Hi all,

Today i followed Jeff Evans great guide to swapping cams on a B series motor, thanks Jeff, swapping b16a2 cams for ITR cams.

Basic setup :
Stock B16
Pfab Log mani 3" exhaust
sc61
Precision cooler
ITR inlet mani.

I swapped the cams and have lost a load of power, since i aint using adjustable cam gears i am guessing that there is just too much overlap and all the boost is going out the exhaust ( so to speak ). Car drives fine, but where it used to really start pulling around 6500rpm, now it just feels slow, also feels slower everywhere else in the rev range. Spools just as quick, but no go at all.

From my understanding there is just to much overlap and this needs to be dialled out with adj gears, but i just wanted to ask you guys if this sounds correct. Its the first time ive done a cam swap so just checking this is what to expect and to rule out any other possiblities.

Ign timing was reset to 16 degrees, cam timing is smack on ( i double checked TWICE lol ). Noticed that the A/f ratio richened a whole point or over, from 11.8:1 to as low as 10.2:1.

Have i messed something else up, or is this purely too much overlap?


Thanks. Craig

 

So it's not tuned for those cams?
I think that's the answer to your problem. Of course any engine runs best when it's leanest, so the richened up AFR really screwed you.
For not tuning it.

 

Its only seriosly richer in vtec, the lower lobe fueling is still around 11.8 in boost. Boost comes in around the same RPM, but the car just doesnt pull hard, then vtec engages and goes alot richer.

Surely even out of vtec the car should pull simular to the B16 cams? Fuelling is very close to before?

There is just no power, feels like ive lost about 25%. I knew that i would have to trim the fuelling and adjust the timing but after the initial test drive i swear there is either way too much overlap, or i have messed something up in the cam swap. Too much of a difference to be just the tune. Or not?

 

go get some adj.cam gears and get it on the dyno asap

 

maybe the added over lap and the "higher" EMP have caused you some problems, or the cams arent in their optimal spots or your engines needs a little more dyno time to tweak them. maybe a combo who knows.

you sure you got them installed correctly timing wise?

 

i have CTR cams and STOCK gears 333whp no problems!

your problem is you need a damn tune! you cant just swap cams and expect a gain.

 

Need to get it re-tuned... Plain and simple.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blinx9900 &raquo;</TD></TR><TR><TD CLASS="quote">i have CTR cams and STOCK gears 333whp no problems!

your problem is you need a damn tune! you cant just swap cams and expect a gain. </TD></TR></TABLE>ITR STOCK GEARS 816WHP http://www.turbooptions.com/video/camgers.wmv DONT MINE THIS GUY WE DRINK TO MUCH UP HERE

 

theoretically it should run leaner not richer. the cams allow the motor to flow more air, so if you dont add fuel it will be leaner. i had to add fuel when i switched from gsrs to itrs.

not to be a dick, but are you sure they are itr cams? like you didnt get scammed on them right

 

Checked the cams, intake has 3 rings on the outer, 1 ring on inner. Exhaust 3 rings outer, 1 ring inner. Looks like these are cams from a B17a according to the following link:
http://www.ff-squad.com/tech/temp/VtecCams.htm

If this is correct then i am a complete idiot and have shelled out a load of cash for some pathetic cams, i have had these for about 6 mths sitting in the garage and didnt even open them to check them out. IDIOT.