i have a integra gsr rebulit to run all motor. now i need to figure out when the vtec kicks in and when redline is. i need help on firguring when these to parts kicks in and stops please help. my head is fully rebuilt. block is high compression.

 

Why? Do you need to set this up in a programmable ECU? Or are you just curious?

Unless your motor was built to rev higher, your redline is right there on the tach. As for the VTEC crossover, this is best tuned on a dyno. If you're just looking for the stock setting I would suggest you download Crome so you can look at the factory calibration.

 

on a gsr u would usally set it around 4k 4200

 

yeah it is built for higher reving.

 

put it on a dyno. play with vtec until the graph is smooth. You will also find out how far to rev the motor or where the safe "redline" would be.

you arent telling us anything. rebuilt means what? there are about 297986089789 different combinations and we dont read minds here.

 

im putting new itr pistions and eagle rods. compression is going to be around 11.3 to 11.5 . bulit head with omni power springs valves and retainers. skunk 2 cams. full gasket kit. stage 3 clutch. thats about most of what im doing to my car. hope i can put about 200+ to the wheels.

 

do u have a chiped ecu?

 

The manufacturers of your valve train components can give you a good idea of how far you can rev. But if you haven't had the crank balanced I would be very careful.

I don't know of any way to determine redline on the dyno.

 

i dont have one right now. i think im buying a p28 chipped

 

pmed!

 

what does that mean?

 

Dont quote me but i recall reading somewhere that on your dyno chart you make the vtec point start where your torque and horsepower cross on the graph. I may be wrong but for some reason i remember something to that effect.

 

Talk to your tuner or whom ever you purchase your ecu from.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostinCX &raquo;</TD></TR><TR><TD CLASS="quote">Dont quote me but i recall reading somewhere that on your dyno chart you make the vtec point start where your torque and horsepower cross on the graph. I may be wrong but for some reason i remember something to that effect.</TD></TR></TABLE>

i have heard the same thing

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostinCX &raquo;</TD></TR><TR><TD CLASS="quote">Dont quote me but i recall reading somewhere that on your dyno chart you make the vtec point start where your torque and horsepower cross on the graph. </TD></TR></TABLE>
I had to quote you. The torque and horsepower will cross at 5252 RPM every time. Not every motor will want VTEC at 5252 RPM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
I had to quote you. The torque and horsepower will cross at 5252 RPM every time. Not every motor will want VTEC at 5252 RPM.</TD></TR></TABLE>

wow he has a point there that why most stock vtec ecus come with vtec at 5000.most they guys that ive chipped there ecu they want it anywhere from 4500 to 4800

 

Where the engine wants VTEC is a function of the size of the cams, combined with the efficiency of the induction and exhaust systems. For instance, stock B16 cams will want VTEC considerably lower than, say, a set of Skunk Stage 3's.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b19coupe &raquo;</TD></TR><TR><TD CLASS="quote">
I had to quote you. The torque and horsepower will cross at 5252 RPM every time. Not every motor will want VTEC at 5252 RPM.</TD></TR></TABLE>

I read that and thought the same thing.

 

People like to choose their VTEC crossover based on advice over the internet. And they prefer it to be low. But I have seen dynos of it set too low vs set correctly and it's just sad.

The going theory is to do a dyno plot with no VTEC, then do another with VTEC forced on, and see where the hp graphs cross (in other words the non VTEC graph will plummet, the VTEC graph will skyrocket past a certain RPM).

I personally think that the most this method gives you is a starting point and that you should try it a couple hundred RPM in each direction. Switching on VTEC does a peculiar thing to a dyno graph where there's usually a dip in power right before it switches on. Basically you want to minimize this dip, and if moving the engagement point doesn't do it, then you need to take a second look at your intake.

And don't whine if it wants to be set up high. Who the f cares about VTEC or whether you can "feel" or "hear" VTEC? The bottom line is the power you're making. If I made more power without VTEC I would have no quarrels about leaving it off altogether.

 

alright thanks alot. ill just wait until the dyno shop than. i relly need help on choosing the right person to go to for a dyno run. i live in minnesota can anyone help me? or even a state away from minnesota?