mortymower

I have an 87 951 and i love the psshhh sound of the atmosphere vented diverter vlaves. However i know it can reak havoc with my afm. Is it possible to achieve this.

toddk911

If it was before the AFM yes. But seeing how it is after, yes, but you will be very rich as the air being blown off has already been meetered by the AFM and supposed to be in the motor.

mortymower

is there a way to make one that is internally vented to sound like this, also, where does it vent it, i guess after the afm

lart951

if you want more sound, you can use this

http://cgi.ebay.com/ebaymotors/Unive...QQcmdZViewItem

Porsche-O-Phile

Anyone got the video where the guy hooks up the duck call to the blow-off valve? Funny ****.

Opeth

I have a Lindsey stg2 MAF and EVO billet valve, you shouldnt need anymore sounds than that. Hell, one of my buddies that dosent know much about cars goes, "WOW, you can really hear the turbo!"

MR951

It can be done. I have a HKS BOV with the stock AFM and it runs fine. As mentioned previously, the car does run a little rich between shifts as metered air is being released to atmosphere vice the combustion chamber. I noted no change in performance, just a cool psshhh sound (which some dislike).

JimBob951

Can you hear you turbo? I can hear mine, and it's mostly stock, just chips, test pipe, and k&n filter. But with the windows open, passing on the interstate, it is really sweet! Of course, those concrete barriers on the interstate help, but still.. Love that boost!

Jim
87 928 S4
87 951

toddk911

Yea, with MAF much more noticeable. And if you have WG dump to atmosphere

I actually scared the guys when they had my car on the dyno!!

"uhhh, you could have warned us it was gonna be that loud"

I told them I didn't know either as I had never been outside standing next to it at full tilt.

Sounded like a jet engine on take off!!!

toddk911

But if you want to try it I belive you leave the bottom part of the DV/BOV unhooked and have to plug that hole in the J Boot.

JimBob951

Yeah I will have to try to make it for the Mt. Dora GTG. Haven't really gotten to see any other 951's up close, plenty of 928's buzzing around here. I am embarrased going out there in my 951 though, since the clear coat is almost gone, and even the paint is from the roof! (got it that way, doesn't look as bad when wet! lol) It was the same color as Opeth's car, some time before I got it...

Jim
87 928 S4
87 951

mclarenno9

It is possible to run a BOV on your 951, I installed one some time ago. I was using the BOV shown below which is a dual-piston design which works with the air flow meter on our cars because it will alway stay closed when idling. The problem with using a regular diverter valve like the stock Bosch one is that it will not stay closed when under vacuum and the engine will stumble once you get off the gas or are idling.

Of course you will need to plug the hole in the J-boot that was used by the old Bosch diverter valve. The hole is 25mm. I went to autozone and bought an "expansion plug" which fit right in, and could be expanded by a nut on the top. Just make sure it is sealed and that whatever you use will not fall into the boot and get sucked into the turbo (bad news!).

This new valve was quite a tight fit in the stock area, I had to trim about half an inch off of the 90 degree rubber hose that goes to the BOV so it would fit. The sound was quite good, just a good woooosh, not too loud either... I had not felt any difference in driving except I did notice a little MORE vacuum while driving and idling (good thing). I suspect my old Bosch unit was leaking. It seemed to work quite well. No idling or stalling issues. Of course I was running rich during shifts because the engine was not seeing the air that the AFM accounted for, but that wasn't too big of a deal in my mind.

One thing I did not think of was that it is normal for 951's to have a bit of oil in the intercooler piping. This was getting all over my engine bay when the BOV opened. It was misting the surrounding area. I eventually went back to my old bosch unit after about a week, and plan on getting a good diverter valve (Forge preferably) once i'm out of school. But yes it is possible to run a BOV on a 951.


Forge FMDV004

Eyal 951

Get a MAF. Lots more performance, you'll hear the diverter valve plenty fine, and you keep the advantages of recirculation. Just reving my car in the driveway with the maf building maybe 2-4 psi with the K26/6 it still sounds, and surprisingly loud for revving in the driveway.

testarossa_td

^^^^^
What he said.

toddk911

Wish mine made boost while just reving

Although mine makes power well into redline I don't need less lag, just more revs!!!