My Megasquirt 3 M50 setup

[dave.a.cote]

Good note about the peak torque area. I haven't thought of that. If I can remember correctly, I have timing set to about 6 degrees at 95 kpa.

I am at 11:1 CR, BKR7E plugs, 94 octane, and this morning it was about 4 degrees (39F) and misty out and it would still knock if I got into it. What's going to happen in the summer?

I am running dual intake cams on the non-vanos engine. Maybe I could "fake" more aggressive cams by timing them to have a little more overlap.

I bought the LC1 used and the po cut the computer cable so I don't think I can use logworks. The sensor was new and calibrated when installed. I could push the AFR down to 10:1 and see what happens.

[nando]

yeah it just doesn't sound like it should ping under those conditions. maybe the actual CR is even higher than you calculated?

[dave.a.cote]

I did a compression test and it was 206+/- 4 psi across the board when warm.

[dave.a.cote]

Maybe I am hearing wrong. I am going to check that the timing is stable up to 5k with a timing light tonight.

[matt]

That's high.

Your combustion chamber design may encourage knock. (IE the timing may not be the culprit) More fuel...

[dave.a.cote]

Matt - when I was poking around trying to get my IAC working, I noticed I have a 3.0 bar FPR instead of a 3.5 bar. I was thinking I might just replace it with your adjustable one. Do you know of a fuel pressure gauge that works well to complete the upgrade?

[matt]

Frankly, I wouldn't do that in a million years.

You have a megasquirt to control your fueling, you don't need an adjustable fuel pressure regulator to complicate things also. Swap that to a 3.5bar and tune with the computer.

[nando]

agreed, I have one but I only use it for the gauge, it's set to stock pressure.

still waiting for that timing map :)

[dave.a.cote]

Thanks for the honesty - I will buy something from you eventually, you can't stop me :)

I posted my msq file here:

http://www.msextra.com/forums/viewtopic.php?f=131&t=37978

[nando]

yeah, you definitely shouldn't be pinging with that little advance.

Just curious, if you're not boosted why do you have a 400kpa load axis?

how about colder plugs? are you using stock plugs? try one or two heat ranges colder?

[dave.a.cote]

400kpa was the stock axis and I didn't feel like adding a bunch of numbers - at least until I got a feel for how it wants to run.

I am running BKR7E plugs which is one stage colder than stock. I think I will try and push fuel load up to 10.5:1 AFR in the 4 to 5k rpm range and see if that helps. Winter is here now and I won't be able to really push it for fear of wrapping myself around a tree so more WOT tuning might wait until spring :(

[dave.a.cote]

I have been tuning with the VE Analyze Live feature and I am getting VE's in the 110 range where I am talking about also which seems excessive as well doesn't it?

[nando]

no

the VE #s don't neccesarily reflect true VE. You have to get your injector opening time perfect (most people don't even know what or how to tune that) and your req_fuel would have to be 100% accurate too.

as long as you aren't maxing out the VE table (MS1/2 was 255, I don't know what MS3 is - 511?), you're fine.

[dave.a.cote]

I know there are other transient effects going on there. With full sequential setup, I can tune opening time but honestly I don't know how to do that properly and it was my understanding that it would only really change idle conditions only.

[nando]

it affects the entire VE table and acceleration enrichment, but the effect is multiplied at low loads/RPM where the base PW is low.

basically you need either the specifications from the manufacturer or a scope to find the opening time at the base voltage (13.2v in MS3). It's not something you can really tune by hand.