help with tuning

[vaughany]

I have currently had a single turbo conversion to my Supra Twin Turbo. Now i had System 1 kit when the car was running sequential twins so i decided to leave the kit on.

everything has been changed on the car, bigger injectors (650cc) large FMIC so my fuelling and inlet temps are fine. Unfortunately when the car was mapped they mapped it without the W.I. The car was dynoed at 470bhp at the wheels at 1.4bar

All i have done now is put set the water injection to come on it about 1.35bar just as a extra safety measure. Now I know the W.I is an excellent bit of kit but I am not sure how to really get the best out of it.

My intention was to increase the boost to say 1.5 bar and use the W.I so I dont run lean aswell as keep my temps down. Obviously I do not know a great deal about tuning and sort of get lost with the advance timing or reduce timing.

Can someone please explain this "advance/reduce timing thing" to me - Does anyone see any problems with my idea above of increasing boost and use the W.I. to compensate for fuelling and temps

Also i think i am running 6mm injector, I am fairly sure I need to increase the injector as I am running 6 x 650cc fuel injectors so i think i an not injecting enough water.

Here are some pictures of my install W.I is on the rhs as you look at the engine bay towards the back


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many thanks

Vaughany

[JohnA]

Originally Posted by vaughany

Can someone please explain this "advance/reduce timing thing" to me - Does anyone see any problems with my idea above of increasing boost and use the W.I. to compensate for fuelling and temps...

I can be done (I've done it in the past) but it is not for the faint-hearted.
You'd be well-advised to use an indicator for a blockage in the system (available to buy) and ideally you'd need an ECU that can shift to 'safe' maps once blockage is detected.
Otherwise you'd be risking meltdown if something goes wrong with the WI.
Which does happen occasionally.

...or you could play it safe and get fuelling & ignition right for your new boost levels, and then use WI as an extra safety margin, especially since you're running higher than stock boost without having reduced the compression ratio (1.5bar is almost double stock boost isn't it)
In this case the advantage would be that you won't need to be running pig rich over 1bar, as most supras do. A 12:1 will be perfectly adequate, so you'll be making more power, without the need to waste fuel for cooling purposes (quite a desperate practice frankly...)

[vaughany]

Cheers John, thanks for the info, maybe I need to keep the boost the samr as this has the car has been mapped for 1.4bar and do as you suggested.

Trim my fuelling back a bit to create a bit more power, my AFR is at 11.5 at full boost so i could go a bit leaner and use the W.I to keep everything running sweet.

[JohnA]

Using W.I. I had managed to run my old Calibra down to almost 14:1 under high boost.
That is regarded as extremely lean by the standards of normal tuning, but it wasn't in that case. Max power with W.I. was at 13.5:1, instead of the 'usual' 12.5:1, so yes, you CAN lean it a bit while W.I. is operating.

The trouble is to make sure you have an 'exit' strategy in case the W.I. system fails.
Calling the AA is not a good one :lol:

[vaughany]

cheers mate, need to think about how i can monitor the W.I - ERL do a display kit ont they that monitors what pressure it sprays at lets you know that it is spraying (no blocked jets, pump failure)

Vaughany

[unior]

does that car use a knock sensor? you need to pretty much tune for knock man

[JohnA]

Originally Posted by vaughany

cheers mate, need to think about how i can monitor the W.I - ERL do a display kit ont they that monitors what pressure it sprays at lets you know that it is spraying (no blocked jets, pump failure)

that little gizmo measures FLOW, not pressure.
I think that the output is 0-5V, just like most sensors, so you could use one of several commercial gauges for cabin display.

I don't think that linking it to Knock events would do much good. For one if it starts knocking it's a bit late. Then how would a blocked nozzle help with knocking anyway?
It's best to have the ECU automatically using a 'safe' map once the W.I. flow drops below a certain level (when activated ofcourse!)

You can push the detonation boundaries really far with water/methanol injection, I managed peaks of 30psi on my Calibra, with most mechanical parts standard, and on super unleaded. Most people would see sudden detonation at levels over 22psi --- and I backed off mainly because I lost my nerve, not because I had signs of det.