Perfect Running on Dyno. Misfire and troubles on the street... AEM ems GT42 etc
 

Hello Guys after such a long waiting finally the day on the dyno arrive i will make a list of the parts installed when we start the dyno

Super large port performed by glen at AZRR.
A-SPEC GT42 RS TURBO KIT
Aem ems
Brand new modified single turbo harness
cj motorsports fuel kit 2 bosch 044 and 6x1000cc injector dynamics
twin power etc etc etc.

After 45 minutes on the dyno we hit 517 rwhp at 15 psi, pretty good numbers so we decide to go and make a test on the street before turn up the boost and add some water methanol to the mix. after 3 hard pulls on 1 2 and 3 gear the car starts to misfire like it was starting to fowling plug and the wide band goes to lean badly.
So as a first test we decide to change the plugs and add another fresh set of ngk 10.

We let the car cool for 30 minutes we start the car with new plugs perfect iddle prefect revving go to the street 3 puls and bang agin the misfire nd misfire like the car has no fuel at all, i now for sure that is almost imposible to foul a plugs that fast.

We decide to install the new cdi from M&W and 4 independent inductive coils ro see if the xtra sprk will burn maybe better the fuel, this time we run 4 brand new oem 9 spark plugs go to the dyno test the car no problems at all was in the dyno maybe anoher 35 minutes, go to the street BOOMM gain the misfire after 3 pulls.

We check all the grounds fuel lines fuel pumps fo any block or leak under presure and nothing.
We are starting to think that maybe the AEM cannot handle well the 2 aditional secondaries maybe when splitting to get the aditional 2 injector plugs volts and OHMS decreased and is not enough volts. we call AEM and they dont know....

Ill apreciate 5 minutes of your time reading this to know if you can help.
thanks

What type of dyno? Does it have an eddy current brake?

If it is just a roller dyno with no brake, the tuning can be drastically different on the street, particularly the higher you go in HP

Since you are at 500whp, you may want to switch to 10 or 10.5 plugs instead of the 9's. I would go through 9's pretty quickly at 450whp, and then i switched to 10.5 and they last a lot longer. (but I've also heard some people do fine with 9's in the 500 whp range, so who knows haha)

Also, I would recommend starting your meth/water injection way before you get to 500whp.

Hello..
its a dastek dyno with brake the car has been tuned under load like a normal street condition. its not just a roller dyno.

Yes we stop tuning to go with the methanol and yes we were using HKS 10.5 plugs.

We really don't know if theres a electric related problem cause we have check every mechanical part and all seems to be ok.

I don't know if the drivers of the AEM can handle the 4 secondaries cause we have a huge drop on volts when splitting from 2 to 4 injectors....

Over 515whp at 15psi? That's nuts.

I wouldn't be surprised if there was a phyiscal problem with the AEM EMS. They do crap out on people.

Yeah, I don't get how you could have 515whp at only 15psi. that just doesn't make sense. Isn't that turbo just starting to wake up at 15psi?

:rolleyes:


Most decent 13b setups make 27-30 rwhp /bar (absolute)/1000rpm @ peak power.

he is at just over 2 bar so must be making peak at ~8500+ rpm if it is making that at less than 8300rpm i'd say the dyno is bullshit.

Turbos don't suddenly start pushing more air when they reach a majic number, provided intake temps are stable an engine will (at least near it's torque band) consume a consistent mass of air @ any set pressure vs rpm. You cannot sudden change an engines behaviour because a turbo is " in it's efficency zone", :lol:

A WB measures oxygen in the exhaust gases.
Missfiring means the fuel is not burning and not consuming the oxygen.
Thus a leaner AFR reading is consistant with misfiring.

The dyno and road are loading the engine differently. You need to log both types of runs to compare what is happening.

You didn't mention what kind of air/fuel ratio's you're running? Does it misfire all through the rpm's or just in the higher rpms (7k and up)? As chuck said a misfire will read lean due to unburned fuel, but a lean condition could feel similar to a misfire due to detonation or fuel cut. You should be sure which way to tune before damage occurs. Driving on the street puts more load on the engine, more load can cause issues with the tune. 9's are too hot for your setup, go with 10's. If your ignition system is good there is no reason you should be fouling #10 plugs. I had an aem pnp and it would never even start my car, this was 7 years ago though and I heard their electronics are much better. (Shrug)

Why not? Volumetric efficiency of his whole combination could support it.:icon_tup:

Did you try to replicate the problem on the dyno by going thru 1,2 and 3rd gear? You would tune in 4th gear, so maybe not noticing a problem in the lower gears. Although if the A/F is good in 4th gear is should be good in the lower gears. My guess would be an issue with the AEM.

Hello and thanks for the reply s.
Ok to answer all the topics in a fast way when the failure start to happen the reading on the aem wideband goes all the way to the lean section not even reads, goes all the way to the right and starts to hear explosions on the exhaust.

The failure start to happen when the load on the street is constant that is why when we go for a spin and hit 1-2-3 gear with no problems boost is constant and the failure is not on boost starts at lower rpms, on the dyno you have the hood open the fan blowing etc.. Its a dyno with brake so you can simulate load on it, that is why we don't know what is going on.

I must agreed with Jason yesterday in the dyno the failure start in, and you can see in the laptop screen how the duty cycle of the secondaries injectors when table is open freezes all the values are moving excluding the values of the staged injection, it looks like the drivers of the aem overheats or they are not design to control 4 injectors in the secondaries, and of course you call AEM and they don't now what to say. so i think is a malfunction on the AEM

For the people requesting the dyno numbers i will post a dyno soon the 515rwhp was a peak the cars is steady at 15 psi and boast out 477 rwhp.

thanks for the help.

I think somthing may be loose and it is coursing something to short out! Make sure everything is secured dawn, when you’re on the road and your put your foot dawn, you will be have some g-force which may be making something short out, possibly a wire or something like that.

sorry i just read the above again dident see that!

yes we thought that too, we chichi every wire from the aem ems to front of the engine bay and back,,, and we don't find anything...

Some AEM EMS's bug out pretty bad. Several people in the Supra community have either send back their units to AEM for replacement or just scrap AEM and go a different route.

I would be willing to bet that you are right and the driver is having a hard time keeping up with the extra duty because of the split. I would just change out to a different EMS that has appropriate drivers for the application and avoid trying to make something do it wasn't intended to do.

did you log your voltage on the dyno?? your voltage should never fall below 13.00
under full load. otherwise you will be chasin your tail. jus a lil FYI under full load you want to have 13.5 or higher at the ecu !!!!

Hello

Yes we are 99% that is a problem with the ems i think we will take another route.

Yes we have very steady voltage on load on the dyne with don't go any lower than 14 according to the EMS on the laptop screen.

I've had similar problems, but all went away when I read the directions with the M&W, lol. They are very specific with plug wires. I run the 10.5 mm magnacore and everything runs fantastic. Until then it was hit and miss. You can call them and they will make you a custom set very reasonable to your exact length and boot specification. BTW, the AEM is just fine. ;) I run the same setup as you except i have the Pro Drag box with the AEM. Runs perfect.

HELLO ERNIE AND THANKS FOR THE POST.

Do you think my problem is due to the set of cables??
Cause i have the problem before i install the M&W, we have the stock coils with the his twin power and we thought it was a problem that the HKS unit was not enough spark to burn all that fuel, but then we install the M&W with the 4 coils and the problem Persist.
Aparently my driver on the ems that holds the signal of the injectors have a malfunction.

Do you have also 4 id1000cc in your excessive lim? CAUSE THAT WILL MAKE CLEAR THAT THE EMS HAVE A PROBLEM...

ALSO PLEASE LET ME KNOW WHO SELL TO YOU THE MAGNECOR WIRES.
THANKS AGAIN

Call Magnecore direct. Not sure of the number off hand, but google it. And yes I think thats your poblem so long as you checked everything else and it seems you did. Just incase, throw a new set of 11.5 race plugs in as well.

I didn't realize the M&W needed some specific wires to run properly. I'm just using basic Racing Beat wires. Where did you get your wires or could anyone confirm this?

thewird

Not to be a smart ass, bro, but who do you need to confirm it? I read it in the manual. And the car didn't run right (high boost) with a clean pull till I used the recommended wires. The Tec3 recommends them as well. I bought my wires straight from Magnacore.
http://www.magnecor.com/magnecor1/main.htm

Well, I have no issues at all with my current wires even @ 20 PSi with water injection. But if I can get stronger ignition, I'm all for it. Of course I know your running like 30 PSi or more so your experience is more noteworthy. The manual only suggests you use Magnecore wires but doesn't say you have to use them. Honestly, I hadn't really thought about it until I read your post. I installed what I had, it worked, it ran, it doesn't breakup, so I didn't look into it. I guess I was kinda looking for a confirmation it would be better then my current racing beat wires before I go out and spend money on new wires :P.

On a side note, do you know where these could be purchased off the shelf? I set up my coils so I can use stock sized wires.

thewird