• We are no longer supporting TapaTalk as a mobile app for our sites. The TapaTalk App has many issues with speed on our server as well as security holes that leave us vulnerable to attacks and spammers.

Anyone use a Powercommander on an APEX with boost?

MrSled said:
kinger said:
What is your cold start issue? After it fires how does it run now on the GEMS?

MrSled what did the autotune fix for you?

My GEMS unit has been good for me not perfect but good. My sled will be on Ulmers dyno this week maybe if he can show me better power and mpg I will spring for a autotune set up LOL

The only reason I went to it was there was a few spots that would still run bad and I wanted to fine tune it and the gas mileage at cruising speed on the GEMS was terrible.

How much did it improve your mpg?
 

kinger said:
MrSled said:
kinger said:
What is your cold start issue? After it fires how does it run now on the GEMS?

MrSled what did the autotune fix for you?

My GEMS unit has been good for me not perfect but good. My sled will be on Ulmers dyno this week maybe if he can show me better power and mpg I will spring for a autotune set up LOL

The only reason I went to it was there was a few spots that would still run bad and I wanted to fine tune it and the gas mileage at cruising speed on the GEMS was terrible.

How much did it improve your mpg?

Well with 10lbs of boost, I would get like 6 MPG, I can tell you its more like 10 now but its still needs more work in the map to get it right... I will have more solid numbers this winter.
 
DooAssassin

I think that the fix. I was told that there was a way to richen up the entire base curve. Then I could readjust my numbrs down.

Watched the video. It looks like he shows 4 settings and runs them up and down. Do you know which one I need to adjust and what is the range? Are there any instructions anywhere that I could read? I know this will fix my issue. No doubt it's lean with the blower pushing air into the cylinders and no additional fuel.

Maybe there are 4 to adjust the pulse rate of each cylinder?

Appreciate all this help. I think you guys are gonna save me a pile of cash............I'll have to buy a better skid for the tar, that's all!

Marco
 
If you're having a problem starting the sled, start with the throttle bodies. Your sled doesn't make boost during starting or idling, and it sounds to me like your airbleeds are off, which I've had that happen before. Adding fuel during those low areas could cause more cold fouling issues if there is an underlying issue. The air bleed adjustments are the four small flat screws on the idle valve. I'll try to post a link to the service manual, or if someone has it quicker, please post a link?
Your idle valve (thumbscrew) controls overall idle speed via air bleed behind the throttle blades, but the four screws help to balance the throttle bodies and allow consistant airflow to each one. You could have one plugged, or out of adjustment, an idle air hose pinched or clogged, or the thermo-pill inside it could be malfunctioning, since there is coolant inside that idle valve, I've seen one actually have a very small internal leak that slowly corroded the tiny air passages shut, and didn't allow it to get any additional air during start-up, and it idled rough until the engine was warm. Also, if your sled doesn't idle high when cold, then settle down as coolant temp gets up, that's another sign of a bad valve. Sorry for the long post, but I'd start there.

Most EFI engines' idle/start related issues are related to either idle airflow or spark. If you're running ok after you finally get it started, begin with the idle circuitry.
 
nate007,

Once it starts it high idles fine. 2000 RPM or so then settles to around 1300 - 1400. I'll get a look at everything. on the air side. I don't think it is a bad valve.
 
Here are the instructions:

http://www.ulmerracing.com/Stealth.pdf

Nate007 could be right about the trottle bodies and even a valve. does it turn over lumpy or smooth?
You are right the SC is pushing air in even at idle, not much but the moter does not have to work as hard at idle to pull the air into the motor and can cause leaning. If this is a problem since you installed the kit this should solve the problem otherwise if this problem was progressive after installing you might have another problem.
 
I always noticed that even at an idle my sled with it's MPI always had a "lumpy" idle, as if it had a set of big cams in it. I ended up clong the idle air bleeds a bit and balancing them with a vacuum gauge and it cleared up and was easier to start as well. I usually ony had issues starting it if I left it sit outside overnight though.
A sleds efi system is the most basic system possible (Alpha N) which is essentially just TPS over RPM with a small compensation for MAP voltage. Any airflow changes, even at idle affects the mixture, which is difficult to correct on a sled if there is an issue. Adding too much fuel during cranking can quickly foul pulgs, but even during cranking and idle, a supercharger will obviously affect airflow/vacuum (MAP), which changes the engines needs.
If you're just using the dobec style boxes, it's best to make no adjustments to that for idle, and use the factory dash cluster to adjust low rpm fuel demands as the OEM computer has a higher resolution that the aftermarket box. Then only use the box from the rpm range where the factory adjustments stop and up. You'll have less issues with starting, idle quality, driveability and plug life.
 
I know this is an old post but my GEMS controller has packed it in and I need a fuel controller for an 08 Apex with a stage I MPI supercharger. I called MPI but they no longer have any controllers for the older kits? I was told to call Ulmer racing and ask about the PC5 I have left a message there but no reply yet.Does anyone have some info or experience in this area? PC5 auto tune etc?
Thanks in advance
 
Got an 07 APEX with a Stage 1 MPI supercharger on it. Having cold start issues (starting 3 - 4 times before it stays running). I have been told that the controller I got from MPI can only add fuel to the idle circuit after it has been powered up.

Looking for better cold starts. I've used the Powercommander on a cat before and there are lots of data points you can change to get the entire curve right.

Anyone try the autotune? Looks like the cats meow!

Thanks for the input.

Marco in NH
Have a pcv on my 2011 apex se with mcx290hp kit and it seems to run fine
 
I have a brand new Gems controller for a 2011 Apex if it could work for you
 


Back
Top