That's a tuning fail right there. No engine can sustain detonation for any lengthy period of time.

light det for brief periods you may get over a long period of time, but heavy or sustained det will kill the engine pronto.

Next time invest in some detcans and tune properly rather than assuming it'll all be fine...

Ok I agree.

So how could I stop deto? I can't see the difference with a jackson racing kit and my setup...

Tuning, reduce timing & add fuel as appropriate, whether that's appropriate or not is whether you can hear det or not :)

Ok I will do it with focus next time

After a little bit of cleaning...

https://www.miataturbo.net/attachmen...ine=1328520400

https://www.miataturbo.net/attachmen...ine=1328520400

Deto should make melted zone right? There is none.

No, it starts with small dimples with rough centers the size of the head of a pin and get larger and can lead to entire rough areas on the surface of the piston. That is unless the rings break quickly and the detonation isn't continued for a prolonged time.

If you haven't thrown them away, check the insulators on the spark plugs. Detonation will leave telltale little balls of aluminum stuck to the porcelain. The larger the balls, the heavier the detonation, and more balls means higher quantity.

And I think your ring groove issues are cylinder wall wash down (overly rich condition washing all the oil off the cylinder walls and causing premature wear) causing excessive friction between the top ring and the ring groove. Usually you get really severe skirt damage as well with wash down, but detonation simply wouldn't cause that kind of ring groove damage without absolutely trashing the piston crowns and breaking the top ring land off in places...

Ok thanks for your preciseness.

(new word learned: dimples lol )

I will check insulators. thx

Yeah!! second new world learned : telltale

Parts arrived:

-full gasket kit
-ACL bearings
-ACT clutch XTMM
-timing kit
-NGK spark wires
-NGK BKR7E-11
-OEM pistons + rings

https://www.miataturbo.net/attachmen...ine=1330525651

I'm still waiting for connecting rods... Why are USA so far :(

Some painting:

https://www.miataturbo.net/attachmen...ine=1330525651

https://www.miataturbo.net/attachmen...ine=1330525651

did you paint the aluminum oil pan aluminum colored?

Yes, old paint has suffered from salted roads.

I put a light paint fog or film (don't know the best word for paint vocabulary) to keep good dissipatign properties.

It wasn't painted. Should have just bead blasted it.

hum, mine was painted before... Maybe from the previous owner.

I will clean that up. Thanks Falcon.

Likely from a PO. Three pans I've had were all 'polished' alum. 'Polished' meaning a shitty job but it was still raw alum.

Hello everyone,

I need some analysis on my AFR table.

New engine is running well with the G supercharger (muuuuch better than this autoumn, now I think pistons rings were broken before I put the supercharger on it)

I wanted to make a preservative table, am I on the right way or not?

Yellow dots are the active cases in an WOT accel from 1000rpm to 5000rpm

92kpa = 0 boost
127kpa = 5 psi
162kpa = 10 psi

Thanks for your help

https://www.miataturbo.net/attachmen...ine=1339090902

Yeah haha. I haven't seen a G60 that didn't need a rebuild unless it was just done.

https://www.miataturbo.net/attachmen...1&d=1338690675

Credit to Hustler for that one

The targets look sane if that's what you are asking, but I'm not necessarily the most experienced person in the room with this kind of stuff. Is this thing intercooled yet? I seem to remember you had some insanely high IATs, that'll certainly lead to detonation.

Edit: Yeah, its intercooled. My reading fail. What does your spark table look like?

? I don't get why you post this, but I'm starting from 92kpa (engine off) not 100kpa, so 92+35=127 for 5psi of boost

That's what I am asking, you're right. In fact, I wonder if I must add a AFR target like 12.2 somewhere between 12.5 and 11.8? (maybe it will not make a driving or a power difference)
For info, yesterday my IAT was 80°F

Spark table is really conservative under boost, I will post it tomorrow.

Thank you

That does not sound right... you should be sitting @ 100kpa with the engine off unless there is something here that I don't understand. How many thousands of feet/meters above see level are you?

I posted my AFR and timing table in the thread of complaints that I try to pass off as a build thread. I've fiddled with the timing a bit, and my MS2 based DIYPNP has more resolution than your MS1 based MSPNP, but my timing seems to be close enough to safe with my 9.5:1 1.8 engine that nothing has exploded yet. You could rescale it and use it for reference. Don't just blindly use my (or any) map, that would be A Bad Thing™

Make triple sure your base timing is set/configured correctly. I had mine 3° off when I first started screwing with things. Just for fun, I changed it to be 10° off and the car still started and ran, but the additional 10° would probably have melted something if I had driven it under load.

Do you suggest me to rescale the AFR table to 100kpa 135 170 200 like before ?

I'm located at 550meters or 1804 feet above sea level.

Here's the spark table, it's the original table gave by megasquirt, I didn't touch it yet. I prefer to finish the VE table first.

https://www.miataturbo.net/attachmen...ine=1339139769

Nice, I will keep in mind your timing table and I will adapt it to my boost curve later.

Today it's rainning and the car is tricky on the road with the new big torque^^

I found this comment on msextra forum:

"i understand in a supercharger the elevetion has effect on the boost out put because it doesnt have a boost regulator (like a wastegate) a supercharger will give an engine less boost into an engine because now its trying to push thinner air.. but boost is boost it shouldnt remove fuel or have baro correction while on boost.."

I not sure to understand but I don't need to set 92kpa in my target table because MS is already correcting the barometric difference? So I put back 100kpa?

A superchager will pump a (roughly) fixed volume of air for every revolution. Its output is linked to the crank speed, so if the air is thinner it pumps less of it. A turbo, not being married to crank speed, will pump more air at higher elevations.

You dont need set your cell to local baro pressure IMHO. MS uses interpolation for lookup in the ve and spark table. This means that even if the read value is in between your cells it will calculate a value in between them.

^Yes what he said. If your engine is working halfway between two cells the computer will use halfway between the two values in the boxes. This makes it smooth. There is no reason to change the kpa numbers.

The spark table is good and safe which is what you want right now since the last engine blew up. It could make a little more power with more spark but it is more important to be safe right now. It is good not to need to be worried about it and just enjoy driving the car.

Ok thanks for your comment. It was what I needed to know.

Do you have some chrono on 0-60mph of your supercharged miatas?

1.6 Stock N/A is around 9.7 second from what I know.

I also notice my duty cycle is kind of high, at 5000rpm, I got 70%

Fuel pressure is only 30psi, I will raise it to 36psi and go further in rpm.

Does your fuel pressure rise with boost? It should.

oh yes of course. I wanted to say, my FPR is set at 30psi.

Mais bien sur, lol.

I have no idea of the power and no idea how long my setup will last but, for the first track test, I had so much fun and no trouble with the car.

http://www.youtube.com/watch?v=YCmKK...ature=youtu.be

Update:

+
500miles done, 2 track days, no trouble.

-
injectors are out of flow approaching 6000rpm.


So New injectors + high flow fuel pump are comming


https://www.miataturbo.net/attachmen...ine=1348502264

Congrats man! How are the IAT's looking now?

For injectors, check out the Bosch EV14 units. They require adapters but they are pretty much superior to everything else on the market with regards to flow and deadtime. They are a bit pricey though. FIC (Fuel Injector Clinic) and ID (Injector Dynamics) are known good suppliers for the bigger EV14s. I would avoid FiveOhMotorsports though, their quality control seems to be a bit hit or miss as of late.

Good used RX8 yellow or blue Denso style injectors can also be good budget choice. They are direct drop-in IIRC, but be aware that there are really cheap chinese knockoffs out there now, especially on eBay.

Thanks!

My IAT's are around 85 F° on road and I never saw more than 120F° on a track day with 90F° outside temp

About injectors I have already ordered DW 800cc as I would like to avoid the use of adapters.

You have Bosch EV14 or RX8's on your car?


I plan to go E85. I guess 800cc will be enough, right?

Something about your map reading the wrong pressure with the engine off.. essentially this makes no difference as far as your tunning is based on that error. Just make sure you look at the numbers when you take psi into account. For example Map sees -1 psi when its atmo. You hook up your sc to push 10 psi but the map sensor should only show you 9 psi because of that calibration error.

As far as air temp goes, super chargers are fixed to the crank so any cooler intake charge will allow more air to be pushed into the engine because cooler air is more dense. Same thing as higher in altitude. Higher altitude, less pressure, less dense air.

For SC cold air intake makes a bigger difference, for turbo.. not so much. How many psi do you want to run on the 800cc injectors?

At 1800 feet you should be at 95kpa absolute air pressure.

You are right, I notice that air temp and altitude have a huge effect on the supercharger.

Exemple: on a warm summer track day, i have got 10psi at 5000rpm and last saturday night it was 10psi at 3700rpm (MAT was 77F°)

So, I planned to find or make a cold air intake stuff.

I'm a at 92-93kpa engine of.


PS: between 10-12 psi, it will depend how many the G-charger could supply