Timing Question

[Edub1]

I'm trying to decide the best way to tune for a super 60 running at 15lbs.

I know how to tune my eprom but I still don't trust it 100% where timing is concerned and I'm a little concerned about supe expensive dyno time. Anyone here running 15lbs on a self tuned eprom?

Anyway, I have made a tune that begins retard at 2400RPMs and assumes full boost at 2800. From this point, I'm pulling .75 deg/lb. But, like I said, I don't trust it 100%

My other option is a BTM which is starting to look real good. The new ones even let you choose when to begin pulling timing - like after 4lbs or so.

I also like the idea of being able to change timing depending on fuel situations. I live near an airport where I'm sure I can buy aviation fuel but need to be able to run pump gas as well (93). I could even set up the ECU so that the BTM is really pulling less timing? Can they pull .5 or 1.5 deg or is it just 1 or 2 or 3?

Any advise would be greatly appreciated. But please, let's keep the discussion about timing and not stray into fueling or injection setups. I'm sticking at about 11.9 A/F ratio with no injection.

[Craving4Boost]

Enthalpy talks a lot about his timing techniques that he has learned from experience. Should clear up a few things about where you want to start for timing.

[Florida240sx]

JZ has an apexi ITC I beleive. Works great with the safc

[Edub1]

Sweet, I think that is exactely where my tune sits now. I'm going to double check.

[Edub1]

Just so readers are clear, the numbers he gives are for the SR .75 deg/lb or -11 deg gives 30 deg in the SOHC KA, not 21.

[WDRacing]

So your total timing on boost is 30*? I don't have any of the software by the way, I use the BTM, I'm just trying to follow along. I helped tune the SDS Standalone on a buddies car, but that was ALL different. We used the Manifold Absolute pressure's to retard boost. Which ends up actually better in the end.

When your setting the timing, at what rpm do you see total timing with no load vs load? Is 3000 about right?

WD

[Edub1]

So your total timing on boost is 30*? I don't have any of the software by the way, I use the BTM, I'm just trying to follow along. I helped tune the SDS Standalone on a buddies car, but that was ALL different. We used the Manifold Absolute pressure's to retard boost. Which ends up actually better in the end.

When your setting the timing, at what rpm do you see total timing with no load vs load? Is 3000 about right?

WD

I'm using a super 60 which should enter boost about 2400 under high load and see max boost at 2800 under high load.

So, I started quickly tapering up to 2800 high load at which point everything else gets .75 deg/lb pulled. That is 11 deg pulled from all the stock values in high load. Since the highest value is 41, that gives 30.

When your setting the timing, at what rpm do you see total timing with no load vs load? Is 3000 about right?

You lost me.

The thing is with our ECU, no MAP reading, so you have to know or guess where your car is in boost. I am also considering BTM, how do you like it?

[WDRacing]

Has worked awsome for me so far, the new one is the ****.

[Edub1]

I think I'm going to get a BTM, that way there is no guess work and it's adjustable if I want to run racing fuel.

I have a fairly good idea where my timing should be but why take chances or spend huge cash on dyno time when it's not necessary.

[WDRacing]

Exactly, wanna run 87 for a tank, set retard for a full degree instead of .5

[Edub1]

Just bought one off Ebay $132 shipped, brand spankin new.

Do you run .5? Up to what boost level? I'm thinking of starting at 3-4 lbs (they do that now) and then .75 for up to 15lbs. I've heard of running stock timing with race gas.

[KATwo40]

You know, you could just make one whole fueling column ridiculously rich to find exactly where you are in the maps.

Or, you could use an emulator to see live map trace, make up the tune, then burn to a chip, remove the emulator and install the chip.

[WDRacing]

Yes I run at .5 up to 20 lbs of boost so far. But mine is the old version that pulls starting at 0.0 boost...lol.

[Edub1]

The tech at MSD said it pulls X/lb no matter when it starts. So you would pull 10* at 20lbs whether you set it to begin at 0 or at 6lbs.

[S13FX]

How far can the BTM get me? I was thinking of using a rom tune to some what compensate for the injectors and the Z32 maf, then use the SAFC to fine tune, and the BTM for timing.

[nb07bcar]

Don't use avation fuel unless you know its not leaded. Most avation fuel is light lead. So you'll mess your O2 sensor.

[WDRacing]

Yeah, but it'll last about 60 days before its ruined, and thats using it everyday. So Av Gas is ok for track days IMO. The O2 sensor isn't hard to change and not that expensive, you can even switch to a generic O2 Sensor wich are way cheap.

WD

[Edub1]

Found a place that sells turbo blue. I wonder how much more power it would produce.

[KATwo40]

^^^None if you don't adjust timing for it.

A high octane gasoline doesn't contain more potential power than a low octane gasoline, but rather more ability to run more timing because of knock supression. But then again, even the most knock supression available won't get you better than MBT, so unless you plan on hitting the dyno for some in-depth tuning, you'll likely be spending money for fuel you don't need.

[Edub1]

I knew I should have added the words, "and run more timing."

[KATwo40]

I would imagine that your turbo will run out of breath on C16, tuned for MBT.

That being said, Avgas will most likely be a waste of money.