Is this a Fuel Cut Defenser?

batmanfc · 11-14-2009, 04:01 PM

Seen this hooked to the Boost sensor so I figured I would take a pic of it to see what it is. I believe its a Fuel Cut Defenser but I'm not positive.

Whizbang · 11-14-2009, 04:06 PM

yup

batmanfc · 11-14-2009, 04:10 PM

Awesome. Thanks I thought it was but I wasn't sure. I bought the car with everything on it and it has a full 3" turbo back and I know they can cause the boost to go up. I've been really careful driving it to make sure I didn't hit FCD and blow it up.

dawicka2 · 11-16-2009, 07:44 AM

They dont "cause" boost to go up......your exhaust does do to decreased restriction.

How many lbs of boost are you running? That dangerous bast ard will blow your car up, if you havent increased fuel provisions.

Take it out or look into an rtek ecu upgrade from pocket logger dot com....all one word (assuming you dont have one)

john ny

Max777 · 11-16-2009, 09:16 PM

/\ actually, he can get a walbro fuel pump, port the waste gate, and be fine. the rtek is only worth it if you get the 1.7 chip and 720 injectors. (the fuel map is altered for bigger injectors)

Also, hitting fuel cut will actually SAVE your car from blowing up, it's more dangerous to run a car with it and no fuel mods. (pump, larger injectors, etc) There is NO confirmed cases of a car blowing it motor due to the fuel cut, however there are plenty of cases where it was caused due to overboosting the motor cause the wastegate wasn't ported or the guy went lean.

The way fuel cut works, it takes ALL fuel away from from the rear rotor, so it's like the engine shuts down for a sec, the front and rear rotors have individual injectors, so it wont make the front rotor go lean.

Search the evil forum on this topic, it's been discussed numerous times.

Max.

RETed · 11-18-2009, 12:10 PM

Quote:

Originally Posted by Max777

There is NO confirmed cases of a car blowing it motor due to the fuel cut,

Sorry, but I've done it.
I've posted it before, but short version...

1987 Turbo II
Estimated mileage around 70k miles
This happened back in around 1997 or so.
The car had relatively low miles given it's age back then.
Assume motor was in good condition due to low mileage.
STOCK exhaust but all cats punched out.
60mph on the freeway in 5th gear
Punch it once, engine hesitated
Wondered if it was overboost fuel-cut...
Do it again.
Engine stutters.
Clutch in...idle screwed.
Subsequent teardown shows rear rotor let go.

I have said this before, and I will say this again, the stock overboost fuel cut WILL kill the engine.
The stock ECU only kills fuel to the REAR rotor.
Banging off the overboost fuel-cut results in too violent of an effect.
I'm living proof that it is possible.

FCD + upgrade fuel pump is usually all you need to fix this problem.

-Ted

Max777 · 11-18-2009, 02:33 PM

There are plenty of people who have a fuel cut rev limiter, or a fuel cut traction control system that they use with a rotary, and have reported zero problems from it. And this is with the system banging off the limiter at full blast, the engine stayed together just fine multiple times. (but it was both rotors as far as I know)

Rear rotor cut only: the intake separates the front and rear runners, as well as front and rear injectors. Since all the fuel is cut from the rotor, a lean condition is not supposed to occur, and it should be just like the engine stops running for a sec. This is what I've gathered from 3~4 hours of research on the subject...

Multiple people said that it's a lot more common to blow the car up not because of fuel cut, but because of overboost and lack of fuel... so what's been recommended to me is to upgrade either the fuel system along with the FCD like you said, or to port the waste-gate so that the car can maintain lower boost easier.

Perhaps in your scenario, the engine went lean right before the fuel cut, hence making it seem as if the fuel cut itself made it happen?

The whole debate almost makes me want to take the FCD out of my car and try to repeat the same condition, but with an upgraded fuel system, ported waste-gate, etc... as well just to see if I can get it to happen. Until then I'll remain skeptical.

RETed · 11-19-2009, 06:32 AM

You can believe me or not.
Call it a data point, but I'm standing by my experience.

-Ted

dawicka2 · 11-19-2009, 08:24 AM

Quote:

Originally Posted by Max777

/\ actually, he can get a walbro fuel pump, port the waste gate, and be fine. The 1.5 chip doesnt really do much more than the ...........
Search the evil forum on this topic, it's been discussed numerous times.
EDIT: it appears that the 1.5 chip DOES do more than FCD, but I still say that it's not worth it untill you get 720's as well because you already have the most important part of it. (FCD)

http://pocketlogger.com/index.php?pi...age=1&ecu=S4T2

lol....Yeah i researched all that on the evil site a couple of years ago when i built my car.

I was simply saying that an fcd is bad news if you dont have proper fuel provisions.

Was reccomending rtek1.7 to remedy that.

Just was making sure that OP doesnt think that the fcd raised boost and made his car hit fuel cut....thats how his post read.

John ny

Nismo · 11-19-2009, 08:36 PM

The 1.5 does alter timing maps, and lowers the secondary injector staging by 300RPM, it works great!!! I made 240whp with one, with stock fuel pump, IC, 550's, and turbo, this was on a JSPEC that I daily drove for 3 years putting an additional 50000km's on it, it did eventually blow up in vacuum after having fuel starvation issues due to a clogged intank sock.

Max777 · 11-19-2009, 11:55 PM

Really? Damn, that sounds good, maybe I will get a 1.5 for now until I bother spending money on the 720cc....

How difficult was it to install the 1.5 chip? Did you have to desolder anything or was it just a chip swap? Another reason I am hesitant about the 1.5 is because it doesnt have the flood clear. =(

I'm also considering going with a megasquirt, however this would mean possible trailering the car to a tuner, which sucks.

Quote:

Originally Posted by RETed

You can believe me or not.
Call it a data point, but I'm standing by my experience.

-Ted

I DO believe your experience.

Nismo · 11-20-2009, 06:10 PM

Quote:

Originally Posted by Max777

Really? Damn, that sounds good, maybe I will get a 1.5 for now until I bother spending money on the 720cc....

How difficult was it to install the 1.5 chip? Did you have to desolder anything or was it just a chip swap? Another reason I am hesitant about the 1.5 is because it doesnt have the flood clear. =(

I'm also considering going with a megasquirt, however this would mean possible trailering the car to a tuner, which sucks.

I just sent them the computer.

Max777 · 11-20-2009, 11:13 PM

oh....

11-14-2009, 04:01 PM	#1
batmanfc Rotarys Ruin Lives Join Date: Aug 2009 Location: Wise, VA iTrader: (0) Posts: 66 Rep Power: 16	Is this a Fuel Cut Defenser? Seen this hooked to the Boost sensor so I figured I would take a pic of it to see what it is. I believe its a Fuel Cut Defenser but I'm not positive. __________________ '88 Turbo II '89 GXL '07 Cobalt: DD

11-14-2009, 04:06 PM	#2
Whizbang Respecognize! Join Date: Jul 2008 Location: Δx = ħ/2Δp iTrader: (5) Posts: 3,190 Rep Power: 20	yup __________________ For current updates and event coverage check out Follow on Twitter! @WhizbangRally Whizbang Rally's Webpage \| Facebook

11-14-2009, 04:10 PM	#3
batmanfc Rotarys Ruin Lives Join Date: Aug 2009 Location: Wise, VA iTrader: (0) Posts: 66 Rep Power: 16	Awesome. Thanks I thought it was but I wasn't sure. I bought the car with everything on it and it has a full 3" turbo back and I know they can cause the boost to go up. I've been really careful driving it to make sure I didn't hit FCD and blow it up. __________________ '88 Turbo II '89 GXL '07 Cobalt: DD

11-16-2009, 09:16 PM	#5
Max777 Pirate Join Date: Mar 2008 Location: Central IL iTrader: (5) Posts: 1,323 Rep Power: 18	/\ actually, he can get a walbro fuel pump, port the waste gate, and be fine. the rtek is only worth it if you get the 1.7 chip and 720 injectors. (the fuel map is altered for bigger injectors) Also, hitting fuel cut will actually SAVE your car from blowing up, it's more dangerous to run a car with it and no fuel mods. (pump, larger injectors, etc) There is NO confirmed cases of a car blowing it motor due to the fuel cut, however there are plenty of cases where it was caused due to overboosting the motor cause the wastegate wasn't ported or the guy went lean. The way fuel cut works, it takes ALL fuel away from from the rear rotor, so it's like the engine shuts down for a sec, the front and rear rotors have individual injectors, so it wont make the front rotor go lean. Search the evil forum on this topic, it's been discussed numerous times. Max. __________________ Rotaries:They are NOT that complicated! Last edited by Max777; 11-19-2009 at 11:48 PM..

11-18-2009, 02:33 PM	#7
Max777 Pirate Join Date: Mar 2008 Location: Central IL iTrader: (5) Posts: 1,323 Rep Power: 18	There are plenty of people who have a fuel cut rev limiter, or a fuel cut traction control system that they use with a rotary, and have reported zero problems from it. And this is with the system banging off the limiter at full blast, the engine stayed together just fine multiple times. (but it was both rotors as far as I know) Rear rotor cut only: the intake separates the front and rear runners, as well as front and rear injectors. Since all the fuel is cut from the rotor, a lean condition is not supposed to occur, and it should be just like the engine stops running for a sec. This is what I've gathered from 3~4 hours of research on the subject... Multiple people said that it's a lot more common to blow the car up not because of fuel cut, but because of overboost and lack of fuel... so what's been recommended to me is to upgrade either the fuel system along with the FCD like you said, or to port the waste-gate so that the car can maintain lower boost easier. Perhaps in your scenario, the engine went lean right before the fuel cut, hence making it seem as if the fuel cut itself made it happen? The whole debate almost makes me want to take the FCD out of my car and try to repeat the same condition, but with an upgraded fuel system, ported waste-gate, etc... as well just to see if I can get it to happen. Until then I'll remain skeptical. __________________ Rotaries:They are NOT that complicated! Last edited by Max777; 11-18-2009 at 02:40 PM..

11-16-2009, 07:44 AM	#4
dawicka2 The Newbie Join Date: Nov 2009 iTrader: (0) Posts: 9 Rep Power: 0	They dont "cause" boost to go up......your exhaust does do to decreased restriction. How many lbs of boost are you running? That dangerous bast ard will blow your car up, if you havent increased fuel provisions. Take it out or look into an rtek ecu upgrade from pocket logger dot com....all one word (assuming you dont have one) john ny

11-19-2009, 08:36 PM	#10
Nismo 400WHP or bust Join Date: Mar 2008 Location: Kincardine, Ontario Canada iTrader: (1) Posts: 165 Rep Power: 17	The 1.5 does alter timing maps, and lowers the secondary injector staging by 300RPM, it works great!!! I made 240whp with one, with stock fuel pump, IC, 550's, and turbo, this was on a JSPEC that I daily drove for 3 years putting an additional 50000km's on it, it did eventually blow up in vacuum after having fuel starvation issues due to a clogged intank sock. __________________ 1986 GXL- Being built with a 13B RE... http://www.rotarycarclub.com/rotary_...ead.php?t=9602 1986 Base-RB Exhaust, HKS filter, Solid Aluminum motor mounts, S5 TII motor, ACT Clutch, HKS SSQV, Light Weight Flywheel, Haltech E6X, 720cc 2ndaries, Koni Yellows, Tein Springs Koyo Rad, 250 WHP 230 FTLBS Stock turbo, and stock IC at 10psi. RIP!! The daily bitch- 1995.5 Toyota Tacoma- Trueflow airfilter, and Bilstein HD shocks. 2009 Toyota Corolla "S" TRD Filter... 40MPG

11-20-2009, 11:13 PM	#13
Max777 Pirate Join Date: Mar 2008 Location: Central IL iTrader: (5) Posts: 1,323 Rep Power: 18	oh.... __________________ Rotaries:They are NOT that complicated!