I don't believe all magazine articles until I see a trend of good things.
Oh yeah, and with a high stall converter at the track you WOULD feel a difference with the single plane over the dual plane on this engine setup. Pure street car should have a working cat, not run a "hot" cam, working EGR, etc. This is just my proof that the single planes are superior on a performance car as long as the whole car is MATCHED up to the cam and torque converter (gears too). If you run a dual plane on a "fun cam" but have deep gears and a higher stall speed tcc....it's crap. You might as well install a single plane on a 383 mild stroker with 2.73 gears and a stock torque converter!
Links below have all the info you need to understand where I'm coming from.
Now to show the other side: I like dual plane for many other reasons other than performance. Let me keep it short and just say I'm using a dual plane until I get my 2800 stall converter installed along with a hot cam.


------------------
, Jon (350 TBI!)
91 Red My website


[This message has been edited by JPrevost (edited November 30, 2001).]

 

I agree with your comments entirely, but I believe the artice proves MY point and we are actually saying the same thing just using different thinking... AVERAGE TORQUE is listed on good dyno sheets for a reason: Torque moves the car! DP has more than SP in this test, and I'll take the 10lb-ft at launch and the tq advantage through 5000rpm every time... I think you really do understand/agree with what I was trying to say: ie, MOST people have a mellow-ish cam, improper gears and too-low a stall converter to get the most out a single plane (over dual plane) for the majority of driving/racing... The article dyno-test data plainly proved my point about the lower-rpm torque superiority but the upper-end torque inferiority of the DP... Higher peak torque for the DP as well. Very typical... Too bad they didn't put the two different engines into a car and drag test them!!! That woulda been worthwhile info!!!

Thanks a bunch for the article posts... You got the rest of the pages???

I believe (90% sure) the Edelbrock RPM Vortec flows better than the GM Vortec dual-plane, too, but cannot remember the flow comparo numbers Edelbrock gave me a while back. The RPM Air-Gap does not flow as well as the plain RPM, I think, too. Colder charge, though.

NOTE: It isn't clear about what rockers/ratio they used??? Did they use the 1.5 stamped pieces??? If so, these are some nice numbers... Sound like the GMPP self-aligning 1.6ratio true roller rocker (hot cam KIT pieces) numbers to me, though.


[This message has been edited by fast_broker (edited November 30, 2001).]

 

hmm...

 

It seems like they both have the same torque curve but the single plane having it at a slightly higher RPM and having more HP. A simple gear change would have the single plane negate the benefits of the dual plane. I think you'd get better fuel distribution with the single plane too.

------------------
-Tas
'89 Formula WS-6

305, TBI, 700R4, P.A.W. 14x3 open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips, Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248)
Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options

 

i always thought a traditional single plane intake only had good flow when you are "up there" in the RPM range. i mean like up to 6500 or even up to like 7500 RPM. and, i also thought that it was pretty crappy down low, like where our cars idle at. probably doesnt make a difference that much on the street, but it seems to extreme at least as far as i am concerned.

i mean the edelbrock torker intakes say "2500-6500", and the RPM line is from "1500-6500", while the regular performer line is from "idle to 5500".

i have the performer RPm air gap, which is in that 1500-6500 range, and i have about a 2400-500 stall converter.

this brings up a lot of good points though...

-brian

 

HP = torque produced over time... More torque at ANY rpm = more HP at that rpm. That is that. I agree, more HP with the SP, more torque with the DP.


If you have a street/race engine that runs at 4500-7000rpm only, you are good with a SP manifold. There is no way our STREET cars will hook up with a 3500-4000 converter and 400hp/400lb-ft. Hence, my argument that street vehicles that are raced periodically will give you better results with DP manifold. I am NOT arguing the top-end hp thing here, guys. Just that in reality, it makes no difference in the type of vehicles discussed here!!!!!!!! Sakes alive, a simple mistake on installing your intake manifold and gaskets improperly/crooked can cost you 10hp/10lb-ft!!!!

Have any of you driven a car with 400hp? How about a 400hp car with 3000rpm converter? a 4000rpm converter??? My Wrangler has 400 carbed HP now with a 2600rpm converter for crying out loud and 400lb-ft of torque that will spin about anything... AVERAGE torque over the run will win the race. Be it on the street, or at the track. Anyone ever drive a car on the street (daily drivre or not) with a 3000rpm converter? 4000rpm converter??? Talk about heat generation!!! Most guys here are talking of their only CARS with 3.23 gears or higer! The only one!!! Get them to work , home and out on dates. I am just trying to be real here and help from experience. It's like using too big of a cam. You probably only need a DP manifold and will have better streetable and race results from the DP as well... IF you have a trailered racer, run 4.56's and a SP for sure! I got 4.11's in my Wrangler now with the Pep Boys 295/50/15's and I bet it'll scare about anyone on this board... Dual Plane and all.

My only argument is that whoever has the most average torque over the run WILL win the race, all other things being equal. It's a fine line of actual rpm usage during the drag race or street run. Most guys here will have MORE AVERGAE TORQUE OVER THE RUN IF THEY USE A DP.

 

I should have mentioned this to help prove my point but have any of you check to see what happens to your engine rpm when you shift? ie, at what level does it drop to??? When are you guys shifting????

I assumed that you realized this but a 700R is not a race tranny and is not close-ratio:

If you hold to 6000rpm and shift, here are the shift rpm changes for ANY GEAR RATIO:

1st 6000rpm ==>into 2nd at 3175rpm
2nd 6000rpm ==>into 3rd at 3700rpm
3rd 6000rpm ==>into 4th at 4200

I bet most of you shift below 6000rpm, too...

Now, what happens if have a gear you cannot really pull, as most do here? You end up in the lower rpm ranges for a longer period of time, especially because of the last gear used. ie, most guys here are at about 4000rpm at the traps in 3RD GEAR... right????? The dyno graph above CLEARLY shows a torque advantage to 5000RPM!!! Get it??? Can you run from 5000-6000 only in a race including all the shifting? Not. Now, combine the concerns of streetability, reliability, mileage, etc and the DP is the clear winner.

I build cars/trucks that I will drag around the last tranny gear to be used (ratio, that is, correlating to redline rpm desired), the desired trap speed/ET and then pick the axle ratio and tire diameter and then engine combo to get all to match. Here, for our cause, a DP matches best for the improper combos that most have...

If a guy here has 4.11's-4.56's, good heads, SP manifold, big cam, 3000rpm stall converter or so, don't race him...


[This message has been edited by fast_broker (edited November 30, 2001).]

 

Ok I'm convinced. I'll build my 350 back with the Hot Cam, reworked and ported Vortec's.

But I have the regular Performer. How will this intake work with the Hot cam?

How will the cam work with the 3:42 gears that I have to install?

------------------
91 RS 5.0 TBI....LT4 cam....Edelbrock headers....3"Dynomax exhaust....5spd.... 3.08.....Ultimate tbi....afpr...ZR 255-50's...Koni's

 

A single plane has 2 sets of 4 runners.
A dual plane has 4 sets of 2 runners.

You can't get a dual plane to work completely right at any rpm. To get the mixture about right, means heating the manifold.

Single plane while not perfect is close, and they run well without any heat.

About the only single plane that has 8 equal runners is the cross fire, and that one takes tons of work to get right. When used with a different lid so that it's carbureted.

Low speed drivibility is more about tuning.

Once you get to about 1/2 throttle the Single plane walks the dual. So if you racing at 1/3 throttle the DP will win.

Use a Weiand 7525 and have fun.

Fast whatshisname mentioned the most overlooked part of a converter.
Flash speed, it is what allows the engine to recover and get to speed again after a gear change. You really need a ride in a car that uses a 4K stall (and needs it) to get how important this feature is.

One my well tuned LG4 I ran a weiand 7546 8012, Performer Performer RPM, and several others. Even on a lowly LG4 the 7525 was fastest in the quarter get the best MPG and was the most fun to drive, thou I did optimize each tune. With a poor tune a single plane would be a PITA compared to a well tuned DP (and the reverse).

 

Yeah, those WOT dyno tables posted above are all fake. Lies. Untruths. Maybe the dyno operator above held the throttle at 1/3 for a bit, to say 5000rpm, then went WOT... LOL.. Let's race??? Well, he may have HAD to go 1/3 to 2000rpm because he had a 750cfm DP carb, which is too big for 400hp... Whole nuther conversation...

Ok, Grumpy. You think the SP in the above test beat the DP above 1/3 throttle??? Prove it. ALL WOT DYNO USE.

Noone here uses a 4000rpm converter. Not even a 3000 converter. Not even sure why flash was brought up... RPM is RPM... Torque at an rpm does not care about flash... That's a weak argument, to say the least. Wrong, wrong, wrong. Doesn't matter for any configuration. How would someones 2000-2500rpm converter fair in this argument??? I was being kind above... How about a stock converter? LOL.

I hope I can get to NJ for the 15th... Lessons will be learned. I may just show up in a vehicle that you guys do not suspect as my Wrangler is a MARKED vehicle, from what I hear... Pink slips may be exchanged?

I have to laugh.


[This message has been edited by fast_broker (edited November 30, 2001).]

 

I just want to make something clear broker. You understand that we have a v8, 305, 350, 383, you name it, they're all v8's. Can you tell me what v8 DOESN'T have torque. That is my point to a T. With a small block chevy you want hp, the torque is already enough to run great 60' times. Ever notice those imports with lots of hp and no torque still manage decent 60' times. Yeah it's because the car weights less BUT they're playing with less torque all over the curve and they're front wheel drive (that goes both ways but I don't want to get into that factor). Like Grumpy said, flash speed, torque converters and cam go hand in hand. We all agree so that isn't something to contest. What me (and I think Grumpy) are trying to point out is that single plane has more advantages when setup right. The dual plane is more of a fool proof way to get an engine to run decent-good.
Let's also agree that nobody races at 1/3 throttle, it's all about the WOT and max performance. Some people (like me) don't have everything perfect on the car and so running a dual plane lets me get off with a lot more room for error in the eprom burning. I can also run a stock torque converter and it doesn't hate me. If I ran a single plane and made the proper adjustments I'm sure even my mild 330hp motor would through some fits. This is why I brought up the stall speed in the first place. Get a higher stall speed and a good converter (with good flash speed) and a single plane will take you to the finish line faster than the dual plane.
One thing I don't like about the single planes is like you said, the loss of low end but for me and most v8 guys, we have to suffer in some area's to exceed in others. Give up a little "off the line" for more fun . You can't have the best of both worlds unless you own an Lt5 motor or that new inline 6 vortec pumping 270hp .

 

you all know how i feel about sp vs dp, I think grumpy hit the nail on the head and Jprevost aswell

one thing no one has mentioned in defense of the single plane (in addition to all the stuff said allready) has to do with this whole low speed torque foolishness... as far as i know, we are in the tbi forum meaning these manifolds would be used with TBI. What else does this mean? Well as im sure you all know, TBI and carbs are quite different in the fashion they meter fuel. A carb relies on a vacuum signal and TBI does not. Thats why you cant throw a 1050 dominator on a 305. Theres just not enough airflow through the thing to make it work. Similarly, conventional wisdom states that you cant run a huge single plane on a mild motor partly for the smae reasons. Why do you think people get away.. or rather need a smaller carb when they run a single plane? All comes back to the vacuum signal thing. And if you dont think its really a factor you might wanna look into some carb vs carb comparisons. Ive seen some carter thermoquads hand holleys their *** when it comes to low vac. signal torque production. All in the design of the primary boosters and venturi. To think that its still behind injection merely reinforces my point. Granted, there are a number of things you can do to bandaid this sort of problem with a carb.. but it will never be as "right" as with injection, and it definately has been nowhere near "right" for the carbs in the sp vs DP dynos. For all we know if some form of injection was run for those tests the sp equiped version could have been hands down the winner in all the rpm ranges. Or at the very least, the gap in power on the low end would be greatly deminished.

You might also want to consider that in a street car (take mine for example) I only see under 3500 rpm 1 time for the entire quarter mile, and i spend the MOST time above 4500 rpm (end of the track). It would seem to me youd want to improve your power in the rpm range where you spend most of your time, no?

and that engine is awesome.. I bet with a few more minor tweaks they could hit 430 hp

 

Btw yes im ignoring runner design just for the sake of argument, I guess the size and shape of runners has some bearing on the way the engine performs but thats only part of the equation, and that doesnt neccessitate a tbi vs carb comparison to show the differences although I imagine its still somewhat related to the whole vacuum signal thing but you can see the differences there carb vs carb. I just wanted to focus on the single vs dual part of it

 

OK, have it your way when you.
I was just trying to educate a little, but you seem stuck on what you think you know.
BTW, your again wrong, since I am here and I have more the a 3K stall converter.
Laugh all you want, I really couldn't care less.
NJ?
Isn't that where they sentence people to live? (Just meant as to be something that is laughable, ie, a joke).

BTW, you never did mention any real testing that YOU did. I tried a number of manifolds, have YOU?. How much time did you put into optimising them?.

Are you assuming my current ride is a TBI'd or TPI'd car?. Or even naturally aspirated?. Hmm, assuming maybe embarassing.

But, in closing, even my LG4 ran better, in all repects with single plane. Same was true when converted to TBI, and also a 355 with TBI.

BTW, try to get to a PT+E seminar, they had some great info on converters.

 

If you actually think you will have more average torque with a SP, run one. If you think you have more usable torque in your used rpm range, run a SP... The dyno data above clearly states you will have more torque below 5000rpm with a DP. Whatever makes you happy. If you typically run 5000rpm+ (which you won't), you'll be happy... Your rpm average in the quarter will probably be less that 5000rpm... And if anyone runs a 3000rpm converter with 2.xx-3.55 gears and 26" or so tires, you have a lot to learn about drags.

I have done enough TBI dyno work in the last 12 months (engine and chassis, carb on most of the combos for ha-ha's/setup) with different manifolds and cams on a few different head combos (two block combos) now that you all should realize I know of what I speak... I won't bore you with the details. They more or less mimic the above dyno results, which all testing pretty much will for obvious reasons. I have shared the data with certain persons here, anyhow... I have done more TBI dyno work than most will do in a lifetime. Because I want to learn, no other reason. Learning that TBI cannot overcome the low-rpm downfalls of a SP is one reason I did it... No big surprise...

As an aside, most non-professional racers will NEVER notice the above differences in a motor during a race... You just don't know when/how to shift and it just won't happen. So, just build it and drive it... This was never meant to be a flame post and I agree about the peak HP thing. I just disagree about average torque, race implications and basic drivability issues. To each his own. We don't build cars for others to drive, and I will never drive your car and you will surely never drive mine. Build what YOU want to race/drive, not what I give a krap about... It's your money, spend it as you like. Also, I have a Grand Cherokee with less HP and MORE torque than before the big-block swap, and it now has a heavier motor (than an SBC with 500+hp) and it is faster in the 1/4 now... How'd that happen??? Average torque, baby.

Hope you all had a nice weekend. Was Saturday's Northeast weather the BEST or what??? The Holidays approach'eth... (sp)

 

umm im gonna stay out of this one...but yeah..saturday's weather was pretty damn nice...

-brian

------------------
1991 Camaro RS
GMPP 350 HO crate engine - Holley TB, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
My car's webpage - z28boy.cz28.com
President - Central New York F-Body Association
Email - z28boy@twcny.rr.com
AIM - "Z28 Boy"

 

I didn't even get to touch any vehicles this weekend... shame. Well, touching the pedals is always ok, I guess.

 

Whew, now you just need to convince GM and Ford of that.

Maybe if you looked at it this way. Dual planes use several different lenghts of runners so as to enhance the torque over a wider range. OK, sounds reasonable, and what most authors claim they do.

Then why are the latest engines running equal lenght runners?. Like the LT1s, LS1s, etc..

Look at the fastest, most economical, best BSFC engines, and they all run equal lenght runners.

 

same-length runners are always better, but in order to get a carb-type short manifold to work under dual plane conditions with the 18436572 firing order, the only way is with different length runners... ie, it's the the only way to get alternate bank-firing on each "side" of the divided plenum...


Now, if you could change the firing order so that the left and right banks are always firing alternately, you'll be able to properly design a "better" dual-plane manifold, but harmonics don't allow it... Or, just use a Ram-jet, TPI, etc... Me, I'm still waiting for electro-mechanically actuated valves: no more cams, just a computer program and some more wires. but, UNLIMITED control of valve lift and duration at any time... Someday...


How about the SBC RamJet manifold with 7747 control? Anyone do it, yet? I rather like the looks of that setup. I like the 502's better, with its "hidden" rails, injectors and ECU, though, but SBC is SBC. Do they still sell the SBC RamJet manifold????? Could you use that with an OEM TBI TB as the air control? It would look like toilet but in my wrangler, I don't much care, as long as it works.

They sell it:
http://www.sdpc2000.com/cart.asp?act...d=741&pid=1987

...but that is a lot of money. I got injectors but rails, reg, etc has to add another 150 bucks. Plus, add TB and other misc stuff, another 200bucks... I guess it's not all that bad/expensive. The look has to be worth something? Easier to just keep TBI, though, and modify/tune. But, having 350hp (400lb-ft?) out of the MELLOW roller cam that GM uses in the RamJet350 would be nice, if it is an honest 350hp...

On a side note, I am having the worst time tuning the 400hp/ZZ4 cam engine I got in there now with WINALDL. Serious open-loop, idle problems and Main VE table stuff. I may need help on this one. Plus, I am using the 350TB with 65pph injectors at 20psi, probably only enough for 350hp. I REALLY need a 454 TB with 90pph injectors (HINT) ASAP to get to the ATCO run in TBI form, plus the PROM will be totally different with a 454 TB over the 350 TB (ie, more than jsut a BPW change?) I don't want to show up with a carb... You guys will egg my Jeep...



[This message has been edited by fast_broker (edited December 03, 2001).]

 

So, hows the new job Pablo?

I'll have to be a **** and disagree with this, that all depends on what sorta 305 you are throwing it on. Most it would be massive overkill but its not all of them.

"You might also want to consider that in a street car (take mine for example) I only see under 3500 rpm 1 time for the entire quarter mile, and i spend the MOST time above 4500 rpm (end of the track). It would seem to me youd want to improve your power in the rpm range where you spend most of your time, no?"

This is the most important thing to consider. I see the same stupid argument about low end torque on every board on the web, and maybe if you were building a towing engine I would understand the argument. Most stock street cars during a race are under 3000rpm... ONCE! So, what do you care how much torque your car makes at 1500? I dont. I'd rather sacrifice up to around 2500-3000 depending on the car and setup, and add more to the top end... unless I am building an 18-wheeler.

 

Hey whats up miffedmaxwell, the job is allright actually, I cant believe they throw all this money at us just for signing a paper(not directly of course) im now in this class working on a hydraulic component test stand so i guess this means im gonna end up being the hydraulics dude. All i know is im gonna have the baddest hard lines and fittings on my car now hehe

[This message has been edited by Pablo (edited December 03, 2001).]

 

Guess you missed where GM has changed the SBC firing order?.

You could very well do a dual plane with *equal lenght* runners (*equal lenght* as well as a single plane has).

Again the characteristic that defines the current dual planes is that they use different lenghts to spread the torque curve out.

The electro valve technology valves are in use.

http://rbowes1.11net.com/dbowes

I guess you'll have to tie a bunch of them together to actually propel your car. <g>

 

Dual planes use (very!) different length runners only because they have to, not to change torque parameters. It's the only way to evenly distribute the banks of the engine so that the carb venturis will see "even" cylinder drawie, so that the pulses always alternate. ie, left venturi draw, right venturi draw, left venturi draw, etc, all through the firing order. Grumpy mentioned other ways around this, like cross-fire, the old HEMI-ram manifolds, etc. Dual plane manifolds are the only short/small/practical way to do it cheaply.

Evenly spaced pulses to the carb make the carb more efficient at low, mid and sometimes high rpm levels... At high rpm levels with an manifold, there is so much flow through the carb that the venturis are plenty efficient. Even with uneven pulses/distribution, the SP's can get the job done just fine up there... It's a constant/proper velocity thing, along with other factors.

EDIT: Thanks for that link, Grumpy. Yeah, I guess a group order would be necessary for just one V8. If I had a prayer of writing the software for it, I might even consider it.



[This message has been edited by fast_broker (edited December 04, 2001).]

 

You just answered the big question. TBI doesn't require that special vacuum draw, it would inject fuel no matter what as long as there is vac for the map (depends on cam not intake as much). This is why TBI can run with single plane and still get an awesome torque curve down low.
If I had a carb and a daily driver with a mild cam and stock tcc I would use a dual plane. If I had a higher than stock tcc around 2500-3000 then I would opt for a single plane. Like I said before....we have a v8, not an inline 4 banger. We have lots of torque and what Grumpy said made lots of sence....you don't tow with your car so why build a motor just for low end. You DO have a jeep....so yeah, that would want a lot of it's torque on tap off idle....the car...come on. Give it the max performance and go single plane . And with TBI...you should definatly use a single plane for performance applications.

 

I understand what you are trying to say but you must understand what actually goes on inside the plenum on dual vs single plane intakes. Lots of flows changing, moving and influencing other flow. ie, what happens when cylinders 5 and 7 suck pretty much at the same time from the same area? 5 steals from 7, get it? That has nothing to to with fuel delivery, just air movement and physics... Even pulses across all internal flow areas is what one desires and it cannot be accomplished with DP or SP, really.

When you have true isolation of runners and pulses, which is dificult/impossible to actually achieve, you have the ideal system, which is still only tuned to a small range of rpm usage...

I did some SP vs DP dyno work with TBI vs carb as some of you know. Again, it just verified the tried and true SP vs DP low-mid rpm range argument. It all comes down to the desired velocity of charge desired by the intake, heads, combustion chamber and to another extent at high rpms, the exhaust. The combination you run must be matched to the desired usage and rpm range.

My Jeep is fast as all get out with 4.11's and 4.56's and is only 2wd with all extra weight removed. Not actually sure what it weighs, but more than your car, I am sure. If I really want low-end torque, I just change the motor or cam/intake/etc. I JUST bought a 1992 full-size Blazer this weekend, 160k. That will be my "new" mule after I replace the engine and some particular bearings in the thing. Heavy duty truck in great shape. I'll probably drive it for the Winter and sell it. Now, that truck will have some low end, surely to get the 3702 194/214 Edelbrock cam that I did TBI dyno work on in the Wrangler. that was a great combo.

EDIT: JP If you think that "low-end" torque means more torque below 5000rpm (as the DP vs SP dyno data above clearly shows!) then I guess I want more low-end torque. A mellow cam with a Performer carb and small carb will not have more torque at all over the SP data above. It is TOO mellow... There are 3 levels of performance in this discusion... Street/daily, street/race, race/no-daily, IMO. I am arguing the street/race point, that is all. I removed a 500hp carbed SBC (nice to have ASA friends) from my Wrangler to do this TBI stuff. What manifold do you think I ran on that engine??? SP, of course, but lord sakes, it was not fun in the city.

I'd love to haggle with you guys over some beer/food/races but I won't be there UNLESS I GET HELP FINDING A 454 GM TB!!! Classifieds up, yet?

[This message has been edited by fast_broker (edited December 04, 2001).]

 

Responses clever hidden in quoted text.

 

Just wanted to point out one thing... kind of nitpickey but what to hey.

Average TQ does not win races... Average HP does. A motor that averages 400 ft/lbs at low rpm can loose to a motor that averages 300 ft/lbs at high rpm. Case in point: Ever race a diesel.

 

My Jeep has a ZZ4 cam with GMPP 1.6/1.5 roller rockers, ZZ4 short block, ZZ4 cam (.505"/.510" lift, now) and Fastburn heads. A "fancy" FastBurn 385 with 400+hp, if you will. Little more power from more total lift on the intake, litle more power from the Roller Rockers reducing friction...

194/214 was my first TBI PROM cam. Nice and easy to work with.


I'd still like to see the rest of the artice!!!!!!!!

[This message has been edited by fast_broker (edited December 05, 2001).]