Exhaust system, Hooker headers, X pipe & dual exhausts

[wsa111]

I finally got this mustang to a point where I can give you some photos of my combination. Hope it runs as good as it sounds & looks.

The mufflers are flowmaster hushpower II. They exit to dual exhausts with a stainless 2 1/2 extension from the tailpipes.
Runs great, sounds good,& very satisfied.
only negitive point i stress is the hooker headers are very low, they have to be because of the 38" primary pipe length. I hope the small 1 1/2 primary tubes help in more low & midrange torque & horsepower. Thanks William

 

[addo]

Nice and tidy under there. Did you clearcoat your C4 bell and extension housing? I've tried that and it just goes a flat, dull grey.

 

[MandarinaRacing]

AWESOME!!!!!!! Looks great man! BTW how does it sound with the x-pipe????, I know 5.0's change exhaust tone when you switch from H to X....

Very nice!

Alex

 

[Anonymous]

Wow, looks good!

 

[Anonymous]

Nice job!!!!

I wish I could go with a "X" pipe on mine but, I will have to settle with a "H" pipe since its all allready installed!

Have you had a chance to really thrash on it yet or are you still in the breaking in phase??

Later,

Doug

 

[wsa111]

Adam, the transmission shop painted the trans grey before I picked the unit up, otherwise i would have left it natural in color with as you suggested-clearcoat.
Doug, the combination runs great with the 350 carb & definately stronger on the top end with the 500 cfm. the 350 for now gives the most consistant performance just by the exhaust tone. i am going back to the 500 cfm with more pump shot & or a larger pump nozzle or both. Just reving the engine with no load the 500 carb just exposes so much throttle response that the results are deceiving. I have the 350 carb very close to where i want it, but the 500 i'm still playing with.
Alex & others thanks for the compliments on the exhaust post, but I may pull the head & jump the compression & possibly advance the camshaft 2 degrees to pump up the low end & up the cranking compression per Jacks recommendation. Thanks guys. William

 

[Anonymous]

dude where did you get those headers?????
i have a 70 maverick and a 200ci engine ive been looking for full length headers. also did you fabercate a new mount on your intake for the holley or is it a carb adapter?

any info. would help me.
love the exhaust!

 

[Asa]

for all your header needs, just turn to FordSixParts.com

http://cquesttechnologies.com/fspp/products.asp?cat=61

 

[WhitePony]

Hmmm.... What's the deal with the way the primaries are routed on the Hooker? Cyl #1 lookes like it's stretched tight, #2 & #3 roll forward, while #'s 4, 5, and 6 pretty much head straight down and back. It just looks kinda wierd. I can understand the design of the FSPP and Pacemaker dual outs that have #6 rolling forward to give access to the starter, but the Hooker design doesn't seem to make sense. Did they do it for sound or preasure tuning purposes?

Kris

 

[Anonymous]

they probably did it to keep the lengths of each tube equal, or as close to equal as possible.

 

[wsa111]

Kris, DB is right on the primary pipes are 38" long, each tube is very close to that length. The equal length are the same reason you use a exhaust port divider, so all cylinders are equal.
The cylinder head log has been milled with a 2 barrel adapter plate.
What looks as an adapter is just a 2 barrel spacer plate to get the carb higher & give a little more plenum volume. If i had to do it again i would purchase a argie head or an OZ head. The dollars spent on brazing in the low spots on the log & all the custom machine work in adapter plates could be spent on a head which not only flows better but has better fuel distribution. My modified log is light years better than the single 1 barrel.
The cam & roller rocker arms help to compliment the extensive bowl & valve work. William

 

[AzCoupe]

Great job Will, very well executed. :mrgreen:

Looking forward to some dyno results. : Or at least some quarter times.

 

[Anonymous]

Will,

Great job!!! What size is the x-pipe? I'm planning my exhaust now. I think from my research that 2" pipe is best for true duals but I can only find x-pipe in 2.25". How about a sound clip for us?

Bob

 

[Anonymous]

68coupe if you want a 2" x-pipe look up Dr.Gas they have 2" X-pipes that are universal that you have to weld together, the x-crossover is already welded together and provided all you have to do is cut and weld the pipes as you like them. Here is the link:

http://www.drgas.com/Universal-XPipe-Crossover-Kits.asp

 

[66200i6]

Your setup looks great installed, but---

That x-pipe design was developed because of the uneven firing order of the V8’s. There is an un-wanted amount of turbulence in the exhaust pipes running to the back because of the out of sync exhaust pulses caused by the firing order of the V8’s. For years we installed dual exhaust on our V8’s without the standard H-Pipe crossover because the location of the crossover was different for every engine. In fact I just read an article recently on one of the Auto Mag sites that talked about this same process. What we did was install the duals with the runners painted white. We would then take a healthy run down the highway and back home again. The white paint would discolor on each of the two runners at the points where the turbulence was the worst. The crossover was then installed from hot spot to hot spot. The idea was to reduce the turbulence and increase exhaust flow.

The beauty of these Inlines is that the firing order is a full 180-degree design. When using a header with equal length runners, the exhaust pulses reach the header-collector evenly spaced. Even with dual outlet headers the need for a method to reduce the turbulence caused by un-even firing order isn’t needed.

There are several sites that discuss exhaust theory. Do a search for 180-degree exhaust design.

Have fun, Ric.

 

[Asa]

what you say about not needing the crossover pipes is true, but that doesn't mean that our sixes don't benefit from them
i believe that FTF, as well as several others are strong believers in them

 

[66200i6]

I have to admit that when applying the x-pipe properly there is a benefit. I don’t know enough about the runner size and position of the x-pipe to apply it to our Inlines. If you check out all the different x-pipes that are out there, look at the angle of the runners. Some are 45 degrees while other varies in the angle. Which is correct?

From what I’ve read the idea is that when the exhaust passes through the cross it creates a negative pressure in the other pipe. This is the same principle behind the venturi in our carburetors. As the velocity of the gas passing through this area increases, the negative pressure that is created increases also. If enough negative pressure can be created the exhaust gasses can actually be sucked out when the exhaust valve opens. This of course is a good thing.

The question is what kind of flow is needed to make it actually work. With the 180 degree design, equal length header pipes and lower gas velocities through these exhaust systems most of the rigs we run don’t need that type of design.

Are there any other engineers out there that have studied this?

 

[wsa111]

Ric, on our lexus inline six's they combine both headpipes to a single center pipe then to duals.
I think Jack said bmw & or mercedes used a Xpipe or combined the headpipes then to duals. There must be some gain when a major manufacturer uses them. William

 

[66200i6]

I agree with what everyone has written so far.

BMW has a large R&D department working on designs from the time the air enters the intake, how and what happens to the flow of air down the intake runner all the way out the tip of the tail pipe. The design of the entire system is studied that places those exhaust pipes at the correct position in the system, at the proper length and diameter. There is a great example of this that can also be found on the web. BMW is studying the effects of fuel attaching to the inside surface of the intake runner during operation. They are working to find the best inside surface texture to keep the fuel combined with the air.

I guess the point I’m trying to make in a round about way is that when it comes to most of the modifications and upgrades that our young backyard mechanics are making, better performance can still be had while spending less money on a simpler exhaust.

Have fun, Ric.

 

[wsa111]

Ric, todays fuel injection systems do not put fuel into the intake manifold at all, only air flow to the intake port where the fuel is sprayed into the port from the fuel injector.In the pre-fuel injection era you are 100% right about the intake interior surface. The new engines from lexus inject the fuel right into the combustion chamber just like a diesel. The intake runners & head port only supply air. The new technology is mind boggling.
The secret for the best performance is a matched package, right from the carburetor to the exhaust pipe. Some of these backyard exhaust shops have more knowledge than you think. The owner of the muffler shop that did my exhaust work has build & raced vehicles for years.
i believe if you are going to spend mucho dollars in carbs,intakes,head modifications, why not use the latest technology in the exhaust system, be it a x pipe or a crossover pipe. they say when use use a crossover pipe or a x pipe it gives the headers 2 exits rather than one.
Ric, at least with a dual exhaust system the sound is what many of the forum owners like. why not spend the extra $50.00 or more to do the job right & with the use of dual outlet headers there is power to be had.
I hope mike finally gets a dyno test to prove the benifit of a well designed exhaust system. William