single or dual plane intake???

I did some searching but did not find anything.

They seam to push dual plane but many people say stick with single.

If you load your engine info into desktop dyno a single plane is better.

so what the deal with this, which one is truly better.

 

...

 

dual

 

Single plane manifolds work well at developing hp at higher rpms. Thus they are endorsed more heavily for a strip only car.

Dual planes make more hp and torque, usually, at rpms that are condusive to street driving, i.e., lower rpms. That's why they are recommended for daily drivers.

 

If it's a 80/20 street/strip car, then use the dual plane. Better throttle response, better MPG, easy to tune a carb on, and less sensative to CFM when matching a carb to your engine requirments.

I can't see your first graph very well. It's part pink. However, I'll bet your peak torque is lower with the dual plane, and is at a lower RPM.

One thing you gotta keep in mind is a 305 has very little torque compared to a similar modded 350. You can help this along by using a smaller cam and a dual plane. Don't get too crazy on cam selection for a 305. A mild cam for a 350 is a hi-po cam for a 305.

Just for grins, calculate your average TQ and HP numbers on both engines (or should I say both intakes). I'll bet you'll be surprised at the results.

AJ

 

better for what? you negelected to mention what you're doing with the engine the intakes going to sit on.

 

stock 305 heads
600cfm carb
single plane intake
small tube headers with mufflers
stock cam

261 hp @ 5000
319 torque @ 4000

stock 305 heads
600cfm carb
dual plane intake
small tube headers with mufflers
stock cam

251 hp @ 4500 [single plane 260 @ 4500]
315 torque @ 4000 [single plane 319 @ 4000]

----------------------------------

stock 305 heads
600cfm carb
single plane intake
large tube headers with mufflers
stock cam

267 hp @ 5000
322 torque @ 4000

stock 305 heads
600cfm carb
dual plane intake
large tube headers with mufflers
stock cam

255 hp @ 4500 [single plane 263 @ 4500]
317 torque @ 4000 [single plane 322 @ 4000]



what im wanting to do is get some good hp without raising my torque too much as my T5 will shread with too much. I think the stock 305 has plenty of torque I just want 250+ HP.

 

HP is an estimate based on torque, which is real and can be measured. it's hard to rasie HP and leave torque where it is.

 

I still find it confusing how everyone seams to push the dual plane when the numbers tell a different story.

I mean open any mag and you will find pages n pages of dual planes, maybe 1 page of single plane. webistes are the same. Single planes are hidden at the bottom.

 

Agreed! Do this and you'll probably have you mind made up.

 

D you have boobies??? or is that just the shading from the tree???

 

NOT shading from the tree.

 

You ever have them times when you question your sexuality? I just did and I passed with flying colors.

I’m not gay. [Not that there is anything-wrong wit it]
And Tom91Bird is cute.

 

Just get the Weiand Stealth and get the best of both worlds.

 

I do know that the dual plane is more popular but them programs make you second guess what you know. one thing I dont like is , it does not show any results till 2000rpm. There could be some good info in that 0-2000 rpm range.

I found those programs to be a joke kinda.

 

I was already thinking about going with them. Isnt the Holly one the same thing.


I guess my next question will be what RPM range do I want.

A normal launch on the v6 is 1500 so I really dont need the off idle.

but it dont matter. They just have so many

off idle to 5500
2000 - 6500
idle-7000

But I do like the Stealth intake but what rpm range.

 

Well, be reasonable about it!

This seems to be a daily driven street car you are building. There is no sensible reason to put a single plane intake on, as I stated earlier.

Are you planning on turning 6500 - 7000 rpm? I doubt it because you would have to delve into the short block to do it. So pick a dual plane intake that is good to 5500 rpm and be done with it. If hp goes up, so does torque. Just the way it is. Don't worry about your T5. The 305 isn't likely to "shred" it.

And there is so something wrong with homosexualty. It is completely weird, whether that is politically correct or not. That's why G0D made women.

 

And Desktop Dyno is usually 20 to 25 hp too generous in its estimations.

It can't differentiate between an Edelbrock Performer and a Performer RPM, even though the latter is usually good for another 20 hp at higher RPMs.

Other than that, it does a pretty good job of giving you an estimate. After a while you learn each program's idiosyncracies and work around them.

 

Why do you call yourself Tom then?

 

And plenty of them.

 

I was just trying to be "PC" Like on Seinfeld.

I was also confused by Tom91Bird nick and also the nicks for yahoo and aol in her user info.

Just glad I was not attracted to a man.

 

is the Holley and Wieand stealth intake the same thing???

 

.

 

I attached an image that clearly shows the sacrifice made to the low end torque.
Both curves are the same hardware accept for the Intake.

The current is a Victor Jr. single plane, and the Last is a Performer RPM.

I did the swap last month, and by my own seat of the pants feel, backs up those graphs to a point.

The torque does get bruital above 3500rpms. I love it!!!, but off the line - eeeeeeeee. You realy have to keep the engine above 3500 to enjoy the gains. Hence why it's for my road racing car, and not for the street.

BTW: Holley owns Wieand Those intakes look like Spread bores. Do you have a Spread bore Q-Jet or Square bore Edelbrock/Carter AFB?

Ron

 

the two intakes in the pic are both spread and square bore. but the same intake, just different names. ie holley wieand

 

They are VERY different intakes. Look at the runners. Don't even have to look closely, cuz it'll smack you in the face.

And I agree. If this is a daily driver street machine, dual plane all the way. Especially if you're running stock 305 heads. There's NO way you're gonna make ANY high end power with the flow on those to justify a single plane, where the whole point of a single plane is high end power.

 

I agree all the way on single plane but I got my friend who spent 4 years in colledge [Mechanical engineer] showing me numbers and crap when I know he is wrong. I know what I know from 20+ years of Hot Rod mag.

 

Holley and Weiand are part of the same company. My Weiand intake had the name Holley on the box.

 

Well I hope i did not make a mistake????

I won this on ebay for 56 bucks, 19 shipped.

Weiand Stealth Part #: 8004
Intake Manifold
Chevrolet 262, 283, 305, 307, 327, 350, 400 V8
1962-86 All Models


Features
Low rise/dual plane design
Idle-6000 RPM power band
No EGR provision
Spread bore and square bore carburetor mounting flanges
Lunati camshaft and lifter kit available under P/N 01001LK


Carburetor Recommendations
For Street Legal carbs, see application chart. 0-80555S (650 CFM spread bore); 0-80457S (600 CFM square bore); 0-4776S (600 CFM square bore)

Installation
Square bore carburetors may require plate P/N 9006 to seal properly. HEI will clear.

Specifications
Height - front 3.50", rear 4.00". Shipping weight is 17 lbs.

 

.

 

Oh yeah, slap a nicely tuned QJet on there and you're off to the races!

 

[.

 

I second Sitting Bull's notion there. Rock that thing. Edelbrock's Q-Jets aren't half bad and you could probably find a rebuild Q-Jet somewhere for a decent price, if you don't already have one.

 

Would a EDELBROCK 600cfm carb be plenty big enough???

like a 1405

 

actually on the debate of the intake manifolds its not really a question of daily driven or not its just where the motor makes its power range at. my motor pulls up to about 6500 and i had a RPM intake and then went to Victor jr and you can honestly tell a difference in the two but when switching to a single plane you will also need to adjust your carburetor because it sometimes deprives itself of the proper fuel mixture at lower RPMs but if you arent making power over 5500 stick with the dual-plane.

 

simple as this

for fast cars or cars lookin' to be fast = single plane


for slow cars lookin to stay slow= dual plane




thats a little bit of a simplification hehe

but lets face it, who races the quarter at 2000 rpm?.. Even then a properly set up single plane setup doesnt give up much if at all to a dual plane. The big gains are 3500+

I only see sub 3500 once on my 305 and it still has plenty to get off the line. This is with an edelbrock torker II single plane, 1405 600cfm edel carb, and 214/224.

If I had to buy a new one now id get a victor Jr instead. Hell, even car craft managed to gain hp across the board with one on a stock LG4 if I remember correctly.

 

Don't even consider using a single plane with stock 305 heads on the street. A Performer rpm is all you'll ever need.
Desk top dyno will not show the difference between a stock dual plane intake and a hi performance dual plane like the Performer rpm.
Desk top dyno is way to simple of a program to be used for designing a good motor. It only shows general trends.
A performer rpm will make power well into 7000rpm on a good
breathing 305. A dual plane with a fully divided plenum will always drive better under cruise conditions on the street.
This is how you'll be spending most of your time while driveing.

 

I would say personally if your rpm's in your powerband begin at 3000 on up use a single plane if below 3000 use a dual-plane intake. I dont mean to argue with anyone but some people make it seem like its impossible to have a single plane on a street car and have driveability.

 

i agree harley


i drove it everyday and didnt notice anything wrong with it it was faster across the board from stock anyways

 

I know of a low 11second third gen that slowed down .08 second when a perfrormer rpm was replaced with a vic jr. This thing had 400+ cubes and was turning 6000 rpm with 3.9 gears and auto trans. The entire .08 second was lost in the 60foot and never made up.

Torque is VERY important in launching (especially autotrans) and losses might not ever be made up in 1/4 mile.

As far as DD2k goes,, its is pretty well known that it is optimistic for torque readings especially at low rpm. That would pretty much make any intake comparison results questionable when using it.

 

I have the Victor Jr. Vortec single plane #2913 on my 406. With that size engine you have adequate torque at the lower rpms anyway. Not so sure about that on a 305. Harley83, with my setup it really gets happy at 3000 rpm.

 

With your setup definately go with a dual plane. Desktop Dyno doesn't do a good job of estimating power when it comes to certain things. It doesn't do a good job of showing when a cam or carb is too big. It always shows a single plane as better than a dual plane even in a conservative street engine. I took about .15sec off my 1/4 mile time with my current engine when I switched from a Victor Jr. to a RPM Airgap intake.

 

super chevy did an article on this some time this year. either in april or may i dont know. IIRC the single only made like 6 more hp and that was at 5700+ rpms. this was on a mild SBC. in the end they recommended a dual plane with a carb spacer for sub 6000 rpm street motors

 

Something tells me, that's his girlfriend.

 

Maybe its just me but i can sorta feel the difference between the two on a modded engine if you have a 3000 stall with an RPM its sorta sluggish bolt on a Victor Jr. and you get that big strong snap of torque. like i said unless its a modded engine dont use it unless you are making power over 5500 anywhere over there id use a Victor Jr. especially with a 3000 stall or higher