How can I lower my FP with the Walbro and Cartech?
08-03-2003, 11:28 AM
#1
How can I lower my FP with the Walbro and Cartech?
Well the issue is that at 5psi im pushing about 70psi FP. Its way too high and it keeps bogging the engine at partial throttle because it running way too rich.
So I turned the cartech all the way down to the lowest setting, and still I hit about 65psi on the FP. Almost seems like the cartech is doing nothing when I make the changes.
Is this because the Walbro is High Pressure fuel pump and its going to push in those high levels?
Do I need to replace the OEM FP regulator or just raise the boost and map it to that? I know I need to raise the boost, but need to resolve a few issues before that.
Dixit
So I turned the cartech all the way down to the lowest setting, and still I hit about 65psi on the FP. Almost seems like the cartech is doing nothing when I make the changes.
Is this because the Walbro is High Pressure fuel pump and its going to push in those high levels?
Do I need to replace the OEM FP regulator or just raise the boost and map it to that? I know I need to raise the boost, but need to resolve a few issues before that.
Dixit
08-03-2003, 12:30 PM
#4
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The s-afc does not remove fuel in this sense, he wants to lower fuel pressure, the s-afc doesn't do that.
The s-afc changes the pulse lengths of the injectors....
The only way to lower fuel pressure is with his cartech fpr.
The s-afc changes the pulse lengths of the injectors....
The only way to lower fuel pressure is with his cartech fpr.
08-03-2003, 01:20 PM
#6
seximagtr: I turned the one on the side, the only ****. The other adjuster is the bolt on the top that needs to be adjusted with an Allen Key. That is basically where the FMU starts kicking in.
But Ive turned the Cartech all the way to the left and all the way to the right and get really no change.
I just wanted to know if this is normal when Im using the Walbro 255lph High Pressure pump? Can it not go below 60psi when it starts boosting?
Jay25: Turning it to 7psi is going to be tough, Im going to need to get an electronic boost controller. This manual crap dont cut it in trying to keep it at 7psi. It changes when the engine bay gets hot and allows it to boost to 10psi then.
Dixit
But Ive turned the Cartech all the way to the left and all the way to the right and get really no change.
I just wanted to know if this is normal when Im using the Walbro 255lph High Pressure pump? Can it not go below 60psi when it starts boosting?
Jay25: Turning it to 7psi is going to be tough, Im going to need to get an electronic boost controller. This manual crap dont cut it in trying to keep it at 7psi. It changes when the engine bay gets hot and allows it to boost to 10psi then.
Dixit
08-03-2003, 01:30 PM
#7
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OOPS sorry I see, me and baggs may take a trip up north for a couple of mins maybe youd come along, just to see an install in progress, let me know, you got my home number or cell or call kirk later on
Jaime
Jaime
08-03-2003, 01:45 PM
#8
Originally posted by seximagtr
The s-afc does not remove fuel in this sense, he wants to lower fuel pressure, the s-afc doesn't do that.
The s-afc changes the pulse lengths of the injectors....
The only way to lower fuel pressure is with his cartech fpr.
The s-afc does not remove fuel in this sense, he wants to lower fuel pressure, the s-afc doesn't do that.
The s-afc changes the pulse lengths of the injectors....
The only way to lower fuel pressure is with his cartech fpr.
If he can't lower the fuel pressure then obviously he needs to go to the next logical step and trim out the fuel with the AFC.
08-03-2003, 01:51 PM
#9
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you didn't mention fuel pressure, but adjusting the pulse width is not what bigdojonx wants to do... I'm sure he knows that it's an option, but it's inneficient if you have to remove say 20% fuel across the band by shortening the pulse... a much better way would be to actually use the cartech for what it was made for.
08-03-2003, 01:54 PM
#10
Originally posted by seximagtr
you didn't mention fuel pressure, but adjusting the pulse width is not what bigdojonx wants to do... I'm sure he knows that it's an option, but it's inneficient if you have to remove say 20% fuel across the band by shortening the pulse... a much better way would be to actually use the cartech for what it was made for.
you didn't mention fuel pressure, but adjusting the pulse width is not what bigdojonx wants to do... I'm sure he knows that it's an option, but it's inneficient if you have to remove say 20% fuel across the band by shortening the pulse... a much better way would be to actually use the cartech for what it was made for.
You're not the only person that realizes this.
Adjusting the AFC would be an easy temp. fix untill he solves the cartech problem.
08-03-2003, 06:49 PM
#12
Re: How can I lower my FP with the Walbro and Cartech?
Originally posted by BigDogJonx
Well the issue is that at 5psi im pushing about 70psi FP. Its way too high and it keeps bogging the engine at partial throttle because it running way too rich.
So I turned the cartech all the way down to the lowest setting, and still I hit about 65psi on the FP. Almost seems like the cartech is doing nothing when I make the changes.
Is this because the Walbro is High Pressure fuel pump and its going to push in those high levels?
Do I need to replace the OEM FP regulator or just raise the boost and map it to that? I know I need to raise the boost, but need to resolve a few issues before that.
Dixit
Well the issue is that at 5psi im pushing about 70psi FP. Its way too high and it keeps bogging the engine at partial throttle because it running way too rich.
So I turned the cartech all the way down to the lowest setting, and still I hit about 65psi on the FP. Almost seems like the cartech is doing nothing when I make the changes.
Is this because the Walbro is High Pressure fuel pump and its going to push in those high levels?
Do I need to replace the OEM FP regulator or just raise the boost and map it to that? I know I need to raise the boost, but need to resolve a few issues before that.
Dixit
08-03-2003, 08:09 PM
#13
Its at 44 with are zero vacuum. With the vacuum connected its at 40. Most of the time it sits around 42psi at idle at around 16-18hg vacuum.
I cant take it below 44psi at zero vacuum, the bolt it pretty much loose on the top of the cartech.
Dixit
I cant take it below 44psi at zero vacuum, the bolt it pretty much loose on the top of the cartech.
Dixit
08-03-2003, 08:38 PM
#14
Originally posted by BigDogJonx
Its at 44 with are zero vacuum. With the vacuum connected its at 40. Most of the time it sits around 42psi at idle at around 16-18hg vacuum.
I cant take it below 44psi at zero vacuum, the bolt it pretty much loose on the top of the cartech.
Dixit
Its at 44 with are zero vacuum. With the vacuum connected its at 40. Most of the time it sits around 42psi at idle at around 16-18hg vacuum.
I cant take it below 44psi at zero vacuum, the bolt it pretty much loose on the top of the cartech.
Dixit
08-03-2003, 08:50 PM
#16
Originally posted by seximagtr
that check valve on the newer cartech's, like the 2020 are reversible from what they say.
that check valve on the newer cartech's, like the 2020 are reversible from what they say.
reversible check valve...
air ventilated condom,
glass hammer,
screen door for submarine,
selling your car for gas money.
08-03-2003, 10:34 PM
#17
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Heheh! I like the way you think! Running fat? Turn up the boost!
Seriously though, this won't fix the problem at 6 psi as you pass through, it will bog. The only way to really do it is to remove fuel using an S-AFC or other computer. The S-AFC can be set to remove fuel right at the rpm you are running fat. however this does not work in every gear only the gear you tuned in and at the specific rpms. it is possible to change the S-AFC to run boost referenced tuning with the aid of a boost sensor. If you are trying to tune with only an FMU or just and AFC, then you will undoubtedly run into issues! Please get yourself at least an S-AFC as well.
Good luck!
Seriously though, this won't fix the problem at 6 psi as you pass through, it will bog. The only way to really do it is to remove fuel using an S-AFC or other computer. The S-AFC can be set to remove fuel right at the rpm you are running fat. however this does not work in every gear only the gear you tuned in and at the specific rpms. it is possible to change the S-AFC to run boost referenced tuning with the aid of a boost sensor. If you are trying to tune with only an FMU or just and AFC, then you will undoubtedly run into issues! Please get yourself at least an S-AFC as well.
Good luck!
Originally posted by JAY25
Turn up the boost to at least 7PSI, that should help you with the problem.
Turn up the boost to at least 7PSI, that should help you with the problem.
08-04-2003, 06:02 AM
#18
sxr7: Havent pulled the plugs yet, what should I be looking for if Im running really rich?
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
Nigel: I do have an SAFC2 but havent used it yet to remove fuel, I wanted to redo some of the piping before I start dyno tuning crap.
Dixit
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
Nigel: I do have an SAFC2 but havent used it yet to remove fuel, I wanted to redo some of the piping before I start dyno tuning crap.
Dixit
08-04-2003, 06:34 AM
#19
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With Cartechs we have found quite a bit of variability in how much fuel it actually delivers. Usually we found it runs lean. It could be a spring/adjustment issue with these things, we haven't troubleshot why this is. Your theortical calculation is correct, but depending on your FMU adjustment it may not follow this. Don't know if you can get your hands on a vortech to swap out but that might be something that's pretty easy to do. If you are running rich, you will hear popping when you let off the gas after a boosting. If you run your car through boost and shut the car down immediately then pull the plugs, if you are rich then you'll see black carbon deposits on the plugs. Note don't even let it idle cos that may burn off some of the deposits. One more thing you might want to check for is boost leaks (less likely, but possible). If the leak gets worse under boost your MAF may think you have more air going through it than is actually getting to the engine. If your MAF is close to the TB just check the pipe between TB and MAF. I have had a problem where the boost pipe was not all the way on the TB and would start blowing under boost making it run pretty nasty, when off boost, it would be fine.
Originally posted by BigDogJonx
sxr7: Havent pulled the plugs yet, what should I be looking for if Im running really rich?
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
Nigel: I do have an SAFC2 but havent used it yet to remove fuel, I wanted to redo some of the piping before I start dyno tuning crap.
Dixit
sxr7: Havent pulled the plugs yet, what should I be looking for if Im running really rich?
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
Nigel: I do have an SAFC2 but havent used it yet to remove fuel, I wanted to redo some of the piping before I start dyno tuning crap.
Dixit
08-04-2003, 06:55 AM
#20
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One more thing, if you do have a leak or something like that, if your S-AFC is hooked up you can check max air flow. If you are getting more than about 80% to 85% (somewhere around there) then you probably do have a leak. Your ECU will think it needs to add fuel and will do so.
08-04-2003, 07:59 AM
#21
Originally posted by turbo97SE
The S-AFC can be set to remove fuel right at the rpm you are running fat. however this does not work in every gear only the gear you tuned in and at the specific rpms.
The S-AFC can be set to remove fuel right at the rpm you are running fat. however this does not work in every gear only the gear you tuned in and at the specific rpms.
08-04-2003, 09:48 AM
#22
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Different gears apply different loads and you get different amounts of boost. It's difficult to get full boost (or any decent amount really) in first gear no matter what rpm you get to. Even within the same gear if you are at 3500 rpm, depending on whether you go WOT or just a little throttle, you get different amounts of boost. Boost referenced fuel adjustments are typically better. Please correct me if I am wrong here.
Originally posted by Stephen Max
??? The inputs to the s-afc are engine rpm and mafs voltage. Why does it care what gear it is in?
??? The inputs to the s-afc are engine rpm and mafs voltage. Why does it care what gear it is in?
08-04-2003, 10:10 AM
#23
Nigel, the Throttle percentage on the 5th gens cant be more than 85%, its stated in the FSM as well. Is this the same thing you are talking about?
Im definetely not getting popping noises when I let off the gas when boosting, all I hear the is the SSQV going off.
See heres my problem, when I boost at partial throttle, it kind bogs its way upto 5000 rpm, if I floor it seems better, but still not to the point where it feels like its hauling azz. On the highway for some reason when Im at 80mph, if I need to get to 100mph and do it in the same gear without downshifting (auto) it gets up there really quick and dont feel any hesitation. Last night this cobra stang was trying to leave me and I was right there the whole time without downshifting. Feels good.
But seems that from a light to about 50mph, it dont feel right, its like it hesitates while it gets up there at partial throttle unless I go WOT.
Im going to move the MAF to the intake side as you stated to do months ago, and then see how it reacts, also need to re-do half the piping, the MIG welder is ready to weld, just im too lazy to do it at the moment.
Dixit
Im definetely not getting popping noises when I let off the gas when boosting, all I hear the is the SSQV going off.
See heres my problem, when I boost at partial throttle, it kind bogs its way upto 5000 rpm, if I floor it seems better, but still not to the point where it feels like its hauling azz. On the highway for some reason when Im at 80mph, if I need to get to 100mph and do it in the same gear without downshifting (auto) it gets up there really quick and dont feel any hesitation. Last night this cobra stang was trying to leave me and I was right there the whole time without downshifting. Feels good.
But seems that from a light to about 50mph, it dont feel right, its like it hesitates while it gets up there at partial throttle unless I go WOT.
Im going to move the MAF to the intake side as you stated to do months ago, and then see how it reacts, also need to re-do half the piping, the MIG welder is ready to weld, just im too lazy to do it at the moment.
Dixit
08-04-2003, 10:14 AM
#24
Originally posted by turbo97SE
Different gears apply different loads and you get different amounts of boost. It's difficult to get full boost (or any decent amount really) in first gear no matter what rpm you get to. Even within the same gear if you are at 3500 rpm, depending on whether you go WOT or just a little throttle, you get different amounts of boost. Boost referenced fuel adjustments are typically better. Please correct me if I am wrong here.
Different gears apply different loads and you get different amounts of boost. It's difficult to get full boost (or any decent amount really) in first gear no matter what rpm you get to. Even within the same gear if you are at 3500 rpm, depending on whether you go WOT or just a little throttle, you get different amounts of boost. Boost referenced fuel adjustments are typically better. Please correct me if I am wrong here.
08-04-2003, 11:29 AM
#25
Originally posted by BigDogJonx
sxr7: Havent pulled the plugs yet, what should I be looking for if Im running really rich?
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
sxr7: Havent pulled the plugs yet, what should I be looking for if Im running really rich?
Also I thought FP calculation is 1/2 x (Base FP) + Boost psi x FMU Disc size. If that is correct then 1/2 x (34) + 5 x 4 = 37psi. Is there something wrong? This is where I get lost on the calculation. The base FP is 34psi. Im just lost on how you calculated a 4:1 ratio when Im thinking 65psi is near 10-11:1.
08-04-2003, 01:26 PM
#26
Damn Thomas, you lost me on that calculation of the pressure ratio. Is this another way to get to the FP from what disc size you are running? That caculation you got above, does that show a 10:1 or ? Sorry I lost you on that calculation and im still trying to figure out why im at 65psi even though the cartech is down at 1:1 ratio, or is that normal?
Dixit
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