Was looking through some pics and have seen this at local car shows and they got VTEC but still have a carburated engine? How can this be done?

 

doesnt vteconly apply ay certain rpm to raise compression

 

Ya, and increase air intake, ive seen this and it would be cheaper than doing a dpfi to MPFI swap then VTEC head

 

so it should work, you planing on doing it.
might have to use afterrmarket carbs though like weber

 

I want to, I just need a how to cuz there are non, everyone says do a MPFI swap first

 

wow there's some mis information goin on in this thread.

o/p yes you can still have vtec with carbs. vtec has NOTHING to do with bumping compression. to do that you have to decrease the total volume of the combustion area, by either shaving the head or using domed pistons, to name a few.

now back on topic. o/p you will need an rpm switch, people used to do it before obd1 conversions were popular for our cars. that will send the signal at a set rpm to the vtec solenoid to activate the wild cam rocker arms.

is it wise to do it this way? no. the stock tune on most vtec engines actually has slightly different engagement points based on load rpm speed air density etc. the ecu also automatically advances/retards the ignition timing and bumps up the fuel to compensate for letting more air into the cylinders. using an rpm switch will get you a very crude form of vtec, but why do the guess work? with an ecu pin out sheet o/p you could easily wire your car for mpfi. even easier if your already dpfi.

 

VTEC is just a mechanical system that's controlled via one wire, handled via the ECU "out of the box". But you can easily override that and "engage VTEC" with the car not even running by applying voltage to the VTEC solenoid; give it a shot sometime, you'll hear the solenoid click when it engages. Hooking it up with a carb would be easily done by using an RPM switch like a shift light controller, or more ghetto, a manual switch on the dash.

It would work fine with a carb because the carb would adjust relatively quickly to the changed airflow when VTEC is engaged.

 

what engine do you have? is it carbed or does it have Dual Point Fuel Injection (DPFI)?

 

its been done bro its possible just the best way you could do it is to get a vafc and tune the engine with that and the vtec will engage on its on

 

It's so much better just ot go MPFI, IMO.

 

D15b2, I thought DPFI was carburated. That's what I've been told

 

looks like a carb but in reality it has 2 injectors in it . old chevys used to have this same setup in the early 90's. it works simular but very different form a carb. its not just spraying fuel from the primary jet's and secondary jet's its controlled by the computer a similar way but with 2 injectors.

 

Tbi throttle body injection

 

you need 3 things to have VTEC work

1. oil pressure

2.speed sensor signal from the cluster

3.coolant temp either the one on the back of the block for obd0 or the one on the thermostat housing for obd1.

all these have to go to the ecu . then the magic will get sent from there and work

 

uhhhhhhhhh no the coolant temp sensor is on the side of the head under the distributor. the sensors you sir are talking about are the fan switch's

 

uhhhhhhh nooooooo that one is for the cluster un plug that in the hole where the boot is stick in a wire and the other end of the wire stick it to your shock tower bolt come back tell me if it goes all the way to hot. hahaah

to have vtec work you need the coolant temp going to your ecu not your cluster . go read another super street. this is honda tuning my friend.