally when i build it will more then likely be non vtec sohc as well. but on stock vs stock, we have had turbo stock d series, b20, b18, b17gsr...the b17gsr felt the slowest becuase lack of torque etc but guess what it was the fastest...

again what the op stated is parts he had and what power he should expect its been stated and frankly he hasnt even posted to this thread so to me this is now a mute point.

HumanResource

I drive 80-90% of the time in the low to mid-range of the powerband
1.6>1.5
price diff shouldn't be much, say $100
try to spend that on a 1.5 to get more bottom end.

Tyson

its not correct.

K2e2vin

He's comparing two modified motors, which is already difficult to do. What we can compare is results seen by other people and ourselves, not the rated hp.

I would agree the Mini-me seems like it would possibly make more power(with tuning) than the milled ZC, but there's really no way we would know...but when you refer to that mini-me as being a "D15B VTEC", that's pretty incorrect. Then you go on to compare the specs of a stock D15B VTEC vs. a stock SOHC ZC(which really does not apply in this case).

IMO, I would rather opt for the SOHC ZC from a performance stand-point. I have a D15B VTEC, and I can tell you it's overrated. 100cc may not seem much, but every little bit helps.

digitally_remastered

i agree. the d15b and so is all vtec engines, over rated. i like the feel of a punched out and built b20b over a gsr swap or b16 swap. more or so it depends on the driver and the purpose the car is intended to do. personally, if i am to go from my d15b2/y7 combo currently in my car im going straight h series. the purpose being that the motor/trans combo only wieghs approximately 35-40 lbs more than a b swap so its. and has a hell of a lot more torque imo.

SIred91

Wow.

Benchracing at its finest.

allgo88

the jdm 1.5 vtec is great.ive made 170hp to the wheels,and drive(rape)it daily.with a hmt turbo kit.