Rb25 Cam Switching With Aftermarket Ecu Qs .

[discopotato03]

Hi all , have had a few minor dramas setting up cam switching with a ViPec plug in . Is the best way to make up a table of MAP vs revs and run with the solenoid switched off up to say 3000 revs and 100 kpa (atmo) pressure ? Mine had been using a TPS vs revs table and that created drivability problems .

I set up a MAP/revs table which is off up to about 1600 revs and the off/on divide is sort of a diagonal line from 120 kpa at 1600 revs to around 0 kpa at 4000 revs . Its not really linear more a curve with its radius facing the lower RHS of the table if that makes sense .

Referencing off TP cost lots of off boost torque and fingers crossed I'll get better fuel consumption if not booted everywhere .

It's surprising how wild 256 Tomeis get with the solenoid on at very low revs , no hope of idling anyway .

Also it's set to switch off at all pressures between 4690 and 4700 revs .

Sorry if a silly question but I migrated from a PFC and you had no choices in this area , you did the idle learn and hoped it sorted itself out . Hopefully this is where I get the consumption back I had with the Apexi .

Realy like the versatility of the ViPec but it's a learning curve , cheers Adrian .

[89CAL]

Easiest way is off a GP output then put your desired parameters (Rpm>1100, tps> 5% or whatever)

I forget which digital output it is but it is shown in the help section somewhere (in the wiring section)

Hope this makes sense. Im going from memory.

[Guilt-Toy]

its AUX 1, set it to gp output.

Condition 1 and 2 - (OR 3)

SC 1: rpm> 1400

SC 2 rpm< 4000

SC 3 map< 180

start with this and then fine tune it to how you like it.

basically this is setup so its off on idle, then at 1400rpm to 4000rpm it will be on until the map goes over 180kpa where it will switch it off.

hope this helps

[discopotato03]

This is what I'm using and it seems to work quite well . It feels much better at part throttle for most of the sub atmo 2-3000 rev area and the 4 across the middle of the top row is an attemp to lose the closed throttle kick/buck I'm get in this area when cold . I think the cam switching and throttle closed fuel cut resumption were fighting each other in the 1400-1600 rev area .

I guess it makes sense to get the best trapping efficiency (shortest overlap period) at light loads and aside from a bit more torque in this area I could use better fuel consumption numbers too . My consumption yardstick is how far I get before the needle drops to the top line from full to the neck - which is real scientific is't it . Better than 50 is reasonable and better than 100 by the first 1/4 has been hard in the past .

A .

Edited May 30, 2013 by discopotato03

[Joshbigt62r]

Can you post a video of how wild the tomei 256's sound disco? I have a vipec plugin myself. Can you go into a little more detail on what your actualy setting up doing.? I'm very new to all these awesome vipec capabilities lol.

[discopotato03]

My tuner did it while I was with him once , its really only around idle up to dunno maybe 13-1400 revs . Best comparison I can give is trying to make a engine with full race cams idle too slow . Wild shaking and constant stalling . You wouldn't go there intentionally if you didn't have to .

I'm guessing std cams do a similar kind of thing with the sloenoid switched on at idle .

The main issue is engine characteristics change if the solenoid switches at the wrong times , obviously too much valve overlap costs you part throttle off boost torque because the inlets close too late and the exhausts open too early . Once the gas speed is up a bit its better able to flow in the right directions .

I also look at RB25DETs as a lowish CR engine off boost and they seem to work best with conservative valve timeing for normal part throttle driving .

When my PWM table was referencing off throttle position there was no way to have the solenoid off up to 100 kpa/atmo pressure into the 2-3000 rev range (see table above) and with it on the overlap timing was to much to allow it to make best torque in these areas . It didn't really run camy or rough but it didn't feel sweet and at times a little breathless . Now its very smooth and has more torque meaning you open the throttle less just getting around . It made a big difference to the cold start and warm up characteristics meaning it drives a lot nicer initally now .

I am also starting to lean out some parts of the sub atmo pressure fuel map because I had it a tad rich in these areas looking for better part throttle performance .

I'll know later today how the consumption looks and theory suggests it should be better . Anything that improves fuel consumption (E70) and gains torque at the same time is all cake I reckon .

Cheers A .

[discopotato03]

Just as an update the consumption ended up ok but it drives better overall . I also changed the accel load table from MAP to TPS and I think thats going to work better overall too .

Do we have a Vipec/Link G4 plug in tuning thread here or do we want one ?

Cheers Adrian .

[89CAL]

I would. I need to learn some more

[Joshbigt62r]

I think it would be good. I think I need to learn a lot more of the vipec/link g4 features.

[KiwiRS4T]

There is a forum on the Link Site:

http://www.linkecu.com/forums/engine-tuning