Can I bleed the BOV to Atmos..with CIS

[timc]

Originally Posted by JFairman

This sideways or backwards orientation is how I have my 25mm turboxs recirculation BOV installed in the 965 rubber elbow. It works either way but installing it sideways lets boost pressure push the piston open along with manifold vacuum sucking it open at the same time. I think it reacts faster that way but I'm not sure. All I know is it works smoothly and I have little turbo lag between upshifts.

Yeah I found an old thread, posted in one of my previous posts that discusses just that, which recommends orienting the piston side of the BOV to the IC for your reasons above.

I found some spring kits, ordered, should be here tomorrow, so I'll play around with the different rates looking for a rate that will hold up to about 20ish inches to keep the piston closed at idle.

I really miss the old 962 sound between shifits during their heyday in the 80's at Daytona and Sebring....

This has been an interesting experience with the vacuum (both neg and pos) that is created on each side of the TB due to the turbo pressure.....

[T77911S]

i vented my synapse to atomsphere in the push mode. i can here it opening some times. my hearing is VERY bad.
i had some big flames last night after a few hard runs. the lady behind me got a light show. i did not stick around to hear what she thgouht. i dont think she was too happy when i nailed it after she pulled up to the side road.
i dont think the DV had anything to do with the flames.

[Hirevtuner]

Originally Posted by JFairman

I won't try to rewrite everything I thought of before but here's a couple 2 year old pics of my second 32mm BOV that lives under my intercooler.

I use the intake manifold vacuum line from the throttle body that operated the deceleration valve tee'd off to open both of the BOV's and a little brass air valve to control how fast the vacuum hits and opens the black 32mm BOV in relation to the 25mm turboxs recirculation BOV you can't see in these pics.

I think the 25mm recirculating BOV in the 964 elbow hose off the air flow meter is dumping most if it because of how I set that little brass air valve I soldered to the brass vacuum tee, but thats just a guess.

In this pic I have a vacuum solenoid in the vacuum line going to the black BOV so I could disable it from inside the car for comparisons. I've since removed that and they both work all the time.

I started out by venting my good working deceleration valve to atmosphere under the intercooler with the same stainless steel mesh air filter on it but it's small, unadjustable, and ugly so I sold it for $40 and bought this 32mm black anodized adjustable one off ebay for around $35. It's been on there working fine for a couple years now.
I have one of the spring tension washer shims they give you under the piston spring in the black BOV and I greased the spring and brass piston to keep it lubed in it's cylinder.
The small stainless mesh air cleaner is silicone glued into the air horn on the black BOV so it filters the air that is sucked in after decelerating 3-4 seconds or longer when the turbo slows down enough that boost goes away and turns to vacuum inside the intercooler.
The nicely machined aluminum horn is threaded so it can be removed and replaced with a hose fitting. It's only there to make the throttle lift woosh noise a little louder.

I ground the Kokeln Racing label off the intercooler end tank and polished it with air tools.

Hey that's kind of cool! Think I will try that for some giggles.
Plus I can get a cool picture at night with the flames!
Still a kid at 46. lol

[baloo]

Originally Posted by JFairman

...break break...
JF,
What kind of condenser setup for your AC do you have?
How effective is it?
Thanks.

[TAF]

I decided to vent my diverter valve to atmosphere trying to correct a stumble when shifting at high RPM. But let's not talk about that right now. I have mine splitting from the intercooler (Garretson) and the air valve. My problem is, the diverter valve is blowing oil on boost. What have I done wrong?

[JFairman]

Sounds like your turbo seals are shot and blowing oil.

Someone asked about my rear condensor in the post above. It's a stock 930 condensor with a 10" fan on it.

[TAF]

Changed out the turbo and did not fix the problem.

[smurfbus]

Did you wash your IC inners? Sounds like left over oil in there.

[16Volt]

Necro bumping this thread.

I have a similar setup to JF, a Forge diverter off a 965 style elbow and a adjustable Forge BOV attached to a cutoff stock manifold/long neck spacer.

I am pulling signal for both off the T port on the back of the throttle body.

The issue I have is the same as TimC, the diverter opens under idle. Tested it and it opens under very little vacuum, it came with some other springs so I am going to try those.

The adjustable BOV however doesnt open under any amount of vaccuum, not sure where to start there.

The one thing I really want to confirm is that I am pulling the signal from correct port on the throttlebody. Is the big T correct?

[TurboKraft]

Yes, that is the correct vacuum source.

[16Volt]

Originally Posted by TurboKraft

Yes, that is the correct vacuum source.

Thank you Chris. I will try a stiffer spring in the diverter and continue to test the BOV.

Side note - Do you make a full bay long neck intercooler or is it only short neck or 3.2 manifold?

[TurboKraft]

Right now, all TurboKraft's full-width intercoolers are only for EFI, either flat manifold, Carrera manifold, or custom (ex: 964 application).

Full-width intercoolers work with rotary A/C compressors (factory and aftermarket) and the wing-mounted 930 condenser must be relocated.


We've made one-off full-width intercooler that fit with the CIS injection, but our Longneck Intercooler already supports more power than the CIS is capable of supporting, so... bigger likely won't net any gains other than "mine is bigger than yours" bragging rights. Still, if we find there's enough demand, we'll make fixtures to manufacture them, too.


Longneck intercooler for Carrera manifold -- we've done this on a per-request basis for customers who still have a 930 A/C condenser in the rear wing and don't want to relocate it.

[16Volt]

Pheew....bullet dodged. Thank you.

[16Volt]

Just a quick update - put the stiffest spring in and still had the same issue with the valve being open/hanging at idle. Caused some lean running and hunting idle. Ended up just removing valve and running a single unit under the cold side of the intercooler vented to atmosphere.

Still doing initial tuning so I will report back with how that works.