frog169

i have a 92 hatch, with a b16. im trying to get me a p30 chipped ecu, and ive noticed a few places who chip have different Vtec engagements, what would be a ideal time to use? some have it kick in at 4400rpm, some at 4800, and some at 5000. what would be the best to use?

Essenar83

What kind of motor work? (Not bolt ons but actual head/block work)

If nothing, then keep it modest. 4800 RPM with an 8100 RPM limit.

If you have some head work done, most people would suggest a higher rev limit and a 5200-5500 VTEC engagement.

Normally B16's VTEC engages at 4800 RPM. GSR is at 4400 (Same as EX I believe)

frog169

umm dont think ne head work was done, just mainly a standard b16 with some bolt-ons :-).

what would be the difference in having it kick in at say 4400 then the 4800? would it make that much of a diff? be better? be worse? (sorry im a newb to reasons why they have certain limits about vtec :-P)

frog169

oh i think the heads were port and polished? tink thats what they did.

fmrprojects

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by frog169 &raquo;</TD></TR><TR><TD CLASS="quote">oh i think the heads were port and polished? tink thats what they did.</TD></TR></TABLE>

haha heads, this aint no v8. but anyways turning back the vtec isnt gonna do any good, you just gonna have a big dip in power when the vtec engages. get it tuned and that will be where it should be

JDMlyfestyle

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Essenar83 &raquo;</TD></TR><TR><TD CLASS="quote">What kind of motor work? (Not bolt ons but actual head/block work)

If nothing, then keep it modest. 4800 RPM with an 8100 RPM limit.

If you have some head work done, most people would suggest a higher rev limit and a 5200-5500 VTEC engagement.

Normally B16's VTEC engages at 4800 RPM. GSR is at 4400 (Same as EX I believe)</TD></TR></TABLE>

4800???? your kidding right.. Stock for a B16 is 5600 or 5800. to distinguish where u want the vtec placement to be. you want the vtec transisition smoothe. so get the car on a dyno and see how ur graph looks..

Syndacate

I'm pretty sure it's somewhere between 5.2 - 5.5k stock.

If those are your only options, have it kick at 5k, see, vtec (which I forgot what it stands for) isn't like, motor nitrous like everybody makes it out to be, it's not like 50 extra hp at a certain RPM's, it simply switches the lobes of the cam to keep the valves open longer making it better for high end torque, but loses low end torque, this is why you can't put it into V-TEC too early, the lobes are designed for high end torque so if you have it say..in vtec all the time, it'll REALLY dog it when u try to start and u'll have no power off the line.. Certain engines have different cam shafts and w/ different torque numbers can afford to have the VTEC Cross at different RPM, too low, and you won't pull much in the low RPM's, too high, and it'll be useless b/c you have to redline at somepoint, so it'll pretty much be using standard cams until redline, so it's got to be right at the right amount..

now on a B16, it has a later Vtec engagement than the D series' so if you have it kick in at 4k RPM, it's going to bog like a *****, b/c it's meant for 5+ I'm pretty sure, somebody'll tell ya the correct stock crossover... Now with ur setup, boltons, turbo, whatever, ur car will react differently, that's when you have to take it to a dyno to see when u should set the vtec for to get the optimum power, on the flipside, that's usually only done in drag racing or 10 second cars...if I were you, I'd look up the stock RPM vtec crossover spec, set it there, maybe 200 or 400 lower, depending on what it is (wouldn't go any lower though), and leave it at that..

Hope that helped

JDM_Ej

Don't buy a "chip". Buy a socketed ECU and use a program like Crome or Uberdata to tune it.

Remember switching your VTEC points is pointles unless your changing the fuel and ignition maps to relate to the new point.

And trying to tune anything without a dyno is pretty useless.

frog169

yea the chipped ones i was looking at have the upgraded fuelmaps to match there vtec engage, i personally dont wanna do it my self cuz im afraid ill end up ******* something up lol. then ill be screwed once again with no running car.