AO

I think I know the answer to this, but this morning, on my way to work I was doing a bit of testing (now that I can see my gages). When I punch it, my boost goes to about 7 but as I get into higher rpms, the boost drops off - down to 2 or 1. I think this means that my belt is slipping. I do have some belt dust, so I'm pretty sure this is what is happening. Do you concur?

DR

Andrew,

BTW, Killer job on the gauge install!! I like A LOT!!

Yes, when you installed the new belt it has now gone thru it's initial stretch (just like the timing belt) and is slipping. Tighten that sucker back up :-)

Tim Murphy

Andrew,
I ran the Provent in my car and some of the seals failed and caused it to block off all flow to the outlet. It turns out the vacuum relief diaphram is not compatible with under hood temps and petroleum oil (go figure). I was able to fix it so it would work again but was still not up to the task for my 15psi car and lengthy WOT conditions. I showed Tom F at SITM what I did to fix it and I can show you when you visit next week.
Now for a disclaimer: I was saturating mine with oil that most of you will not be doing.

AO

Ok DR... I'll get 'er done.

Tim-
That'd be great to see. Looking forward to getting my hands a bit dirty next weekend.

Tim Murphy

That is where I had my Provent hooked up and I had all kinds of problems.

Finally I followed Todd's idea and had him make a separator box like he made for his car. I did some research on the theory of separating solid oil particles from air and incorporated some that into his design. The box doesn't look like much but there is a lot going on inside with a bunch of quiet zones, baffle plates for solids to hit and collect on etc. I think the air has to turn 17 corners to get out. I've put it through some pretty good testing and so far it is 100%. I have one -10 hose on each forward valve cover and I run those two hoses through the fender to the air box. I have a -8 drain hose that feeds into the oil drain on the oil pan via a metric adaptor fitting to AN8.

Here is a picture of it in the fender.

hacker-pschorr

I was talking to Todd about having him make another air / oil seperator for my track car. Looking at the install location - it will block my brake cooling ducts (not an issue on the S4's) need to rethink the mounting location.

Louie928

Nice looking separator and novel approach to mounting it where the cross brace was to hold the fender liners. Todd's work is pure art. When your major crankcase vent is from the cam covers you'll have a lot of oil to deal with and this evidently is the answer.

Tim Murphy

So far soo good.

This one cost a bunch of money to make because of the time trying to figure everything out. Then it was all hand cut with a jig saw and welded together.

If there was enough interest, I could have this all drawn up and have a metal fab shop cut it and bend it and then Todd weld it. If we made them in lots of 5 or 10 the price might not be too bad. I was tired of dealing with the problem so I was willing to pay the piper to get it fixed and move on. I'm guessing the price would be 3+ times the price of a Provent which Dave sells for $125 (that's a lot better deal than what I paid for my Provent). If that doesn't scare everyone then I would be willing to put some time into getting a firmer price.

Carl Fausett

I reported the ProVent failed on my SC 928 also - first at Road America and then at the Milwaukee Mile. The pressure releif valve in the cap was blowing out - that was the first problem. I "fixed" that and then we discovered that the underhood temps were making the plastic soft, and the top was unlatching itself from the body. The top would pop off, and oil flows out over the headers, and you can guess the rest.

When you spend $360 in entry fees and your ProVent dumps oil all over the place so you get flagged - you get pretty upset.

Like Tim, I started researching good air/oil separator designs. Every design I could find or engineer I could talk to insisted that the breather be top-most in the catch can/separator.... the best designs have the air exit out the top. The ProVent is dumb that way - runs the air flow in the opposite direction - air/oil mix enters high and exits lower.

Glen Larson reported that once the media in the ProVent got oil-soaked, it was restrictive. It could not pass significant amounts of CFM once oiled. That's a problem too, creating unwanted crankcase pressure.


PS: I have a ProVent for sale.... only has two races on it... might be good for street use or lower boost application where it might be just fine.

Airflite40

i'm not boosted, but I have a provent, and i happened to look in this thread. my provent is mounted where the belt fan used to be, so it should get a good amount of airflow. when i first mounted it, i thought the oil return port was very small, compared to the other two ports which are 1" in diameter. do you guys think that it is still good enough for street use? i removed the original oil seperator because it was cracked and pouring oil. my car hasnt seen the road much since i installed it and i am not running synthetic oil, but regular mobil1 20W50.

pmotts

Count me in as 1 of 5

Darien

What's the concensus on Fuel Pressure at WOT and max boost?? I'm only showing 60-65 psi, I think that's low??

My idle is 30-35 psi, so if I try to dial in the BEGI for more fuel at max boost, I'm getting too rich too soon (damn 30lb injectors ).

If someone has already posted a similar question, please show me the way

BrianG

What is max-boost for your car?

What is your A/F ratio at WOT?

I suppose that some relationship of boost/F-P/ and A/F ratio, to RPMs would be critical to answer your question, too?

Darien

I'm getting 9.5-10 psi max boost.

My next question is can a bad O2 sensor cause erroneous fuel pressures? My A/F gauge shows rich at idle times with minimal fuel pressure?

John Speake

>>>>>>>>>>>>>>>>

The answer is to use a SharkTuner !