NZConvertible

Definitely.

It also hints at what I've said before about non-stock systems not providing enough pressure to open as early as they should. RB have moved the pick-up point as far forward as possible to open the ports as early as possible. It'll still be later than stock though.

Sideways7

iTrader: (7)

Yeah, I have the RB collected system (with pick-up in stock location, basically). I just tested when the aux ports are opening and they are barely starting to move at 5800 RPM, and don't fully open until close to 6.5k..... It is possible that they need to be cleaned to operate properly, but still, thats pretty late.

BTW, the air pump will work great for what I need. Once I get a megasquirt (or build my own programmable RPM switch) I can make a really nifty opening circuit. Since the pump is made to hold pressure, you can kick it on then have the pump turn off but hold the pressure until you want to release it. Unfortunately this requires more than just an on/off switch, which is why I need something programmable. I can still rig it to work in on/off mode, but its not ideal for extended high-RPM times like at a track. I also think the car it came out of might have been a Crown Vic after all. I'll have to check it out next time I get out there.

Red'vert

Due to insights gleaned here I was suspicious of my 6PI actuation due to an apparent lack of low-end torque made apparent on the infamous SF hills. (This after installing a RB DP and Random Technology cat with air tube.)

I visually checked the actuators while manually revving the throttle under the hood and no go.

I manually actuated 5 and 6 no problem.

Then I figured I needed just over 2 PSI for actuation? I can do that...

So I put a little piece of hose on the 6PI actuator pipe and tried a "Dizzy Gillespie 6PI Test Method":


Not a hookah, testing 6PI actuation.

Sure enough, the actuators pushed when I blew. I'm clearly not getting enough backpressure off the high-flow RT cat. They claim they're the highest flow on the planet, apparently so. They're probably great for Turbo exhaust if you need a kitty-cat.

I need to do the solenoid actuation ASAP...

NZConvertible

If you don't have enough backpressure then the auxiliary ports will be opening later than they should. They'll still be closed at low rpm so there won't be any loss to low-end performance. It's the mid-range that suffers if the ports open too late.

jgrts20

Just do an electric conversion on the ports, thats what I did and I have never had a problem yet. Its been 3 years since I did it, just to let you know.

TitosToy

i have a straight pipe also and the person that had it before me drilled a hole and welded a bung to the straight pipe to connect the split-air pipe. been working perfectly (s4 btw)

NZConvertible

When you say "working perfectly", what did you do to confirm this? Do you know when (or if) the ports are opening?

TitosToy

when i give it some gas, i can see the actuators working. it doesnt need any load to get them to work

HAILERS

It's good to see RB upgrading their product. Five or six years ago I had a RB dual exaust system on the n/a, and the pickoff pipe for the auxillary ports was where that one is in the picture, BUT if did not have the reinforcing piece of metal to support the pipe. The pipe has since done did falled off/breakoff. humor

NZConvertible

What RPM do they open at? That's the important bit.

Lemme go find my English-Texan dictionary...

Red'vert

I should have said mid-band power loss. We've got some hills with stop signs here in SF that require 3800+ RPM to mount, esp. when a tourist in a Taurus is on your ***.

(San Francisco eats clutches for breakfast...)

-Rob

NZConvertible

That makes more sense. Basically between when they should open (~3800rpm) and when they do open, you're making less power than you chould be.

Childhood fantasy: Go to SF and drive downhill at speed getting air thorugh the intersections like in the movies...

tjbubb007

has anybody hooked up some sort of a pressure gage to the RB header to see when the acuator tube reaches 2 psi if so does it open the ports at the correct rpm (~3800rpms)

TitosToy

it opens around 3500 rpms. a lil early but it works.

GET R' DUN!!!

NZConvertible

Unless you have a very restrictive exhasut, I'm having trouble believing simple exhaust pressure activation could open the ports earlier than stock. It breaks the laws of physics...

Red'vert

Yup, you need a 4000+ RPM rev to crest some of the hills here with stop signs. Scares the heck out of tourists, a friend of mine was whacked on his motorcycle by a tourist afraid to stop. A lot of people roll-back into each other waiting in line to come down the twisty part of Lombard.

Little known SF fact, Vermont St. on Potrero Hill is twistier than Lombard...


That, my friend, is a remarkably violent stunt to try. The gouges from landings made in movies like Bullitt back in '68 are still there. ( http://www.rjsmith.com/bullitt-locations.html )

Filmmakers have broken so many rules over the years that it's now virtually impossible to shoot real stunt-driving in the heart of the city.

TitosToy

as soon as i get my camera back i'll post a bid for ya

Red'vert

I had an email dialog with Jim Langer of RB about this and how they actually DO tune the 6PI tubes on the headers and presilencers to operate properly.

Probably no guarantees on their 6PI pre-silencer with a non RB downpipe though...

bugman1973

ive heard of some adjustable valves and thing guys put on the exhaust ports to make sure they are not getting too much pressure at the right rpms so they open up right

0verb00st

I have an 88 GTU with a rusted through exhaust. I know that any changes that are made to the exhaust system will change the aux port actuation. How drastically will the actuation be impacted if If I keep all of my emissions (cats), but have a catback exhaust (I'm getting corksport).

pfsantos

iTrader: (1)

Hey, I remember this thread...the operation of your 6PI system will always be affected to some degree. The only way to be sure is to test it, either on a dyno, or with micro switches on the rods. Some posts above say the system works in neutral while stopped, so you could check it in the driveway, but I haven't confirmed this myself.