B18C Valve train differences - Auto vs 5 speed
 

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

Re: B18C Valve train differences - Auto vs 5 speed (Fishcat37)
 

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.

Re: B18C Valve train differences - Auto vs 5 speed (Havokmkr)
 

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...

Re: (vain)
 

<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.

Re: (Kendall)
 

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.

Re: (Fishcat37)
 

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... https://honda-tech.com/forums/images...s/emsmileo.gif

Re: (b18c3)
 

bump for being scared

Re: (Fishcat37)
 

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

Re: (db8sirg)
 

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...