I don't have an equation for timing advance vs elevation, but certainly there are posters here that have advanced their timing appreciably. Advancing to 8* is no problem. More info here:
http://www.suzuki-forums.com/suzuki-sidekick-escudo-vitara-geo-tracker/54562-timing-advance.html

 

Standard tests are specced at sea level but the ECU will automatically correct for altitude using the readings from the barometric sensor. The OBD2 interface on these ECUs is very limited, if you want to check the baro reading then you need an OBD1 tool.
These ECUs do run the timing a little retarded so a few degrees of extra advance can help, however it may not meet emissions regulations.

 

I currently live in Colorado. Most of my driving is above 6,500 feet. Often times my drives in the mountains will be in the 10,000+ range. I recently got my 1997 1.6 16 valve motor rebuilt and after the install did some tests to be sure the vacuum pressure and cylinder pressure was in spec.
(yes compression will be less. need the corrections?)_
yes vacuum is less, do to thin air. the pump can no longer suck as hard
and produce way less power, all small aircraft manuals show this drop.
need it?
at 6000 feet the error is..84
at 7000 feet .81
8000 is .79




The ECU can compensate for all changes.
in fact some like being stopped and restarted every 3000 feet
the 96 has on on board atmospheric baro, (look inside ecu see it?)
so dont need restarts like early years.

I had a vacuum steady at 14 hg and that had me worried because the spec i could find was around 19 i think.
read the fine print, it says at sea level.


I also took a cylinder pressure test and WOT, plugs out, ect hot was around 160 in all cylinders (less than 600 miles, rings probably not seated all the way) This also concerned me. However after doing some research on other forums i found the formulas to show what the specs would be at sea level, which is where i am assuming Suzuki calls out their specs, and low and behold i am well with in the pressure and vacuum spec.
sure are.

My question is about the static/base timing advance. I currently have it at 5 degrees before TDC, which is where the FSM book says it should be. If i increase to 8-10 degrees i notice the vacuum increases and also the car feels a little more peppy.
that spec, is not what the engine runs at., the ECU sets timing agressively at all speeds, so all you do here is lie to the ECU.
yes, total advance will be more.

My question is: Is 5 degrees set for sea level? If i spend all my time at higher elevation should i adjust the timing more? Or will this mess with the ECU? If i should advance it how much should i be doing? I found a rule of thumb online for carb motors at 2 degrees advance over base time for every 1,000 feet, but with EFI i am not sure that rule applies. I only use 90+ octane fuel. Any one have any input on higher elevation settings?

you like to walk a tight rope, huh?
the kick has no detonation sensor,?
it can do that for 2 reasons, the nice quench combustion chamber.
and
owners don't mess it it...

the timing is a compromise. why are you messing with it, if>
1: motor gets too hot ,now your illegal advance starts detonation.
2: the fuel pump goes weak, and AFR goes lean and again detonation.
id avoid ping , i sure would.

They guard band (eng. term) this spec, so you stay out of trouble at all times (all temps, all altitudes, wear, different fuels etc)
The old ECU dont compensate for Fuel Octane like new cars.
new cars can tune each cylinder to a different timing. (vectored spark)
New cars can find the ping point and back off.... (learn mode)
yours can't so now you get in to trouble.


now if the crank cog key is stripped, then changing timing will make it run better
but that is whole other deadly issue.


IF you dyno a good motor (good crank key ,etc)
you will discover that power does not increase with illegal advance added.
why> because it was designed to do , exactly that,

is your motor holding closed loop hot , is the o2 fresh. not 200k miles old
but under 100k?

id use a scan tool and plot 02 and long term trim. to see if all is well.
I would
and not inspecting the key slot,day 1 is big time error. IMO.

 

So, Jerry (xxx), in a nutshell don't mess with it? No gain or is it just a little and not worth the risk? I do the same high altitude, only in the dirt, and would like a small gain at no cost....no free lunch eh

 

See Rhino and Fordem's posts in the above link. These cars are basically factory timed according to the gas that was intended for use, ie, regular, low octane. If, as Rhino says, the timing on these cars has been set to 89 RON, the conversion to AKI (rating used in the US) is usually 4-5 points lower than that, or 84/85 octane on a US pump. So, actually, the gas you are getting in the US is a higher octane than what the car is actually timed for. The higher the octane you are using, the more you can advance your timing - gas not only ignites from spark, but also from compression. The higher the octane, the more the gas resists ignition.

 

Your ecu is a variable, i run 12* with an additive, i'll test 14 in the spring, temp, altitude and timing need to be tested to get your best hp/mpg gain. Ask fat finger.

 

They run a little retarded as stock, the manufacturers have to allow for someone setting the timing wrongly and also for the occasional tank of bad fuel. There seems to be a myth that the manufacturers set up the timing to perfection but its not possible, there are many different compromises that must be made, particularly when, like Suzuki, you use the same tune throughout the world.
On an imperfect engine the O2 sensor compensation keeps the fuelling correct but there is no similar correction for timing, hence some engines can run more advance than others. If it doesn't pink then its not a problem.
On a Track/Kick you usually gain around 3% peak on a stock engine from tweaks to the timing but te real benefit is at part throttle where you get the economy gains, very few dynos can measure part throttle improvements.

 

vast variables exist. and few stated, even brands of fuel. (E10 anyone?)
perfect timing under all loads and other conditions is a compromise.
the 3 big variables are RPM , LOAD and peak cylinder pressure .
in 97 , the ECU is not fancy. 2nd year of OBD2, no vectored timing. (diffr. on each cylinder, etc. like today) the most important are the guard bands, a buffer for detonation.
motor runs a little hot, over load it? (then AFR goes lean for some reason?, oops)
poor grade of fuel, old fuel.
not only that, we don't even know how many tables there are: (discounting cold)
"in a 97 USA ECU"!
1 for spark at STOICH . closed loop , lean.
2nd for spark at open look acceleration or for WOT?
3rd a table for amplitude? (some newer yes, older no)
not knowing what's in the box, & why, and its limits, makes guessing hard.
the biggest variable is wear. (lost compression, or you shaved the heads too much?)

most times if more advance seems to help, look for other faults.
not holding Stoich at cruise.?
the stripped crank key, again.
thermostat floating , PO using wrong seal, now water runs 150F
air leaks in the induction
200,000mile 02 Sensor not cutting the mustard?
ECT or IAT sensors drifted way off? common after 17+ years..
100s more, fill in the blank....
The 97 uses a MAF and a Air temp sensor to get AFR mix right.
The ECU knows the Altitude (open lid see it) an will compensate for altitude.
The FPR also compensates for Altitude, holding the pressure across the injector at a constant from 0 feet to the tallest mountain, (i dont know upper limit)
If you try to second guess it, good luck there.

From my experience most old cars, on the road , have issues.
missing parts
wrong parts
damaged, weak or faulty parts after 20 years.
eg: no cat? no EGR (or dead), (messes up tables too, and spark.)

One more fact, it was proven by SAE , under controlled tests, there is unheard
pinging, (for sure with load exhaust) and this unheard pinging (detonation) does do damage. best practices is the avoid it completely (Suz has no sensor, or algorithms to avoid that , hint ) But the modern combustion chamber quench designs , keep peak power at least 5 degrees from ping, on modern engines.
How well this works (this motor ?) lean and too hot and under full load, who knows.?
thus guard bands....
(ever degree your crank pulley? with a dial indicator on the piston crown, who knows what you got, and is the rubber center in your slipped. who knows. huh?)
YMMV

 

not only that, we don't even know how many tables there are: (discounting cold)
"in a 97 USA ECU"!
1 for spark at STOICH . closed loop , lean.
2nd for spark at open look acceleration or for WOT?
3rd a table for amplitude? (some newer yes, older no)
not knowing what's in the box, & why, and its limits, makes guessing hard.YMMV

I've published the source code for the EE93 binary for those that can understand these things.

 

how did i know you would say that.? (thus my lil USA flag )
you have binary's for USA 96+ ECU ROM?

 

The uncommented source code is here:

http://www.rhinopower.org/ECUs/71EC1/docs/ee93.asm

The commented source code is not released.