SBM Dual Plane Intake vs Single Plane Intake Dyno Results on a Rowdy 408" Stroker

[PROSTOCKTOM]

I am posting this magazine article below because I sell a lot of 408" stroker kits and everyone is always quick to choose a single plane intake when they buy a kit.

This article re-enforces what I tell customers all the time. Unless it's a track only car, keep the dual plane even on a 408" street engine.

Most customers don't have the cylinder head flow, compression ratio, or camshaft profile in their engines that the one in the article does, and yet they still think a single plane is better

Single or Dual-Plane; Which Meets My Needs? Hughes Engines Provides the Results - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Tom

 

[33IMP]

That motor looks like it was built to showcase the super Victor, and still the airgap kicked its butt. So, unless you plan on spinning it to 7500-8000......?
The advantage might not be so large, on a milder motor, but a milder motor CRIES for a two plane.

 

[Phreakish]

For a fun car, I'd take the Victor every time. From 4700rpm on up, the Victor is equal or above the AG. But I also take every opportunity to shift well north of 6k.

Shifting a 4spd at 6550, the revs will never drop under 4700 with each gearchange. No need to take it to 7500, but the Victor was still making power at 7k! Shift at 7 and the gearchange never drops below 5k, and from 5-5400 is where the Victor really stomps the AG setup. With 3.91 gears and a 26" tire, 4700 rpm is about 35mph in 1st. Neither car is going to have traction on the 'street' anyway but the lower torque is going to make managing initial traction a bit easier - from 35mph on up it's all over though, the Victor will eat that AG.

I've also gotten to experience the difference first-hand. My 408 wore an AG at first, and later I swapped to a ported Victor340 (TF heads, Fitech EFI, 4spd, hooker headers, 2.5" x-pipe exhaust thru mufflers out the back). With the AG, it really was not rev happy but had plenty of grunt. It felt labored shifting at 6500, I typically shifted closer to 6k. With the Victor, I've got traction problems (265/50/15 and a 3.91 rear) all the way through 3rd on the street - something the AG never exhibited. I cruise around 2500-3500 rpm, and the Victor shows no bad habits in that range, so no change for me when tooling about. Under 3k there's a slight loss of torque, but getting to and past 3k is ridiculously quick. Typical shifts are now closer to 6500, but it's still pulling as I close in on 7k (rev limit at 7200).

The dual plane would be fine in my pickup though, and that's where mine is destined to go.

 

[ch1ll]

So I’m thinking with 3:23 gears or less you would go with the dual plane. If deeper gears like 3:91 or deeper,the single plane as your tack’d up at low speed already.

I’m also thinking that with a rpm engine that revs like a chainsaw you go with the single plane cause your there so quick. If you have a low rpm grunt engine like a Pontiac or Buick you go with the dual plane. But mostly keep it parked in the garage with the door closed so you don’t lose races.

 

[gzig5]

Is it possible the Super Victor has too large of a port/plenum for the low end and the 340 Victor or something like the Holley Strip Dominator or M1 single plane would give better results on the low end while keeping most of the top end advantage? As mentioned in the article, everything is a compromise but my impression is that the SV may be too much of a good thing for this kind of comparison.

 

[rumblefish360]

So I’m thinking with 3:23 gears or less you would go with the dual plane.

A bunch depends on the driver, cars weight, camshaft, etc.
I can see a dual plane usage even with 4.10’s. As the article says, it’s what your doing with the car.

If deeper gears like 3:91 or deeper,the single plane as your tack’d up at low speed already.

Same as above.

I’m also thinking that with a rpm engine that revs like a chainsaw you go with the single plane cause your there so quick. If you have a low rpm grunt engine like a Pontiac or Buick you go with the dual plane. But mostly keep it parked in the garage with the door closed so you don’t lose races.

Even if the engine itself revs up quick, that is also the rest of the car that allows it to. Car weight, converter, gears, tire size, etc…

As the article said and we have been told for decades, this still holds true and will normally show best performance results.
Dual plane on the street, single plane at the track.
But there is always a rule to break and that rule can be bent really well.
It’s all in the combo.

Honestly, if you want to run a single plane, realize that is a race intake. Most people under cam a single plane intake.

 

[cpearce]

Following

 

[Rat Bastid]

I am posting this magazine article below because I sell a lot of 408" stroker kits and everyone is always quick to choose a single plane intake when they buy a kit.

This article re-enforces what I tell customers all the time. Unless it's a track only car, keep the dual plane even on a 408" street engine.

Most customers don't have the cylinder head flow, compression ratio, or camshaft profile in their engines that the one in the article does, and yet they still think a single plane is better

Single or Dual-Plane; Which Meets My Needs? Hughes Engines Provides the Results - Mopar Connection Magazine | A comprehensive daily resource for Mopar enthusiast news, features and the latest Mopar tech

Tom

Why the Super Victor? Crap test.