Rjc plate

[bison]

If the plate flows a higher cfm than the engine uses then there will be no pressure drop. I cant see it being a problem on a 231ci until well over 6000rpm where 98% of the sigs on this board never even come close to. The correct answer to lean cylinders in EFI (assuming no other problems like injectors) is to add plenum volume to slow the air down and minimize the pressure drop relative to other cylinders when the valves open.

 

[bison]

OK then, so your saying that the boost is higher in the plenum than the intake? I highly doubt that. Maybe with the RJC plate it would be.

Now don't you think that would play true to the intake/plenum with one of these plates?

This could easily be data logged with an xfi if you simply ran two MAP sensors. One above and one below. Id bet $500 that below 6000 rpm on a 231ci with a cam with minimal overlap there would be less than .1psi difference.

 

[TurboBuRick]

TurboBuRick,

I see what you're saying and you would be correct if things were static in the intake. However things are not static. The fact of the mater is that air has mass and therefore inertia. Take a look at this picture that I have taken time out of my busy day to draw. Assume valve "A" and "B" are the same size and have the same flow capability. The portion underwater represents the intake and the hose represents the airflow into the intake. The water is the air. If you shut the hose off both valves will flow the exact same amount of water because they have the same pressure over them.

Now, if you turn the hose on enough to maintain the water level and start alternately opening the valves valve "A" WILL flow more water because the hose is right over it and the water will want to continue to flow that way because of inertia. Like water, air resists changes in motion.

That said I can't say for sure the PP works or not. Just looking at it it looks like a restriction. However, it's very easy to say you could go faster with a restriction if that restriction enabled you to use ALL of your cylinders to there fullest potential instead of just two. FWIW some of the guys with big blocks at the track sure look like they'd be ALLOT faster than my old Buick.

Thanks for taking the time. O don't forget to put a plate with some holes under that feed line and see how that effects things.

 

[TurboBuRick]

The correct answer to lean cylinders in EFI (assuming no other problems like injectors) is to add plenum volume to slow the air down and minimize the pressure drop relative to other cylinders when the valves open.

You kinda lost me on this one Bison. I think there would be less pressure drop if there was more on tap. Your saying with the plate there is more plenum volume? I have to think about that a little.

This could easily be data logged with an xfi if you simply ran two MAP sensors. One above and one below. Id bet $500 that below 6000 rpm on a 231ci with a cam with minimal overlap there would be less than .1psi difference.

A pretty good source has already tried it. You might want to pull back that bet. LOL :biggrin:

 

[jhanson1750]

As far as a restriction that is a simple issue of the compairing the open surface of the throttle body vs open surface of the power plate. The point of air air having mass is the key to this issue.

Will the pressure equallize above and below the PP? Not unless the valves stopped opening. The proof of this is in what is called "resonance tuning". I will not get into this but google is some time it is amazing the research done on the topic.

I run one and know, that in my case, I could run 2lbs more boost with no other changes. I think tuning my 86' has been vastly easier after the PP. Before the PP I had to really chase the tune when I ran more boost but after I could tune easier (less time, less aborted runs). HTH Jon Hanson

 

[BlackBandit]

Thanks for taking the time. O don't forget to put a plate with some holes under that feed line and see how that effects things.

Hey dude, the time thing was a joke. I was kinda mocking my drawing so don't take it personal. I'm actually sitting in a hotel room doing nothing if that helps you put into perspective just how busy my day is.

Since you said it though lets take a look.

I have now installed my power plate. I put a smaller hole to restrict airflow to the cylinder that was prone to leaning and put a larger hole over the other valve due to the fact that the water will have less inertia after it changes direction twice. In this scenario the water (air) is above the plate and pressurized although still entering the area through the hose. Because I want the same flow from both valves I needed a smaller hole above the valve that has the hose over it. Also, it's important to note that even if there is a pressure difference above and below my plate this setup would still even out flow through the valves. The only real question is this: Is it worth it?

Edit: I forgot to attach the pic. Also, my drawing (including the holes) probably isn't that accurate on any type of scale!

 

[BlackBandit]

I run one and know, that in my case, I could run 2lbs more boost with no other changes.

Jhanson, regarding this do you measure boost before or after the PP? I think you can see why I ask. I'd also like to point out the equal surface area does not necessarily mean equal flow.

I'd also like to say that I have run a PP in the past and didn't notice any downside to it. I couldn't run more boost but it didn't seem to slow me down any.

 

[Grumpy]

we ran 9.94 @ 138+ in Melissa's street car .. that was with a stock plenum an TB with Jasons "restrictor" in it :biggrin: never tried it without.. Car runs to good :biggrin:

 

[Jerryl]

Here is an old thread.
http://www.turbobuick.com/forums/ge...y-low-10s-high-9s-cars-using-power-plate.html

 

[TurboBuRick]

Hey dude, the time thing was a joke. I was kinda mocking my drawing so don't take it personal. I'm actually sitting in a hotel room doing nothing if that helps you put into perspective just how busy my day is.

Since you said it though lets take a look.

I have now installed my power plate. I put a smaller hole to restrict airflow to the cylinder that was prone to leaning and put a larger hole over the other valve due to the fact that the water will have less inertia after it changes direction twice. In this scenario the water (air) is above the plate and pressurized although still entering the area through the hose. Because I want the same flow from both valves I needed a smaller hole above the valve that has the hose over it. Also, it's important to note that even if there is a pressure difference above and below my plate this setup would still even out flow through the valves. The only real question is this: Is it worth it?

Edit: I forgot to attach the pic. Also, my drawing (including the holes) probably isn't that accurate on any type of scale!

Nothing personal, I appreciate your efforts. Sorry if I came off wrong.
On the second drawing, the plate position is not really accurate to actual placement in the flow track. The plate would be at the bottom of the feed line but I see what your trying to say.

 

[TurboBuRick]

we ran 9.94 @ 138+ in Melissa's street car .. that was with a stock plenum an TB with Jasons "restrictor" in it :biggrin: never tried it without.. Car runs to good :biggrin:

Well I guess I can't argue with that. LOL :biggrin:

 

[BlackBandit]

Nothing personal, I appreciate your efforts. Sorry if I came off wrong.
On the second drawing, the plate position is not really accurate to actual placement in the flow track. The plate would be at the bottom of the feed line but I see what your trying to say.

No worries man. I put the hose over there because in our upper plenum the air would be following the back of the plenum and the majority of if would be hitting the back side of the lower intake or pp if it was installed.

 

[jhanson1750]

BlackBandit Quote:
Originally Posted by jhanson1750
I run one and know, that in my case, I could run 2lbs more boost with no other changes.

Jhanson, regarding this do you measure boost before or after the PP? I think you can see why I ask. I'd also like to point out the equal surface area does not necessarily mean equal flow.

I'd also like to say that I have run a PP in the past and didn't notice any downside to it. I couldn't run more boost but it didn't seem to slow me down any.

I really didn't think about that! I see your point though. I have always read boost from a "T" off a line comming from the upper plenum so you could have a ligit issue there. I think there is some research on this. I would contact RJC and just see what they offer as far as research and testing. Good Luck. Jon Hanson

This is good and all but mine is staying on!:biggrin:

 

[TURBOPOWERED68]

we ran 9.94 @ 138+ in Melissa's street car .. that was with a stock plenum an TB with Jasons "restrictor" in it :biggrin: never tried it without.. Car runs to good :biggrin:

Well I guess I can't argue with that. LOL :biggrin:

Plus 1
After i beat Grumpy's time and MPH i'll take my "Choke Plate" off, until then it will stay on.

 

[Grumpy]

Well I guess I can't argue with that. LOL :biggrin:

NO we can't !! winter is over :biggrin: