If I advance the timing using Tweecer,should I increase Fuel Press or set richer?

[Pokageek]

I was going to try these two options to increase timing. Number one obviously increases timing and number two would effectively run the car a little richer I guess to avoid ping. What are your suggestions. Is setting maf to "richen" by like 2% across the whole curve a good idea? Should I also increase fuel pressure? Thanks.


#1 For the timing, go to "Global Spark Adder" in the scalars menu and put in a value. Say you want your timing at 14* and your base is at 10* right now, so just stick in a 4 for the value. If you want 8* and you're at 10*, just stick in a -2.

#2 To change the A/F ratio I would go into the functions menu, then go to the MAF transfer and adjust thoes values there. Say you want a 10% leaner mixture, take the number on the bottom row, lets say 100 for ex. and multiply it by .9 to get 90 so its 10% leaner (100 x .9 = 90), if you want it 10% richer, multiply it by 1.1 to get 110 (100 x 1.1 = 110)

 

[Rootus]

I was going to try these two options to increase timing. Number one obviously increases timing and number two would effectively run the car a little richer I guess to avoid ping. What are your suggestions. Is setting maf to "richen" by like 2% across the whole curve a good idea? Should I also increase fuel pressure? Thanks.

The beauty of the TwEECer is that you can adjust the timing more specifically than just globally. I'd advance the timing at each point in the mid-upper RPM until it started pinging, and then back it down. You'll get much better results than global changes.

Changing the MAF curve to richen or lean is not what you're looking for -- the EEC will adapt in any case, and your changes will become moot. What you want to do with the MAF curve is dial it in so that your KAMRF values get as close to 1.000 as possible (which means the EEC isn't having to do much adapting, because the MAF curve is very accurate).

Fuel pressure I'd leave at 39 psi, unless you're trying to overdrive small injectors. The EEC would adapt anyway, as with changes to the MAF curve.

Closed loop will always target stoich. If you want to adjust open loop target, have a look at the stabilized fuel table. Grady will jump in and point out exactly what the name is, I don't have a TwEECer anymore. And Grady knows ten times more than me anyway...

Dave

 

[Pokageek]

"The beauty of the TwEECer is that you can adjust the timing more specifically than just globally. I'd advance the timing at each point in the mid-upper RPM until it started pinging, and then back it down. You'll get much better results than global changes."

Cool. Rootus, thanks man!

 

[final5-0]

I'm with Dave on using the tables to get your spark curve just the way you want it.

I've never used the global thing myself cause ...... at least to me it seems like ...... the global thing is no different than using the mechanical method of spark adjustment which is ...... twist the dizzy.

Or in other words ......... one pays out the cash for the Tweecer to have precise adjustments and the global scalar, well ......it just don't do that, lol.

As for your fuel adjustments .................

Like Dave said, its the stabilized table all right but, until you get your self tuning legs under you with a firm standing, and also, since you don't have a wb ................... I'd steer clear of wot fuel tweecs for a while.

Grady

 

[Pokageek]

Taking your advice. Thanks guys!

 

[Nagash01WS6]

How does the EEC control the spark timing advance since it has a distributor?

I could easily see it if it was an LS1 ignition setup, no dizzy, but how is the timing changed with a dizzy by the EEC?

 

[Pokageek]

I am assuming this is what you guys are talking about using when adjusting timing more precisely?

"Spark Adder Vs RPM : The first number is RPM and the second is additional timing advance. Similar to the Global Spark Adder as it adds additional spark advance. Increase the spark adder number and increase the ignition timing at that RPM. Change the RPM value and change when spark is added.

?OR/

Do you change those 3 spark tables?..Base..altitude and...doetonation?

 

[BlackVert]

How does the EEC control the spark timing advance since it has a distributor?

I could easily see it if it was an LS1 ignition setup, no dizzy, but how is the timing changed with a dizzy by the EEC?

that is what the TFI module is for. the dizzy tells the computer where the crank is, the computer tells the TFI when to fire the spark.

 

[Rootus]

I am assuming this is what you guys are talking about using when adjusting timing more precisely?

"Spark Adder Vs RPM : The first number is RPM and the second is additional timing advance. Similar to the Global Spark Adder as it adds additional spark advance. Increase the spark adder number and increase the ignition timing at that RPM. Change the RPM value and change when spark is added.

?OR/

Do you change those 3 spark tables?..Base..altitude and...doetonation?

Only need to change one table -- the base spark table (leave the spark adder stuff alone). The values in the base spark table are for total timing -- they assume that you have set the distributor to 10* initial, I'd make sure you have it right at 10* before playing with the table values. For power tuning, you really just need to pay attention to the top row of values, for the highest load, because that's what will be used at WOT. Adjusting with the low-load values can have benefits but you really need to have a handle on what they're doing or it'll just get messy.

Dave

 

[Pokageek]

Ok. Thanks man. The basics really aren't hard to get ahold of on this Tweecer at all in my o. Especially between the help of some of you experts lending your brain, the search and the manual in part. You can make some nice impovements and gains to the car without getting too deep.

 

[blksn955.o]

To use the base spark tables alone you will have to kill (or enter 55's into all cells) Alt. table, MBT table, and Boarderline table.

You can also kill just the Boarderline and MBT and make the Alt. and Base the same at say .5 load to WOT at like 2000rpms+.

or

You can Kill the boarderline and set the base to what you want, then set the Alt. table to 2*+ (to what you entered into the base) and make the MBT match what is in the Alt. (or as close as possible it is a diff. size table).

I have datalogged each and found each gives controle to the timing...find what works best for you and what one you want to mess with and stick with it or see if there is any diff. in power.

As far as the timing settings go...from what I have found have all your timing in by 2,500ish rpms at WOT, I featherd' mine down according to the load col. SO I have 32* in at WOT by 2,500rpm, then 31 in the next row, then 30 in the next, then 29 load.

 

[Pokageek]

"As far as the timing settings go...from what I have found have all your timing in by 2,500ish rpms at WOT, I featherd' mine down according to the load col. SO I have 32* in at WOT by 2,500rpm, then 31 in the next row, then 30 in the next, then 29 load."

Thanks for the comments blksn955.o. I am not sure what exactly that means. Do you mean start uping the timing at 2500 RPM and up? That's what I did basically. I up'd it 2 degrees on each load setting after starting at the second load setting on up to a max of 40. Am I getting the jest?

 

[Rootus]

I up'd it 2 degrees on each load setting after starting at the second load setting on up to a max of 40. Am I getting the jest?

Sounds basically right. Although 40 sounds a little high at any RPM for iron heads. I found that my AFR's liked about 36 in the midrange, and a couple more degrees above 5000. Aluminum heads generally like a little more timing than irons, in my limited experience.

It is pretty easy stuff, as you mentioned -- at least, as far as WOT power is concerned. It ends up coming down to fuel & spark for the most part. You can get a little more interesting with the fuel timing, and when you fix driveability concerns is when it really becomes interesting . By interesting I mean

Dave

 

[Nagash01WS6]

that is what the TFI module is for. the dizzy tells the computer where the crank is, the computer tells the TFI when to fire the spark.

Hrm... I guess what I am asking is... you have a rotor and a distributor cap and a coil. Coil provides a shot of electricity to the distributor cap, which transfers to the rotor, which transfers to the cap terminal when the cylinder will be fired.

Distributor can tell the EEC what degree the cam is at for spark fire, but, there would only be a certain interval of degrees that the spark can transfer as the rotor passes the contact of the cap, unless there is a way for the internals of hte dizzy to adjust, correct? And what does the spout do?

Ive never really worked with a dizzy car.

 

[blksn955.o]

" I am not sure what exactly that means. Do you mean start uping the timing at 2500 RPM and up?

I mean have all your timing in at 2,500rpm, like 32* in at 2,500rpm, then in the next load lower row set it to like 31* at 2,500, then the next load row to 30 or 29, then the next to 29-28*. All having the timing reach the full amount of timing by 2,500. at the 29-28 point you can have it come in further at say 3k or so.

Iron heads should not be run to 40*....I think max would be like 36ish, if you have any shave on the heads then even lower...I have 65 in shave and am scurd' to go above 31-32*.

 

[Pokageek]

I mean have all your timing in at 2,500rpm, like 32* in at 2,500rpm, then in the next load lower row set it to like 31* at 2,500, then the next load row to 30 or 29, then the next to 29-28*. All having the timing reach the full amount of timing by 2,500. at the 29-28 point you can have it come in further at say 3k or so.

Iron heads should not be run to 40*....I think max would be like 36ish, if you have any shave on the heads then even lower...I have 65 in shave and am scurd' to go above 31-32*.

This is strange to me because the "y" axis for the stock tables shows 40 at the highest loads from 1500-5000RPM and then goes to 28. Any ideas?

 

[Pokageek]

For example:

1500 goes (based on load) 17, 18, 20,22, 30,34,36,40, 28
2000 goes 19,21,23,25,30,36,38,40,28
2500 goes 21,23,25,27,30,37,39,40,28
3000 goes 22,24,26,28,30,38,40,40,28
4000 goes 24,26,28,30,32,40,40,40,28
5000 goes 25,26,28,30,32,40,40,40,28

This is after adding like 2 degrees to the stock tables for 2500 and up. How would you change this differently? Add more time in sooner with less over all time? Even thought the stock tables went to 40 at some point, bring that down? Thanks.

 

[final5-0]

Hold on a second Guys!

I most likely am not understanding some of you but lets talk about this a bit.

Forget rpm & spark values for a while and lets focus on load.

Lets use the following driving condition for an example.

Say you are on level ground at about 15 to 20 mph with the rpm between 1000 and 1500 in 3rd gear and you mat the skinny pedal.

You're gonna be at max load before you can even see the rpm's climb 100 to 200 more.

Now if your tuning focus is on wot spark, then the load rows below the max load row ...... don't mean squat.

Again, maybe all the rest of you are thinking the same but I wasn't sure from reading this thread.

If its needed ... just tell me to be quiet and go away, lol.

Grady

 

[blksn955.o]

in regards to the 40 or so degrees at idle and such, yes timing can be high at idle like if free revd'. I think the high mid load timing is also part of the timing strat. to use the EGR tables or be close to them assuming they work (and why the GT has a ping issue esp. with the EGR dissconnected but not turned off in the eec.).

I basicly left that mid range area alone as it drives fine with no pinging... I stepped down my timing in the higher load area not for WOT, but to see about part throt. driving to see if there was any diff. I realy have not found much but then again I am sorting out issues. I realy dont see that it HAS to be set that way... and did it only to make things seem more -not so drastic in change from no timing to timing.

However, the WOT timing load area is were I am mostly wanting to make sure I have timing. From guys I have talked to N/A getting all my timing in as soon as possible is the way to go...now on the jug a slower advance rate will help keep the tires or tarr's from spinning and net a better launch.

 

[Methodical]

Only need to change one table -- the base spark table (leave the spark adder stuff alone). The values in the base spark table are for total timing -- they assume that you have set the distributor to 10* initial, I'd make sure you have it right at 10* before playing with the table values. For power tuning, you really just need to pay attention to the top row of values, for the highest load, because that's what will be used at WOT. Adjusting with the low-load values can have benefits but you really need to have a handle on what they're doing or it'll just get messy.

Dave

This is good info. because I was curious about this same topic. OK Rootus if I understand correctly, for power tuning, I need to up timing only in the upper load area only - which is .799999 for CBAZA. Do I up timing at all rpm points in the upper row in a smooth transition and have all timing in by 2500rpms and then fall off after that - smoothly of course (see example 1 below) . Do I up timing in all rpm ranges in the upper row and have the timing remain the same from 2500-5000 rpms (see example 2). Or do I up timing in all rpm ranges in the upper row and have the timing increase up to 5000 rpms (see example 3). Lastly, should the timing be matched to the torque range of the Camshaft (i.e mine is 2500-6000).

Also, another question, why is the timing at 42* & 43*in the lower load areas? Thanks for any help

Note: upper row (load) for CBAZA is .799999 - this is what you guys are talking about - right

Ex. 1
900 - 32*
1100 - 33*
1300 - 34*
1500 - 35*
2500 - 36*
3000 - 36*
4000 - 36*
5000 - 36*

Ex. 2
900 - 32*
1100 - 33*
1300 - 34*
1500 - 35*
2500 - 36*
3000 - 36*
4000 - 36*
5000 - 36*

Ex. 3
900 - 32*
1100 - 33*
1300 - 34*
1500 - 35*
2500 - 36*
3000 - 37*
4000 - 38*
5000 - 38*