I know this is not really V-10 related let alone Ford related, but I was wondering if you guys have seen pics of the new Tundra 5.7 exhaust manifold? It is more header like than a big cast iron piece. Since we talk headers around here quite abit I thought it was interesting to see.


http://www.autoblog.com/photos/toyot...rewmax/126288/

 

I did see that. There is a better shot of them on Toyota's tv commercial. I would say they are headers. Each cylinder has its own equal length tube back to a flange.

Good god. What are the header nay sayers have to say about that.

 

I say they are easily only 1.25 inside diameter and if some one wants to make a set for the small volume of the v10 cylinder then we can probably see some significant gains

But as long as truck owners are stuck on "Bigger Is Better" then you will continue to see Gibson and others oblige with 1.75~ 2.25 inches of exhaust velocity killing primary tubes...

 

I guess the Tundra headers would qualify for "shorties"?

Fred, what should we be looking for in a header tube size for our 2V engines?

 

If I was fabing a set they would be no larger then 1.5 inches inside diameter with a primary length of no more then 28~32 inches and the first cross over either "X" or "H" in the 39~47 inch range from the header flange... The longest run all the way to the outlet under 94 inches including all cats and mufflers...the absolute largest diameter tubing before the cat of 2" and 2.5 out and 2.5 into the muffler with 3" out or twin 2.5s out if not a true dual system

I have seen a few impressive HP and Torque gains on the local dyno by a couple of guys who listened to a local motor tuner... they each used locally fabed headers and the factory giant catx2 into twinFM 40 series with true dual routing dumped just before pass wheel well....

designed properly you can raise the overall power levels across the majority of the rpm band by about 12~17HP. Keeping the heat in and flow velocity up and balanced is the key.... large diameter tubes works very well for drag racing with 90% WOT all the time but there is a growing group of folks who now believe mid band torque is more important as 65% of the run is in this RPM range...

Exhaust system tuning is a science and a art....circle track guys spend a lot of time figuring out 180 degree header systems to promote max scavenging by have each power pulse timed top help clear the cylinder that just fired before it... unfortunately on the very wide and deep 2v V10 the primary tubes would need to come together Right under the pan and not be the optimum length for the correct timing...as it is on a true dual, for proper balance the "X"or "H" cross over will end up right under the transmission and cause a bit of clearance grief for off road use.... this motor really likes to have a BALANCED and fast exhaust flow

For the

 

Looks like Toyota is having to resort to some of the aftermarket's tricks to get their horsepower numbers up. Hopefully Ford will step up to the plate and do something similar.

 

Tubular headers from the factory are nothing new. Just look at the 5.0 Mustang GT's from the early '90's. The factory "headers" are even plumbed with the O2 sensors.

 

Those ain't "headers" in the typical usage of the word. They aren't equal-length, according to that picture.

But like Ken/Webmaster said, it's probably just to eek out a few more HP for bragging rights, while doing nothing for the notoriously bad low-end torque of their motors.

Fred, don't forget the V10 is an "even-fire" for each bank. One bank of 5 cylinders are all exactly 144 degrees apart - good for scavenging. With a long primary...

For instance, a Ford FE 390 is not an "even-fire" in each bank - so scavenging isn't very usefull unless you start jumping over to the other bank.

 

Am I mistaken, or is that first cylinder's tube picking up the second cylinder too? I see three tubes, but 4 cylinders. Almost looks Photoshopped...

 

If you get a chance to see them in the ad on TV, they look real nice. Be quick with the eye though. I'm sure it will be on plenty of time during the Super Bowl.