Update: Car still runs like ****. Vacuum/boost looks fairly stable. I noticed it's really obvious in 5th gear on the fwy when it's under a load. It happened a few times yesterday and while I was accelerating in 5th, I looked over and my wideband read a solid 10.0 from about 3-5k rpms. I tried it several times afterwards and had different readings. The next try, it was about 10.7-11 and it seemed fine.
I also took it to Sam on thursday to see if he knew what was up. I took him for a short spin and it did do it but not to the degree it does it on the freeway. He again mentioned that it's more than likely the EU not being suffecient enough for the amount of boost I'm running.

Again, I don't understand how the car could run perfect and then gradually run worse. It turned from a slight hiccup every once ina while to hiccups all the time. I know the VPRO is superior to the EU and I would love to have it in my car but I don't see how someone can install something and realize it runs perfect......then months and months later tell me that it's the EU all of a sudden. I'm very confused and frustrated at this point.

I think Sam knows what he's doing and I trust my car @ GTM but something isn't right here. I don't think it's wrong of me to THINK the car should run perfect from the time I got it back til now, do you guys? If you guys had a perfect running car and then all of a sudden the installer told you, oh well it's ur Engine management, you would raise questions as well.

-Anthony


For those who missed the first thread:

Car ran perfect for the first couple months. Car started OCCASIONALLY hiccuping on fast upshifts or downshifts. It's now to the point where it will not move anywhere until I let off the gas and do it slowly or keep on the gas and wait a whole second or so. It sometimes feels as if it's hitting a brick wall. Emanage Ultimate + GTM build engine.

 

what boost whp u running btw?

list your mods

u could always upgrade to utec which is better prooven on the Z than EU with out paying the fcon price tag if you want.

 

I would ask sam to dyno the car again and check the A/F to make sure everything is in order. He might just need to retune it again. I would do that first before going onto the HKS. It just seems like GTM wants all their customers to have HKS even if its minimal hp goals. They have to understand that not everyone can afford a 3K engine managment and they need other options.

 

I would also be skeptical, but it has been proven that there have been numerous headaches when running the e-ultimate.

 

+1

Like recommending the HKS IS over the Utec. Not stating which is better because i do not know all of the features of the IS, but i did find it kind of interesting. But i do know the IS is a piggy back and uses 16x24 maps.

 

Weather/temps changing causing change in A/F's?

 

sounds like it's going into limp mode and/or an electrical/ECU issue... any CELs? 5AT or 6MT? Did you use a prewired harness? Got a datalogging tool like Cipher? Get some logs and narrow it down...

 

switch to the UTEC or FCON. I have seen EU's do the same thing. There was this rediculous hesitation between shifts that we could never figure out, on one particular car. Switched to the UTEC and it went away. ECU electronics are very sensitive to EMI, and maybe your car has developed a little noise or interference that suddenly has caused this issue for you.

My best advice, is remove the EU.

 

Thanks everyone for the responses.

low boost ~10 psi ~422rwhp
high boost~15 psi 509rwhp
NO CEL'S, no wierd idling, nothing out of the ordinary until it happens.
6MT

As far as weather...It's done it in 65 deg. weather all the way to 95 deg. weather. It's done it equally as bad on a cold night. The weather has gone up significantly since the tune in January though.

Sam did tell me the EU was not very good past 400+rwhp but I went ahead and tuned it anyways...and like I imagined everything was perfect...I couldn't be happier. I don't have anything to log it with and yes it has the autosport harness I believe. Sam said he'd change it out for the FCON and if the problem didn't go away he would yank it...but that would still leave me with this PROBLEM. By no means am I an EManagement expert but it seems odd to me that the EU would just screw up the A/F so badly over time. Whatever the fix may be I deff. want to find out soon and have this problem resolved.

Sharif: It happens while i'm accelerating as well. Example: 3rd gear run on the fwy last week- went hard from 4-5.5k rpms and hit a brick wall at around 5.5. Like the feeling of traction control kicking in when you're spinning your tires. It's happened while accelerating on the onramp half-throttling it. One thing i noticed was that it seems to happen more when there's a bigger load on the car (a/c on going uphill).

-Anthony

 

i say reset your ecu and see if it happens again bc it might just be in limp mode.

 

VDC off? That brick wall-limiter type feeling could be EM pulling timing for knock? Not sure if the EMU pulls timing like the UTEC....

 

VDC off it still does it. Tried unplugging everything for a whole day/nite and nothing changed at all. If it does happen to be the EU then I would imagine it doing what Alberto said. I'm not 100% sure if the EU pulls timing like the UTEC but I would imagine that's what's happening and it's running pig rich? Of course I'm not an expert but anything could help me out here!

Alberto: how's the UTEC working for you? We have almost the same amount of power/boost...any problems with it AT ALL?

 

From what I have read about the EU does indeed pull timing. I too have the EU and I didnt have any issues with it and I was making 430hp.

Did u use the autosport harness and soldier the connections? Did u try unplugging the EU and making sure everything is plug in fully? Maybe loose wire connection?

U mention earlier that u were running pig rich with 10 A/F at WOT so could it be bogging out due to having too much fuel up top?

 

friggin A... same shat happened to me. car ran like a champ for couple of months. than started running weird.. hesitation came back, under acceleration. then felt like I lost power. then the timing chain guide broke, several weeks after that. It's back at GTM for some TLC.

 

Mr. PharmD: unplugged the EU and the battery for over a day and a half. Nothing changed.

Canny: What's your story? You said it 'came back' ?
Anyways I will be extremely pissed if this results in me leaving my car at GTM for weeks. Blah. What EM are you running?

 

so u dont thinkk u are bogging out bc of your richness? I believe canny was using the the unichip.

I still think u should get it back on the dyno bc at this pt only thing we can do is guess.

 

long awhile back, my car hesitated as if the fuel was getting cutoff. got it retuned and did a bunch of other stuff.. and was running like a champ for couple months. then the hesiation came back and it sort of 'slowly' died. later timing chain guide broke off. My car, basically shutoff on the freeway... pretty weird.. I'm running 12psi with unichip.

 

Well I'm sure it's hesitating because it's dumping too much fuel. But why is the question and what's the fix! The problem with the dyno is...it's not free. This really sucks. Ever since I've put on the TT I haven't had it run perfect for more than a couple months.

-Anthony

 

There is nothing here that I have not communicated with Anthony several times, here is a recap:


Cause:

The car does has a rich bog down condition (rich spot) that is the reason why the car does what its doing. This is very apparent because when it does happen the AEM wideband gauge shows 10:1A/F ratio, since this is the lowest the gauge can read it could actually be running richer than this.

So you may think well simple just lean it out right? Not so simple, when configuring the e-Manage Ultimate for tuning you set the RPM vs. Load axis for what ever boost pressures you are going to be running. If you want to have the best drive ability possible you will have to allow as many cells (real estate) as possible for vacuum on the 16X16 map. Well this definitely will allow you to have a well tuned car with great drive ability, BUT it will take away from the boost side of the map since we are trying to squeeze 1 to 15 psi in 10 cells.

This was proven because when I tried to pull some fuel out in the smallest increment that was taken out would now cause a lean condition. (lack of resolution)


Correction:

Re-tune the car and reconfigure the map to be focused on boost and not vacuum. This will fix the rich spot, but now driveability will probally suffer, I am not saying that the car will run poorly on cruise but definetly driveability will get affected. Since this is a daily driven car and not a race car I would not recomend that. I think the majorty of the driving ant830 does is melo cruising style, and that is why there was great emphasis on having perfect driveability.

At the end of day the car made 509 to the wheel on 91 octane pump gas using a 16X16 resolution maf offest device.

Recommendation:

Run less boost, max 10 psi for better resolution or acquire a better engine management system.

Sam
GT Motorsports

 

Thats one thing i like about Sam.
He lays it all out for you so that even the "noobs" (me) can understand. Once again, great work.

SAMS CLUB FTMFW. =)