Mark, It's likley the EMS having problems charging up the stock coils. I've also heard of other people having problems with that.

 

Coolguy, I was thinking the same thing... talking to aem..

 

What plugs are you using and what are they gapped too?

What air fuel ratio are you running?

I don't have experience with the AEM or this dyno so..., but when I have run into ignition missfiring under high loads in the past, the power output/dyno graph was far more eratic/abrupt compared to what I am seeing here.

This almost looks like the AEM is making adjustments possibly due to the knock correction or possibly eratic boost control?

What do the data logs show?

The stock EVO coils actually have the igniter built into the coil, so an aftermarket ECU cannot put an amplified signal into the coil and burn it out. From what I understand, the problem with the emange happened because with the ignition on and the engine not running they were byassing the igniter on all the time. So if you left the ignition on with the engine not running for more than 15 seconds it would burn up the coil. I do not believe any of the other ECU systems have this problem. Coil charging should just be a matter of adjusting the timing.

BTW, the reason the torque and HP do not appear to cross at 5252RPM is because the TQ/HP graphs are scaled differently. If you look at the TQ/HP values at 5200 RPM you will see that they are in fact the same.

 

why is the torque so low considering the much bigger turbo? The stock turbo gave me 322 lbs and at 3600rpm(on a dynojet awd). Its upsetting to see that up until about 5500rpm the stock car will chew you up. I was considering this turbo kit but I will not give up so much to get back a lot after 5500 rpms.

 

Superz:

Dyno's are relative. Let's compare apples to apples. If you look at my earlier post before tuning, the car was at 239 lbs at 4200 rpm peak stock on this dyno.

here it is: https://www.evolutionm.net/forums/sh...ghlight=mmlvmm Note the stock numbers.

I am at over 300 lbs by 4600 rpm so you need to read the chart correctly. It is confusing if you don't look clearly. This tune is not close to done yet because of the spark scatter issue and finishing engine mods so we are running stock boost level.

I went from 239lbs peak torque with the car stock at 4200 rpm to 333 lbs at 4900 AT STOCK BOOST LEVELS with the gt40...

94Lbs more of torque at stock boost isn't the point of this big turbo though. It is interesting just how much more cfm it flows than stock at a given level of boost....

I will report what happens when I turn up the boost and actually use this turbo's capability after finishing the motor and aem
tune....

 

I spoke with Josh, a tech at AEM who actually called me back after I left a message about the spark scatter...

Kudos to him for calling me back and takiing some time to answer my questions.

Josh said that he wasn't familiar with it on the evo but he said it was common once you make 400 + on supras'

Bottom line is more spark is supposed to be the cure as well as will help produce more power. Plan on upgrading your ignition if you are doing the ems apparently....

I am not sure why it is an issue when using the ems vs not but I have gotten 2 other experienced aem tuners who said the same.

 

cough, cough...

 

HAS ANYONE EVER THOUGHT THAT THE FLUCTUATION HAS TO DO WITH DIFFERENT DYNOS?

The dyno that Al's using seems more inexact in general. The reason i say this is that looking at MY stock dyno chart from Brainstorm, the stock graph also shows those fluctuations as well. Being that my car is completely stock, it seems to me that the dyno is just more exact and more responsive that whichever one AL is using.

 

Alex Alex,

Kudos for making things obvious... Stock evos dyno about 236 hp and 250 torque on this dyno... Mine is doing 403 and 333 with major spark problems... It is what it is....

 

give me the red graph please!

 

?

 

So iits an expensive setup that runs like crap what else is new?

 

Quote:

So iits an expensive setup that runs like crap what else is new?

Hey Andre 3000, contribute or shut the **** up and get off this thread... Useless insults are not appropriate for a tech forum... especially ones that don't even try to say anything remotely of value...

 

Well you say that the spark system isnt adequate yet there are lotsa people running higher power than this and even using the same system to do it with no irregularities and your tuner says you now need a MSD box to fix a tuning prob?

 

Actually the AEM TECH said that not my tuner... This problem exists with the aem ecm- that is the point... It is occuring on the aem with supras according to the tech and I have 3 other tuners finding this to be true with the aem. The fact that you probably want to upgrade the ignition if your going with the aem is not necessarily a bad thing... you probably should be if your modding the car enough to make the aem worth it.

Stand alones are never for the faint of heart and piggyback vs flash vs standalone depends on what you are willing to do to the car... The aem can be made to run as good as stock though with proper tuning. See what Tim at Burshur or RRE comes up with for example. Once this baby is dialed in you will see a lot more of them.

As others have said, not for everyone... are you going to do headwork or internals or be willing to invest in dyno time for instance...?