NB8A timing advance and fuel choice

[siege]

Hey so I haven't been able to find the specific answers with search so am asking if anyone has experience with this.

What I'd like to do is buy the adjustable timing wheel that flyinmiata or 5x racing sells and advance base ignition timing to 14 degrees. I know it won't make my car as fast as a turbo. It'll be fun to do though.

The car is an NB8A and by the time I do this will have I/H/E. OEM ecu.

I would like to run it on 94RON E10 for the sake of cost of I can get away with it. Has anyone else done this timing bump with a higher compression ratio motor than the NA8 and what fuel do you use?

On other forums people speculate that you might need premium fuel, referring to 93AKI American stuff which would be 98RON here. But we also have 94RON and 95RON options, with the E10 being cheap and plentiful.

[GR124]

I'd like to hear what people have to say about this as well.

[NitroDann]

How to do it, step by step.


1- Google search "Engine pinging sound youtube".

2- Watch and learn what it sounds like

3- Drive your modded car up an incline using low/medium revs and press the pedal deeper and deeper until you hear pinging.

4- Use a better fuel and repeat.



There's no other good way to be sure.

Dann

[Magpie]

If you can afford to do those mods then running 98 should not be an issue.

If cost is an issue leave it stock and use the recommended OEM fuel.

Feel free to use NitroDann's advice, however be warned that if you miss the 'pinging' or leave it 'ping' for too long the cost of fuel will be nothing to the cost of a melted piston...

[NitroDann]

Bit of a ping here and there while youre testing it on a stock 100HP engine wont hurt it.

If it were turbo or supercharged on the other hand..

Dann

[hks_kansei]

Also, running ethanol fuels isn't just about timing, it's also to do with the different amount of fuel required for a good tune (not that E10 would be that different, e85 would be a different story)

You'll also want to look into making sure the mx5 fuel system can cope with ethanol, since it's more aggressive than petrol at eating at seals and stuff.

No point saving a few cents per litre if you're rotting out the seals in the fuel pump or injectors.

[93_Clubman]

You'll also want to look into making sure the mx5 fuel system can cope with ethanol [E10], since it's more aggressive than petrol at eating at seals and stuff.

^+1:

Minimum RON 91. E10 is not approved for pre-NC standard MX-5s

viewtopic.php?f=18&t=74947&p=913469&hilit=e10#p913469

[StanTheMan]

dosnt the NB8A come with a knock sensor?

if it does knock...should this not retard the timing automatically?

[NitroDann]

Yeah but that's not the point.

My Camry drops from 20+ to 4 degrees advance when it detects knock. When it turns the timing back up its like a 25 shot of nitrous. You don't want to let it just pull back to limp mode the entire time you're driving in a performance car.

[hks_kansei]

A knock sensor only works once it's already knocked.

Kind of like waiting until you bump your head, then putting a helmet on after.

[siege]

Yeah I'm comfortable with the E10 and rubber corrosion fears. E10 to E25 is a mandatory minimum in many countries with mx5s and I've only read about people's fears rather than experiences with ethanol.

I guess I'll go with your advice Dann and hopefully have a keen enough ear to detect anything going wrong.

At 15,000km a year I estimate the difference in cost per year of using 95 compared to E10 as $250, compared to 98 would be $350 per year. So yeah it's not sheep stations but everyone says mx5 owners like going fast for cheap!

[NitroDann]

The fuel system is ethanol safe, but use an air gun to blow your fuel filter backwards a few times when you start usinf ethanol to clear it out of all the varnish and stuff the ethanol will strip from your 25 year old dirty fuel system.

You can pull the plugs out and visually inspect for pinging if you cut the motor immediately while loading it under lower rpm full throttle conditions, perhaps using a gentle slope.

If it were turbo or if you were uncomfortsble with this please dont do it. But if youre handy its incredibly unlikely you will hurt anything with intake exhaust 14* and e10, and this is the process i would use.

Dann

[Demes]

You don't have to buy the timing wheel all you need to do is get a small round file and take a small amount out of the existing plate. I lined one of the notches up with the timing marks and kept filing until I had moved the plate the 6 degrees I found it did make a huge difference in low down throttle response. I have a little spot up a back road where I have been doing my acceleration tests and would you believe I have picked up around 8kmph to a given spot. I am also running 98 ultimate and it sure does improve the performance. Nitro Dann modifying some 2002 headers for me so hope to make a slight gain with those as well. I have only filed on the advance side so to put it back to standard just loosen four bolts on pulley and retard wheel back to where it was and tighten bolts easy.

Dale Sheppard
Blue 99 NB8A

[siege]

That's a great diy way of doing it. And I like that you can't accidentally retard the timing when you're repeatedly twisting it to get it just right

[Mr Morlock]

Siege- "Yeah I'm comfortable with the E10 and rubber corrosion fears. E10 to E25 is a mandatory minimum in many countries " Oh really that contradicts advice which is easy to look up including Mazdas recommendations.a Many believe ethanol is about business not about what's good for cars or the environment. I never use it. Rubber is made with specific formulations i.e. line call out for properties and testing and the rubber in an older MX-5 for say fuel lines is not going to be the same as late model cars. If the spec is wrong then ethanol could easily attack fuel lines.

Pinging- the 1-4 that was the standard practice for the old clunkers of the 50/s / 60s and 70's and finally vehicles got computers and stayed in tune.