I started tuning Johnwag's car today (9:1, Gibb header, ARTech intake, 949 clutch). Unfortunately the dyno went on the lam and stopped reading output properly so we had to cut it short. I bumped spark up until it "sounded" like it wasn't increasing power based upon "that sound" of spark advance and the time it took to spin the brake. We used the Polish Det-Cans and never heard detonation.

AFR is 13.1-12.6 @4000rpm+.

The spark "block" around idle is to help the 11lb flywheel situation...which is a pretty awesome situation. We're going to take the car back when the dyno is fixed to get a number.

edit: I cleaned up some amateur ****.

 

I think that advance at WOT is perfect for a low compression motor like that.
Its not overly aggressive, but its not a ***** map like a lot of people run.

 

This is 2* back for headroom, not sure if I hit MBT or not due to the dyno acting up. We'll pull another 3* out for 91-octane in Oklahoma.

 

I'd be surprised if he would need more than 30° with that base compression.

 

That's what I'm looking for. I would have realized MBT if the dyno didn't break. Oh well, free tuning.

 

Is this a 1.6 or 1.8?

 

1.8

 

We usually see no more than 30° from ~70kPa and up on a 1.8. Here's a GA93 pump table from a typical healthy but stock NA8 with standard breathing mods.

 

Thanks, I'll reduce a few of those. Do you agree with 3* spark to drop down to 91-octane Oklahoma fuel?

I'm somewhat impressed with myself for getting it so close to where the professionals put it.

 

Making hard and fast rules like that makes me uncomfortable. That's probably going to be too much timing for 91, but I'd rather not make a specific recommendation on how much timing needs to be pulled so much as I'd rather recommend tuning with the fuel that will be used.

 

Thanks. We use 93 here in Texas 90% of the time but make it up to OK twice per year and can either get 91 or 101.

 

Damnit, I'm glad Damon pointed me to this thread. I didn't run this much spark angle on my 1.6 when I was tuning it, but did find a good bump in output going from ~28 to around 30* in power, this on 93 octane. If you ran this much advance w/o hearing det on the cans, I may add in more angle.

Trey, do you mind sharing target AFR tables that you were using? Good stuff, thanks again for sharing.

 

You can lose power by over advancing but still not get into det. If you're going to add timing, do it on a dyno where you can monitor torque output.

 

This ^^, the last time I dyno'd my NA I pulled a few degrees of timing and gained a bit of power.
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My current sparktable. For now at least, waiting for megasquirt to come home again after MS2 upgrade.

N/a BP with exhintake swap and adjustable camgears. Tuned on dyno yada yada

 

Oscar, did the bump in timing at wot at the upper/mid range help boost up the sag in the torque curve that our motors have?

Anyone have an n/a afr target table they wanna share?

 

I acutally held it hostage until you pay the shipping costs back to you.

 

Oh my bad brainy, I'll send it out tonight xoxo.


Yeah, although I did not notice that much of a dip at all after tweaking the cams.

Have a look at this.

 

Damnit, here I was starting to tune in the 12.8 range, then 13.2 and made more power. Now I see Oscar's targets all above stoic except all the way up top, wtf?

Oscar, what compression ratio are you running, and what are you fueling with? I'd bet I could make bigger power by continuing to lean it out a bit and giving it more advance.

 

Thanks for the info, btw, everyone.