Which intake is better?

[RangerSVT]

Soon I'll be strapping an eaton to my motor, and I was looking at the 5.0 truck efi lower intake, and the runners (rectangle)look larger than the gt40 runners (round). Keep in mind I won't be using the upper plenum of either, just the lower. Right now I have a choice of either an 89 mustang stock (ho), the f series rectangular, or the gt40 round intake. Which one flows more? I'll be P&P the intake I use, so keep this in mind also. Post up brothers


SVT

 

[Tominator]

I was under the impression that truck lowers were round port and very similar to the GT40

 

[RangerSVT]

The trucks are rectangle, its hard to see, but its 1.25x2.25..

The gt40 is 1.5 round..

In theory, the truck should flow more, but does it actually flow more? The upper plenum will be the same no matter the lower(in the form of an M122 Eaton), but the flow characteristics will be different cause of the lower's flow characteristics. So, the question is, which do I go with?

SVT

 

[shane96ranger]

I can tell you right now to take the stocker right out of the equation under any circumstance. What's going on top? Tominator and I both are running a Downs Ford upper on a GT40/Cobra/Explorer style lower (although I don't have forced induction - yet). There used to be a Downs Ford upper for the truck lower as well IIRC. These are the only flow numbers I have, but they are all WITH the upper, and essentially the same lowers.

 

[shane96ranger]

Here's another:

 

[RangerSVT]

Shane, I hear what your saying, but those charts compare the differences in the upper plenums, none of which I will be using. The Eaton will be the upper plenum. Do you have the numbers on the truck intake?

SVT

 

[stmitch]

I'd guess that you'd make more power with the GT40 than the truck intake. The truck intake is so open, that you'd probably see a big drop in boost. It looks like the truck intake would flow just about anything, but maximizing flow on a boosted engine doesn't necessarily mean increasing power.

 

[RangerSVT]

Thanks for your input, Mitch. Sometime next year I plan to get a set of AFR185's, but for now its using the stock 99 block (stock internals wit P heads, intercooler with low boost) as I'm going to build my 89 mustang block in the mean time. I just bought the M122 today as we speak, so it'll be in soon, coming from ga. With the 2.5 pulley it made 14psi boost on the 09 GT500 so I need to get a stock pulley until it goes on the mustang block, then its getting the smaller 1.9 pulley, power limitations providing. As it is now power is estimated to be at 350hp without boost, and my limit will be set at 450 til I can afford the A4 block so I don't split this one in two. Of course, I could use the block from my 77 bronco, I think its stronger than my 89, but I haven't pulled numbers to find out...

SVT

 

[shane96ranger]

You know SVT, I can probably point you to a guy who would most likely know which flows best. Tmoss over at allfordmustangs.com would more than likely know. He's got his own porting business.

http://www.tmossporting.0catch.com/

Cobra/GT40/Explorer Intake
The Cobra intake has average flow of 205-210cfm. This is adequate for ported E7 heads or stock GT40/GT40P heads. If you use this intake with heads that flow more than 210cfm, then you will benefit from porting the lower intake. Just like the stock intake, the restriction in these intakes is in the lower. They can be ported to support a 250cfm flow rate head without welding the lower runners. My customers have made over 305RWHP/340RWTQ - 325RWHP/350RWTQ on 302-331 ci engines with ported Cobra style intakes.

 

[RangerSVT]

Thanks Shane

SVT

 

[Tominator]

The truck intake is so open, that you'd probably see a big drop in boost.

One of the reasons the Down intake is great for boosted applications is it's lack of runners. You might think that would cost some torque, but after reading several articles written by some notable engine builders it's my understanding the requirements are quite different for NA than a boosted application. The question still remains which would work the best with a Eaton blower.

Look up a member TMOSS on AllFordMustangs or the Corral. He ports SBF intakes and quite a few racers swear by his work.

You might try posting at SBFTech or at least do some reading. VERY informative site BTW.

 

[shane96ranger]

One of the reasons the Down intake is great for boosted applications is it's lack of runners. You might think that would cost some torque, but after reading several articles written by some notable engine builders it's my understanding the requirements are quite different for NA than a boosted application. The question still remains which would work the best with a Eaton blower.

Look up a member TMOSS on AllFordMustangs or the Corral. He ports SBF intakes and quite a few racers swear by his work.

You might try posting at SBFTech or at least do some reading. VERY informative site BTW.

I run my Downs N/A, and I love it. Previously I had a stock lower with a Harwood (later sold to Comp Polymers) upper. That was a great intake as well, but boost would blow it to pieces. I picked up a brand new Downs in the $250 range on Ebay about 12 years ago.

SVT, as far as your Eaton is concerned, I suppose you are building a custom piece for it?

 

[RangerSVT]

Shane, yes. Similar to the piece I made for the jeep..

But mine will be slightly different and lower. On his I had to clear the dizzy, and this was for an M90, mine is an M122, slightly larger. Well ok, a LOT larger. Pics will be up soon, its being shipped now...

SVT

 

[Mac]

You know SVT, I can probably point you to a guy who would most likely know which flows best. Tmoss over at allfordmustangs.com would more than likely know. He's got his own porting business.

http://www.tmossporting.0catch.com/

Thanks for the link Shane, I had his old site bookmarked. He does mention at his site the EECtuning site, that is just filled with good info. One of the administrators (Chris) has a V-8 Ranger and working on a 331 motor.
Dave

 

[RangerSVT]

Ok, so I get back from the in-laws today and guess what's on my doorstep??

Just to give you an idea of how big this M122 is..

For now I'll be using the GT-40 lower on the motor that's in my Trac now, but I think I'm going to use the truck lower on my mustang block with 60 lb squirters and turn up the boost a little north of 20psi What ya'll think ??

SVT