Vvt

[ashy_gtt]

Hello,

Right the 172 engined 5 has now been MOT's insured, taxed and is zipping about on the roads :evil:

The thing that i need help with is the VVT, I don't currently have it connected up. The DTA ECU has the facility to switch the solenoid valve on at a certain RPM. What i need to know is what RPM does the VVT kick in on a std car? Also does it kick in in stages or is it on or off?:S

Cheers Peeps.

Ashy.

 

[TheCake]

VVT has nothing to do with the kick.

The VVT on the Renault engines is totally unlike the VVT at Toyota or VTEC from Honda. It is more to do with idling and emissions.

 

[BenR]

its on or off, its a lowside switch, if your going to use a simple rpm based trip point then do one run with the vvt on from 1500rpm and one with it off and then compare torque graphs and switch it at the point the two cross.

 

[ashy_gtt]

I don't have the use of a rolling road to set it up, its being mapped on the road.

 

[White16valver]

Get some pics up!

 

[BenR]

oh, then just use your bum and switch it when it feels best.

 

[ashy_gtt]

VVT has nothing to do with the kick.

The VVT on the Renault engines is totally unlike the VVT at Toyota or VTEC from Honda. It is more to do with idling and emissions.

so the VVT reacts fast enough to cut in and help with the engines idle?

Are you sure?

 

[BenR]

yea, its an instant switch.

Plain 16 deg advance when you activate vvt.

Try it, just put 12v accross the solenoid when the car is idling.

 

[ashy_gtt]

yea, its an instant switch.

Plain 16 deg advance when you activate vvt.

Try it, just put 12v accross the solenoid when the car is idling.

Ok i'll give it a shot.

I was under the impression that the VVT solenoid worked on directing the oil pressure to the inlet cam phase shifter to modify the cam timing. Are you saying it moves the cam 16 degrees which is nearly 2 teeth or is it modifying the ignition advance?

Just i wouldn't want to advance the inlet cam 16 degrees at idle.

Ashy.

 

[edde]

Ok i'll give it a shot.

I was under the impression that the VVT solenoid worked on directing the oil pressure to the inlet cam phase shifter to modify the cam timing. Are you saying it moves the cam 16 degrees which is nearly 2 teeth or is it modifying the ignition advance?

Just i wouldn't want to advance the inlet cam 16 degrees at idle.

Ashy.

It advances the cam 16 degreees.
People have fiddled with the VVt at idle idling becomes terriable with the VVT activated.

 

[ashy_gtt]

It advances the cam 16 degreees.
People have fiddled with the VVt at idle idling becomes terriable with the VVT activated.

f

Yeah just read the 172 guide and it says

The solenoid valve is closed at rest. It authorises
the passage of oil to control the phase shifter in
line with the operation of the engine:
- if the engine speed is between 1,800 and
6,500 rpm,
- if the throttle potentiometer is not at no-load.
WARNING: if the solenoid valve is jammed in the
open position this will result in an unstable idle
and the pressure in the manifold at idle will be
too high.

so i guess you can run that solenoid anyway between 1800rpm and 6500rpm as long as the tps is reading a value greater than fcuk all!

 

[BenR]

yes, its cam degrees advance, and there is no problem advancing it at idle, it come come near the pistons, it'll just idle rough.