Im looking at eventually spraying 200hp nitrous on my engine but I currently have an dual plane RPM intake. From what Ive seen these are my choices



Im looking for the intake that retains or even improves on the torque I already have with my rpm intake.

Here is a pic of the super victor
carb height 5.630"
3500-8000rpm


The GMPP single plane 12496822
3500-8000rpm


and here is a Proffessional Products Hurricane
height 5.960"
3500-8000rpm


It looks like the runners of the Super Victor and the GMPP prodrude into the plenum more so than the Hurricanes runners which should help torque, right? Then there is the weiand 7546 and the Victor jr, which, although won't bolt up to vortec heads are still sbc intakes. the Weiand had got a much lower power making range 2000-6800 than the three above but has a wide open plenum. The same goes with the Jr except for the rpm range of 3500-8000.

Victor jr height 4.580"


weiand 7546 height 4.845"


my vortec RPM intake has a height of 4.750" for reference sake. Any opinions out there on which of these intakes would make the best power on a 400sbc from 3000-6500rpm?

 

There will be many options to skin this cat. If you want the max performance from any out of box intake that is priced within reason-you will have to port the runners, and under carb area then into runners up there also. To have a shop do this to maximize it around here's it starts at $100 for a really quick clean up and a better job at $200 and top notch upwards of $400-in addition to the price of the intake. All of the ones you've listed above will require port work to work at full capacity, especially since you plan to hit it with juice.

I have not perosnally seen flow sheets, but have talked to the guru's at our local head shop and we were discussing intakes, best out of box, etc...and they all agreed hands down the best untouched out of box they're flowed was the Dart intake followed close with the Brodix. And as they put it, you either spend the $325 for out of box performance with the Dart of Brodix, or you buy a Edelbrock/Weiand, etc...and then pay the additional $2-300 for the same results...so then which would you do?

I bought a Hurricane last spring since alot of dirt packers and dyno guys were seeign pretty good results for the money, BUT they failed to mention the amount of porting required to open it up. So uninformed I bought one, slapped up one of my 1206 intake gaskets to the ports and about puked since the factory out of box runners were soo small. $125 in 2 carbides and 6hrs later (they still need touched up with some sanding cones) the intake is almost ready to bolt on, but to be truthfull I lost intrest and stuck in back on the shelf since it still needs a few more hours to make it right. I easily took 1/4" off the top/btm and then another 1/4" off sides of the runners to gasket match and blend into the runner itself...was'nt real happy to say the least, so IMO i would rule that out.

 

Out of those, I have seen a lot of people make a lot of power and go really fast with a super victor. It's a good manifold. Tests nice in the magazines too. If it wasn't almost bedtime I would try to dig out some articles for you to look at with test results.

But you know. there's another option. It's more expensive, although not brutally expensive like forced induction.

It's also fallen out of favor, for some valid reasons.

But it's still a good idea and they make more torque than you would think they would. I've seen some surprising dyno flogs.

I'm talking about this.

 

I didn't realize that there would/could be that much porting involved on an intake. At least I'll be prepared now for a few extra hours prep before everything is together.

that tunnel ram would be really cool, but it won't bolt up to my vortec heads. If you find time I wouldn't mind an overview of a test or too, especially if its against another manifold.

Anyone done or seen any before and after tests on an RPM intake with the divider cut out?

 

There's an online article I'll try to track down this afternoon that did a comparison among many different types of manifolds. It was on a slightly different engine than yours (still Chevy though), but the comparison showed some results that I didn't expect to see.

I'll look for it this afternoon after I get home.

 

You are talking about Vortec heads... the GM and Edelbrock piece are the same and bolt right up to them.

On a vortec head you only need to do the plenum area on those intaked. It takes a while to do it right but you can have virtully zero flow loss with the intake installed if it's done correctly.

Bret

 

Bret,


Whats your opinion on the Dart and Brodix Single Plane Intakes. My 468 BBC is going today to start all the machine work so im eventually gonna start ordering the extra stuff sometime in the near future. I had planned on running the Super Vic but i wanted to know what I can about the other ones. Il send ya a PM either tonight or tomorrow ive got a few questions For ya.


Thanks man,
-john

 

All depends on the heads really. You can make any intake work well.

I'm not the biggest fan of BBC's so I don't get into those intakes too much.

Bret

 

I have a 502 in a 94 Camaro and I've tried a couple of intakes both Eldelbrock and the old Holly Strip Dominator, and I new use a Weiand Team G. Excellent intake, with spray, 60' 1.41, ET 10:41, 128 with drag radials. This thing flat works that's all I can say. I've help you do the testing, now the decision is yours. Good Luck!

 

I'm having trouble finding the article I was looking for, which compaered MANY types of manifolds and flogged them on the dyno.

I did however locate a single-four vs tunnel-ram article. It's on a Mopar small block, albeit a pretty serious one. More importantly, it does a good job of comparing the two types of intakes.

The advantage of the tunnel ram comes down to this:
It does surprisingly well at low revs AND keeps pulling at high revs after the single four runs out of steam.

Tunnel-Ram vs. Single-Quad

 

I got a good deal on the super victor so thats what I'm working with now.
What type of porting work has to be done in the plenum are to get better flow? thinning the center port dividers the first 2-3 inches? I have never ported an intake before so I might need a few points or suggestions to follow. any pictures of a finished product?

 

I'm sure you know this, but a lot of how the final product will work is going to depend on the porting done, whatever manifold you start with. I am sure you know this, but for those who may not, these manifolds are designed with a lot of extra meat in them to allow for porting. The end result may depend as much on who does what to the piece as on the original chosen. Anywway, a Vic. Jr. with a spacer of an inch or so ought to work good. I think the Super
Vic. would not be optimal for your rpm range.

Rich

 

IMO...the dart intake is a first choice for a "bolt on" Obviously, you will need some rectification to use the vortec heads.

The dart BBC intake is a pretty killer piece out of the box with minimal work...it takes me about 8 hours to make a super-vic work as nice.

Dennis

 

Airflowdevelop, do you have any pictures of a finished super victor that you could post or email me? Should I try and narrow the first few inches of the dividing port walls or is it good to keep the divider thick for air flow reasons?
Some of the jobs on my to-do list include: basic clean up of casting flaws, port match to heads, round-steamline plenum to runners, narrow runner divider wall near entrance. anything to add?

 

Don't narrow the divider walls. They should have the largest radius you can get on them.

The big issue with the Super Vics and porting is the vertical transition from the plenum to the runner, and making that as smooth as possible.

Bret