Hey guys I just recentley swapped my GSR head with skunk2 stage 2 cams, skunk2 manifold , and stock valvetrain for a new setup which was ITR head with same cams, JG manifold, and skunk2 valvetrain. It went from 177hp to the wheels on the dyno to 172!!!! The check engine light is also on which im still not sure why. Could the check engine light be causing it to lose power or is the manifold just no good????? Let me know guys (this is all on a B18C-1 by the way).

 

probably because you dropped compression. gsr head raises compression because of the combustion chambers

 

you need to check to see what ECU codes you are throwing to see what exactly is wrong. In many cases the the check engine light being on means your car is running in limp mode - which means you are not going to get the best dyno #'s

ITR head lowers compression ratio by approximately .2...you might not lose to much especially in the upper RPM's because of the better flow of the ITR head...not sure if the JG mani flows better than skunk2 (might wanna search on that)

if you don't know how to check you ECU codes - go here to learn how to check them http://www.c-speedracing.com/faq/06.php

go here to identify the codes http://www.c-speedracing.com/faq/05.php

if you don't know what codes you are throwing...I would not dyno the car...you could make things worse

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WrongWD &raquo;</TD></TR><TR><TD CLASS="quote">probably because you dropped compression. gsr head raises compression because of the combustion chambers</TD></TR></TABLE>

 

i thought JG manifolds were only good if u have really high compression ....so that could also be y u dropped HP just from the manifold alone...id go back with skunk 2 manifold

 

lost of compression and the intake manifold my be too big if the motor is still a 1.8

 

The .2 loss of compression isn't going to cause that much peak power loss. I think it's a combination of too large a plenum intake manifold, the fact that the GSR pentroof design combustion chambers are a better design then the PR3 and finding out what code it's throwing because it is more then likely dumping a lot of fuel with the CEL on.

Did you retune with the new head package and did you compare A/F charts?

edit: Did you also just think about conditions? Same dyno or not, temps, air temps, humidy etc... It's not uncommon to go back and gain or loose a couple peak hp. How's the rest of the chart look?

 

well the code is a solid long flash with a pause in between each flash, which i figured had to be code 1 which is the oxygen sensor. But when I changed heads the O2 sensors werent even messed with. I have a test pipe in place of the factory cat so the sensor has never given me trouble being unplugged in the past. Could the larger intake manifold be throwing the oxygen levels way off???

 

going back to stock ITR valvetrain for s2s2 is not recommmend...engine check light on i think you over rev the engine and ur stock ecu reacts to that....maybe im wrong

 

get cam gears and tune it......no reason to get lower number....air and fuel ratio since s2s2 will requires more air i believe

 

Dont mean to be rude here, but why not get the person who swapped the heads for you to check the code. I would sure think if you can do a Honda DOHC Vtec head swap, you should be familuar enuff to run the codes. If they cant, that would be the first indication to me that they dont really know what ther are doing, so how could they possibly set it up........ie.. cam timing, valve lash, ignition timing ect....
hell, even the cheap $15 autozone manual tells you how to run the codes

 

I already have gears and its been tuned, I actually am not running the ITR valvetrain, Im running all skunk2.

 

I swapped the heads myself and adjusted the valves myself pretty damn carefully, and yes I do know how to check the codes, like I said the code is 1, I dont know where you got the idea that I didnt know what the codes were?????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18cx &raquo;</TD></TR><TR><TD CLASS="quote">Dont mean to be rude here.........
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Your origional post was a little misleading