[mullenc525]

Im all excited about getting an afr and tuning my fuel via my wideband, but cant help but notice emanages and their ability to adjust timing. Ive heard of people gaining between 15 and 45 hp from fuel tuning on a BPU car - how much gain can be expected from adjusting the timing maps?

How do you know where to add and subtract advance? IE, a wideband is used for fuel, what do you use for timing?

My mods are shown below, I will probably be running 94 octane.

 

[chevyeater-on-sf]

In order to properly tune for best ignition timing, you'll need to spend some time on a load bearing dyno tuning for best torque. Gains can be extremely large or almost nill. It depends how close you already are.

 

[mullenc525]

eh, too bad it cant be done on the street.

How 'close' is the stock ecu at around 15 psi?

 

[chevyeater-on-sf]

Once again, it depends. Fuel octane, engine, intercooler, turbo and other miscelaneous variables come into play. I would be careful trying to tune timing with the stock ecu as your control is very limited.

 

[Suprawill1]

Im all excited about getting an afr and tuning my fuel via my wideband, but cant help but notice emanages and their ability to adjust timing. Ive heard of people gaining between 15 and 45 hp from fuel tuning on a BPU car - how much gain can be expected from adjusting the timing maps?

How do you know where to add and subtract advance? IE, a wideband is used for fuel, what do you use for timing?

My mods are shown below, I will probably be running 94 octane.

Your best advantage for advanced timing is going to be preboost.
Whether you have a stock ECU with an advanced piggyback or a standalone, timing will be pulled once boost hits to avoid detonation if tuned right. You can tune on the streets but it will take more time.
You would also have to have portable equipment to support what a dyno would supply; computer, data logging ETC.
Chevyeater is correct on the miscellaneous variables that come into play.

 

[chevyeater-on-sf]

Re: Re: gains from tuning timing maps

Your best advantage for advanced timing is going to be preboost.
Whether you have a stock ECU with an advanced piggyback or a standalone, timing will be pulled once boost hits to avoid detonation if tuned right. You can tune on the streets but it will take more time.
You would also have to have portable equipment to support what a dyno would supply; computer, data logging ETC.
Chevyeater is correct on the miscellaneous variables that come into play.

More timing under boost makes gobs more torque, untli you run too much.

How would you hold RPM steady and measure delivered torque on the street? Please explain in detail.

 

[jt2ma71]

I've tuned my timing map on the street. I've never tuned during a dyno session just because they charge more than when you just do a regular pull. You should be able to run more advance than stock if: you are running race fuel or have water injection. It's also neat to be able to run more advance just before boost up to low boost which really helps in spool up.

 

[mullenc525]

^^ hold rpms steady by pulling boats up big hills!

 

[chevyeater-on-sf]

So, how did you do it Ron? Just listening/datalogging for knock, then backing off? From my understanding, that will usually result in too much timing.

Tuning on a load bearing dyno, you advance until there is no more torque increase while holding the engine staedy state at a given rpm. This is usually a few degrees before the knock threshold.

Brian

 

[jt2ma71]

So, how did you do it Ron? Just listening/datalogging for knock, then backing off? From my understanding, that will usually result in too much timing.

Tuning on a load bearing dyno, you advance until there is no more torque increase while holding the engine staedy state at a given rpm. This is usually a few degrees before the knock threshold.

Brian

Well, I kinda started with a lot of research; datalogs from mine and stock timing map from a MKIV. Started really conservatively and made small adjustments, listening for pinging and observing engine response. Inspecting the plugs and pistons (boroscope) for signs of detonation also helps too. It's probably not at its optimum setting yet.
But yeah, you are right. The load bearing dyno is the right way of doing it. It's faster that way too.

 

[Nyrockcity21]

is it possible to incorporate VVTI into the 7mgte engine?

 

[Suprawill1]

Re: Re: Re: gains from tuning timing maps

More timing under boost makes gobs more torque, untli you run too much.

Agreed but probably not with pump gas and no supporting injection.

How would you hold RPM steady and measure delivered torque on the street? Please explain in detail. [/B]

I'm not disputing that a dyno is better for tuning, just costs more.
It still can be done on the street but like I said, it would take longer. You would definitely need datalogging and a good tuner.

 

[adjuster]

If you want VVTi, get a 2JZGE, and turbo it. (From a IS300 for example.)

The 7M family of engines do not support VVTi at all. (It would take a custom head/cams/valvetrain and computer to run it.)

Back on topic, I messed with the timing on the Eman, and found that advancing the timing off boost seems like the best gains of all. (Left it at 0 across the board when boost was over 10psi.) Zero on the Eman is "Stock" settings and maps.

This really works best on the freeway. You nail the gas in 5th gear, and wait for the larger turbo to spool up, and then back off the gas as the boost hits and you just about run over the guy infront of you. With more timing, your turbo hits faster, so you don't have to "plan" as much to pass, or make a move. Less turbo lag is a very nice thing.

 

[Suprawill1]

^^ hold rpms steady by pulling boats up big hills!

LOL (slappping knee)