What is the difference between the 2 motors that makes the JDM version 8 hp more?

 

p30 pistons vs pr3 pistons would be the main thing

10.2 compression on 1st gen b16s and all USDM b16s pr3

10.4 compression on 2nd gen b16's JDM p30

Im sure there are other LITTLE differences, some people say cams are different and ecu timing and fuel maps

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">p30 pistons vs pr3 pistons would be the main thing

10.2 compression on 1st gen b16s and all USDM b16s pr3

10.4 compression on 2nd gen b16's JDM p30

Im sure there are other LITTLE differences, some people say cams are different and ecu timing and fuel maps

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

Yes, the cam profiles on the 2nd gen B16's are better than 1st gen cams, as well as the OBD1 programing/electronics ownz over the non-OBD programing.

Throttlebody size differs as well:
60mm = 2nd gen
58mm = 1st gen

all of this contributes to the 8+ hp difference between the 2 versions of JDM B16 engines.

 

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

Yes, the cam profiles on the 2nd gen B16's are better than 1st gen cams, as well as the OBD1 programing/electronics ownz over the non-OBD programing.

Throttlebody size differs as well:
60mm = 2nd gen
58mm = 1st gen

all of this contributes to the 8+ hp difference between the 2 versions of JDM B16 engines.</TD></TR></TABLE>

but he was asking about the dif from US and 2nd gen JDM

the US spec has the 60mm throttle body along with what appears to be near identical cams to JDM spec.

I was just comparing 1st gen, 2nd gen JDM cams and USDM b16 cams
there is an obvious difference between 1st and 2nd gen
but comparing USDM to JDM, i cant see any difference.

1st gen has obd0 which isnt as good compared to obd1
1st gen has the factory oil cooler, 2nd gen does not (cheap asses)
but on 2nd gen b16's they were nice enough to leave the hole threaded so you can easily convert to a oil cooled system.
1st gen has the cast cam rails
1st gen head uses an older casting technology compared to 2nd gen
I dont see any performance difference between the cast and milled rails and the difference in casting between 1st and 2nd. 2nd gen casting seems to be a little cleaner, maybe just more cost effective way of doing things.


the blocks however seem to be identical




Modified by irev210 at 11:56 PM 7/7/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by irev210 &raquo;</TD></TR><TR><TD CLASS="quote">
but he was asking about the dif from US and 2nd gen JDM
</TD></TR></TABLE>

oopsy, my baad.
I was paying attention to his subject question rather than his subject title.
Shame on me.

but yeah, the biggest mechanical diff between a US B16 & JDM 2nd gen B16 engine(s) are the pistons. All U.S. B16's use a PR3/10.2cr piston & all JDM 2nd gen B16's use a P30/10.4cr piston.

Head components, cam profile, etc are virtually identical. 60mm TB's for both US & JDM engines.
Only 89-91 B16's had the 58mm tb size.

Tranny/Gear ratio is identical as well, except the optional LSD factor for JDM version.

Then there's the OBD1 and OBD2 electronics difference. I assume you all know about that, right?

what contributes to the 10+hp on the JDM B16 has to do with the compression, and possibly the cam profile, less emissions equipment, but moreover, the higher octane rated fuel Japan readily has and uses.

 

what octane rating are the using in Japan?

 

from memory, I think the lowest octane in Japan is 94 and it goes up from there..


Modified by Katman at 11:23 AM 7/10/2003

 

anybody dynoed a usdm and jdm b16a with i/h/e do you notice any wheel horspower increase due to compression difference...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Lysawy &raquo;</TD></TR><TR><TD CLASS="quote">anybody dynoed a usdm and jdm b16a with i/h/e do you notice any wheel horspower increase due to compression difference...</TD></TR></TABLE>

http://www.importreview.com has some intresting dynos

 

Is the increased compression piston or head? I forget.

Technicaly, every point dropped in compression is about 2-4% power loss. Not an acurate guide, but helpful to understand the benifts of increased compression. Someone correct me if I'm wrong.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 976 &raquo;</TD></TR><TR><TD CLASS="quote">Is the increased compression piston or head? I forget.

Technicaly, every point dropped in compression is about 2-4% power loss. Not an acurate guide, but helpful to understand the benifts of increased compression. Someone correct me if I'm wrong. </TD></TR></TABLE>

increase in piston dome height....head's combustion chamber is exactly the same between 1st & 2nd gen b16's.

 

i believe the USDM B16A has a redline of 8,000RPM, compared to the JDM which is 8,200RPM, higher compression and higer redline makes up the extra hp.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EG6 SiRII &raquo;</TD></TR><TR><TD CLASS="quote">i believe the USDM B16A has a redline of 8,000RPM, compared to the JDM which is 8,200RPM, higher compression and higer redline makes up the extra hp.</TD></TR></TABLE>

nope..
US B16A ecu does not redline at 8000rpm (are you kidding me?ha). It redlines at 82-8400rpm. Higher redline doesn't make up the extra HP on a JDM engine either. lol.


Modified by Katman at 4:40 PM 7/14/2003

 

katman, I changed my redline to 9k and i gained 14.425236hp

get with the times, the higher the redline, the more power. lol

 

all things being equal the cam profile and slightly higher c/r accounts only for about 3-5whp differnece on a dyno, between first gen and second gen.
1st gen =135-140whp
2nd gen/USDM=137-143whp

while USDM B16A will be on par or within 1-2whp of 2nd gen JDM b16a. there is no reason to go JDM unless of course you're getting a tested/cleaner/lower mile motor and/or LSD tranny.