228R cam A4

[WICKEDOWESIX]

Anyone have a tune for 228R cam? I have a 06' Silverado SS with a 228R 228/228 588/588 cam (112 LSA) and 3600 stall. I am having surging issues after a while of driving the truck. Any input would be great especially in the low speed idle. TIA!

[gmperformancecentre]

post up your tune

[WeathermanShawn]

I run a 228/232 Cam, but there are so many variables involved that I am hesitant to label it as available to 'copy'.

People probably never believe me, but I did spend about a week just working on idle. I followed SSpdDmon's Idle Tutorial to the letter..http://forum.efilive.com/showthread.php?t=4661, especially where it pertained to base spark and all the Idle Learning Airflows. My Idle portion of my tune looks very similar to his.

You could write a book on surging. A lot depends if it is throttle-on or throttle-off. Most of us have worked on the TC Table (reduce airflow) to limit off-throttle cam surge. Of course fueling must be perfect too.

Good luck..

[WICKEDOWESIX]

Here is my current tune.

[WICKEDOWESIX]

I run a 228/232 Cam, but there are so many variables involved that I am hesitant to label it as available to 'copy'.

People probably never believe me, but I did spend about a week just working on idle. I followed SSpdDmon's Idle Tutorial to the letter..http://forum.efilive.com/showthread.php?t=4661, especially where it pertained to base spark and all the Idle Learning Airflows. My Idle portion of my tune looks very similar to his.

You could write a book on surging. A lot depends if it is throttle-on or throttle-off. Most of us have worked on the TC Table (reduce airflow) to limit off-throttle cam surge. Of course fueling must be perfect too.

Good luck..

See but you are also M6 and have throttle by cable too. I am A4 with DBW TB. I have looked over on his threads but still cant seem to ge it right.

[WeathermanShawn]

I am M6, but not drive-by-cable. I have the ole throttle-body and IAC system too.

Probably the best way to nail it down is to post up a tune and log. Otherwise, we are all guessing. I always break Idle problems down tho this. Is it happening when the engine is cold or hot. Is it happening when you apply throttle and when you are not on throttle. Is it certain speeds, etc.

If it is truly Idle (0.0 mph, 0.0 TPS) then what is the MAP and AFR doing. What are the IAC Counts. If it is not Idle, what is the AFR. What is the Spark. Is the vehicle stalling or bogging. Is it truly 100% cam surge (AFR, Spark, Air perfect, but surges off-throttle). Does it surge when on-throttle.

Thats the way I looked at with a cam of 10 degrees of overlap. I have no surge, no stalls, etc. M6 only helps when the car is just sitting there.

Hope that helps..

Edit: I see you have a Tune posted. I'll look it over.

[WICKEDOWESIX]

I will try and get find my log. The surging only occurs at low speeds (slowing down to a stop/reversing). Its starts surging while I am off of the throttle and about to slow down to a stop. While I am on the throttle everything seems fine. Thanks for any input!

[WeathermanShawn]

Yes, that good information.

See normally I would consider the additional air in the TC B4309 the culprit. I don't know how A4's do with zeroing out lower Rpms and MPH in B4309, but thats a thought.

Otherwise all I can think of is that your Base Spark is enabled at low TPS B5916 and that is not enough spark to keep a cam like that happy. I run about 22-24 degrees of base spark, where you run 14 degrees.

As dumb as it sounds, I always try to think Fuel, Spark, Air. What Table in my Tune is controlling each at that point. Since you are closed-loop..probably not fuel. At low TPS, MPH, too much air can cause surging. Not enough Spark would usually stall you..but if the Spark is jumping around it might feel like surging.

Hopefully someone with your exact platform can comment. But those are a few things to consider..

[WICKEDOWESIX]

Yes, that good information.

See normally I would consider the additional air in the TC B4309 the culprit. I don't know how A4's do with zeroing out lower Rpms and MPH in B4309, but thats a thought.

Otherwise all I can think of is that your Base Spark is enabled at low TPS B5916 and that is not enough spark to keep a cam like that happy. I run about 22-24 degrees of base spark, where you run 14 degrees.

As dumb as it sounds, I always try to think Fuel, Spark, Air. What Table in my Tune is controlling each at that point. Since you are closed-loop..probably not fuel. At low TPS, MPH, too much air can cause surging. Not enough Spark would usually stall you..but if the Spark is jumping around it might feel like surging.

Hopefully someone with your exact platform can comment. But those are a few things to consider..

Ok thanks! I will see if those adjustment make a difference in my platform.

[The Alchemist]

http://forum.efilive.com/showthread.php?t=11571&page=2
check this thread out mate...saves repeating myself