Some of you may recall I swapped from a dual plane to a single plane at the end of last year in hopes of improving ET. Well, after two outings and ~15 passes later I was getting no where with the single plane. The first outing with the single place I ran in -1,000' air and the car only ran 10.70@124, .02 slower than the best pass with the dual plane only weekends before in +700' air. The second (and last) outing with the single plane the air was +1,200'. The car slowed all the way to 10.88-10.90. I also lost ~600 RPM of stall speed swapping from the dual plane to the single plane. That was my first clue that the car wasn't making as much torque with the single plane. During my single plane trials I also completey replumbed my fuel system thinking perhaps there were some issues there. This included replacing my Fram canister style filter with a Mallory filter, rebuilding my Mallory Comp 140 fuel pump, removing all sharp 90 degree fittings and replacing them with full flow AN fittings, modifying my factory pick-up tube from 3/8" to 1/2" to match my -8AN line, and finally adding a -8AN fuel log (thanks Ed).

Last weekend I reinstalled my trusty Edelbrock Performer RPM. Today I took my car over to Silver Dollar Raceway in Reynolds, GA to see if I could get the car back to where it had been running before swapping intakes.

Previous best with the dual plane was as follows:

60' 1.48
6.78 @ 101.36 1/8 mile
10.68 @ 124.64 1/4 mile

First pass off the trailer was:

60' 1.51
6.77 @ 101.78 1/8 mile
10.64 @ 126.88 1/4 mile

Needless to say I was pretty pleased with this pass. The second pass was even better:

60' 1.51
6.75 @ 102.12 1/8 mile
10.60 @ 127.11 1/4 mile

graemlins/thumbsup.gif

It wasn't quite the 10.50's pass I've been gunning before, but poor starting line preparation was to blame for that. You can tell by the MPH that the car had a mid-low 10.5 pass in it with a decent starting line. There were only ~10 slick tire cars at the track today, and probably 50 street cars, many of which were front wheel drive. So starting line preparation was pretty much non existant.

In summary I do think that the modifications I made to the fuel system helped. The air today was slightly below sea level (590' altitude, 48 degrees, 30.11 baro, and 26 degree dew point) and there was a tail wind. I've ran at this track before with the dual plane in even better air with an equal tail wind and the best MPH I could muster was 125.6. So the car is making more power. My next project now that I'm solidly back in the mid 10's is to weld in a set of merge collectors. I picked up a decent MIG welder a couple months ago so I'll be doing the welding myself smile.gif

Stay tuned....

Nice :D 56 days till my track opens, if all this damn snow is gone :mad:

Glad someone is having fun at the track this time of year graemlins/thumbsup.gif

Thanks for the test results-great info..new bests now too?

Ken,
Nice results, I think the dual plane set up is really working for you. It is this type of testing that helps others compare. Maybe a dual plane really works in building lower RPM torque to accelerate the mass faster than a single plane setup would even with a higher HP peak. Of course this is given the combo is setup to take advantage of the totque gains as your is. Great info. torque rules....

Ken,
Nice graemlins/thumbsup.gif
My handy little guesstamate formula says you are right at 600 engine HP with 3700 lbs.
These are the results I would expect from an engine that makes peak power about 6000.
If you had a 6800-7000 rpm combo the Vic might have come out on top but I almost always recommend the Perf RPM or air gap as it makes more torque in just about every case
I recently did two 493 Chryslers, one with a solid ft & one with a hyd ft.
Both made at least 15-20ft lbs more torque with the dual plane compared to a Weiand single with no measurable loss in HP at peak which was about 5800 with the HYD & 6000-6200 with the solid.

Thanks for the feedback guys.

Yes to the new bests, Chris. In fact two new bests in the same day, lol.

Mike,

I'm always puzzled by the HP estimates. Right after I put the solid roller in at the beginning of last year I had the car chassis dynoed. It made 463RWHP and 576RWTQ. I was a little dissapointed with the numbers as I thought it would be 500RWHP. The car had dynoed 484RWHP with a hydraulic cam and 4 speed prior to the solid roller switch. One thing is clear these high stall converters (mine flashes to 5,300) do crazy things to the dyno readings. The HP by weight/MPH calculator on prestage has my car at 592 RWHP. While it's certainly making more than the 463 that it showed during the initial shakedown dyno runs (lots of tuning and refining the combo since then), it's defintely not making almost 600RWHP, IMO. I think the engine is probably somewhere between 600-650HP at the flywheel. At any rate it makes for a pretty fun pass down the 1,320, and I get lots of compliments because it looks pretty well stock (all steel except hood, full factory interior). :cool:

Ken,
Your estimate is very close in my opinion.
The basic formula Prestage is using is the same one that has been around for about 30 years that I know of & is for flywheel HP.
I emailed them a couple of times about it but got no response so I assume it isn't a big deal to them or they don't agree.

I have posted this before but here it is again for you to ponder: ;)

Prestage supposedly gives engine HP I believe, all I can tell you is to do a few calculations & see if it makes sense to you.
If that calculator was right a 204 mph Pro car woud be making over 1500 rear wheel HP
Here is a little formula that has been around since at least the 70's & was used by Chrysler Corp. in their drag racing program & written up in the American Journal of Physics in 1973
HP=(.00426*MPH)cubed * WGT
I add about 50 HP to the number because MPH is measured differently now than it was in the 70's.


I find this formula works pretty fair until you get into some of the very hi end cars like Pro Stock. I find with cars like these it will give you a higher HP number than you usually see, especially adding 50HP.

This formula might be old but I believe most of the laws of physics still apply,,,,,,unless of course you are using that "Good LA air" when you dyno :D :D

Mike are those number rwhp or flywheel?

what numbers?
If you are talking about the formula it is flywheel HP.

Ken, the formula hp= (mph\234)^3*weight gives me 593 rwhp. 127mph is 127 mph...
My friend has a turbocharged mustang using a stick where the dynojet hp and formula hp were off only by like 10hp. His pre-turbo #'s on the chassis dyno were 320hp, and the formula says 328rwhp.
Do we have anyone here with a high horsepower car that has a stick, been engine dyno'd and chassis dyno'd, and has a mph from the track?
I don't want to brew up a storm or anything here, and I am going off my memory, but, the guy who is doing my cam change and dyno session said this, basically.
a 1990 mustang makes about 180hp on his chassis dyno. the same engine taken out makes about 218hp on the engine dyno. he then said, so how much power does it take to run the driveline and other junk? then he goes, about 40.
he says the "percentile" thing about tranny's is all wrong, and that engine dyno's that aren't real world are just to make customers happy or for comparing parts. there may be some small percentile stuff involved, but what he is saying makes sense.
So lets say your turbo 400 slushbox with a mega slushy converter and 12 bolt takes about 60hp to run (just a number I am guessing here...!) and a few more to run the accessories.
its generally agreed a 10:1 engine with a roller can make like 1.4 or 1.45 hp/ci if its combo is dead on..
which yours seems to be.
so take (whats yours, a 460?) 1.45*460=667. 667-593=74. So 74hp to run your trans, rear, and accessories, and your really making 593 rear wheel hp?
This is what I thought the guy said. It sort of makes sense. I am not trying to start a war here, but just some sort of reasoning for your 127mph pass..

matt

Matt,
This formula has been aroound since at least the 70's & as I said in my previous post, if it were for rear wheel HP them a Pro car would be making over 1500 RWHP :eek:
If you took a best case drive train loss of say 10% the engine HP would be over 1600HP
Again take a few common NHRA record runs that are not padded & use the formula & see what you come up with.
It's great to think you have 600RWHP but this would equate to well over 700 engine hp in most cases.
Not trying to be a smart ass but a little common sense needs to be used when you look at these formulas to see if they make sense to you ;)

Congrats on the new bests Ken. It's good to see the car running to it's potential. I bet there's still a little left in it with some work. I have no doubt that it'll run mid 10.50's if not high 10.40's if everything falls into place at once.

Matt,

I honestly feel the calculations and dyno stuff is all bogus for the most part. The formulas are great for bragging rights as are the Dyno's. I feel a dynos best use to to be able to tune a car under controlled parameters and be able to eliminate variables that you would normally see at the track.

All dyno's will yield different results. My chassis dyno guy tells me he see's 30% loss in his three 8 second N/A Fords when there engines are dyno'd on Kuntz's engine dyno vs his own Mustang chassis dyno. Again, one dyno could be calibrated conservative while another may be a bit more optimistic (read: Westec).

No arguement on the subject rather differing point of view on the subject. I really don't care how much power it makes as ling as it runs a certain ET for what ever power it does make. Knowing what your combo makes on a chassis dyno now will help with decisions down the road if you want to go faster. OK, now I make "X" hp/tq and run this ET/MPH at this weight. I now want to run "Y" ET/MPH at this weight, so we can guestimate how much more power/tq will need to be increased to reach your goal.

Congrats again Ken...you coming out this way of weldig lessons or not? ;) :D I hope we get the chance to get together and BS and race this season.

You discovered something I learned a long time ago about single planes. If the weather changes at all your combo has to be changed or it won't run. I got so tired of playing with things during a long bracket race that I went to dual planes on everything. The worst thing you have to do is change the jets a couple of sizes even when the race goes from a hot afternoon to nite. In a heavy car it usually will always work better with a dual plane unless you have a killer motor that needs the RPM to work. Your 10.50s should come with a little playing. Good luck

Nice Results Ken...I say this as I stare at the 2 Performer RPM's I have to test against the Vic Jr. Currently on my mill.. :cool:

In my defense so I don't sound like a complete idiot, I was just passing on a theory offered by someone else..
all I think dyno's are good for are testing parts, like when my builder tried putting an oval port manifold on my rect port heads, or putting on a different carb, etc....

matt

Congrats Ken! Always nice to see new bests! Just need to get on a sticky track now. I agree with Todd, 40's look doable if things go right.

Nice job. graemlins/thumbsup.gif

Nice feedback everyone. One thing I found curious about the single plane vs. dual plane comparison is the following, perhaps Mike (WolfPlace) or some of the other pro builders/porters can comment (all comments are welcome, BTW).

The intake runner measurements for my heads and both of the intakes are as follows:

Canfield 310cc aluminum head:

1.850" wide
2.550" tall
2.800" cross section

Edelbrock Performer RPM dual plane:

1.775" wide
2.450" tall
2.705 cross section

Edelbrock Victor Jr. single plane:

1.500" wide
2.335" tall
2.500" cross section

The dual plane has more runner volume than the single plane! :confused:

Now, I should mention that the Performer RPM was fully ported by a pro to match my Canfield heads. The Vic Jr. was untouched out of the box. I was stunned to see that the dual plane had more runner volume, and it wasn't just more at the flange is was more as far back into the runner as I could measure with my dial caliper. I remember cringing when I got the bill for the ported RPM ($350 for the manifold and port work), but in hindsight it may have been money very well spent :D

All this said I can't help but wonder what a single plane with more intake runner volume would have done (say a Team G, Dart, or heavily ported Vic). One of my good friends that does headwork says the differences in performance between the two intakes may have little to do with the cross sectional area. I don't know. To provide a little more insight into this for those wanting to venture a guess... With the dual plane I'm running a .5" open wooden spacer and a carburetor heat shield. With the single plane I had a 1" open plastic spacer. So in addition to the increased plenum volume of the Vic Jr. (square opening) I added even more volume with the 1" open spacer. Could it be that all this additional plenum volume with a decrease in runner volume was to blame for my poor results with the Vic Jr? I would have liked to of tried the Vic Jr. without the 1" spacer, however I needed the spacer for other reasons. I run power brakes on my car and therefore need a vacuum connection. Rather than drill/tap a vacuum connection into the brand new Vic Jr. intake I chose to drill/tap the 1" spacer instead. I always knew that there was a chance the single plane wouldn't perform as well as the dual plane on my car and I wanted to preserve the Vic Jr. for maximum resale value.

Anyways, sorry to ramble but I thought some of you might be interested in my theory. graemlins/waving.gif

Ken, was your vic jr port matched to the head intake runners? I mention this as my Vic jr had about 1/8" of extra material around the intake port opening to allow for easier matching to the head intake runner. Basically, the manifold intake runner opening was 1/8" smaller than the gasket/head out of the box. The instructions of the manifold showed this and how they were to be ground open back 1" to allow for matching to the head.

I'm sure you knew this, but was curious of yours was matched to the head or did you leave that extra material?

Lookin' good Ken... Get that baby ready I still want that match race with ya..
graemlins/thumbsup.gif

Never bored by your theory Ken! I'm not a racer,( but I'll try to be one only to get a 11.97 timeslip with my old resto) but find it fascinating. But most importantly...

NICE TIMES DUDE! graemlins/thumbsup.gif

Can't wait to see how much you chip off that 10.60 this season.

Awesome Ken. You gonna make the March 6 opener at Atlanta Dragway? I'm hoping to be there, and I'd like to see a 10.5X run. Gives me something to dream about smile.gif

Originally posted by 10secBu:
Ken, was your vic jr port matched to the head intake runners? I mention this as my Vic jr had about 1/8" of extra material around the intake port opening to allow for easier matching to the head intake runner. Basically, the manifold intake runner opening was 1/8" smaller than the gasket/head out of the box. The instructions of the manifold showed this and how they were to be ground open back 1" to allow for matching to the head.

I'm sure you knew this, but was curious of yours was matched to the head or did you leave that extra material? Todd, the Vic Jr. was box stock with no port work. Directions? What directions :D I didn't want to port the Vic Jr, although in hindsight that may have been a mistake. However, it seems that my results (slowing down ~.2) are in line with what others with low compression/heavy rides have reported when switching.

Originally posted by shannont:
Lookin' good Ken... Get that baby ready I still want that match race with ya..
graemlins/thumbsup.gif Thanks. As far as match racing you...That would be like bringing a knife to a gun fight :D

Thanks, Gene. Bolt on some slicks and you should see that 11 sec pass based upon your MPH. My only advice is to have some spare everything (rear end, u-joints, trannies, etc...) with you so you can make it back home. At least based upon my stick racing experiences. smile.gif

Mike, affirmative for the season opener. They have a T&T the previous weekend which I will be at to test out the merge collectors. Are you running the points race this year, and if so in what class?

nice job ken ,great test even with the varibles of the intakes.it looks to me that 10.50s are there with the best 1.48 sixty foot times.as you know race day the tracks are always better .try the b/m race in montogery in 2 weeks that should yeild a good track

FYI, I went back after first posting this last night and reviewed the videos that my wife had taken from the day. My car was pulling the front wheels pretty good on a few passes before the rear tires unload. I may be looking at some custom rear suspension upgrades in the not too distant future (read Racer1320 style).

1300.00 in a dark alley Ken...but we must factor in inflation...but to me it would be worth it graemlins/thumbsup.gif Great times Ken, I need some more TNT with new converter/trans on a better track,TNT at the end of the year on a cold track didnt do me any favors. Our track was supposed to open last sunday,run again this sunday, but the snowman visited us again...there's always next week graemlins/hurray.gif

Yeah Ken, I plan to race more this year, but I probably won't get there often enough to run for points. I'll probably stay in Trophy Street until I get my new 355 installed, than maybe I'll run Sportsman a few times. Look forward to seeing you in March.

Originally posted by kjett:
Nice feedback everyone. One thing I found curious about the single plane vs. dual plane comparison is the following, perhaps Mike (WolfPlace) or some of the other pro builders/porters can comment (all comments are welcome, BTW).

The intake runner measurements for my heads and both of the intakes are as follows:

Canfield 310cc aluminum head:

1.850" wide
2.550" tall
2.800" cross section

Edelbrock Performer RPM dual plane:

1.775" wide
2.450" tall
2.705 cross section

Edelbrock Victor Jr. single plane:

1.500" wide
2.335" tall
2.500" cross section

The dual plane has more runner volume than the single plane! :confused:

Now, I should mention that the Performer RPM was fully ported by a pro to match my Canfield heads. The Vic Jr. was untouched out of the box. I was stunned to see that the dual plane had more runner volume, and it wasn't just more at the flange is was more as far back into the runner as I could measure with my dial caliper. I remember cringing when I got the bill for the ported RPM ($350 for the manifold and port work), but in hindsight it may have been money very well spent :D

All this said I can't help but wonder what a single plane with more intake runner volume would have done (say a Team G, Dart, or heavily ported Vic). One of my good friends that does headwork says the differences in performance between the two intakes may have little to do with the cross sectional area. I don't know. To provide a little more insight into this for those wanting to venture a guess... With the dual plane I'm running a .5" open wooden spacer and a carburetor heat shield. With the single plane I had a 1" open plastic spacer. So in addition to the increased plenum volume of the Vic Jr. (square opening) I added even more volume with the 1" open spacer. Could it be that all this additional plenum volume with a decrease in runner volume was to blame for my poor results with the Vic Jr? I would have liked to of tried the Vic Jr. without the 1" spacer, however I needed the spacer for other reasons. I run power brakes on my car and therefore need a vacuum connection. Rather than drill/tap a vacuum connection into the brand new Vic Jr. intake I chose to drill/tap the 1" spacer instead. I always knew that there was a chance the single plane wouldn't perform as well as the dual plane on my car and I wanted to preserve the Vic Jr. for maximum resale value.

Anyways, sorry to ramble but I thought some of you might be interested in my theory. graemlins/waving.gif Ken,
The Vic Jr comes small & is intended to be port matched to your application.
Just for more to chew on,,in back to back tests on the 496 I posted a while back I ran it box stock & port matched to the AFR 315's & if there was any difference it wasn't anything to get real excited about. Maybe a few HP but so close it was virtually the same.
Still it is probably worth the time to match them & it isn't like it going to cost you anything but a little time. Just don't expect that magical 20 or so HP that the rags tell you is there ;)

++++++++EDIT++++++++++++
Also, the Vic had the best numbers with a 1" spacer

Congratulations on the new bests Ken!!!! graemlins/beers.gif

graemlins/thumbsup.gif Very nice!!

Ken - First, congratulations on your new bests and your perseverance.
Originally posted by kjett:
...The dual plane has more runner volume than the single plane! :confused:

Now, I should mention that the Performer RPM was fully ported by a pro to match my Canfield heads. The Vic Jr. was untouched out of the box. I was stunned to see that the dual plane had more runner volume, and it wasn't just more at the flange is was more as far back into the runner as I could measure with my dial caliper. I remember cringing when I got the bill for the ported RPM ($350 for the manifold and port work), but in hindsight it may have been money very well spent... Second, it has been my experience that the better the heads, the more benefit there is in porting the intake. Unported intakes can easily restrict flow thru a good set of heads by 30 cfm. That's a lot of potential hp to leave on the table.