I've been interested in the Single plane FI conversion to replace the TPI. While most have use a Victor JR or similar, those manifolds seem to be best in the higher RPM ranges. While I realize that the Super Ram is the best for what I want, the price is out of sight. Has anyone ever tried to bulid a FI system out of a dual plane intake for street applications? It seems to me that it would be a great intake to build power in the same range as the Superram. You could even have EGR hook up if you used the right intake. Of course, I am talking about fabbing it myself or that cost would also be out of sight. What do you think?

 

Do a search on my username + single plane intake....that is what I am and a few other members are running now. Its not a duel plane, but the single plane is a tough intake to beat and a proven winner in the carb world. We just brought it on over to the EFI world and couldn't be happier.

 

I have read many threads about your racing results and I must say that I am very impressed and value your opinion highly. The Single plane is great for drag racing but what about a daily driver withan A4. What I hate about my 86 is how it falls on it's *ss at about 4800. Can't beat the low end but top end with a TPI is the pits. I have ported the plenum, and bored out the TB ( old one wore out) but every thing else is stock. My next mod will be LT headers but I'm going to put some AFR's and cam at some point. What I really want to do is to build a new engine from scratch and moth ball the stocker. Something like a 427 small block. I suspect that the single plane will work fine on that monster, even on the street. But why not try the dual plane?

 

Plumbing for one reason. With a dual plane, you will have injectors at two different heights...minimum. That would make for an interesting looking fuel rail. Nothing is impossible, but...

RACE ON!!!

 

Isn't the Holley StealthRam kind of based on a single plane intake?

 

its loosely based on a tunnel ram

 

Dewster. The single plane was/is not not a bad intake for the street. But you should consider instead of our super victors, the victor jr on a smaller inch motor. The future 427 motor, would be fine obviously with the SV intake.

The duel plane would probably work fine, but as mentioned you would have to play with the design quite a bit more. The single planes offered themselves quite nicely to be done without tooooo much modding.

I would say for a motor you hav now, you can't look past the SR intake. Its an increadible intake and works GREAT. But would probably be too small for the 427 if you do that in the future.

 

the dual plane works better on the street and street and strip rides is because on a carb it can use the longer runners for the signal to be stronger to pull the fuel through the main jets the shorter runners on a street setup especially with a large carb the signal is very week and not very responsive at all

but on a fuel injection car you do not need that stronger signal at the carb so in fact the dual plane would not help that much at all so you are down to runner lenghth compared to runner efficency which the sigle plane wins out there with the straght shot it gives you if you want longer runners go to a steath ram like stated above longer runners than a single plane but not as efficent as single plane or if you want really long go to the super ram which i think is argubly the best street strip manifold out there

look at what gm did they came out with the tpi with its very long small runners see i said small then they came out with the lt1 lt4 intake which they realised that was a mistake too too short and then they setteled on the ls1 intake which is almost between the two previous designs which is a happy compromise with high hp and low end torqe


but back to the dual plane conversion i would either get a small single plane conversion on a smaller motor like a vic jr or smaller or a stealth ram each of these manifolds will work nicely and ease of installation is a breeze but ther are fitmant problems with the steath ram too
or you can put on the super ram works great but is one nightmare to work on or around

 

For a low cost enhancement to your TPI intake give the siamese intake base a try. This mod amounts to cutting a 1" deep x 1" high hole in the partition between adjoining intake base runners where they meet the TPI runners.

This mod raised my L98s output from 160rwhp to 205rwhp at 5,800rpm. Peak power dropped from 247rwhp at 4,500rpm to 240rwhp at 4,700rpm. More importantly the power curve no longer drops off rapidly above 4,800rpm. Power is now the same at 5,800rpm as at 3,400rpm, which makes my 5,800rpm shift points just about right for best 1/4 mile times.

I have subsequently increased the siamese depth to 2" with a drop in overall power but have a problem with fuel delivery, which may be the cause of the power loss. As soon as I adress this issue I will get more dyno pulls to see if the added depth gained anything over the initial cut.

 

As others have said a dual plane would be a PITA. I've looked at doing one in the past and it could be done but I'd have to use special injectors that use hardline plumbing (like an N2O fogger uses). I've used this before on Enderle and Hilborne systems I converted to EFI, but it's a pain.

Additionally there's really no need. The rpm band that is typified in descriptions of carb-style manifolds aren't applicable to dry-flow EFI manifolds. The effective powerband changes between wet and dry flow. To put it in an easy perspective lets look at a MiniRam; 3.5" runners. Now a SuperRam (which if I recall) is about 18.5". We have two extremes here; one a torque biased lower rpm band intake while the other is a powerful rpm manifold. The single plane and tunnel rams fall in between; a Super Victor's runners are approximately 7" in length (measuring from the port floor where the air runs), most tunnel rams are between 8" and 12". So what you have is a manifold that will retain low and mid-range torque (though not to the extent as an SR or TPI style manifold) while providing a large increase in high rpm power. The actual powerbands of single plane EFI manifolds (particularly on large cube engines) is BROAD. The Victor Jr., actually has shorter runners than the Super Victor (at about 5.5") and a smaller plenum, but it's a better choice for a smaller engine (350-383) with smaller heads. The port cross-section is much smaller than the Super Victor and the air velocity is much higher which is better for throttle response and torque in smaller engines. The dual plane with its different length runners is similar in concept to a tuned runner intake but it simply isn't easily feasible or optimum in an EFI conversion.
-Jeb

 

Thanks to all, especially Jeb and Ski Down It. What Jeb says here is what I needed to know. I really like the idea of a single plane EFI set up. The C4 has too much low end torgue IMO, because It will spin it's a** off in stock trim. So what I'm going to do is build my motor around the single plane concept, ie. cam and heads for proper flow/rpm. I'm still in the 427 CI frame of mind. Call,me crazy or what but I can't seem to shake the desire to build one. Sanity may return when I start adding up the bill but It' s my dream car.

 

There is nothing wrong with a single plane intake.

On my old sbc 327, has a single-plane, with a
Carter AFB 625. It ran fine. Idled fine.
.

This talk about ...xyz intake only runs
from 3000-8500 rpm.... or.... some 'vacuum' signal
is needed at idle is ...
.
When I get around to putting a carb on my '84,
I'm thinking about the Victor-jr or a Weiand Team G,
for an intake.
{there are fitment issues}