Pinging @ High Ambient Temps Revisited !!!!!

[Dirty Howie]

Before I started messing with my tune (when I got HPT) I would get a lot of pinging as ambient temps started going up in mid to high 70's and worse in the 80 plus range. Pinging will often be very audible but KR not recorded.

After doing my VE and MAF along with some help on the Spark table my pinging was tamed in the 70 degree range. But yesterday the temps were in the high 80's to high 90's and my pinging was back with a vengence.

The log from yesterday showed some KR and also my timing droping to 19.5 from the normal 20.5 ( 21 if you are looking at the histogram).

So I adjusted my tune so the spark was not being removed and fuel was being added at the 86* and up IAT's

Well it was pretty damn good today. Did several pulls where I was hearing lots of ping yesterday and barely heard on little ping which corresponded to a .6 KR (frame 3150-3200 on log #2 today). Ambient temps were very high 80's into the 90's.

I did one 0-60 mph (end of log #1 today) where I usually get 3.8 seconds and it was 4.1 today at 91* IAT. Would 20* ambient make such a big difference???? Maybe should have done a couple of runs and let some air out of tires.


DH

[Dirty Howie]

Hey guys....any comments or suggestions


DH

[Dirty Howie]

Man, 14 views of log/tune and not ONE comment..............

So is my tune PERFECT ??????

Should I try to add more spark ???????


DH

[WS6FirebirdTA00]

yes it would make a big difference. As you can see, the car cannot handle the timing when it gets hot, which is typical. I would not worry about it. Hot air is bad for racing.

[Dirty Howie]

yes it would make a big difference. As you can see, the car cannot handle the timing when it gets hot, which is typical. I would not worry about it. Hot air is bad for racing.

First of all thanks for responding

Not sure I understand "yes it would make a big difference" ........ I think you are saying not to try to add more timing??

The car actually did handle the timing with the added fuel...didn't it????

And as far as racing......I race all year round in southern california high desert....so ambients in 80-90's is expected. I do add a quart of racing fuel concentrate at the track to increase octane.


DH

[Russ K]

Howard,

I set your IAT spark table the same as mine. It will start removing timing at 98*F IAT instead of at 104*F IAT. I would try to increase the sensitivity of the knock sensors until you can see the spark retard on the scan logs. Try decreasing the Knock Sensor Global Gain vs. RPM vs. MAP values by 10% at a time from 55 down to 105 kpa.

Russ Kemp

[Dirty Howie]

Howard,

I set your IAT spark table the same as mine. It will start removing timing at 98*F IAT instead of at 104*F IAT. I would try to increase the sensitivity of the knock sensors until you can see the spark retard on the scan logs. Try decreasing the Knock Sensor Global Gain vs. RPM vs. MAP values by 10% at a time from 55 down to 105 kpa.

Russ Kemp

Russ

Thanks as always......its late right now so I will check out your calibration
tomarrow.....as well as try to absorb the advise about knock sensors. I thought we adjusted the sensitivity a while ago

Neither you or WS6 commented directly about where I added fuel. It seemed to have worked. Isn't it better to add a little fuel than to reduce the spark. Richer is safer, especially on the track isn't it.

Maybe I'm just missing the point as I thought my results were good


DH

[WS6FirebirdTA00]

First thing I would do is make sure the fuel is dialed in, maybe around a 12.8-13.0 or so. Then if you still get knock, just set up the IAT retard table to pull timing in the areas where the temps cause the issues. This way you dont have to keep changing the tune.

[Dirty Howie]

Howard,

I set your IAT spark table the same as mine. It will start removing timing at 98*F IAT instead of at 104*F IAT. I would try to increase the sensitivity of the knock sensors until you can see the spark retard on the scan logs. Try decreasing the Knock Sensor Global Gain vs. RPM vs. MAP values by 10% at a time from 55 down to 105 kpa.

Russ Kemp

Russ

You probably don't remember.....but after fixing my P0101 code you set my IAT spark table just like yours. When I found that was where my timing was being pulled from I bumped your settings 1* and not to start till the 104* temps. I then added .02-.03 fuel via PE (Add vs. IAT) in the 86-104*range. And it seemed to work.

I guess I am trying not to reduce my timing further as I think it is already in the very low range compared to other tunes I have looked at.

You also did some adjustments to KR sensitivity back then. I am more comfortable making changes now so I will mess with it as you suggest. As before I definately will get some pinging without corresponding KR. But I do get KR at times.

Here is my ORIGINAL tune before you got your greasy hands on it


DH

[Dirty Howie]

First thing I would do is make sure the fuel is dialed in, maybe around a 12.8-13.0 or so. Then if you still get knock, just set up the IAT retard table to pull timing in the areas where the temps cause the issues. This way you dont have to keep changing the tune.

WS6

I don't want to have to keep changing my tune (although its not a problem for me to do it if I had to!!!)

I just added fuel instead of removing timing in the high IAT range. (see above post)

If you can look at my histograms you will see my AFR as reported by my WB

Thanks for your input!!


DH

[WS6FirebirdTA00]

I have not had a chance to check the stuff out, let me open it.

[WS6FirebirdTA00]

looks like the fueling is better, in the low 13's may just cause issues on your car. With the fueling around 12.8, I would say you are good where you are at right now.