[kettlekev]

I am just starting a AWD classic mini build with a B18C Honda Vtec engine and turbo.

As a general question can Speeduino manage the Vtec setup? Anything to watch out for?

Thanks

[miker]

Generic answer to a specific question. Speeduino can handle variable valve timing (vvt) on two channels (but the v0.4 board only has electronics set up to manage one vvt).

It can do on/off, open loop or closed loop.

If VTEC is the same as vvt (I think it is but please check and don't take my word for it) then you're ok. You need to do a lot of reading of the wiki to understand how it works and what to wire to what.

[kettlekev]

On the B18C6 engine the Vtec is triggered at a specific RPM. It then activates a solenoid that moves the cam to the higher lift pairing. This is simpler that the variable valve timing found on newer models. So a RPM based relay trigger from Speedy should be good!

The Vtec has other sensors which I am trying to match to Speedy. It has 3 sensors based on timing wheels in the distributor (TDC, CYP, CPK).

Anyone played with a Vtec before? My main concern is crank and cam sensing....

TDC - just used for starting? Ignition timing
CPK - crank position sensor
CYP - described as engine sync?
CKF sensor - crank fluctuation? Misfire detection?
TPS - throttle position
MAP - manifold pressure
IAT - Inlet temp
TW sensor - coolant temp
Vehicle speed sensor -? RPM output? Not sure what the ECU uses it for?
Evap solenoid - evap purge control. Triggered below 73 celcius
Idle control valve-this seems to be just an additional cranking/WUE type of system but focused on the air side

[kettlekev]

Has anyone got any B series base maps? With or without turbo?

Thanks.....

[miker]

Your first step is to find out what the crank and cam patterns are. Eg is it 36 regularly spaced teeth with one missing (36-1) or 12 regularly spaced teeth with one extra slotted in (12+1) or something else. Once you know that you need to check speeduino supports it by looking at the wiki decoders section.

If it supports the decoder, then you can start worrying about other things.

[JohnBYC]

You can run vtec open loop just an on and off rpm based

Tdc , cyp and ckp are crank/cam trigger , in speeduino you can run only the ckp with 1 less tooth off, or buy a vr conditioner that can run that setup, since honda distributors are a bit noisy

[kettlekev]

Small edit.

It seems the Vtec cut in/out is controlled by 3 sensors as far as I can see.

Oil pressure (too low and it won't engage)
RPM (good article here) - https://www.hondata.com/help/flashpro/i ... _point.htm
and the MAP sensor

So for speedy I will need 3 inputs OR'd together I guess? Has anyone tried this? I can't see much about it on the forum.....

[kettlekev]

Speedy's programmable outputs allow for 2 inputs so RPM and MAP are covered.

OP.PNG (184.85 KiB) Viewed 12814 times

It would be great to have a 3rd condition of oil pressure........

[kettlekev]

Edit: I guess I could just run a second programmable output with oil pressure as the input and electrically OR the outputs of the two programmable outputs to the Vtec solenoid?

The Vtec crank wheel is a 24 tooth
The 'engine sync' wheel (CAM signal?) is one tooth

the 24 tooth CKP sensor is in the missing tooth decoder section.....but I dont think it can manage the 1 tooth CYP engine sync sensor pattern?

Is engine sync just the cam sensor?

[kettlekev]

from the Integra service manual...

craank.PNG (7.98 KiB) Viewed 12807 times

So I read this (probably incorrectly) as;

Forget TDC sensor. Speedy can handle that with cranking enrichment/timing
CKP 24 teeth - can I just use this as a crank signal for Speedy?
CYP - I think I am missing something with regard to cam signals and Speedy. This only seems to locate the position of cylinder 1?

I get I need both crank and cam signals for speedy but cant see how CKP and CYP give me this?