Smart injection

[Kapt. Q]

Hi Richard,

SC is 1 o'clock, Gain 12 o'clock.

I get quite a surge when injection turns on, if i turn SC down so I can see the surge then it is 6-8 bars+ then it dies down to 3-4 bars, is this correct? (I usually set SC so normal flow is 6 bars (1o'clock)). I have checked the nozzles and the spray pattern is ok and it continues to drink heavily. I am worried that the tank was contaminated (I rinsed it with windshield washer concerntrate, shaking it vigoursly, then Meth/water, then water before installation), perhaps I have damaged the pump?

It is difficult with no experience to know, lol.

Will the surging cause the failsafe to activate? Do I perhaps have a partial blockage? I swapped the pre turbo injector to check, but no difference. Perhaps I should do the same for the post IC nozzle to check it?
The 'O' ring I lost (idiot) in the check valve injector must mean that the intake vacum is drying the lines between the injectors, will this cause a startup surge untill replaced?

I have not adjusted pump pressure yet (can't see the allen bolt but haven't looked hard yet), perhaps this would reduce the surge?

The car is running really well! Did over 100 miles to a VW show and it loved it!

Thanks for your help, hope to get an appointment with the tuner tomorrow for this week, fingers crossed.

Cheers!

Lucian

[Kapt. Q]

Ps. Perhaps I should link MAP and FIDC before the remapping?

[Richard L]

Observation 1: .......... SC setting
It appears from the SC setting the flow is matching the flow sensor's turbine speed pretty well. Do not alter the SC. It will not cure the surge.

Observation 2:........ Surge:
This can be caused by the empty line post FAV. As you have installed the FAV at a higher level than the water jet (not that you have much choice). The water inside the line will naturally empty itself during non-injection period. At the first instant of system trigger, air is purge off the line at greater speed than water alone, so the flow sensor will over read.

Question: have you been running the CV jet without an o-ring?

Two possible solutions:
1. Lower the FAV below the water jet.
2. Use checkvalve for the second jet.

Observation 3: .......... surge will trigger the upper limited of the failsafe window
Two solutions if it is triggering persistently:
3. Increase a couple of clicks for the upper window (WH)
4. Increase the failsafe trigger delay on the controller (FL-DL trimmer) - to 2pm (default =12 o'clock)

Observation 4: ........ decreasing the pump pressure to stop the surge:
5, It will have minimal effect to surge.

[Richard L]

Originally Posted by Kapt. Q

Ps. Perhaps I should link MAP and FIDC before the remapping?

I would not use it just yet. At present. the flow is mirroring the true engine load. Based on the assumption of more fuel = more power = more heat.

Putting in the MAP sensor signal will make tuning more complicated as boost ramps and peaks differently in different gears.

[Kapt. Q]

Hi Richard,

Yes I have been running the CV jet without the internal 'o' ring since losing it yesterday, silly but I am addicted and have a larger Brabus 101 turbo to install next week and a spare identical turbo.
Any drips would have to go around an immediate sharp 90 degree bend and might hit wall of pipe then before travelling through at least 40cm more tube prior to turbo, was hoping this might minimise damage to turbo anyway.
I can lower the FAV but it will still be higher than the lowest jet, even if in the engine bay because the bottom of the intercooler where the jet is is at driveshaft level.

The extra check valve seems sensible.

I was running failsafe today, hence the issue was highlighted, I raised WH to stop having to clear CEL already (X-gauge allows me to do this while moving).

I'll raise the FS timing delay as suggested and retest tomorrow.

Cheers!

[Richard L]

Without the o-ring, the jet will dribble and empty any fluid between the two jets. Once the o-ring is reinstated, the surge should go away. We'll send the bits out tomorrow.

[Kapt. Q]

I only raised SC setting to be able to visualise degree of surge, before returning it to normal position (1 o'clock and 6 bars).

[Richard L]

The SC should only be adjusted once for the duration of a particular set up. WL and WH can be trimmed daily if necessary.

[Kapt. Q]

Thank you Richard!

I think that I had surge before, but perhaps not to the same degree, there is a lot to get your head around all at once but I think I'm getting there. I'll pop the relays in the post tomorrow.

Cheers!

[Kapt. Q]

Hi Richard,
interesting development, I did have a slight blockage of the post IC jet, cleaning it solved a bit of the surge and now it is a solid six bars at max FIDC with no wavering after initial surge (after reducing SC 1 click). I learnt how the nozzle is put together (never took the last few bits apart before), the machining of the components is something to behold.

What is the best thing to clean with? I used very strong acetone (expanding foam gun cleaner).

I am now feeling confident about the remap and injection, because I feel I know what is going on better. There is a lot of info being provided if you have the experience/knowledge to read it.

I have given up telling my fellow Smart enthusiasts about the benefits because they will not believe me! Some think you can get similar effects with an intercooler spray! Perhaps if I tow a tanker trailer? lol.

Cheers!