TurboCharger and Vtec Controller

[anjingbalap]

Dear Guru's of the Oz Honda

i just wondering.. what is the benefit of putting a Vtec controller on the Turbocharger honda?

i heard that Vtec controller is engaging the VTEC on low RPM so boost the turbo lil bit?

but is it.. really2 important to do that? and will the engine withstand without damaging it? because on TURBO is already high Compression and with VTEC engaged it will make EVEN higher ?

so will it benefit a turbo HONDA or just waste of money?

[fatcivic0_0]

i bought a vtec controller for my car 4 when i put my turbo kit on as it helps to build boost quicker and high compression wit turbo is bad man wat u mean by that lol.

[yourfather]

moving VTEC crossover on a stock motor up or down 1000rpm can / may improve your power curves, this is dependant on the modifications you have. It can only be proved while you are on a dyno.

You don't need a vtec controller, or VTEC crossover modifier - it should be part of a fully customizable ecu package, and unless you are using aftermarket camshafts or you've increased the compression, if you've had your head flowed, or some other form of internal work that means that you'll have to get your crossover reoptimized.

since you will be going turbo, you will have a standalone ECU hopefully, like a power FC or hondata, that is when you will need to look at this. - you wont need another device.

Because every car is different, and not just the condition of the motor, but the fuel you use, the weather and moisture in the air is important factor different cars need different points.

Just baseline dropping your VTEC crossover point to like, 5000rpm, or 4,500 rpm, won't really be of any benefit unless you tune it to perfection.

on a dohc vtec motor, you should know, there's a primary and secondary cam lobes for the non vtec, and then a vtec lobe that is engaged by a pin that is placed into a hole on the cam. At the highest range of RPM, the small lobes on the cam cannot let enough air into the motor, or keep them open enough to continue the motor to make more power! It also depends on what kind of turbo you are running, whether you need the lobes open earlier to let more air in. So when the VTEC lobe takes over the close / open cycles from the primary + secondary lobes, it's a more aggressive, longer duration, and taller lobe! so more air, valves open for longer.

So if you were to just dump your vtec crossover to say, 2000 rpm, it makes the lobe that's designed to let heaps of air in, run at a point where a) it is not needed, b) the motor will bog down like a fat pig, and then when it reaches a point where the extra air the motor requires can actually be of assistance to it, it'll jump forward, hence the absolutely ghey "VTEC YO" bullshit.

When you do get your ECU installed, try it one day, set your vtec to like 3000, thats as far is it goes down I think, and see how much of a slut she is to drive. Then set VTEC crossover to like, 7000 rpm, and see how its normal to start, then chokes when it needs more air, and then when it finally does kick in, it'll be like a rush of power. And dont let the butt dyno tell you otherwise, the thing about these honda motors is that they're designed for consistent, linear power delivery. But if you modify your crossover for no reason, your curves aren't optimized to make use of the dual range that the vtec lobe provides.

To sort out the best way to get VTEC crossover, do a dyno run with your turbo setup, with vtec engaged as low as possible, then do one with it engaged as high as possible. compare the graphs on top of each other, and where the two torque / power curves meet up, this is your optimum RPM vtec engagement point.

[poid]

as the above post says in a longer form, you dont need one because if you havent cut corners you already have an ECU that can control the vtec engagement point once you are turbocharged.

VTEC engagement doesnt alter the compression ratio by the way.

[anjingbalap]

oh ic...
thx for the explaination.... its because.. of these my turbo mechs always tell me to install the VTEC controller.. now I know that i dont have to install it..
so he try to rip me off

[locote]

My car was on the dyno last week.
Turbo in a B18c and it wasnt responding to well to altering vtec cross overs..
I have a power Fc it will be goin back on dyno again next friday for more tuning and road testing...
So far its running rich and has 2 flat spots one at 3k and other at round 7500.
But so far ive mowed down a few cars only one that i could just keep up was a BMW M3. but once it gets smoothed out im sure ill be quikker...
BTW im only runing 6psi.
But if i was to do it all agin id get a B18B !!!! vtec is a bit of a hassle lol specialy as im gona have to get turbo vtec cams now.

[saxman]

oh ic...
thx for the explaination.... its because.. of these my turbo mechs always tell me to install the VTEC controller.. now I know that i dont have to install it..
so he try to rip me off

any mechanic who tells you this is obviously incompetent to a properly designed turbo set up for a honda and should be avoided for any work.

As previously mentioned, a proper turbo set up will include a proper engine management solution that will take care of any vtec issues you may want.

[anjingbalap]

ok say if i got piggyback ecu.. should i use vtec controller?

is buddyclub v-con better for turbo vtec rather than apex vafc

[tinkerbell]

do you have NO aftermerket controlers or what?

are you running a turbo without any sort of controllers?

actually, hold on - do you even HAVE a vtec turbo Honda?

[anjingbalap]

well i got vtec.. n i use Power FC atm...

i just saying.. "IF" i got piggyback ecu (hks f-con) should i install VTEC controller? or the piggy back can do the vtec controller also?

if u do need vtec controller which on is better? is buddyclub v-con better or apexi vafc

[tinkerbell]

if you have a Power FC you already have a VTEC controller

[anjingbalap]

jeez... i said IF.. because i just buy a engine k20a.. n i putting a turbo on with piggyback n gonna make a kit car...