Tuning 8v SPI ECU Remap

[crazySnublz]

Right after much consideration and thought between remap, bike TB's and Megasquirt, I have come to the conclusion of remapping the standard SPI ECU.

I was sceptical as to whether anyone would actually be able to do this as several posts indicate that these ECU's are unable to be remapped, but after several phone calls and messages to different places, I have come across one place in my local area that say they are able to do it. The better news is that they reckon they could give the old girl anything up to 15BHP more for a reasonable price.

They took a little while to get back to me with a confirmation but they said they had to look it up.

What do you guys think, is it worth it?
(No stupid replies, I'm all for a bit of banter but I'm not in the mood for it this week)

 

[woj]

IAW 16F ECU not remappable?

Yes, it is re-mappable, but +15hp on a standard 1.1 engine is not going to happen I am afraid, more like +5. Unless you have mechanical mods that would allow this...

 

[smart51]

On a non-turbo engine, a remap can only do two things, advance the spark and enrich the fuel.

Advancing the spark gives a few percent more power and it is good power. No more fuel consumed. No increase in emissions. It can lead to knocking, however, meaning you need high octane fuel. Unfortunately, if your engine has a knock sensor, this gain has probably already been made.

Making the fuel mixture a richer can also give a few percent more power. It increases fuel consumption, makes dirtier emissions and can cook your cat. Some cars run rich at wide open throttle and run stoichiometric at part throtte, which is a fair compromise.

So you can have a bit more power from an off the shelf remap, but 28% more isn't going to happen. The best remap results are done on a rolling road after you've done a set of engine mods. Letting the engine flow more can make the fuel mixture a bit lean. The ECU will try to compensate for this with the lambda sensor and fuelling trim but it can be too a blunt tool for the job. A remap sorts out the lean spots without affecting the areas where the fuelling is OK.

 

[jatkinson]

as Woj pointed out , it is able to me mapped ,

But 15 bhp and a Engine that has 54 nhp i dont think so but i will keep a eye on this thead were abouts are you looking at getting it mapped is it going to be a "live map" or a "generic" map ?

 

[crazySnublz]

Cheers for the reply lads.
I do have a build thread on here, but here's the basics of the mods:
• 1242 bottom end (fully rebuilt)
• 4-2-1 mani
• 50mm stainless exhaust (I think, will check later when she's on the lift to swap tyres over)
• 40mm TB
• C&B fast road cam
• Lightened flywheel
• Pipercross panel filter
• Bosch equivalent of iridium plugs
• Running on Tesco momentum 99 fuel (not a mod but a bit of info)
Probably other things but I'm drawing a blank at the moment.
I'm hoping to give her a dyno run to get some base figures next week, if I can get the paperwork sorted for college.
woj, I'm not expecting the claimed +15BHP, would be nice but I would be happy with a max of +10BHP.
smart51, Nice bit of info, more physics and theory side as I'm aware of the basics. But correct me if I'm wrong, I was told that ideally you'd want a leaner mixture on open throttle to get a more violent burn, where a richer mixture would make a cooler burn? But I agree with stoichiometric is at cruising/part throttle. Not arguing just relaying what I was told in college last week.
jatkinson, It's a company in the arse end of nowhere in Milford Haven, South West ish Wales. As far as I'm aware it's a "live"(custom) map, if it's not I wouldn't trust it so I wouldn't want it.

 

[smart51]

@smart51, correct me if I'm wrong, I was told that ideally you'd want a leaner mixture on open throttle to get a more violent burn, where a richer mixture would make a cooler burn?

Lean burn gives best efficiency as every last drop of fuel can be burned. You're right, it does make your engine run hot, which it's why it is usually avoided. But burning less fuel releases less power. Putting more in gets more out, even beyond stoiciometric. Running slightly rich gives the most power, but only if you run slightly rich.

When fuel burns, the hydrogen burns off first. It doesn't give off much heat. Then the carbon burns to carbon monoxide. But most energy is released when the carbon monoxide burns to carbon dioxide. If you put too much fuel, all the oxyegen is used before the CO to CO2 burn is complete, reducing power output.

Have a look here: http://www.autospeed.com/cms/article.html?&title=Tuning-AirFuel-Ratios&A=1595

 

[crazySnublz]

smart51 cheers for that, I'll have a read through the link tomorrow, some useful info is bound to be in there that I can put into practice in work and college
The phrase, You learn something new everyday comes to mind.

 

[woj]

Not to kill a nice theoretical discussion but on a more practical side AFR 12.5 is considered to give optimal power, richer AFRs are used on turbo cars to keep burning cooler to avoid knock and overheating. If you look at the vid below that I also posted earlier in my thread, you will see how the torque (number just above the car figure) drops with riching up the fuel from 12 to 11. (In this particular case it was also the intercooler not keeping up at constant full boost, but you get the picture).

I think with your setup you can get a nice result. Look at what @LeonL got out of his without even remapping the ECU.

[ame="https://youtu.be/R3yLHfEe4mA"]https://youtu.be/R3yLHfEe4mA[/ame]