After deciding on not buying a Hogan's manifold, I started cutting up the stock manifold to see what I could make of it. To my surprise the plenem is about half the size of what I imagined. So plans are to box in a new plenem that will be at least 1.5 bigger but will keep tb in stock position and port the runners to match heads

What do you guys think? Any input would be great

 

Sounds like you are doing something similar to the LTx manifold that Steve Quinn makes. I would guess the major hangups are the fuel rails and throttle cable bracket.

 

I have that same thing sitting in my shop right now lol..... you can do a lot of surgery to that thing on a mill and with a TIG welder.

Bret

 

One of the biggest shortcomings of the LTx intake is the intake port roof is very low right upstream of the injector. Increasing the plenum size and port-matching doesn't remedy this. If you're doing that kind of extensive surgery, you might as well fix the biggest problem.

Also, port inlet radii really suck on the stock intake. Radius those as best you can. Some have seen large increases by welding in a piece of 1/2" aluminum barstock between the siamese ports so there isn't a sharp corner there.

 

Just curious, but does the EGR port on the driver's side filter back into the main intake plenum? I've never been able to get a definitive answer as to whether it filters into the plenum or the space underneath the plenum.

 

Hey bret what ever happend to that LT4 intake you had with the nitrous system inside the plenum i remember seeing way back when at your shop??


-john

 

Sounds interesting, but I can't picture what you mean.. Any pics or info somehwre about these mods and results?

 

It is easier to make power with a single plane over a LTx intake, but application and other variables have to be taken into account. All of the speed bumps when converting a single plane can be overcome with lots of money, but not many people want to spend that much. Plus you have to buy all new stuff and get creative with finding ways to retain all your sensors, hooking up linkage and making it fit under the hood/cowl.

 

For what it's worth and for a little inspiration for you. I modified a TPI set up by increasing the plenum volume and siamesing the runners. With no other changes and on the same dyno SAE corrected I pickup 22 horsepower and 27 foot pounds of torque. There was an increase across the rpm range. You may be on to something. Good Luck in your quest.

 

Are you moding that to fit a Carb?

 

Must be digging around again for something to argue about....

Other than the single planes that sit around the shop I have LT intakes laying around and I had a spare hour to cut it up to fool with it. It's going to take a lot of welding to get it where I want it and then it's still not going to be as good as a single plane.

Bret

 

it travels underneath the plemum and then enters the intake right behind the tb opening. there are 2 dime/penney sized holes in the intake floor were they enter at.

the small holes in each runner are the iac passages.

i cut a spare intake up a while back and just havent had time to mess with it anymore. after cutting it apart you realize how much its really lacking interms of volume. i have already cut the entire egr area off the back and everything will get filled in and smoothed.

here are my pics
http://www.mustangmods.com/ims/u/865/1625/53468.jpg
http://www.mustangmods.com/ims/u/865/1625/53469.jpg
http://www.mustangmods.com/ims/u/865/1625/53470.jpg

 

So what are you gong to add to it for more Volume?

 

as forest gump once said "i'm not a very bright man" is there a way to make runners up to the TB bore or close to it. kind of like making a mini ram effect. i always thought about using some thin wall tin sheets and tig welding them together to make it happen. that would be a PITA to do. who wants to give up 50 or so hours to fab 1 up for us??

 

Sometimes he comes across that way.

Most of the time you come across that way.