Exhaust and Perfomance Recommendations

Good evening.

I have a 1972 Mach1 with a 351Q code and a 4300-D 4V carb. I have some credit ($) at CJ and the wife and I are talking about what is next. EVERYTHING is stock on the car so I wanted to see if anyone had a recommendation for exhaust. I have been looking at Flowmasters (Super 44, 40 Delta Flow, or Super 40).

Second question is are there any suggestions to tweak some power out of the stock 351?

Unless you really like the sound of flowmasters, I would pick something else. There are several others that flow better, and drone far less. Spend some time on youtube listing to exhaust clips with different setups wit a similar engine to yours.

I have the same as you for 1973 and I switched to:

- from 2 1/4 original exhaust pipe size to 2,5" exhaust pipes (had to adapt one side a little to my staggered shocks)

- Hooker headers 3" to 2,5"

- Flowmaster American Thunder mufflers - they don't drone on the important range from 50 to 75 mph! But when I kick the pedal they bring out the hell on earth

This setup gave me a lot more kick in several rpm ranges. Other than that I have an old school Offenhauser matte silver aluminium intake manifold which looks not overdressed, is a little bit lighter, keeps the whole cooler than the massive original intake and gives it more flow too. The carb I would NOT change - there is nothing better than a good serviced and adjusted original carb. I only installed an original Ford 4V spacer under the 1970 4300 carb for a little more flow and cooling and an open air cleaner housing to match the distance between the hood.

That are relatively cheap and easy upgrades which bring a lot and don't overdo a good healthy engine. And they are all reversible without any traces...

I am happy with it !

Tim

rugbyguytx,

Make sure you add your cross X-Pipe for exhaust equalization.

Example:

X-Pipe Crossover (Junction Only)

http://www.drgas.com/X-Pipe-Crossover-Junction-Only_p_37.html

mustang7173

Can I vote to keep the car 100% original and if not I will say I have an x pipe and I hate the sound-totally wrong for vintage muscle. An H pipe can be welded in that will give you most of the improvement and for less money and it will give the proper muscle car sound

Can I vote to keep the car 100% original

Click to expand...

+1 ::thumb::

Can I vote to keep the car 100% original and if not I will say I have an x pipe and I hate the sound-totally wrong for vintage muscle. An H pipe can be welded in that will give you most of the improvement and for less money and it will give the proper muscle car sound

Click to expand...

+1.H pipe sounds period correct. My x pipe sounds more like a late model car

Thought I would mention that my exhaust system is a stainless Magnaflow kit it came in a box with the car. It doesn't drone the sound is awesome and sits about a foot behind the car. You can talk without yelling at highway speeds. But like I said its not the authentic sound of the muscle car period. I think we covered some of this in another thread not so long ago. Do a quick search. At the end of the day your car your choice could be its the modern tune you want or swinging prowling and growling sound of the 70s

All,

Actually, I should have mention H-pipe instead of X-pipe. The idea is to introduce balance to the exhaust system.

Excerpt from www.Jegs.com

http://www.jegs.com/c/Exhaust-Headers-Mufflers-Cat-Back-Kits_Crossover-X-and-H-Style-Exhaust-Pipes/11525/10002/-1

X-pipe and H-pipes synchronize the balance of the exhaust pulses from each bank of cylinders based on firing order which increases velocity and scavenging from each cylinder. Most people agree that X-pipes are better at improving performance than H-pipes, especially at the top end. However, H-pipes tend to have a deeper sound than x-pipe equipped vehicles and generally build power down low. These are general claims and your engine and exhaust combination could have different results.

Jeff73Mach1 - Plus 1. I did not realize that the X-cross over would change the exhaust tone of the 1971 - 1973 mustangs. I learn something new here all the time from the forum member!

mustang7173

First off, as a modifier myself...I think you should keep it stock. The way you stated it - "EVERYTHING is stock" tells me where your heart is.

If you do decide to go in another direction this is what I did (very similar to Luke's and others on the board). I went with Hooker Competition headers and collectors; Pypes 2.5" stainless steel Street Pro w/X-pipes exhaust system with Violator mufflers; 3.5" MBRP dual wall polished stainless steel tips. It is a little bit more expensive but should last almost forever and it really gives me the sound I was looking for. It's not real loud inside the car, which is very important in a 'vert but yet gives me that muscle car sound when I step on it. As Luke mentioned the best sound is about a foot behind the car. I do get tons of complements on the sound of the car. Here's a quick video that can help explain X-pipe versus H-pipe technology.



And my system:

jhawk635,

Thank you for the video. It is interesting that the X-pipe and H-Pipe can differ and alter the performance of the engine.

mustang7173

I have a set of tri-y headers, to a x-pipe flowing to a set of flowmaster super 44's ..... to sound is killer...BUT don't plan on trying to have a conversation while driving on the highway, ain't gona happen...hahahah over all I love the 44's

JHawk,

I like this idea (coming back to the thread after a few months). Do you have any video of what yours sounds like with this combination?

First off, as a modifier myself...I think you should keep it stock. The way you stated it - "EVERYTHING is stock" tells me where your heart is.

If you do decide to go in another direction this is what I did (very similar to Luke's and others on the board). I went with Hooker Competition headers and collectors; Pypes 2.5" stainless steel Street Pro w/X-pipes exhaust system with Violator mufflers; 3.5" MBRP dual wall polished stainless steel tips. It is a little bit more expensive but should last almost forever and it really gives me the sound I was looking for. It's not real loud inside the car, which is very important in a 'vert but yet gives me that muscle car sound when I step on it. As Luke mentioned the best sound is about a foot behind the car. I do get tons of complements on the sound of the car. Here's a quick video that can help explain X-pipe versus H-pipe technology.

Click to expand...

My car sounds like a Nascar with my full length headers and Flowmasters. I may switch to dynomax.

I have the exact same exhaust system as jhawk635, and I'm very pleased with the sound. I don't know what his engine specs are, but mine's had some goodies built-into it which I'm sure has affected the sound... since I'm more of a restomod guy:

• 274/274 CompCams Hi-Energy roller cam
  
• CompCams 1.73 roller rockers
  
• 3-angle valve job
  
• CNC balance/blueprint
  
• mild port & polish on stock 2V heads w/hardened valve seats
  
• Edelbrock Performer intake
  
• Edelbrock Performer 600cfm carb
  
• 9.5:1 flat-top pistons
  

Here's the first fire-up of my slightly warmed-up 351C-2V:



Sorry for all the wind noise - it's an old camera.

I am in the minority with respect to exhaust preferences, but my feeling is that much like carbs...bigger is not better.

Putting a 3" exhaust on a stock (or near-stock) 351 "Q" code is dramatic overkill, and will lessen your bottem end (low end torque) considerably and noticeably.

It seems that it is common for many to embrace 2 big ideas that are either meaningless when considered by themselves, or misleading to point of being pointless.

One is horsepower. I know that everyone wants the highest horsepower as possible, but that is not a singularly true indicator of how a car performs where it counts. All aftermarket product manufacturers bandy about HP figures as the surest way to sell thier products, and it works. To sell the product.

But...you can't "feel" horsepower, you feel "torque". Horsepower is nothing more than torque sustained over a moment in time.

Torque is what moves you off the line, and if you build a car for max horsepower without consideration for the torque aspects...you do not necessarily end up with a fast or quick car, but it might put a big number on a dyno!

99% of enthusiasts drive their classic cars on the street at "stop light to stop light" speeds, with a a little impromptu "Street Drag" going on every now and then. Rarley do you have an opportunity in a street-driven situation to wring a classic Mustang out to its maximum overall track potential.

We all love to quote 1/4 mile times, but most steet races are nowhere near a 1/4 mile.

I have always felt that a street-driven car should be built to satisfy on the street...not just the track.

Case in point: The '82 GT with the debut version of the 5.0 liter "HO" seems pretty lame by todays standards: 157 horses, 240 lbs torque.

However, with a sluggish 3.08 rear-gear and skinny street tires, this car easily turned in mid 15-second 1/4 miles, and 0-60 in about 6.5 seconds.

I had an '82 GT I bought brand new, and a simple switch to 3.55 gears, much better tires than those awful "TRX" turds got this car down into the high 13's in the 1/4. Nearly as quick in the 1/4 as my 429 Mach 1.

That is with a stock 2 barrel carb(356 CFM!), stock SINGLE exhaust (2 1/4" and 2 1/2") and the crappy RAN/RAT 4-speed trans Ford put in them.

That is with 157 horsepower.

The torqie was 240 and was all there at 2400 rpm...where you want it.

What am I saying? Basically, a 3" exhaust on almost any street car will kill your botton end. Stick to a factory 2 1/4" dual system with a factory "H" pipe and you will get the best low-end bang for your buck. The slight backpressure will help to increase cylinder-filling at lower RPM, giving you better low emnd torque.

You may lose some maximum high RPM power, but how often are you really going to run the thing up there?

Assuming all of the engine hard parts are good, I'd start by confirming the correctness of the tune-up, point setting, timing, plug gap (and heat range), coil, cap, rotor, plug wires and confirm carburetor settings and air filter condition (consider a high flow cleanable filter). If not already done, consider upgrading the coil and wires with something that is near stock appearing to ensure reliable combustion. If you want a different sound with some potential increase in output, select mufflers with a straight through design that look reasonably stock (no need to change the complete system at this level). I personally do not care for any Flowmaster muffler. If the differential ratio is numerically less than 3.25:1, consider a gear change. If the transmission is automatic, a mild shift kit may help things along a bit.

After this point, it is down to doing things like advancing the camshaft (retarded by Ford to help meet emissions) and changing engine hard parts.

Chuck

Good info, Kit... and I pretty much agree with what you're saying. That's why I didn't go any bigger than 2.5" on mine.

I'm not biased toward X- or H-pipe set-ups either. I ain't gonna lie - I got the X-pipe because it just looks cooler underneath... I saw some information on X- vs. H-pipes and honestly didn't see That much of a difference. I seriously doubt if my "Butt Dyno" would notice the slight difference in performance between the two.

I've also heard the sounds newer Mustangs make with H-pipes and Flowmasters... and while it's a pretty cool and distinctive sound, I didn't want mine to be mistaken for anything other than what it is. I figured X-pipe would flow more efficiently because it looks to create less turbulence in what would otherwise be a separated dual exhaust system.

I like the sound of mine. I think the only thing that would sound better to me would be a set of glass packs and no crossover pipe whatsoever. But then again, why would I put in so much sound deadening material if I didn't want to hear a nice set of glass packs? Boggles the mind, eh?

Excellent advice, Chuck - as always. ::thumb::

I think the only thing I'd add is to maybe consider going with a solid-state ignition (eliminate the points) for longevity and consistency in maintaining the tune once it's all dialed-in.