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Discussion Starter #1
Alright,

What I am experiencing is what I have concluded to be Fuel Cut.

All I currently have is the AEM CAI and HKS BOV. No boost increase or any other performance mod.

It first happened when I was at the track, right before I hit the 1/4 mile mark, high rpm in 4th gear, the car just jumps, as if I applied the brakes hard.

My question is, is that fuel cut? Why exactly is it happened on an almost stock car?

Also, Wednesday I removed my stock DP just for kicks and well wow its loud, but I experience the jumping again but in mid-3rd gear.

Why is this happening and what can currently be done to fix this?

Thanks for the input. I can't even get low 14's because of this :/
 

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Alright,

What I am experiencing is what I have concluded to be Fuel Cut.

All I currently have is the AEM CAI and HKS BOV. No boost increase or any other performance mod.

It first happened when I was at the track, right before I hit the 1/4 mile mark, high rpm in 4th gear, the car just jumps, as if I applied the brakes hard.

My question is, is that fuel cut? Why exactly is it happened on an almost stock car?

Also, Wednesday I removed my stock DP just for kicks and well wow its loud, but I experience the jumping again but in mid-3rd gear.

Why is this happening and what can currently be done to fix this?

Thanks for the input. I can't even get low 14's because of this :/
[/b]
Most all of us running boost controllers run into the same thing in 3rd and 4th gear at about 6500 rpm. At 15psi at 6500 the car will just cut off and the whole thing jumps. It sucks. If I boost higher then I hit that mark earlier...sometimes as early as 6k.

I've never heard of it happening at stock boost levels though.
 

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Alright,

What I am experiencing is what I have concluded to be Fuel Cut.

All I currently have is the AEM CAI and HKS BOV. No boost increase or any other performance mod.

It first happened when I was at the track, right before I hit the 1/4 mile mark, high rpm in 4th gear, the car just jumps, as if I applied the brakes hard.

My question is, is that fuel cut? Why exactly is it happened on an almost stock car?

Also, Wednesday I removed my stock DP just for kicks and well wow its loud, but I experience the jumping again but in mid-3rd gear.

Why is this happening and what can currently be done to fix this?

Thanks for the input. I can't even get low 14's because of this :/
[/b]
IF YOU dont have a boost controler then you got something wrong there !!
 

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I don't see how a fuel cut would have this effect. It should be the same as going in neutral.
[/b]
I don't follow that logic - you're still in gear. If you cut fuel at high RPM in gear, the drive train and engine compression will slow you down in a hurry. Unless I'm missing something....
 

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No down pipe? Your going to get boost creep like theres no tommorow... thats whats causing it in 3rd....

Pathik, how hard was removing the DP?


IF YOU dont have a boost controler then you got something wrong there !!
[/b]
Something that can't be eliminated from the car if it occurs other than porting the wastegate...

Alright,

What I am experiencing is what I have concluded to be Fuel Cut.

All I currently have is the AEM CAI and HKS BOV. No boost increase or any other performance mod.

It first happened when I was at the track, right before I hit the 1/4 mile mark, high rpm in 4th gear, the car just jumps, as if I applied the brakes hard.

My question is, is that fuel cut? Why exactly is it happened on an almost stock car?

Also, Wednesday I removed my stock DP just for kicks and well wow its loud, but I experience the jumping again but in mid-3rd gear.

Why is this happening and what can currently be done to fix this?

Thanks for the input. I can't even get low 14's because of this :/
[/b]
The 1/4 time you mentioned is not because of the fuel cut.... unless your stopping mid way through 4th.... what was the 60'?
 

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Most all of us running boost controllers run into the same thing in 3rd and 4th gear at about 6500 rpm. At 15psi at 6500 the car will just cut off and the whole thing jumps. It sucks. If I boost higher then I hit that mark earlier...sometimes as early as 6k.

I've never heard of it happening at stock boost levels though.
[/b]
I actually found a little trick with the e-01 that that stops that. I've actually (ONE TIME) cranked it to 19.3psi and and hammered it 1st through 4th. That made this local punk kid with a modded evo mr (funded by daddy) shut up for the rest of the night at the air-strip. Later I saw him peeling a few stickers of his car, lol!!!

Not sure what's going on here. Do you seriously drive it with no downpipe on the car? That probably causes alot of extra heat (~80*-100* I would think) in the engine bay, and might bubble the paint on your hood or melt plastic components. Not to mention the turbo probably spiking like crazy. Try disconnecting your battery for an hour or so. It might go away. Also make sure to run your BOV in recirc. I tried vta with the greddy rs and I remember it poping quite a bit, but I run an open stock dp...
 

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I don't follow that logic - you're still in gear. If you cut fuel at high RPM in gear, the drive train and engine compression will slow you down in a hurry. Unless I'm missing something....
[/b]

I didn't use the right word :)

I meant to say it should be the same as letting off the gas. He described it as hitting on the brakes hard.

I've hit a fuel cut off on my 6s several times and it never felt like hitting on the brakes. 200km/h in 4th gear, high rpms.
 

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I actually found a little trick with the e-01 that that stops that. I've actually (ONE TIME) cranked it to 19.3psi and and hammered it 1st through 4th. That made this local punk kid with a modded evo mr (funded by daddy) shut up for the rest of the night at the air-strip. Later I saw him peeling a few stickers of his car, lol!!!

Not sure what's going on here. Do you seriously drive it with no downpipe on the car? That probably causes alot of extra heat (~80*-100* I would think) in the engine bay, and might bubble the paint on your hood or melt plastic components. Not to mention the turbo probably spiking like crazy. Try disconnecting your battery for an hour or so. It might go away. Also make sure to run your BOV in recirc. I tried vta with the greddy rs and I remember it poping quite a bit, but I run an open stock dp...
[/b]
Hey what trick did you use to hold 19psi all the way?
 

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Discussion Starter #10
I removed one section of the DP, as seen in this picture:



Even with just an intake and BOV I get this experience.

Again, it may not be fuel cut, but the car doesn't shut off. It 'bogs' not sureof a word to describe it but the car jerks for a split second and continues driving.

It only happens under hard acceleration (track). Or during spirted moments.

I might take a video of it someday, try to catch it.

Also, I have read and heard from many turbo drivers of various cars, that Fuel cut results from a car running too rich. Not enough fuel being delivered.
 

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Hey what trick did you use to hold 19psi all the way?
[/b]
Well, on the e-01 I have an option to draw back on boost by a percentage once it hits a certain (set by me) psi level. I had origionally had this set too high, which was giving me some form of power cut. It was happening with 36% set opening, 40% gain, and start boost feature off (it is only applicable to high boost situations). I turned off the "safety boost-cut-back feature" and am now running it at 40% set and 43% gain. That puts me at 19.3psi. Holds great, keeps going, and comes through for me, every time.

I removed one section of the DP, as seen in this picture:



Even with just an intake and BOV I get this experience.

Again, it may not be fuel cut, but the car doesn't shut off. It 'bogs' not sureof a word to describe it but the car jerks for a split second and continues driving.

It only happens under hard acceleration (track). Or during spirted moments.

I might take a video of it someday, try to catch it.

Also, I have read and heard from many turbo drivers of various cars, that Fuel cut results from a car running too rich. Not enough fuel being delivered.
[/b]
That's exactly how I have my exhaust right now. How do you like the cold starts, especially in front of alot of domestic muscle-heads??? :D
 

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Fuel cut is when reach a preset MAF voltage. The ECU is set to only see X amout of voltage at a given load, whne it hits higer, the ECU gives you fuel cut and the car falls on it's face. This can be at 5v or anywhere arounf that mark depending on how the ECU is programmed.

When I ran the MPI on my turbo'd MP3, I could adjust the max voltage the ECU see's from the MAF so you would NEVER get a fuel cut. An FCD (fuel cut defender) kinda does the same but it is not adjustable, I would rather be able to adjust the limit.
 

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Ate Baller what kind of Boost controller are you using again? And you get 19.5psi all the way to 6500rpm? I am going to have a boost controller installed next week and have it setup on a Dyno. Just curious what Boost controoler everyone is using?
 

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Well, on the e-01 I have an option to draw back on boost by a percentage once it hits a certain (set by me) psi level. I had origionally had this set too high, which was giving me some form of power cut. It was happening with 36% set opening, 40% gain, and start boost feature off (it is only applicable to high boost situations). I turned off the "safety boost-cut-back feature" and am now running it at 40% set and 43% gain. That puts me at 19.3psi. Holds great, keeps going, and comes through for me, every time.
That's exactly how I have my exhaust right now. How do you like the cold starts, especially in front of alot of domestic muscle-heads??? :D
[/b]

Interesting. And no fuel cut even at redline?

On the Profec there are the same settings pretty much. Set Gain being the level you want to boost. %50 puts you back around stock 15psi and then gain being how hard it tries to hold that as rpms increase.

"set gain" is where the wastegate starts to open... I've been playing around with that to see how much difference it makes. I can set a warning and the percentage it scales back also but that's usually set so high it never comes on.
 

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I have a cpe intake and I just put a cpe exhaust on and when under heavy load I get a back firing/spudering about the same rpms .I got to see whats up on monday but it did not start till I put the exhaust on friday
 

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Discussion Starter #16
Yeah, whatever it is is because our cars run extremely rich.

The removed HF cat/DP section turns too many heads. My problem is wow its loud. Sounds like a diesel truck, no joke.
 

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Yeah, whatever it is is because our cars run extremely rich.

The removed HF cat/DP section turns too many heads. My problem is wow its loud. Sounds like a diesel truck, no joke.
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Imagine how a car without a catless downpipe and a cutout is going to sound :drool:
 

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Ate Baller what kind of Boost controller are you using again? And you get 19.5psi all the way to 6500rpm? I am going to have a boost controller installed next week and have it setup on a Dyno. Just curious what Boost controoler everyone is using?
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I have the GReddy Profec E-01, Greddy's "self-proclaimed" best ebc on the market.
Here, the install is on page 2...

http://www.cardomain.com/ride/2436049

Interesting. And no fuel cut even at redline?

On the Profec there are the same settings pretty much. Set Gain being the level you want to boost. %50 puts you back around stock 15psi and then gain being how hard it tries to hold that as rpms increase.

"set gain" is where the wastegate starts to open... I've been playing around with that to see how much difference it makes. I can set a warning and the percentage it scales back also but that's usually set so high it never comes on.
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Those don't sound like the same settings I have. I have a "Set- Boost" setting which is a percentage the valve opens, I have a "Gain" setting which is descibed in the book as the rate of boost increase or boost acceleration, and I have a "Start-Boost" setting which allows you to offset the boost to not make it to the motor until it hits a certain level of boost (the book states that this is only for high boost applications so I leave it alone.
 

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Those don't sound like the same settings I have. I have a "Set- Boost" setting which is a percentage the valve opens, I have a "Gain" setting which is descibed in the book as the rate of boost increase or boost acceleration, and I have a "Start-Boost" setting which allows you to offset the boost to not make it to the motor until it hits a certain level of boost (the book states that this is only for high boost applications so I leave it alone.
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The "start boost" setting holds the waistgate closed until you hit the boost level you set it at. Everywhere I have read, it says you should set it 4 psi lower than the boost level you want. For example if you want 17 psi, then you set it at 130 which equals 13 psi.
 

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Discussion Starter #20
Baggio is correct. But don't quote me. That is just what I recall when helping a friend install on on his EVO8.
 
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