Exhaust Options

[Silverback]

What are the good off the shelf exhaust options (my car is a 71 Mach 1)?

My concerns are:

• flow- if i"m going to be honest, I'll be much more pissed off if it costs me .1s at the dragstrip then if it does anything else wrong
  
• quiet- baring the first concern, I'd rather have it as quiet as possible, I've had loud cars, I like loud cars, this car will never be a sleeper, but for some reason I want it drivable and nice
  
• Access- haven't taken a good look under the car, but I don't want it to make anything a pain in the butt to work on. To that end, tailpipes will make it generally nicer to drive, but I'm considering mufflers and turn downs to make it easier to work on and lighter
  

What I really want (I think, and I know that I'm not going to buy this off the shelf):

• 3" tubing
  
• x or h pipe
  
• 3" mufflers, the larger and freer flowing the better
  
• turndowns or 2.5" tailpipes (I figure that after the mufflers the tailpipes are not going to be the biggest restriction and 2.5" tailpipes will quiet things down, leave more room to work around and be less of a hassle. I might consider v-band flanges to connect them to the mufflers if I decide that it's likely that I might have to pull the exhaust off
  

That said, I'm not sure that 2.5" pipes all the way back will be that much of a restriction (my brother's car has had 2.5" H and mufflers of various brands, mostly turbo mufflers and a set of dynomax ultraflow magnums and now 3" pipes and walker turbo mufflers with 3" in and out (indecently I think they neck down to 2.75 and them 2.25" inside) on his car that's deep in the 10's and he hasn't seen an appreciable difference in dyno numbers between any of the 5 or 6 different combinations that he's had on there, so I'm really wondering if something off the shelf with 2.5" pipes and mufflers would work fine

 

[MotoArts]

OK, what engine/gear/trans combo? How radical?

Dumped stock mufflers make the interior noisy. Like, a lot.

On up the chain (turbos, Flowmaster, Cherry Bomb, etc.) gets worse from there.

The more HP, the louder any combo will be.

It's all a give and take.

 

[TommyK]

http://www.amazon.com/Magnaflow-15819-Stainless-Cat-Back-Exhaust/dp/B000COP87O

Although listed for 67-70 I know the 2.5" will fit 71-73 with standard rear shock layout. I bet the 3" would too with a little tweaking.

 

[c9zx]

Does the car have staggered shocks? How much power do you think the engine will make?

 

[Silverback]

'71 M code C6 car with staggered shocks (someone swapped 2bbl heads on it, 4bbl single plane, big cam, long tube headers...), it's only going to get more serious from here. For now just to get some reasonable power out of it I'm probably going to spray it with some N2O, but it will end up a pretty serious build, probably some aluminum heads (if I can figure out what the deal is with them and manifolds) or some 4bbl heads, depending on what the cam ends up being it seems a bit mild and will probably get swapped (I'm guessing it's in the [email protected] range, I'm thinking something in the [email protected] range will make me happy) I suspect with a blower or turbos eventually (I used to work for a speed shop, everything I worked on was more late model but I've done kenny bell and magnusun blower kits as well as a few custom supercharger and turbo kits, my brother's car has a custom eaton blower setup that runs 10's. This will go faster). I'm debating if for my own comfort I'll pull the manifold, weld and machine it for injector bungs, I have a spare set of 88lb injectors, intake elbow and 90mm throttle body that would make a pretty sweet setup but sort of has the wrong feel for this car.

Anyway. Eventually I'm sure I'll have the power to justify 3" all the way back, not sure I want to run it.

Yes, I know what dumps will do to the noise level, but I'm not pretending that that combination that I list will be quiet (well, with turbos it could be, but like the injection, right now that just doesn't go with the feel of the car).

If the magnaflow setup would work with the staggered shocks I'd do that in a second.

I've also been looking at the pypes SFM04 setup (2.5") with a set of their pro race mufflers on it (which interestingly they say that their pro race mufflers are both their best flowing and quietest mufflers), but am not thrilled with the 2.5"

I'm debating getting into building something (just don't have the time and space right now, but if i did I'd probably just get bends and start cutting and welding or maybe start with the pypes 3" x-pipe kit (it's stainless and cheaper than I could get the parts to weld up my own), 3", 18" long (long case, quieter) pipes pro race mufflers, and then either turndowns or try to find some 2.5" tailpipes (looks like 2.5" mild steel tailpipes are easily available, but it would be a little weird to do that with everything else in the exhaust being stainless). The messed up thing about stainless is that trying to find hangers and hardware or even some stainless rod to make them out of will probably end up costing more than just buying the whole 2.5" stainless pypes exhaust

 

[cazsper]

Everything I have read on X and H pipes, the X seems to make slightly more power. At least the ones that were tested. As for the muffler, what if you ran two Cherry Bomb mufflers as resonators and then a pair of Magnaflow mufflers? Since the Cherry Bombs and the Magnaflow mufflers are both a flow through design, there should be minimal restrictions with them.

 

[Silverback]

OK, how about I approach this slightly differently... Who makes tailpipes, 2.5" or 3" that actually fit with staggered rear shocks?

 

[Don65Stang]

OK, how about I approach this slightly differently... Who makes tailpipes, 2.5" or 3" that actually fit with staggered rear shocks?

Your local exhaust shop? There are a few shops in my town that can bend 2.5". I don't know about 3" since I've never bought those. Try calling some shops up there and if they say they can't do it ask if they know of a shop that has that capability.

It's been a while but the last time I bought a full exhaust it was a 2.5" with Magnaflow mufflers from a local shop for $325ish. They are fairly quiet at lower rpms. The rumble sound opens up at 3-4k. I'll probably go with magnaflows again on my M-code in the near future.

 

[Mister 4x4]

I have a Pypes 2.5" stainless system with Pypes Violator mufflers behind Hooker Competition long-tube headers (ceramic coated). I have no idea what it sounds like, I haven't fired it up yet (soon, though).

What I can say is that the kit was easy to install and came complete with pretty much everything, except actual instructions (which I had to download a generic set from their website).

As to the staggered shocks issue, I can't say because I have a standard shock configuration.

 

[Silverback]

so anyone have the pypes tailpipes clear staggered shocks? The other ones that seem to be out there are magnaflow (can't seem to find the tailpipes separate), and flowmaster has 2.5" ones that you can buy separate cheap. I haven't found anyone that's claimed that they fit staggered shocks.

Finding a good exhaust shop will probably take more time than for me to just do it myself which is what I was trying to avoid...


Looking at magnaflow's site, they don't list anything for a 71-73, and even though it looks like the rear section should be close, it explicitly says that none of them work with staggered shocks...

 

[c9zx]

I spent considerable time searching and making phone calls. As far as I know no one makes 2.5 let alone 3.0 tailpipes to work with staggered shocks. I used generic Mustang pipes from flow master (don't like their mufflers) both pipes had to be cut reshaped and welded back together and SS tips welded on. Chuck

 

[mustbrad]

DynoMax Super turbos sound good low resonation not too loud

 

[Silverback]

I got the pypes race kit, but I haven't had time to play with it to see if I can get the tailpipes to fit. I may for the time being just put turn downs on after the muffler.

 

[Totalled]

Keep us posted. Another comp suspension car looking for 2.5" tail pipes here.