Looking for Tuning Guru for asphalt Apex

[vollender]

I have a 2006 apex fuel injected in a dragster. I am looking for some one that knows how these are tuned. I struggle with it in the heat, It is very inconsistent, when cools do it runs same numbers and way quicker. I tried a auto tune and with a 2 step it slows down car a bunch and is still inconsistent. In the heat it will run 11.15 and when temps are cooler it will run 10.95.

So my thinking is it has a winter tune in computer and when it gets hot it does not know what to do.

I am wondering if it tunes off the mass air flow sensor. I have thought about making a box to hold ice or dry ice to put the air flow sensor in.

Any ideas or know of some one I could call and talk to about this.

Thanks Ray

 

[NOS-PRO]

Hi Ray, I raced an Apex for a few years on asphalt and had the same issues. It seems as if the fuel injection quits adjusting at 50° F (That's what I noticed anyway). The cooler the weather, the faster, the better and more consistant it ran. Another issue I had when it was warm was the sled seemed to develop a bog and my reaction times would vary to the point where I would either redlight or have a .2xx something from a bog. Happened to me at the Team Finals where I placed 2nd in points at my track for IHRA, but couldn't react or run my numbers at the Finals......

This Apex engine is a real bear to figure out when warm one day and cool the next.

"What to do" now that is what I wish I knew to keep the engines running consistant for all different weather. You have some pretty good ideas there to try, but just being honest....any sled, car, motorcycle or quad I raced at my track would always suffer and have lower times in warmer temperatures.

Pretty cool dragster there!

 

[MrSled]

So you have tried running a PCV with different makes for different temp ranges?

 

[vollender]

I did not get the pcv, I bought the dobeck performance auto tune afr 4. One problem is o2 takes for ever to heat up. Our last pass it never turned on till the end of the run.

 

[MrSled]

I did not get the pcv, I bought the dobeck performance auto tune afr 4. One problem is o2 takes for ever to heat up. Our last pass it never turned on till the end of the run.

Are you running race gas? That will surely shorten the life of that O2 sensor.

 

[vollender]

No I run 91 pump fuel. And put fresh in every 2 weeks when we race.

 

[NytroMisfit]

I would thing Allen Ulmer could chime in on this one doesn't he tune sleds all the time for different situations. I don't see why you couldn't tune this to run better in warm weather. Especially since they are putting the 3cyl in the yxz wheeler. Are you running a larger radiator with electric fan or just air cooled?

 

[NytroMisfit]

@Srxspec would probably have valuable info.

 

[MrSled]

I agree, he would be better at tuning that.. I would normally try and run a few maps with different tunes.

 

[NytroMisfit]

The issue I see him having is that you can throw tunes at it all you want but if the ECM is still programmed for cold temps I'm sure it is going to default or retard timing to keep the engine safe?

 

[Srxspec]

What type of cooling do you have for the engine? Larger radiator? Are you leaving the starting line at similar engine temps at all times? If you unhook the barometric pressure sensor between the #3 & #4 cylinders it will lock the ECU into a "safe mode" for both the fuel & ignition maps and it will no longer adjust for weather conditions, but it will throw a code on the dash. On the grass we had no problems running within .05 consistant times from one week to the next as long as track conditions were similar. Also, how is your air intake system routed (where is it drawing air in)?

 

[Srxspec]

Also, where are you located?

 

[vollender]

I have a large radiator in front of foot bulk head with fan. We have no thermostat. She goes to the line at about 130 degrees. It gets pretty hot by end. Its about 180 by time back at trailer.

We run at western Colorado dragway in grand junction Colorado. 4600ft elevation. she runs 1/4 mile with it.

In the hear average is 11.15 at 115 mph cold weather 10.95 at 119 mph.

I have made a bike water bottle and put the air sensor in the bottom. then I filled it with water and froze it.

My air box is home made out of a 4in pvc tube with big air filter 3 in inlet.

All sensors are in place and hooked up, but speed sensor.

 

[NytroMisfit]

If you froze the air sensor wouldn't you be throwing off the readings and confusing the ECM?

 

[vollender]

So I unhooked the barometric pressure sensor and had the air temp sensor unhooked and fires up fine. has codes flashing.
So looking at Fail safe chart, code 13 locks at 85.0kpa and code 22 locks at 0 celces. any idea if both unhooked are ok or should I just do the barometric pressure sensor

Thanks for all the input
Ray