I just talked to the guy at Eurotek who told me he, nor anyone else on the planet, can reprogram my old denso ECU to remove timing, and that both his ecu tunes stage 1 and 2 add timing.

Holy smokes is that guy full of

Does anyone know any place that can actually do programming?... or all they all like Eurotek and claim to be tuners when they really only duplicate a tune they have stored?



So at this point I think I would be quite a bit safer to NOT have it tuned because I sure as h-e-double toothpicks do NOT want to add timing to a car that is already running 5 psi over stock, and I'm going to add Nitrous on top of that which also adds timing.

Maybe I'll use the money that would have gone toward the tune and use it on Torco Accelerator constant use instead, since that gives +7 octane when mixed 32 oz/20 gallons of fuel, and up the % of meth a little on the street, and run race fuel 104 octane unleaded if I ever I want to unleash the big dogs on the track with +150 to 175 hp jets of Nitrous.

On the street I can just run my 98 (91+7) octane fuel and water/meth injection with a 50 or 75 shot of Nitrous.

Since I work from home, I don't drive many miles so using octane booster vs money spent on a tune would last me well over a years worth of octane booster.

 

Please forgive my questions; When you say 'add' timing and 'remove' timing are you referring to advance and retard timing of the ignition sparks? And are you referring to your desire to start the fuel burn across the cylinders earlier and or later (further away from, or closer to, top dead centre) depending on engine revs and throttle position (Wide open Throttle' for example?) or have I misunderstood? Thanks Allan

Ok, just did some online research and I think I have answered my own question.....is it that because of the mods you have done to your engine, the combustion pressures earleier than you want and are greater, happening earleier than you want on the compression stroke....and you want to move the 'burn' nearer Top Dead Centre to 1) improve power/efficiency of the burn, 2) reduce cylinder pressures on the compression stroke (spread it out as it has positive crank rotation effect on the down stroke) and 3) to maximise the effect of the combustion on the piston 'down stroke' whilst reducing wear on the piston and crank bearings? Thank Allan

 

Yes, you have it correctly that I wish to retard/delay the spark timing a little bit.

Fortunately, the stock/original ECU program is very conservative, so I can adapt to using large doses of nitrous by having 1 or 2 steps colder spark plugs and running higher octane fuel.

The concentration of methanol of the water/meth injection is one way to do this, and I can add 7 octane with the torco octane booster, and/or I can run race gas on selected occasions.

Generally speaking, each additional lb of boost requires a minimum of 1.5 octane, so if the ECU map of timing was already maxed out (which it is not) and then I added the 5 psi of boost that I have, just by adding the octane booster, I should be ok, even without the water/meth injection. When I add nitrous to this, I would need even more octane.

Nitrous requires a 1 to 1.5 degree in timing retard/reduction per 50 HP gained, same as .5-1.125 octane.

Here are a few other things that add/reduce the need of octane, or can be seen as octane equivalencies:

1 AF ratio = 2 octane
1 degree of advance = .5-.75 octane
10 degrees of engine coolant in the 160-180 degree F range = 1 octane
20 degrees F ambient = 1 octane
1000 feet of altitude = -1 octane
30% humidity = 1 octane

So for my situation, I have a 180 thermostat vs 195, and since I can manually turn on a fan to keep the car at idle at about 185, if the above is true, that is worth 1 octane.

And, even if I was using only water for the water injection, which would make the air at least 30% humidity, that is 1 more.

So if the timing of the ecu was already maxed with 91 octane (which it is not) and I add 7 from octane booster, 1 from a reduction of engine coolant temp, and 1 more from the water injection, I am at 91+9 = 100. At 100 + whatever since I am using at least 25% meth, I feel safe running a 50 or 75 shot of Nitrous anytime I want.

 

Good info lads. I'm starting on my xjr journey and will no doubt be looking for timing solutions in the future.

 

An easy way to control timing safely is a msd dis (for distributorless) ignition box with a boost retard. It allows retard for a given rpm range. Works like a charm.

 

I can use this with individual coils?
Can you provide a link to a product that will work on my car?

 

the short answer is no! The ECU in our Jaguars does not have a PROM chip( programmable read only memory ) which is how you could alter the stock ECU.
To get that feature you’d need to buy an aftermarket ECU such as Megasquirt, MAXXECU. Or Emerald
​​​​​​ if you don’t want to bother wiring one in and learning how to program things. You can buy a plug and play set up for about $5500.00

 

Good on you. I think I saw Water Dragon back on the forum after years away, but the car has been gone for nearly ten years.