VEMS + Turbo + water injection + dry nitrous shot = ?

[mr_g]

I have VEMS, wbo2, egt, with 680cc siemens injectors, opel redtop 2.0 16V (C20XE/C20LET) engine, with 8.8:1 CR wiseco pistons, T3 turbocharger trim 60 with 0.63 ar turbine housing (300-350HP)...

I will put water injection just in case (maybe with some methanol), and I was thinking about adding nitrous...

My primary idea was to add dry nitrous shoot, small amount like 20-40HP before IC just to cool down IC on hot summer track days where IC doesn't have good efficiency.....

But, now I'm thinking about a larger amount of nitrous because turbocharger has big turbine housing and smaller compressor housing, so it could eat up a lot of nitrous... Maybe 100HP dry shoot before throttle body..

Does anybody has any experience with setup like this? VEMS + dry shoot? Or the wet shoot would be better? I would prefer dry, it's less piping's and fittings, and I suppose that VEMS supports nitrous injecting...

Can VEMS control everything? Boost, dry nitrous shot and water injection at the same time?

[rob@vems.co.uk]

I'd go for a wet system, sure theres some functionality in the newer software to provide Nitrous control, but...
When you get a wet system you are assured the correct amount of fuel for the amount of N2O, not a calculated value with all the corrections, you are going to need a lot of fuel to run N2O safely, so you may find that you need to increase the injector size to ensure that you don't run out of duty.

Remember you want to tune for 0.7 lambda when on N2O, if you keep a strong eye on detonation and EGTs you can possibly run as high as 0.72 but no leaner than that, things can go wrong amazingly quickly.

[Sprocket]

Dry nitrous noo noo noo, that is asking for trouble

By yourself a Wizard Of Noz kit by Highpower Systems, and you wont go wrong. http://forum.nitrous-advice.org/

The nitrous control in Vems is realy only to knock back the ignition advance and enable the N2O system

[MWfire]

vems has adding(or trim) fuel when nitro is activated(1.1.58).
you can control boost, nitro and watter at the same time.

[mr_g]

Of course wizard of nos. But dry kit. I saw many pro projects with wizard, that uses stand alone and dry kit... Alto, now, all the new wizzard prokits uses special injectors for nitrous and venom injectors for fuel... I wouldn't go with much nitrous 50-100HP, and I think Siemens 680cc could withstand max 400HP total (turbo+nitrous)...

So I would have to upgrade to 1.1.58.. Does it have dual config and vemstune?

What about progressive applying nitrous?

Wet or dry it's the same I think, because, VEMS is running closed loop so, it would ego correct (lower AFR) alto you have to much fuel applied over added fuel injector. So VEMS MUST be aware of nitrous on board and active (because it would lower AFR, and VEMS would try to ego correct it to the lambda target)...

Can you alter lambda target table on nitrous, or lambda target stays the same? How will nitrous manifest on the engine? Like higher MAP reading or what?

Also, AFR on wet nitrous system is highly affected by nitrous bottle pressure. So the AFR would fall over the nitrous using if you don't have closed loop...

It's not like I'm gonna buy and run nitrous tomorrow. I just like us to brainstorm the idea of wet vs dry...

[gunni]

As it sits now there is no full fuel control extra when under N2O .

You could connect to a switch so that the second config would have different fuel values in the VE table to work with a dry setup.
EGO control will absolutely not do to try and make the ecu adjust for N2O.

It would be good to have a 3d table for N2O control of it's solenoid as well as a N2O fuel compensation table.
So you can adjust PWM of the solenoid based on KPAxRPM and the normal N2O settings, then adjust fuel in another 3d table
based on PWM of the N2O solenoid(N2O-DC%xRPM) from the first table. This would allow you to set up a car that can have a very extensive control over N2O and fuel.

So immitating a larger engine , i.e
75kpa@3k = 30% DC ,
90kpa@3k = 60% DC ,
75kpa@4k = 60% DC ,
90kpa@4k = 80% DC ,
75kpa@5k = 80% DC ,
100kpa@5k = 100% DC

Or something similar to this. This could also be a water/meth injection method for turbo cars based on KPA*RPM

[mr_g]

What firmware version are you referring to? Well, they would definitely install this functions in software at the time I would be buying this nitrous kit... ,

Anyway. Let's say we have wet system installed. Lambda factor for added fuel/nitrous is about 0.5-0.6... VEMS is running closed loop at WOT and let's say, it's about 0.75lambda..

So, added nitrous is let's say 100HP, while engine is 300HP without nitrous.. So, added fuel/nitrous would unbalance AFR to 0.65-0.7lambda... So the VEMS would trying ego correct it to 0.75lambda by reducing fuel, and you have burnt/cooked engine anyway...

So, I'm thinking, VEMS must be aware of nitrous onboard, and must change lambda target when on nitrous (also boost target).. Also, I suppose applying nitrous to turboed engine would slightly rise the inlet pressure (MAP), so, we could work around the lambda target for the new MAP reading (nitrous added pressure)...

The point of using nitrous on turbo engine limited with turbo size is to over-spin turbine with added energy of the nitrous... I think...

What do you think?

[rob@vems.co.uk]

Just turn off EGO correction with any of TPS, RPM or MAP.

[gunni]

What firmware version are you referring to? Well, they would definitely install this functions in software at the time I would be buying this nitrous kit... ,

Anyway. Let's say we have wet system installed. Lambda factor for added fuel/nitrous is about 0.5-0.6... VEMS is running closed loop at WOT and let's say, it's about 0.75lambda..

So, added nitrous is let's say 100HP, while engine is 300HP without nitrous.. So, added fuel/nitrous would unbalance AFR to 0.65-0.7lambda... So the VEMS would trying ego correct it to 0.75lambda by reducing fuel, and you have burnt/cooked engine anyway...

So, I'm thinking, VEMS must be aware of nitrous onboard, and must change lambda target when on nitrous (also boost target).. Also, I suppose applying nitrous to turboed engine would slightly rise the inlet pressure (MAP), so, we could work around the lambda target for the new MAP reading (nitrous added pressure)...

The point of using nitrous on turbo engine limited with turbo size is to over-spin turbine with added energy of the nitrous... I think...

What do you think?

You could your trick with dual config switch, so that the lambda target table is your tuning base when using nitrous,
I.e just put in 0.72 when you want 10% more fuel then 0.8 , but then again you could and should just use the VE table anyway.

No firmware now will change the lambda target table based on knowing if you are running the nitrous or not.

[mr_g]

Dual config is used for bifuel...

Disabling ego doesn't seem to be very brite option to do...

[rob@vems.co.uk]

Disabling ego doesn't seem to be very brite option to do...

You shouldnt have it on at WOT, high RPM or high load... Thats what the thresholds are there for.

[mr_g]

Well, stock ECU doesn't use closed loop on WOT just because it has narrow band O2, and narrow band cannot tell ECU where the 0.8lambda is... narrow band knows only >1lambda, or <1lambda... Right?

But I have wideband O2, and it would correct VE imperfections on higher gears...

[gunni]

Wideband just isn´t fast enough for EGO corrections that´s why you don´t use it
at high load and high rpm´s.

[mr_g]

Wideband just isn´t fast enough for EGO corrections that´s why you don´t use it
at high load and high rpm´s.

OK for first and second, or third maybe, but in forth and fifth and sixth gear it's fast enough I think... Also the AFR must be more precise in high gears, like fifth and sixth, because, these gears blows engines...

[rob@vems.co.uk]

So you're saying that 5000rpm in 2nd gear is faster or slower than 5000rpm in 5th or 6th?