Need a basic lesson on idle tune w/cam..

[Redline Motorsports]

We'll I finally got myself into trying the AutoTune feature of EFI Live. Followed the tutorial and everything is working great! Much in part to the new Autronic WB that we just bought for the dyno. Anyway.........

I am trying to tune a 98' C5 A4 car that we installed a mild cam ( 222/226) and LT headers. Intake tract is stock. This is my first A4 tune that I have done as it seems like 95% of the cars I see are sticks. I thought this would be a good opportunity to apply the autotuning as well as learn the ins and outs of working an A4.

Tonight I did a few cycles on the dyno for part throttle and idle VE tuning. The problem I am having is getting the car to start and idle smoothly. I raised the values in the 4307 desired air flow and also raised the desired idle up 150 rpms from stock. This helped but I was wondering what kind of range the values should be before I am to far off. Once the cars idle stabilized it idles decent but if I give it some throttle and release it will bounce for a bit before stabilizing. Sometimes to the point of stalling. Will the desired IAC park setting being increased keep the throttle blade cracked open more when the throttle is closed?

I have read as much as I can on this site but could use a basic overview of the methods to get the idle setup. From what I have read some of the steps got a bit over my head so I am trying to get a grip from the start.

The auto makes it a bit involved and I'm sure there are some unique steps that must be needed. I don't feel that cam is that big at all so all the error will be in the operator!

When should the IAC effective area be touched if at all? Can some of the idle hunting be controled with some timing advance? Typically some spark can help makeup for the overlap at low speed.... I did notice that the motor was idling with 12-14 degrees of timing.

Any tips would be appreciated.

Howard

[TAQuickness]

Unfortunatey, idle is a complex process and there aren't many simple tips. Set up a map for the b3407 in gear and in park and use RAFIG & RAFPN to dial in 4307. Do not mess with the IACEA or idle air flow park. Start up friction will help you with initial cold start surging. Idle spark tables can help you with start up flare an stablize idle spark.

I've found recently that incorrect base timing at idle makes idle problems more noticeable. My car likes 35-40* at idle.

[Redline Motorsports]

When setting up the map for idle; I assume to use the calc.RAFIG as the data and coolant must be the other factor. Is that all you log? Can I assume that this pid is an EFI pid that is precalculated.....based on what?

Both pids should be mapped independantly. Correct? One is "in gear" and the other is "out of gear".

What about the IAC limits? I thought with the ETC that you can set the amount the blade is cracked upon startup?

Thanks

[TAQuickness]

The RAFIG is the sum of both the short and long term idle trims. RAFIG for in gear, RAFPN for park/neutral. In the map you want RAFxx as the data parameter, ECT for rows, and InGear or PN for column. In order for the RAFxx pid's to work, you will need to select the supporting idle trim parameters as well.

As for IAC, you should target 65-100 steps for hot idle. I find closer to 100 works better for bigger cams. As for ETC, I don't know. Maybe an ETC guy will chime in ;)

[Brains]

I've thought about drilling my TB hole bigger, but it just idles so well with a 238/240 @ .050 112 LSA cam, IAC counts in the 180's :D

[Chris81]

Unfortunatey, idle is a complex process and there aren't many simple tips. Set up a map for the b3407 in gear and in park and use RAFIG & RAFPN to dial in 4307. Do not mess with the IACEA or idle air flow park. Start up friction will help you with initial cold start surging. Idle spark tables can help you with start up flare an stablize idle spark.

I've found recently that incorrect base timing at idle makes idle problems more noticeable. My car likes 35-40* at idle.

Great thread..

TAQuickness, if the values in B4349 have been changed because of a 90 mm TB should (set at .0320 currently) this be changed back stock and the RAF tables recalculated?

Will the start up friction help with very erratic timing on a cold start? The car i'm tuning timing was going crazy on a cold start (set at 28 degrees) so I backed it off with live controls to 20 but I didn't notice much of a difference until the car warmed up more then it stablized better than it has. (I adjusted the spark over/under corrections by 10% as well)

[Chris81]

In the map you want RAFxx as the data parameter, ECT for rows, and InGear or PN for column.

TAQuickness, when you said InGear or PN for column..what are you meaning by that? Is it the desired airflow??

[Doc]

Sorry I'm confused too. I have every idle pid selected and I am just not comprehending. I can' t fin RAFIG or RAFIPN on the map col. Could you please try to explain for the mentally challenged. Thank you so much.

[TAQuickness]

TAQuickness, when you said InGear or PN for column..what are you meaning by that? Is it the desired airflow??

See the attached image of B4307. It's purely a matter of matching the row and column headings so the paste with labels functions work.



Sorry I'm confused too. I have every idle pid selected and I am just not comprehending. I can' t fin RAFIG or RAFIPN on the map col. Could you please try to explain for the mentally challenged. Thank you so much.

in your map properties, select the data tab, then choose RAFIG or RAFPN as your data parameter.

[Doc]

Thank you TAQuickness. This is one of the primary reasons I went with EFI Live- this community is so helpful and understanding.

[TAQuickness]

Thank you TAQuickness. This is one of the primary reasons I went with EFI Live- this community is so helpful and understanding.

lol - me too :D

[slowhawk]

I'm thinking the idle timing has to be raised alot.Probly 20-26degree's total.That would smooth out idle and affect startup.

[ringram]

Agreed, I found best kpa (ie highest vacuum) on stock engine with around 28deg at idle. Stock was around 20.
Apparently "The goal with any idle setting is a "lean-best" setting - that is, the leanest possible ratio yeilds the maximum idle vacuum while maintaining the rpm set point." That from a ford tuning site. If you search for "lean best idle" you will see plenty of links.
Basically you can use bidirectional controls to adjust timing to the best vacuum point. For me it was the difference of 35kpa to 30kpa. Instant consumption dropped 5-10% according to the onboard computer too.
I also dropped my idle to 635 rpm.

[Chris81]

ahh I see now.. thanks!!

[NOSjohn]

Great information !

edit: So, will increasing timing at idle help with big cam surge and/or stalling?

[Brains]

The bi-di controls rock for smoothing out big cam idle. I played with mine for a while, updated the flash, and now my 238/240 .605/.609 112+2 cam purrs like a kitten at 900 RPM. It actually sounds smaller than the ever popular 224/224 cams with a "typical" tune.

[Chris81]

The RAFIG is the sum of both the short and long term idle trims. RAFIG for in gear, RAFPN for park/neutral. In the map you want RAFxx as the data parameter, ECT for rows, and InGear or PN for column. In order for the RAFxx pid's to work, you will need to select the supporting idle trim parameters as well.

As for IAC, you should target 65-100 steps for hot idle. I find closer to 100 works better for bigger cams. As for ETC, I don't know. Maybe an ETC guy will chime in ;)

TAQuickness, I set mine up and had a little problem.. in the column with "Ingear" what is the PID used for this?

I have RAFIG for data and ETC for rows.

[Chris81]

Any ideas?

[Bruce Melton]

I was following this thread trying to run a somtimes hot start stall on a 224 cam LS6. I think we need more idle air.

When logging RAFIPN can someone show me the MAP setup?

Have the PID loaded and supported but can't figure out, after an embarrasing number of hours how to display the RAFIPN data or MAP.

Thanks,
Bruce

Meltn@new.rr.com

[TAQuickness]

you will want to copy all the temperature values from B4307 as the rows in your map, and make the column heading Park/Neutral. Row and column parameter will be ECT, and your data parameter will be RAFPN. Be mindful of your units

[ringram]

Also some recent info for those who need to keep to emissions standards.
A high vac idle with low rpm speed is good for economy, but not necessarily emissions. A higher idle speed and less advance keeps things hotter and heats the cats better due to faster airflow and heat into them. This may be especially important with aftermarket headers and cats back from stock location where they take longer to heat up and therefore dont work properly.
Im helping a fellow owner try and pass emissions. The local emissions place lets us play on their gear for next to free as they are interested in the cars too. Cool. I think we might have an issue as they have 100 cell cats and aftermarket headers etc.
We can zero out HC and CO but only by breaking the lambda limit. If we stay at the top end we get too much CO. I think we/he might need to wrap the headers or upgrade the cats.
Ill start another thread where this is more relevant later with the final results.

[Bruce Melton]

you will want to copy all the temperature values from B4307 as the rows in your map, and make the column heading Park/Neutral. Row and column parameter will be ECT, and your data parameter will be RAFPN. Be mindful of your units

http://home.new.rr.com/meltn/RAF.jpg

Is this what you specified?

I use F in both B4307 and MAP cause I can relate better. I increased the scale of G/S to 40 but expect that is not enough?

[TAQuickness]

Is this what you specified?

I use F in both B4307 and MAP cause I can relate better. I increased the scale of G/S to 40 but expect that is not enough?

No sir. You map should look like the attached image, but in the column heading read Park/Neutral. The parameter for both row and colum is ECT

[Bruce Melton]

Thanks TA, the picture solves my frustration. I was obviously trying to overdo it.
I appreiate your help.

Bruce

Edit -- I ran B4307 up on the "hot end" and it absolutely fixed the problem-