Fuel pulse damper

[J17GT]

I installed an Arcane Stage 3 fuel system and put the car on e85 this spring. Quick facts on the setup: Two Ti 274 pumps, -8an feed to a Y block, -6an feed to each whipple fuel rail, ID 1300 injectors, Deatschwerks DWR2000 regulator, -6an return to the tank. Base pressure set at 55psi with vacuum/boost reference off.

I'm getting some pulsing on the feed lines. You can feel it in the lines and hear it inside he car some, but only while idling. There is some tight routing of the feed lines through the driver wheel well, so I know that is making some of the noise resonate a bit. Ideally though, I should not have this fuel pulsing correct? I do not notice any pulsing from the return line off the regulator.

I called Radium and they suggested a quick test of the return line. Remove the fitting at the regulator and install a short line to a bucket (just use a cheap push lock fitting and rubber hose) and see if the noise/pulsing is still there. This would rule out the smaller return line being a potential cause of the pulsing. If no change there, he suggested a direct mount fuel pulse damper on the fuel rail. The driver side rail has an unused -6 orb port I could use. He did not guarantee this would totally make the pulsing go away as it's all about placement. I could potentially also try an inline damper on the -8an feed before the Y block.

Anyone deal with this? I'm a novice fuel system guy, so looking for input. The car runs great and the tune is dialed in. I just don't like the noise in the car at idle and am wondering if it's ideal to get rid of the pulsing if I can.

Sponsored

 

[HKusp]

You said you can feel it in the feed lines, do you feel it in the rails? I know where you ran the lines in the drivers side fender liner, probably through that sheet metal shroud that the stock lines were in. Are the lines making contact with the fender or that shroud? If so, you might just need to put some rubber between the body and the lines or that shroud and the lines to isolate them so it's not transferring the sound to the car.

 

[J17GT]

Don't think I have put my hand on the rails with the engine running, but I will do that. You can easily feel it on the feed lines in the engine bay.

Yes, I still need to revisit that routing. I have insulated the Y block and that metal plate in the driver wheel well, but for sure there is still some contact. It's much better than it was before, but you still hear it.

Noise aside, is it normal to feel some pulsing in the feed lines?

 

[SheepDog]

Don't think I have put my hand on the rails with the engine running, but I will do that. You can easily feel it on the feed lines in the engine bay.

Yes, I still need to revisit that routing. I have insulated the Y block and that metal plate in the driver wheel well, but for sure there is still some contact. It's much better than it was before, but you still hear it.

Noise aside, is it normal to feel some pulsing in the feed lines?

The pulsing is from the injectors opening and closing, causing an interuption in the flow of fuel. It is normal.

I like to take a piece of heater hose, and split it down the middle. Then I wrap it around any fuel line that makes contact with the car, especially at bend points or potential abrasion or sharp contact points. Then just zip tie the split hose to the fuel line a couple of times. Seems to work

 

[J17GT]

The pulsing is from the injectors opening and closing, causing an interuption in the flow of fuel. It is normal.

I like to take a piece of heater hose, and split it down the middle. Then I wrap it around any fuel line that makes contact with the car, especially at bend points or potential abrasion or sharp contact points. Then just zip tie the split hose to the fuel line a couple of times. Seems to work

I figured it was from the injectors. I just didn’t know what was considered normal or if it’s worth trying to get rid of the pulsing.

Great tip on the heater hose! Wish I would have done that initially, but will have to go back and do that in some areas. I do want to re-route a few things, but that would require changing hose length, redoing ends etc. Probably will at some point, just not in a hurry at the moment.

Sponsored