ok heres the deal.....im running a gsr motor with ctr pistons and a decked head...pnp head full valve train and crower 63402a cams....the car was running ok with the stock cams and stock injectors.....so then i put in RC 310 injectors with fuel rail and it still rain ok but a little hesitation at vtec...so then i put in the cams...and now when it hits vtec the cars hesitates for like 2 secs and then it runs fine up to redline....i thought it was the timing but i checked it and it was fine....then i thought it was the injectors cuz the car was running really rich so i put the stock injectors back in and it still does it...has anyone ever had a problem like this b4 with these cams or any other cams...i dont know what to check next...im thinkin i need a v-afc or something but the car these cams came out of never had this problem wit stock ecu...which by the way im running a stock p72...so any info would be great....thanks

 

My guess: the ecu is the problem. At least get a piggy-back unit.

 

thats what i was thinkin but the car that had these cams in it b4 had a stock p72 in it just like me....so im kinda confused

 

There must be some other difference between when it ran well and now. Pistons? Tuning? Hard to guess, but even if you can get the car running "smoothly," I would still suggest getting at least a vafc, or better yet a hondata.

 

yea i wanted to get hondata and i posted about if there was any good tuners in my area but i only got one reply and they said someone in VA....but the only diff from when it was running good to now is the cams and injectors

 

The "someone" in VA is Steve Sakai. He built/tuned my motor. Worth the trip, trust me.

 

well im first tryin to solve the problem i have now then ill either get v-afc or hondata

 

first of all your vtec comes in way too soon with that ecu. crower states on there site that you have to change vtec ingagement for best results those cams are probably going to like vtec somewhere around 5500-5800 rpm. My crowerstage3's liked 5800. Another thing is your fuel. you are probably running way too rich with those injectors. Is the fuel pressure turned up too high. After tuning you will hardly even notice vtec changeover. atleast with a good tuner.

 

yea i thought i was running way too rich so i put the stock injectors in...and the fuel pressure is at 42....so from 4500 when vtec hits it hesitates till like almost 6000 rpms....and thats what i thought it was.. the ecu..but once again the car these cams came out of had the same ecu and did not happen to him

 

all motors are different. even if they have the same specs some tend to want different things.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbociv &raquo;</TD></TR><TR><TD CLASS="quote">first of all your vtec comes in way too soon with that ecu. crower states on there site that you have to change vtec ingagement for best results those cams are probably going to like vtec somewhere around 5500-5800 rpm. My crowerstage3's liked 5800. Another thing is your fuel. you are probably running way too rich with those injectors. Is the fuel pressure turned up too high. After tuning you will hardly even notice vtec changeover. atleast with a good tuner.</TD></TR></TABLE>

Your dead on.

here's what I've seen when vtec is hit too early or the cam is too big for turbo

 

it sounds like your vtec is coming in too early for the cams

 

thats another thing i was thinkin but what throws me off is that these cams were in my boys car and his vtec hit at 4500 and it was fine...but then again like turbociv said different motors want different things so i dont know

 

DO you have air/fuel readouts? Looks like you may not have enough fuel at the point of VTEC engagement.

If you look at my H22a dyno graph we were tuning th V-AFC and when it hits VTEC it goes super lean...I have it up to +8 right at that spot and it still does it. These are crower stage 3 cams, so it's possible even with the injectors you're running rich most other places but still lean at engagement.



See right after 5000...VTEC engagement it spikes, need a standalone system if I want to really smooth that out. You see me +8 on fuel hurts me by 5500 bringing the a/f way down. So I should fine tune at least.

 

The stock ECU activates the secondary lobes at 4800rpm on the P72. The reason it starts to work at 6 might be the intake runners shifting to the short position, thus getting enough air to use the cams effectively.

 

you mean 5800 right?

 

well i took my secondary plates out of my IM

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AllMoToRB18c &raquo;</TD></TR><TR><TD CLASS="quote">well i took my secondary plates out of my IM</TD></TR></TABLE>

Well then scratch that...I would hit the dyno with a wideband o2 and see what your fuel looks like, go in with a V-AFC and fix it up. If you see the big spike at engagement I still can't tune out, it's quite possible you're getting the same thing but the a/f is way higher cause detonation issues.

 

well i dont think im detonating cuz my octane is at like 102...its half 93 and half 110 so im assuming its around 102 or 101.....and do u know of anyone that will tune hondata in central jersey area...its hard to find a tuner around my way

 

does anyone know where i cn get hondata for cheap?