deep hum after R1 install?

**jankaroni** · 10-24-2008 03:41 PM

I just put in my APR R1 diverter valve and replaced the vacuum line from the diverter valve to the front of the mani., now if i hold the throttle so that my vacuum is at 5 inHG it makes this deep humming noise that is pretty loud and really annoying, anyone have any clue as to how to solve this?

i have to assume it has to do with the vacuum system since it never did this before i did these 2 things today

**jankaroni** · 10-24-2008 05:56 PM

i should also note that the car seems to boost fine as it always did, just now it has this annoying hum when held at or passing by 5 inHG

**jankaroni** · 10-25-2008 01:16 AM

no one has ever had this sound?? that would be my luck though

**burner799** · 10-25-2008 01:19 AM

where does the noise come from? I don't see how having a different diverter valve mill make a noise just from 5 in of vacuum....don't get it.

**jaustin** · 10-25-2008 07:10 AM

I have this same issue but mine does it around 8-10... but im only using a 710N and replaced my line as I thought that might be the cause and it wasnt.

**jankaroni** · 10-25-2008 07:27 AM

it sounds like it is coming from the engine bay, it is hard to tell exactly where from because its not really possible to pull up 5 inHG of vacuum while sitting still the only time i can do it is while I am driving and obviously no one can sit in my engine bay and listen at that point...haha... maybe I used the wrong size vacuum line or something (maybe 1/32 off) but I dont see how that would create this issue. I am completely baffled.

**jankaroni** · 10-25-2008 07:43 AM

i have googled this and found other people having the similar problem with the R1 other people are referring to it as a "honk" noise too but they are saying it is possibly the diaphragm vibrating or making the noise. Where to go from here is beyond me, some people said APR suggested changing the spring in the valve but this only lessened the problem in most cases, not got rid of it

**bbkid43** · 10-25-2008 03:48 PM

had this same problem with a 710n. picked up a evoms dv with metal piston and problem solved

**bandit** · 10-25-2008 04:35 PM

your first mistake was buying the R1

Ive heard that it makes funny sounds.

**Calabria** · 10-25-2008 05:26 PM

Ya, those are notrious for there 'mooing'. Dont really know what the deal is, but everyone who had this problem kept the boost fine, just a weird noise. APR didnt really cover the case for this 'problem' either...

**Accel** · 10-25-2008 06:26 PM

I had the issue with mine, they didn't have a strong enough spring, and you have to send them back to APR to have the spring changed, so my shop exchanged it for a Forge and all is good.

**jankaroni** · 10-26-2008 06:09 AM

Yeah I didn't do a whole lot of research on it other then looking on the APR website, I guess I figured it was an APR product so it would be a quality piece given their reputation and the price of the god damn thing.

**maxspeed** · 10-26-2008 06:23 PM

its because of how it sits in the ic piping,if you push it into far there wont be an even airflow,and itll stick into the tube a little bit, that humming is the equivelant of blowing over the top of an empty beer bottle... harmonic resonance is the term i believe...

**jankaroni** · 10-26-2008 07:40 PM

Originally Posted by maxspeed

its because of how it sits in the ic piping,if you push it into far there wont be an even airflow,and itll stick into the tube a little bit, that humming is the equivelant of blowing over the top of an empty beer bottle... harmonic resonance is the term i believe...

so are you saying I should just pull it back out of the IC piping a little but and clamp it back down?? I mean I could give that a try and if it works great, if not APR is gonna get a nice little call from me. How could they sell something like that? That is something that they would have to notice during the testing and development of this valve.