Exhaust Suggestions (170)

Junior64

Junior64

Well-known member
I just chopped the stock exhaust off my completely stock 170 today. I wanted to see how it was cruising around before I buy a new muffler/glass-pack. It is loud for sure, but doesn't like heavy acceleration. Does anyone have any suggestions on a nice muffler/glass-pack that will keep the back pressure where it needs to be?
 
I like a turbo muff, :nod: but you could use a turbo or glass pack depending on should you want. A 2 inch system should be good (y)
 
I was thinking about a Cherry Bomb glass-pack or Turbo. Anyone try these or know which one will offer better performance?
 
I have a stock 200 in my 64 Falcon. It isn't the cheapest, but I put in a magnaflow round 2 1/4" inlet/outlet and 2 1/4" pipe from the header pipe (the 90 elbow connected to the stock manifold) back. That 200 sounds like a V8 besides it having no compression on #6 cylinder :oops: so it has a miss but I am more than willing to get a sound clip for you if you would like, just let me know.
 
I was reading about the Magnaflows last night. I would really like to get the glass-pack, but think I should play it safe and get a muffler with some louvers to create some back pressure. I would hate to spend the money to get it all welding together and find out it still isn't enough. By the way, I have a two inch exhaust system now. When I do finally decide what I want, do I order the pipes with 2" inlet/outlet or 2 1/4" to mate up with my stock pipes?
 
Not enough backpressure? No 4-stroke engine ever made needs any sort of backpressure. Honestly, any exhaust you put on there will make no difference except for noise, the 170 is hardly taxing the stock exhaust's flow capabilities. Listen to some sound clips on youtube and go with what sounds best to you.
 
That's good reading. I was thinking about just putting a reducer coupling on the end of the pipe (convergent duct) which would decrease pressure and increase velocity. That way the Falcon would still sound like a monster truck and run alright.
 
By the way, I have a two inch exhaust system now. When I do finally decide what I want, do I order the pipes with 2" inlet/outlet or 2 1/4" to mate up with my stock pipes?
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The Turbo, Cherry Bomb or glass-pack performance is very close diff is in the sound. :shock: Old rule used to be a 2 1/4 system for an engine size of less than 350 cu in :unsure:
 
Junior64":2hflm9f3 said:
You need back pressure to create a pressure differential during valve overlap. My Falcon does not run like it used to after I cut the muffler off. Below is a good link explaining this, especially for older engines which do not regulate their fuel flow like today's engines.
http://my.prostreetonline.com/forums/archive/index.php?t-1639.htm
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How much valve overlap you getting on your 170? Backpressure isn't needed anyway. You need a reflected pressure wave on a hot cam, yeah, but that has nothing to do with backpressure at all. Anything that improves flow more than a bit will need a jetting change to compensate, you're running lean with more air going through and that hurts power.

If you needed backpressure F1, circle track, and Nascar would have restrictions in the exhaust. They don't.
 
From the link he posted:

So how can backpressure help power production at any RPM? IT CAN'T
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The largest piping you can fit that keeps exhaust velocity up will be optimal. However, from what I've seen, the critical points are the primaries and secondaries of the headers, the collectors (length and taper matter a LOT), and the bit of exhaust just past that. According to Vizard, what happens past the muffler (as long as it stays unobstructed) doesn't really even matter; the engine sees it as an open pipe.

I'd say that the log manifold by itself is so damaging to scavenging that you can do very little past it to help or hurt. Pressure waves are going to reflect past the 2 or 3 90 degree bends in the manifold in the correct phase to affect that "5th cycle" very much? I just don't see it.
 
So you're saying my car will run better with the straight pipe as long as I re-jet the carb? My plugs are a nice light brown with the straight pipe and current jet.
 
If the plugs are good, that would mean that you don't need any backpressure, yes?

But like I said, on a stock application, there is very little that you can do to mess it up. The backpressure myth is just one of my pet peeves.
 
The plugs are good, but doesn't run right during heavy acceleration now. I have to have some kind of restriction on the pipe to keep from running lean or replace the jet.
 
I'd just put a turbo muffler or glasspack and call it a day. A turndown in front of the axle if you want it to still be loud :eek:
 
Falconman62":2fe3mj7m said:
I have a stock 200 in my 64 Falcon. It isn't the cheapest, but I put in a magnaflow round 2 1/4" inlet/outlet and 2 1/4" pipe from the header pipe (the 90 elbow connected to the stock manifold) back. That 200 sounds like a V8 besides it having no compression on #6 cylinder :oops: so it has a miss but I am more than willing to get a sound clip for you if you would like, just let me know.
Click to expand...
Got the sound clip up finally! http://www.youtube.com/watch?v=SdAaoZSZs8c
 
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