LR billet fuel rail noise?
12-30-2003, 03:29 PM
#17
Burning Brakes
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Originally posted by jwl
tazman, I don't know how you'd add or take air out of the damper because the schrader valve is fuel pressured and the rest of the damper is sealed. I was thinking about talking with the damper manufacture if I can find them,,,, I think it's Marron, see if they have any ideas!
tazman, I don't know how you'd add or take air out of the damper because the schrader valve is fuel pressured and the rest of the damper is sealed. I was thinking about talking with the damper manufacture if I can find them,,,, I think it's Marron, see if they have any ideas!
12-30-2003, 06:20 PM
#18
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Oringinally posted by Laust Pedersen
Think of them as small rockets, each time they squirt, they jump up a bit and actually aid in the dampening. If there isn’t enough vertical motion available they will hit the rail, which will make noise.
Think of them as small rockets, each time they squirt, they jump up a bit and actually aid in the dampening. If there isn’t enough vertical motion available they will hit the rail, which will make noise.
hmmmm,,,maybe take some thin gasket material and place it between the fuel rail mounts? Also, what about adding O-rings at the top and bottom of the injectors to help keep them from jumping up and htting the rail!
12-30-2003, 08:01 PM
#20
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the noise is not from the injectors moving... 90% if not all the noise comes from the injectors opening and closing (void of fuel created)...... the sound can even be transmitted along the body of the car thus intesifying the sound (check if you have fuel lines up against the body of the car) the damper tries to adjust as quickly as it can for these fluxes in pressure. Now if its on a T ?? its not going to work..... The fuel must go through it and the spring loaded diaphram must be able to move to either allow fuel to return or not........
Some of the factory dampers used were adjusted at factory (not sure about porsche or the one lindsey uses). Some use a small screw to be preset at factory. Also some car models had really lousy dampers (noise)...ex. Saab. A few guys I know used a second damper on the line (I don't quite understand that logic) but it seemed to work.....
I think I have to go dig mine out .... ?? I think we better find a solution.... Now where did I put it.... ???
Some of the factory dampers used were adjusted at factory (not sure about porsche or the one lindsey uses). Some use a small screw to be preset at factory. Also some car models had really lousy dampers (noise)...ex. Saab. A few guys I know used a second damper on the line (I don't quite understand that logic) but it seemed to work.....
I think I have to go dig mine out .... ?? I think we better find a solution.... Now where did I put it.... ???
12-30-2003, 08:19 PM
#21
Three Wheelin'
Hmm theres a thought I might have to go to the local hydraulics outfit and get them to put some compression to AN fittings on an old DAMPENER (damper is bread you wallies 
) and then insert it inline with the rest of the fuel setup and see if it makes a difference.
) and then insert it inline with the rest of the fuel setup and see if it makes a difference.
12-30-2003, 10:59 PM
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OK, on the OM rail the fuel enters the damper first then through the rail and out through the pressure regulator. So would you install the old damper on the inlet line before the rail or after it between the tee and the regulator,,,,if that makes sense ?
12-31-2003, 01:53 AM
#23
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OZ951
“Ive tried additional orings on the bottom (manifold) and it didnt help.”
That was less than half the test. If (any of) the injectors make solid contact with the rail then you’ll have the noise described.
Try the following (with the injectors and fuel rail mounted as prescribed): 1) rotate the injectors ± 45 degrees and notice if they feel free to move, except for the friction in the O-rings, 2) you should with you fingers be able to move each injector up and down at least ±0.5mm (.020”).
If any of the above two tests fails, then follow the first part of jwl’s suggestion and add spacers/washers to the fuel rail mounts (not the injectors) until passing the above test.
I just installed 72lb injectors (on OEM an rail) and they are very quiet except when listening to them with an automotive stethoscope.
Again, the injectors have to be free floating and only suspended in their O-rings. When that is the case, noise will not be transmitted.
I have spent 20 years in acoustics and sound transmission, so I do have a reasonably good handle on these things.
Laust
“Ive tried additional orings on the bottom (manifold) and it didnt help.”
That was less than half the test. If (any of) the injectors make solid contact with the rail then you’ll have the noise described.
Try the following (with the injectors and fuel rail mounted as prescribed): 1) rotate the injectors ± 45 degrees and notice if they feel free to move, except for the friction in the O-rings, 2) you should with you fingers be able to move each injector up and down at least ±0.5mm (.020”).
If any of the above two tests fails, then follow the first part of jwl’s suggestion and add spacers/washers to the fuel rail mounts (not the injectors) until passing the above test.
I just installed 72lb injectors (on OEM an rail) and they are very quiet except when listening to them with an automotive stethoscope.
Again, the injectors have to be free floating and only suspended in their O-rings. When that is the case, noise will not be transmitted.
I have spent 20 years in acoustics and sound transmission, so I do have a reasonably good handle on these things.
Laust
01-02-2004, 09:11 AM
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I have written to Dave at Lindsey Racing regarding the noise. His service to me has been really exemplary and I'll buy stuff from him anytime. Despite being sick, he took the trouble to give a detailed reply on New Year's day. Here are his comments regarding the noise, and I quote (with his permission):
"It's a new sound the car now makes with the system that has been changed, not a mechanical problem to worry about. Kind of like installing a big fuel pump. Just not quite like the stock one was anymore... But it's better... Or installing a set of different tires on your car that stick better, but come with a howling when you drive down the street. (I have this on my AO32's)
I have tried a couple of things to quiet it. First, I noticed you can take the injector, pull it towards the rail, then slide it quickly toward the intake manifold and it will make a "Knocking" sound when it touches. That's the direction the fuel pressure in the rail is moving the injector. The injector is opening and closing which is a mechanical movement like a solonoid. Heck, it is a solonoid!
Hard Injector body on Metal Intake manifold. So I took the injectors out and installed a o-ring that was slid over the injector "passed the bottom o-ring" to where it's on the injector just before the housing angles larger to act as a bumper or cushion. Now there is rubber between the injetor and manifold. This helped quite a bit. I have also noticed that when you simply move the position of the feed "in" line, it changes the noise level. Try rotating the line and tightning in a different position.
The manufacturer sent me a different "T" for the back of the rail. It will put the damper out the side or top. I haven't installed it yet due to lack of time, the Holidays, sick employees as well as myself, and a rushed customer car project which leaves tomorrow finally. I may try this T" out today if I can find the ambition on the Holiday and I am still sick.
I "personally" think it's a line issue. When I simply change the line, that will answer that question very quickly. The lines we are using now have a hard plastic/teflon inner core. The stock lines are a rubber line insulating any knocking in the rail. I suspect this hard line is transmitting the noise from the injectors to the steel lines and under the car. It would be like having someone knocking on the water pipes coming into your house. You could hear it throughout the entier house.
I think the answer will be changing the lines we sell to a rubber lined line vs. hard liner. For the ones already out, I will test a small rubber line about 2" long to install at the steel line before going to the stainless line. This "should" be enough insulate the two from one another. Or... the new "T" may be the answer by repositiong the damper."
Hope this answers some questions you guys may have.
"It's a new sound the car now makes with the system that has been changed, not a mechanical problem to worry about. Kind of like installing a big fuel pump. Just not quite like the stock one was anymore... But it's better... Or installing a set of different tires on your car that stick better, but come with a howling when you drive down the street. (I have this on my AO32's)
I have tried a couple of things to quiet it. First, I noticed you can take the injector, pull it towards the rail, then slide it quickly toward the intake manifold and it will make a "Knocking" sound when it touches. That's the direction the fuel pressure in the rail is moving the injector. The injector is opening and closing which is a mechanical movement like a solonoid. Heck, it is a solonoid!
Hard Injector body on Metal Intake manifold. So I took the injectors out and installed a o-ring that was slid over the injector "passed the bottom o-ring" to where it's on the injector just before the housing angles larger to act as a bumper or cushion. Now there is rubber between the injetor and manifold. This helped quite a bit. I have also noticed that when you simply move the position of the feed "in" line, it changes the noise level. Try rotating the line and tightning in a different position. The manufacturer sent me a different "T" for the back of the rail. It will put the damper out the side or top. I haven't installed it yet due to lack of time, the Holidays, sick employees as well as myself, and a rushed customer car project which leaves tomorrow finally. I may try this T" out today if I can find the ambition on the Holiday and I am still sick.
I "personally" think it's a line issue. When I simply change the line, that will answer that question very quickly. The lines we are using now have a hard plastic/teflon inner core. The stock lines are a rubber line insulating any knocking in the rail. I suspect this hard line is transmitting the noise from the injectors to the steel lines and under the car. It would be like having someone knocking on the water pipes coming into your house. You could hear it throughout the entier house.
I think the answer will be changing the lines we sell to a rubber lined line vs. hard liner. For the ones already out, I will test a small rubber line about 2" long to install at the steel line before going to the stainless line. This "should" be enough insulate the two from one another. Or... the new "T" may be the answer by repositiong the damper."
Hope this answers some questions you guys may have.
01-02-2004, 07:38 PM
#25
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Well jwl got the noise to go away this afternoon. He rigged up something,,but I'll let him post the pic(s) of what he found and what he did. He may be trying something else at the moment.....jwl?
01-02-2004, 08:26 PM
#26
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Most newer plumbing in houses has a damper to stop the hamering noise and that damper is a 'T' on the supply line. Might be the same issue here.
Alan C.
Alan C.
01-03-2004, 04:29 PM
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Ok...Jim (jwl) is having computer problems or network problems. I'm going to post the two pictures.
The first one is just an ATTEMPT to get rid of the noise. It's 100 % gone. It's ugly, not practical and you just wouldn't do it; but the noise is gone.
The second is a modification of the first, shorter hoses were made and it was installed in the fender well area. Again, noise 100% gone, car ran fine. I'm going to send this Dave Linidsey, he can send it to Marren and maybe they can come up with something. I am going to try something different when I install my rail; I'm going to install a pc of rubber fuel hose in the fender well, make it have three coils and then hook to the new fuel line similar to below. My theory is the three coils will act as a damper. We'll see if I can get that done with my 89 tranny next week. Here is Jims second picture - installed and operating - no noise.
Thanks Jim for working on it. Good job; we now know it can be eliminated. I'll send the pics to Lindsey so they can forward them to Marren.
The first one is just an ATTEMPT to get rid of the noise. It's 100 % gone. It's ugly, not practical and you just wouldn't do it; but the noise is gone.
The second is a modification of the first, shorter hoses were made and it was installed in the fender well area. Again, noise 100% gone, car ran fine. I'm going to send this Dave Linidsey, he can send it to Marren and maybe they can come up with something. I am going to try something different when I install my rail; I'm going to install a pc of rubber fuel hose in the fender well, make it have three coils and then hook to the new fuel line similar to below. My theory is the three coils will act as a damper. We'll see if I can get that done with my 89 tranny next week. Here is Jims second picture - installed and operating - no noise.
Thanks Jim for working on it. Good job; we now know it can be eliminated. I'll send the pics to Lindsey so they can forward them to Marren.
01-03-2004, 05:52 PM
#30
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Dave may come up with a better solution but hooking in the OM damper (see skis' post) worked from me. No noise,,,100% gone,,,nada!!!
There may be other ways to go about eliminating it but this works and I only spent about 6 bucks doing it!
There may be other ways to go about eliminating it but this works and I only spent about 6 bucks doing it!