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Anonymous_User
03-12-2007, 04:04 AM
I'm starting to look at my timing in Chem.

With the new Chem2 available, I made a new cal and popped it in today. It is the best the car has ever ran. I'm wondering if I can find more power by fine tuning my timing.

I get to looking at the timing curves in Chem and I'm a little confused.

(only looking at what would have an effect on WOT)

Advance from MAP Warm Full

+10* @ Vacuum
-15* @ 5 psi
-24* @ 20 psi

Advance from RPMs Warm Always

+12* @ 2400 RPM

Advance from RPM's

+23* @ 1024 RPM
+26.5* @ 1600 RPM
+31.5* @ 5024 RPM
+42* @ 6368

Advance Allowed from RPM

50* @ 3200 RPM
40* @ 3616 RPM
35* @ 7008 RPM


These are roughly the definable points on the curve as supplied.

So, I'm thinking about WOT around 2500 RPM, say third gear. My car is building boost here, maybe 5 psi. I'm wondering how much timing there is at this point.

12* initial timing
-15* from Advance from MAP warm full (WOTMAP)
+12* from Advance from RPMs Warm Always
+25* from Advance from RPMs (GOVNER)
___

34* total

34*-12* (initial) = 22* is below the 50* Advance Allowed from RPM (SPKLMT)



Am I looking at this correctly? I mean, that sounds about right, I just want to make sure I am understanding how all this works properly.

Anonymous_User
03-19-2007, 08:32 AM
Well, no reply here, but the same information at the Chem site got an answer from Geoff.

Yes, the above is correct. And he also stated that adding timing in the low boost area is going to INCREASE lag. So, I might pull some timing OUT down there and see what happens.

I also may try leaning it out a bit down low. I don't spend a lot of time over 4k rpms in this car so I'm hoping to spool it up quicker without sacrificing for those times that I want to let it breath.

Tony Hanna
03-19-2007, 08:50 AM
Well, no reply here, but the same information at the Chem site got an answer from Geoff.

Yes, the above is correct. And he also stated that adding timing in the low boost area is going to INCREASE lag. So, I might pull some timing OUT down there and see what happens.

I also may try leaning it out a bit down low. I don't spend a lot of time over 4k rpms in this car so I'm hoping to spool it up quicker without sacrificing for those times that I want to let it breath.

That makes sense (at least in my mind). I'd think that starting combustion later in the cycle would have the gasses still expanding some as they pass through the exhaust manifold and turbo improving spoolup. The trick will be figuring out how much timing to pull and under what conditions so that you can improve spoolup without hurting performance in the process. I'll need all the help I can get to spool the holset when I get it on there, so I'm curious to see what you find out.:)

cordes
03-19-2007, 02:26 PM
I have read that the rally cars pull the timing and run it rich to spool it up. Although I have also read that this can create very high heat. I will be playing with it myself.

I actually pulled some timing which was much to strong in my SBEC cal from abotu 0-5PSI and it does spool faster. I can't say for sure if it is a direct result of this though, as I did adjust a couple of other things in there too. The car is running better than it ever has before though, and that makes me very happy.

Anonymous_User
03-19-2007, 05:34 PM
I actually pulled some timing which was much to strong in my SBEC cal from abotu 0-5PSI and it does spool faster

This is exactly what I'm going to try. Hmm... Maybe I'll do it today. Eh. Maybe. Seem to have an ambition problem today.

Anonymous_User
03-19-2007, 09:08 PM
OK, I took 3* timing out between -1 and +5 psi. This made a LOT of difference. It spools up much quicker.

I then took quite a bit of fuel out around the same pressures. Even better spooling.

I took a wee bit of fuel out up top - EGT's were a bit low. EGT's are now close to what I'd like to see at WOT.

I then went and bumped the boost up a bit at a time. 24psi its running really, really nice now. Of course, I need better tires to utilize second gear!

cordes
03-20-2007, 07:21 PM
That sounds great. Let us know how things go for you.

Anonymous_User
03-20-2007, 08:07 PM
Well, the first time out at 24 psi was a blast. Parked the car until work. Driving to work it would not boost past 18 except for a fifth gear spike to 22. Guess I've got a leak somewhere. Gonna have to tear into it this weekend.

johnl
03-20-2007, 09:56 PM
This is a bit off topic as I know nothing about flashing cals, but what Cordes said - "I have read that the rally cars pull the timing and run it rich to spool it up. Although I have also read that this can create very high heat" relates to my problem.

High heat - that's my problem.

At 17 - 19 lbs, I'm seeing 1700+ F EGT with A/F in the 10s. Base timing at idle set to 8* on a GLHS Stage 2 LM - 2 BAR Map. Data is from Zeitronix unit. Stock 2.2block, T2 intake and IC, S70, ported everything, 3" SV/Exhaust.

So - its retarded, its rich, and its hot.

The EGT probe is located in the bottom throat of the exhaust manifold outlet - right before the turbo. I'm rationalizing that it is going to be a bit hotter there as it gets heat from all four cylinders.

I can hear detonation at 3/4 throttle, partial boost.

I am afraid to advance the timing. I am also afraid to turn the AFPR fuel pressure down any further.

The car loves to rev; the S70 doesn't spool until 3500-4000, hits hard at 4500and wants to spin through 6000. Runs strong on top, dog off the line, unless I rev the snot out of it. Checked and re-checked cam timing. Flywheel at zero, key way straight up, Fidanza ("on sale" retarded one from FM) advanced until the engine ran best - about 3 camshaft degrees.

I'd like to move the power band down and see 1500F.

Help.

cordes
03-20-2007, 11:39 PM
I would back the boost off to about 12PSI, richen it up a little bit, get the timing back to about where the stock cal was, and then start upping the boost again.

I will probably be starting a thread about EGT placement in the manifold vs. temp, as I have a shadow which has really high EGTs no matter what I do, and the probe is in the boss between 2-3 IIRC.

Aries_Turbo
03-21-2007, 06:59 PM
you advance the timing and the EGT's will fall.

you will always get knock at higher boost and part throttle cause the timing tables are more advanced and the fuel tables are leaner there. do not run above 10psi on a stock cal at part throttle. even at that level, you might get a little knock retard at that point.

what injectors do you have? i know that ken had good luck with +20's on a GLHS stage 2 LM and was able to run a safe 18lbs with a map cutout installed.

given the reasonable prices of chip burning stuff, Id get a burner and some chips, a 3-bar map and some injectors and go to town. its fun. :)

Brian

johnl
03-21-2007, 09:25 PM
Brian[/QUOTE]

Thanks Brian - Guess I'm in cal no man's land.

" You advance the timing and the EGT's will fall."

I'm confused - I'm hoping you mean cam timing?



"you will always get knock at higher boost and part throttle cause the timing tables are more advanced and the fuel tables are leaner there."

Got that. That's one reason I'm afraid to advance the base timing to get the WOT EGT's to fall. Second reason, is the stock cal has too much advance for WOT anyway, right?


"do not run above 10psi on a stock cal at part throttle. even at that level, you might get a little knock retard at that point."

OK, I'm running a GLHS Stage 2 LM and a grainger. Overboost shutdown enabled. I very could well be getting knock retard - causing high EGTs. Just don't know.



"what injectors do you have? i know that ken had good luck with +20's on a GLHS stage 2 LM and was able to run a safe 18lbs with a map cutout installed."

+40s with accufab AFPR, no cut out yet - right now overboost shutdown is my friend.:nod: California 91 gas is an issue too. I've run many many miles with +20s and a GLHS Stage 2 in my other car, GLHS #463, at 16 -19 pounds - no problems - of course it is so corked up (2.25 SV/exh) that my theory is it can't make enough power/heat to hurt itself. It too though, with right load, will make audible detonation if I let my foot hang around at 3/4 throttle.



"given the reasonable prices of chip burning stuff, Id get a burner and some chips, a 3-bar map and some injectors and go to town. its fun. :) "

Yeah, you are right of course. Its "one of those things" (learned that one from Jerry), since I haven't done it, I'm afraid:confused:

Aries_Turbo
03-22-2007, 09:24 PM
John,

advance the ignition timing = lower EGTs (clarification :)) retard the timing and the EGTs skyrocket cause some of the fuel is buring and expanding in the exhaust manifold making the EGT probe read higher. the in-cylinder temp really isnt higher and is prolly a little lower. its bad for the exhaust valves and the exhaust manifold could suffer over time but prolly not.

another little clarification.. in the calibration there are three main fuel tables based on pressure/vac: FuelNoThrottle, FuelPartThrottle, and FuelFullThrottle. there are also three main timing tables based on map pressure/vaccum, AdvanceFromMapCold, AdvanceFromMapWarmPart, and AdvanceFromMapWarmFull. when you are at 3/4 throttle, full boost and you hear audible detonation, you are using the FuelPartThrottle, which is leaner, and AdvanceFromMapWarmPart, which has more timing advnace in it.

AdvanceFromMapCold is used for both part and full throttle when the motor is below the warmup temp threshold which is around 177 depending on the cal.

the main reason for the high egt's is the 8* of base timing... you are running a 2.2 so this should be 12*. i know that you are afraid of knock but as long as your foot is to the floor when the boost is higher, then you should be fine. you need a scanner or something to show knock retard. i cant fly blind anymore. :) i have to have at least the CEL blink that Geoff has in his Blueberry cals. :)

you should be able to run the stock advance up to 16psi or maybe even 18psi without knock at WOT as long as you have enough fuel. if you wanna run more, back the timing off to 11deg but 8 is a little ridiculous. :)

oh yeah, when you are hearing audible detonation, the computer is already pulling 15deg of timing and cant pull any more so you hear the knock.

when you buy the cal stuff, shoot me a PM, ill guide you in whatever way i can. its cake if you have someone give you a hand for a little while.

Brian

Tony Hanna
03-23-2007, 12:26 AM
Out of curiosity, how hard would it be to change what the cal considers full throttle?
If it could be set up to use FuelFullThrottle and AdvanceFromMapWarmFull at anything much over 1/2 throttle, it seems to me like this would solve alot of the part throttle timing/leanout issues.

Anonymous_User
03-23-2007, 01:39 AM
With the blueberry, I just set the BoostAllowedPartThrottle <- or something real similar that means the same thing -> to around 10-12 psi. This does two things:

1.) If you aren't WOT, you won't go high enough in the boost to worry about the agressive fuel/timing curves.

2.) If you are just cruising around town you won't be boosting real high. I've had this issue on cars with smaller turbos (like the mitsu) while running a grainger.

Oh, yeah, this is all good as long as you allow the computer to control the boost. With a good cal, you do not need any external boost control i.e. grainger valve, bleed, etc.

wowzer
03-23-2007, 01:29 PM
fwiw - just recently had my timing very screwed up on my van. way, way retarded (the van that is!!). in park at 3000 rpm had 10 psi from the turbo!! however, it heated up fast fast fast. CRAZY.

Capt'n Dave
03-23-2007, 04:09 PM
not to high jack your thread Anoymonus,but how is the daughter doing on the driving,just curious?

Tony Hanna
03-23-2007, 04:20 PM
With the blueberry, I just set the BoostAllowedPartThrottle <- or something real similar that means the same thing -> to around 10-12 psi. This does two things:

1.) If you aren't WOT, you won't go high enough in the boost to worry about the agressive fuel/timing curves.

2.) If you are just cruising around town you won't be boosting real high. I've had this issue on cars with smaller turbos (like the mitsu) while running a grainger.

Oh, yeah, this is all good as long as you allow the computer to control the boost. With a good cal, you do not need any external boost control i.e. grainger valve, bleed, etc.

Yeah, I think "2" is my problem. The little mitsu with an MBC really gets up in the boost at part throttle. You can see it in the a/f gauge too. Lift a little at full boost and the gauge will drop a light but the boost stays right up there.

Anonymous_User
03-23-2007, 04:51 PM
not to high jack your thread Anoymonus,but how is the daughter doing on the driving,just curious?

Well........

Failure to completely stop at a stop sign. $100 fine. Have to meet with the DOT to find out how long her license will be suspended. From what I gather it will be 30 days.

So..... she ISN"T driving except for back and forth to work.

*sigh*....... kids :(

Aries_Turbo
03-23-2007, 07:03 PM
Out of curiosity, how hard would it be to change what the cal considers full throttle?
If it could be set up to use FuelFullThrottle and AdvanceFromMapWarmFull at anything much over 1/2 throttle, it seems to me like this would solve alot of the part throttle timing/leanout issues.

easier than that.... at a preset point, like 8-10 psi, just match the part throttle tables (fuel and timing advance) to the wide open throttle tables. problem solved. :)

Brian

Tony Hanna
03-23-2007, 07:13 PM
easier than that.... at a preset point, like 8-10 psi, just match the part throttle tables (fuel and timing advance) to the wide open throttle tables. problem solved. :)

Brian

Nice solution!

If you don't mind, I may have quite a few questions for you in the near future. The Holset is going on shortly and I'm going to attempt to do my own cal. Hopefully by that point I'll be back to work and able to afford a wideband.:)

Aries_Turbo
03-23-2007, 10:30 PM
sure. ask away

Brian

johnl
03-24-2007, 07:03 PM
Hey Brian - Thanks for the help. MUCH appreciated. Just made the changes, will report back.

Aries_Turbo
03-24-2007, 11:03 PM
no prob.

Brian

johnl
03-24-2007, 11:15 PM
Brian -

Dang. Am I dumb! I shouldn't 'a been so scared.

Set the timing at 12* and at 15 pounds, 10.5 A/F, and max EGT is 1550.

Thank you very much.

Aries_Turbo
03-25-2007, 11:18 PM
good to hear that it is running well. :)

Brian