Dyno Results Playing with Ignition Timing

[Myxalplyx]

Car: 1989 2.7ltr Subaru XT6 (AWD/Autotranny)

 

Mods: JC Sports Intake, ProECM Pulley, Custom-made Rallispec Header, 2.5" aftermarket cat and exhaust, 2.5" Dynomax Ultraflow SS muffler.

Extras: Using 93 Octane today and bumped up ignition timing

Car nickname: Redrum

 

Took the XT6 to the dynoshop today to see how ignition timing affects horsepower and torque. I'll be posting a few dyno plots to show what you can expect.

 

Since this car is an auto, I always dyno from the bottom of first gear all the way to the top of 3rd gear. This is to simulate full throttle runs like on a dragstrip to get real world numbers. Also, I dyno the XT6 in FWD mode. I did this previously because my tranny was bad and it would not shift into the next gear in AWD. Plus all the wheels would not move at the same time. Now that the tranny is fixed, I try to stay consistant with dynoing in FWD mode. Drivetrain losses in FWD mode is still 33%.

 

Also, for some reason the car would not stay in gear that long as it used to do. It shifts a little earlier coming out of 3rd gear. Before it shifted post 6000rpm but today it was earlier. I do not know why as the 'Power' mode light did come on. Perhaps I haven't driven it around enough to learn the new settings of the ECU. Oh well!

 

The first dyno plot is comparing HP figures of 20 degree timing (stock/base timing ) vs a ignition timing brought up to about 26-27 degrees. I had to use the Flexplate since my pulley does not have a 'nick' in it for me to see timing with while using a timing light. This plot shows a hp increase in all gears that seem pretty even throughout. Look at the point I chose on the dyno chart. At base timing, I made 117.24hp while with ignition timing at about 26-27 degrees the car made 124.20hp. About a 7hp increase.

 

 

 

 

The next dyno graph is a torque comparison of the base 20 degree timing vs 26-27 degrees of timing advance (on 93 octane). The point I chose to show an example is in 3rd gear. Stock 20 degree timing shows 118.61lb-ft of torque while the 26-27 degree run shows 125.38lb-ft. 6.77lbs of torque gained. Not too bad!

 

 

 

 

These next plot sbelow show where the car is at now vs when it was completely stock. Note, I did runs with and without the Rallispec header installed and they were pretty much the same. So to simulate the gains I'm showing below, all you should need to do is install an intake, exhaust (2.25" or 2.5") and bump up your ignition about 6-7 degrees. Putting the ignition up further showed not difference in hp or torque. I bumped it up once to around 32 degrees base.

Stock at the example point I chose was 107.14hp.

Now it is 124.14hp.

 

 

 

 

Stock torque at the point I picked was 105.23lb-ft

Now it is 121.86lb-ft

 

 

I didn't choose peak hp/torque because my shifts from 1st-2nd gear and 2nd-3rd gear throws the reading off. This is why I show the whole graph. If I had a manual tranny, I could show the gain as a whole in 3rd gear but I don't have one so.....

[Myxalplyx]

Wow! No comments? :-\

[Zefy]

its an auto! POOOOO...

 

just playing... thats running some pretty good #'s... could go for more power!!!

 

maybe add some stickers!

 

any other mods planned?

[avatar382]

That's an impressive amount of power for an XT6, mang!

 

What did it Gtech at for 1/4 mile? 15's?

 

It's too bad the drivetrain losses are so crippingly high. Are the 5 speeds anywhere near 33%?

[Myxalplyx]

That's an impressive amount of power for an XT6, mang!

 

What did it Gtech at for 1/4 mile? 15's?

 

It's too bad the drivetrain losses are so crippingly high. Are the 5 speeds anywhere near 33%?

 

Manny,

I have no idea on the 1/4 mile time. I plan on bracket racing it at the dragstrip, probably this weekend. Will find out then.

 

As for manual AWDs on the dyno, I have no idea. I haven't been able to find data of anyone else dynoing their XT6.