I posted this in the EF forum, but didn't get any responses. I got my JDM B18C longblock from HMO. It's off an automatic Integra Si VTEC, and i was wondering what all makes it have less hp then the 5 speed. The 5 speed is rated at 180ps (177.5 bhp), and I think the automatic has 170ps (so like 167 or somethin bhp). I know the cams are milder, and the ecu is different. Are the valve springs different like on the intake side (like the automatic B16s)? Please let me know what i should replace when I do Civic Type R or Skunk2 cams soon. thanks

 

The only difference between the sir-g auto and manual are the ecu and transmission. No difference in cams, no difference in valve train. I'm not sure of the redline on the sir-g auto, but I do know that it came w/the same tranny as the LS/GS/RS autos.

 

http://www.d1.dion.ne.jp/~hiroq/intS.html
Go there. I know it's in japanese...but it says 180ps 5 speed...and 170ps (w/ AT) That's flywheel hp...so something is making it have less hp. It's at least the cams.

 

it could be more conservative fuel mappings...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vain &raquo;</TD></TR><TR><TD CLASS="quote">it could be more conservative fuel mappings...</TD></TR></TABLE>

This is a more likely answer. I've never heard of cam differences between the two, but you never know.

 

I used to own a first gen B16A (non-OBD). The automatic cams were less aggressive on the VTEC lobe than the 5 speed. The intake valve springs on the automatic were single, and double on the 5 speed (because of the larger VTEC lobe). I'm assuming that the 10ps loss is due to the cams and the ecu....just wondering about the valve springs.

 

man ur scaring me lol, i got an auto b18c from HMO. well actually its a b18c3. but i hope its not 10 hp less then the manual b18c...

 

bump for being scared

 

could it be due to drivetrain lost. can more hp is lost on the auto then the manual tranny?

 

yes it's 30% loss w/ auto, and 15% loss for 5 speed. The hp rating at the crank is 180ps for the 5 speed equipped motors, and 170ps for the auto equipped motors. That takes drivetrain loss out of the picture. Wheel horsepower factors in drivetrain loss. Something is causing a 10ps loss at the crank...