timing curve

tom j

Active Member
What are you guys doing for your WOT timing curve? Are you using a flat curve or are ramping it up, or are starting out high and then bringing it down to the final timing mark. I am running 25deg. I have a slight curve upwards right now towards that 25deg.
 
I will have to go look at mine in the next few days. Car has been down since the Midwest Challenge:frown:
Pretty sure its a pretty aggressive curve. I think mine idles at about 38* and at WOT I get into 21* on the upper end. Havent looked at it for weeks. Just getting it back together. Should be running next week, lots of new stuff to install and not enough time.
Bryan
 
I am really interested in the what timing you are running at different rpm's while in WOT mode. 3500 rpm at 28deg, 4000rpm 26deg. ect... You get the idea
 
I am really interested in the what timing you are running at different rpm's while in WOT mode. 3500 rpm at 28deg, 4000rpm 26deg. ect... You get the idea

I "think" timing is a function of load, not just rpm.
So:
At 2000 rpm and 0 boost, 55 mph, timing may be 38 deg.
At 2000 rpm and 10 boost, 5 mph, timing may be 24 deg.

But thinking gets me in trouble ........ :eek:
 
Whats up Tom, this board is useless latley.

Most people I've talked to on this seem to curve timing down as the prm goes up. I'm running mine flat with no problems. Either 24 or 25 in high gear. I forget exactly but somewhere around there. I need to experiment a little and see what it likes.

You workin today?
 
Whats up Tom, this board is useless latley.

Most people I've talked to on this seem to curve timing down as the prm goes up. I'm running mine flat with no problems. Either 24 or 25 in high gear. I forget exactly but somewhere around there. I need to experiment a little and see what it likes.

You workin today?

24 or 25 :eek: I noticed that on that bin file you sent me. You must be running alky to run WOT timing that high!
 
It really depends on the turbo and amount of boost you are running. Thats a little more timing than Id probably run, personally.
 
I run straight 93 octane so my WOT spark table is set to 17°. I prefer boost (20#) over higher timing.
The only concession I make is at the 5000 rpm point I pull it down to 15° because that's where my WOT shift point is.
Then above that it's set to 16° just in case I get that high for whatever reason.
 
my timing starts at 35* and when at wot it ramps down pretty quickly to 23*.at 22# boost i have it at 22* kind of conservitive for my set up but i have had 3 engine rebuilds in the last 18 months .
 
Ideally you should turn your boost all the way down to say 12psi, tune your car for max timing showing maybe .5* knock, then back it down 1-2 degree. After you establish that, bump boost up 2psi, do it again.... All the way to your max boost setting.

You will find that it will mostly be a linear pull in timing as boost increases.

I say mostly because it all depends on what your engine likes. One tune isnt good for many cars. Hell, one tune isnt good for 1 car. Conditions are changing all the time.

My timing curve. 19 PSI on 93octane only. 19* WOT timing. No Knock. Still in the middle of making it more linear and smoothing it out.
 
I kinda went the other route. Set my boost to 20# (my desired target), and brought the timing up to meet it to a point I can run steady with no knock retard. Ended up at 16.8° with the afformentioned dip to 15.5° at my WOT shift point.
 
If there was a only a way to set up the timing curve according to MAP readings that would be way cool. Follow me here say you are set at 20lbs and 25deg. timing and there was a way a to ramp timing in the downward direction according to boost, but in a s-curve type of ramp not square pattern. Lets say you just put a start point for the timing at 0lbs and a stop point for timing at final boost setting and it follows it according to Map readings.
 
There is.. the variable timing chips I do work based off of boost.
 
I "think" timing is a function of load, not just rpm.
So: At 2000 rpm and 0 boost, 55 mph, timing may be 38 deg.
At 2000 rpm and 10 boost, 5 mph, timing may be 24 deg.
But thinking gets me in trouble ........ :eek:

You think 100% right Kemosabe.. Timing is (should be) a function of load and rpm.

TurboTR
 
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