need power plate education

[Ross L]

I was running a power plate, no issues, at 24 psi with alky. Another member brought up a question and I never found a answer. The question was something like,,, If the lower manifold is seeing 24 psi, the valves all open the same amount, how does the power plate keep the rear cyliinders from leaning out? I can see how it would work on a naturally aspirated engine, but on a turbo application I know many people use it and run fast Just trying to understand.
Ross

 

[rmar]

Do a search on Grumpy's (Mellisa's) car. It is kinda of the current bar for most of us.

I figure if it is good enough for them....

 

[nullrout]

I was running a power plate, no issues, at 24 psi with alky. Another member brought up a question and I never found a answer. The question was something like,,, If the lower manifold is seeing 24 psi, the valves all open the same amount, how does the power plate keep the rear cyliinders from leaning out? I can see how it would work on a naturally aspirated engine, but on a turbo application I know many people use it and run fast Just trying to understand.
Ross

Go look at the shape of a stock upper manifold...air, just like electricity, follows the path of least resistance. You have a throttle body that flows air horizontally mated up to a upper plenum that redirects the air vertically. More AIR (not pressure) follows the path of least resistance (which is along the top of the upper plenum) dumping more AIR into cylinders 5 and 6. So 5 and 6 lean out before 1, 2, 3, and 4. Making knock on 5 and 6 your limiting factor. Yes the pressure is the same above and below the plate...however, the plate changes the path of least resistance, thus equalizing flow. Equal flow even makes more power in many engines without upping the boost.

Free power (well 60 bucks anyways) is great in my book.

 

[toofastforyou]

below the plate...however, the plate changes the path of least resistance, thus equalizing flow. Equal flow even makes more power in many engines without upping the boost.

Free power (well 60 bucks anyways) is great in my book.

The problem is that it equalizes air flow by creating a restriction, NOT by improving the quantity of air going into the engine!... Strange, but my car went faster without the plate...It's true that the improvement may also be due to some other changes though.
What would really help would be to IMPROVE air flow into cylinders #1,2,3,4 by other means than by restricting the air going to cylinders #5 and 6...Look at the holes in these plates... that there's no way it will flow as much air as an open plenum! My late father was an engineer specialized in air handling and I remember him once explaining to me that air behaves somewhat like water and installing a kind of "air turning vane" (similar to those used in ventilation ducts) to help in redirecting air downwards into the engine would be a lot more efficient than using a restricting device (plate) which even if it does equalize the volume of air going in each cylinder, does NOT add more.

Claude. :wink:

 

[bison]

The problem is that it equalizes air flow by creating a restriction, NOT by improving the quantity of air going into the engine!...

Wrong. The plate will flow more cfm than a 231ci will use at 6000 rpm. Therefore it is not a restriction. On the other hand i have never seen a plate vs. no plate comparison that logged egt's on the cylinders to prove that it actually corrected a lean problem in the rear cylinders. Increasing plenum volume will help slow the incoming air down as the valves open and close.

 

[Ross L]

I still picture this large chamber of pressurized air(or water). If the pressure is constant i just don't understand how "more" air will follow the roof of the plenum and into the rear cylinders. If thats the case wouldn't that mean there's more psi on the rear 2 cylinders? Trying to learn(it rainy here, can't get the buick or bike out)
Ross

 

[nullrout]

I don't know what to tell you...if you don't understand with the 189787987 posts that have been made about the power plate then you just don't.

We're not dealing with magic here...its benefits have been proven. Besides if you don't have a problem (with your existing powerplate) why change it? If you want, take it to the track make some passes with and without plate back to back and see what you see.

 

[nullrout]

Increasing plenum volume will help slow the incoming air down as the valves open and close.

Understand that...but how much volume does it really increase...1/8 of inch ain't that much.

 

[nullrout]

The problem is that it equalizes air flow by creating a restriction, NOT by improving the quantity of air going into the engine!... Strange, but my car went faster without the plate...It's true that the improvement may also be due to some other changes though.
What would really help would be to IMPROVE air flow into cylinders #1,2,3,4 by other means than by restricting the air going to cylinders #5 and 6...Look at the holes in these plates... that there's no way it will flow as much air as an open plenum! My late father was an engineer specialized in air handling and I remember him once explaining to me that air behaves somewhat like water and installing a kind of "air turning vane" (similar to those used in ventilation ducts) to help in redirecting air downwards into the engine would be a lot more efficient than using a restricting device (plate) which even if it does equalize the volume of air going in each cylinder, does NOT add more.

Claude. :wink:

Then your car is the oddity out of all the cars out there running plates...either that or it wasn't an apples to apples comparision. I wonder which one is more likely?

As Bison pointed out...the total volumn of the plate is greater than the throttle body...so try again on the restriction statement.

 

[toofastforyou]

As Bison pointed out...the total volumn of the plate is greater than the throttle body...so try again on the restriction statement.

The same holds true for an open plenum without any plate...:tongue: It's not the plate vs. throttle body that's in question, but rather the plate vs. an open plenum...Are you trying to say that there's MORE air going into the engine with a plate than without one??...I'm sorry, but I just don't get it!...The total area of an open plenum by far exceeds the one of the holes in any plate, so don't try to make me believe that there's MORE air going through it..

Anyways, you're entitled to your opinion but I took mine off, got rid of it and never regretted it a second. It's one of those useless "novelty" gadgets in which a lot of guys believe until they go to the track and notice that none of the real, "serious" racers use...like the old school 7th. injectors, smaller diameter crank pulleys, plenum spacers, water-cooled up-pipes, "TPS-tec's"...that's what they are : GADGETS...

Claude. :frown:

 

[UNGN]

I don't use one, but how it works is it directs a vortex of air to the low flowing cylinders and reduces flow to the cylinders that get too much air.

There is a small pressure differential across the plate (it wouldn't work without one) but its only a small percentage of the boost and this loss is made up in better combustion and the ability to increase the boost without detonation.

If detonation is the result of too much air to 3 cylinders and restricting the airflow to those 3 cylinders results in less detonation and more HP, then restriction = good.

A Power Plate in a N/A car would likely show up as a big time negative on a timeslip. But since extra boost is basically free....

 

[Ross L]

Just thinking outloud guys. I know there are hundreds of posts about it. What if our cars came with a power plate from the factory? Do yall think anyone would still be running them? I guess it's one of those things like "gravity" that I'll just never understand. BTW, took mine off(for now)

 

[turbo nasty]

Strange, but my car went faster without the plate...It's true that the improvement may also be due to some other changes though.

What were these other changes...

 

[bison]

Understand that...but how much volume does it really increase...1/8 of inch ain't that much.

I ALWAYS ran at least a .5 inch spacer and usually an inch. It increased the plenum volume a lot.

 

[bison]

The same holds true for an open plenum without any plate...:tongue: It's not the plate vs. throttle body that's in question, but rather the plate vs. an open plenum...Are you trying to say that there's MORE air going into the engine with a plate than without one??...I'm sorry, but I just don't get it!...

The reason you dont get it is because you are thinking the engine needs all the volume thats there to suit its displacement/rpm. More is not going through it. Th engine only uses what it needs. The truth is the engine only needs about 400 cfm at 6000 rpm. Most guys on here rarely go over 5500 so it only needs to flow aboit 360 cfm. Therefore if the powerplate flows over 400 cfm its not causing a pressure drop. I havent measure it out but id guess the open cross sectional area on the plate is way more then the stock or even a 62mm throttle body has. If so the TB is a restriction before the plate is. Understand yet? The only legitmate proof (which doesnt exist to my knowledge) is a before and after with EGT probes on the cylinders with both scenarios. If they were consistently closer after the plate was installed then it could be said that it has been proven to equalize airflow tot he cylinders. One thing that has been proven is that any time you increase the open plenum volume you will get less of a pressure pulsation in the manifold as the valves open and close. nASScar has done a chit load of R&D using these ideas because they are often required to run a restrictor plate under the carb. The engineers have commented that they had to completely re-think the intake because of the restrictor plate and its effects on the a/f distribution

 

[bison]

There is a small pressure differential across the plate (it wouldn't work without one) but its only a small percentage of the boost and this loss is made up in better combustion and the ability to increase the boost without detonation.

Post your data logs proving this. Only 2 MAP sensors would be needed for an easy comparison. At what rpm did the plate begin to restrict? On what ci engine?

 

[Clark6]

I was running a power plate, no issues, at 24 psi with alky. Another member brought up a question and I never found a answer. The question was something like,,, If the lower manifold is seeing 24 psi, the valves all open the same amount, how does the power plate keep the rear cyliinders from leaning out? I can see how it would work on a naturally aspirated engine, but on a turbo application I know many people use it and run fast Just trying to understand.
Ross

I still picture this large chamber of pressurized air(or water). If the pressure is constant i just don't understand how "more" air will follow the roof of the plenum and into the rear cylinders. If thats the case wouldn't that mean there's more psi on the rear 2 cylinders? Trying to learn(it rainy here, can't get the buick or bike out)
Ross

Ok Rossy :tongue: have fun reading: Courtesy of RJC




Test #1
1987 GN stock long block, TE-44, 15 row stretched Stock location intercooler, 009 inj. 4500 ft. ele.
We made 3 baseline passes with the stock plenum at the maximum boost that we could run with the gas we were using. We were running VP C-16

The baseline runs were made at 26# of boost. This was the most boost we could run as we had 3-6 deg knock retard every run.

12.50 @ 108
12.55 @ 107
12.53 @ 107

We then installed the AD Power plate and made 4 more passes. Turning up the boost each pass because we had no knock.

12.49 @ 108 26# no knock
12.45 @ 109 27# no knock
12.40 @ 109 28# no knock
12.35 @ 109.8 29# no knock
12.40 @ 110 30# 8 deg knock. On the last pass we pushed a little through the lights so the clock started before we let off of the brake.

Since we first tested the plate we have tuned an additional three and a half tenths out of the E.T. The car now runs consistent 11.80@ 114. at the same elevation with no other changes

Our conclusion with real world testing confirmed what we were seeing on the flow bench. The Power plate maximized the airflow to all cylinders. Remember you can only run as much boost as the weakest cylinder will allow. This plate allowed us to run 4 more pounds of boost than with out it. Which in turn gave us almost 3 tenths reduction in E.T. and more than 3 MPH.

Test #2 I have tested it on my personal car, an 87 GN with extensive modifications. After installing the plate I made 4 passes they were all in the 10.60-10.65 range. This was at about 22-23psi. I then took the plate off and made another pass, 10.76 with identical 60' as before. This was the slowest pass of the day by .11 of a second.

Test #3 The GSCA "Buick Grans Sport Clup of America" did back to back tests at the 2002 GSNationals in bowling green KY. Their test neted a 2 tenth reduction in E.T. and a 2MPH increase in 1/4 mi times. This was without increasing the boost pressure. How you say? The test vehicle was experiencing slight knock without the plate, once the plate was installed the knock retard was gone and thus netted the 1/4 mi results.





Also
Plenum flow charts comparison each cylinder to average of all cylinders for that plenum.


Stock Plenum

1 -40% 2 -81%

3 +24% 4 -33%

5 +68% 6 +63%

Flow Range; 149%




Stock plenum with AD Power Plate-S

1 -5% 2 -2%

3 +5% 4 +4%

5 -5% 6 +2%

Flow Range; 10%


look at the equality of flow per ea. cylinder



Q1.That thing looks restrictive,is it?

ANS1 When searching for restrictions, you must first look at the most restrictive piece in a system. When it comes to our turbo buicks the most restrictive piece is the throttle body. The Power Plate by itself out flows even the huge 70mm throttle bodies by 50%.With the stock plenum the Power Plate utalizes all of the ports instead of trying to force most of the charge through the back two ports . Because of this, total airflow through the manifold is actually increased !!

Here are some solid flow percentages.
The stock plenum and t.b without a power plate as a baseline.

Stock tb. 100%
Stock tb. with ADPPs plate 100-102%
Precision plenum with 70mm t.b. 123%
Precision plenum with 70mm + ADPPp plate 120%
Kenny Bell plenum with 70mm t.b. 125%
Kenny Bell plenum with 70mm + ADPPk plate 111%
Hemco Plenum with 70mm tb 113%

 

[jdsgnx]

GREAT INFO!!!!!

Thanks JD

 

[UNGN]

Post your data logs proving this. Only 2 MAP sensors would be needed for an easy comparison. At what rpm did the plate begin to restrict? On what ci engine?

I ran an airflow rig in Aerospace for 13 years. I could flow a plate and tell what the opening size was down to .05 square inches by what it flows.

Anything put in the airstream restricts the air. CFM is measured by having a pressure drop between the outlet and inlet and measuring the amount of air that goes from the inlet to the outlet. A system just doesn't see the smallest restriction and ignores all the other restrictions. If a TB flows 600 CFM and something else in the system flows 601 CFM, the entire system will still flow more if you replaced the 601 CFM part with something that flowed 900 CFM.

"CFM" is a pretty meaningless measurement in case of the powerplate, anyway. A turbocharger COMPRESSES the air so it could flow
900 "CFM" through something that only "flows" 300 CFM if it really wanted to. It just hast to compress that 900 CFM of air down to 300 CFM, first.

The power plate makes more HP when the boost is turned up, no? set the boost at the maximun level with no knock without a PP and then install a PP without increasing the boost. I bet the car slows down a little. It definitely won't speed up.

I'm not knocking it. That is how it works.

 

[ROYAL_6]

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