Kuda progress

['Cuda Hunter]

on the fourth picture, what are the L shaped pipes welded to the metal plates for?

Are those fuel lines?

[brads70]

on the fourth picture, what are the L shaped pipes welded to the metal plates for?

Are those fuel lines?

Muffler hangers, slips on the rubber mounts

['Cuda Hunter]

Ah, of course.
I can't believe I didn't see that.

Thanks Brad. 

[Beck]

Final fit up of the complete exhaust. With all the mounts in place it is very sturdy, and has almost no movement when you yank on it.


Welded stainless nuts onto the dump pipe flanges, for ease of removing and installing the caps. I love the golden colour stainless goes when welded. I'll be fabricating thin stainless sheet metal guides onto the caps that smoothly divert the exhaust flow from the 3.5" pipes into the 3" x-pipe.




The whole thing is pretty much invisible when the car is the right way up. Lots of ground clearance.

[brads70]

Just curious.... why did you not use stainless for the tail pipes?

[Beck]

Stainless can have a tinny sound apparently, and be quite raucous, and I've heard a few big stainless exhausts that sound like that.
I would like this car to have a deeper tone, and not be too loud, hence the mild steel tail pipes, and the plans to install secondary mufflers if neeeded. It looks really cool too, to me. I like the contrast between the bright stainless and the matte black pipes.

[nr1freak]

hi!

awesome thread! and i must say, i've been stealing some of your idea's here... the subframe connectors to start with! and after seeing your exhaust setup, i kinda snooped that cutout idea for my '70 too (eventhough illegal in Belgium...) but here's the thing, you depart from the headers and go straight back to the cutouts, having the mufflers routing out to the side. is there a reason for doing that? would it harm or would the "growl" be a lot less if i routed the cutouts out to the side and go straight back to the flowmasters i'm installing? also i'm sticking to 3" for the whole setup, but is going from a wider diameter to a smaller one better for any reason?

[EB3-GranCoupe]

I think a smaller diameter will give you better torque (more back pressure).  if you have a high revving motor, and want more HP at a higher RPM, then a larger diameter allows you that.

[Beck]

The reason I have a 3.5" straight pipe back from the headers to the caps, and a 3" x pipe coming off the inside is basically as follows:
Nothing sounds and performs like open headers, and Y-style cuttouts don't have quite the same effect, so I designed this system to be as close to open headers as possible when the caps are removed.
My headers have 3.5" collectors, hence the 3.5" dump pipes.
The caps will have sheetmetal guides inside to smoothly route the gas flow into the 3" x pipe so there shouldn't be any detriment to performance.
When the car is on the road  I will test the caps with the guides vs plain caps, to see how much difference there is to performance.
If there is little difference then I will install electric cuttouts and perhaps the side exit pipes shown in my concept image.

I like the idea of a reasonably quiet/stealthy exhaust system (hence the four mufflers and x pipe), with the option of easily turning it into what is effectively open headers.

[nr1freak]

hm, food for thought! they're selling these Y-shaped connections complete with flanges (out to the side) but straight backwards should indeed be better!  and don't know if you have this in the States but in Belgium the car has to pass a technical inspection every year and, eventhough i could take off the cutouts and screw on the caps, i think they will be quite suspicious when they see the exhaust setup underneath! don't feel like answering a bunch of "what the hell is that for" type questions... 
might have to consider using some more flanges and coming up with a system that completely takes out the crossconnections (with cutouts), just to pass technical... 
back to the drawingboard!
thx 4 the tips!

[nr1freak]

another open header-question:

is it bad for the valves? or does adding a length of pipe as you plan to do help in keeping cold air from hitting the hot valves?
still, for a street car, i don't suppose you can cruise around the city for a few hours with the open headers, no?
the cutouts are, ofcourse, a great way to "make an entrance" but i'm guessing they'll have to be closed most of the time to save the engine a bit!

[Beck]

I don't see how any cold air is going to make it up the dump pipes and the headers...

I've run open headers in the past and the sound was much louder and more epic than cars I've ridden in with Y style exhaust cuttouts.
The sound of it echoing off the hills was awesome, and tunnels were insane. And that was just my old tired small block, I can't wait to hear
the 440 rev under load.

Special occasions only though. It's not very pleasant to drive around with open headers for very long. You get out feeling pretty numb.
But again the sound though tunnels was seriously addictive.

I figured if I was going to the lengths I have to fabricate a custom stainless system, then I was going to make something special.
Hence the dump pipe setup etc. The guides I'll be fabricating will mean there is no performance drop from excessive back pressure
from the dump pipe setup with the caps on. And the caps should be easy enough to take on and off when peace needs to be disturbed.

Cheers!

[GranCuda1970]

When you open it up and rev it...  It is peerly a Orgasmic event 

 With just the stock accurate exhaust system I ran her a few time with just the resonators, w/o the mufflers and Holy shart it sounded like a Dragster. The mufflers REALY QUIET IT DOWN ALOT!! I liked the resonator only BARK!

[nr1freak]

yea, dunno, it was just something i read about on another forum, people were talking about how bad it was to run with open headers, valves could get burned or whatever... and there was talk about "cold air hitting the hot valves"... maybe if you drive without headers :-) open heads!! maybe worth a shot one day, see how that goes! 

[72cudamaan]

yea, dunno, it was just something i read about on another forum, people were talking about how bad it was to run with open headers, valves could get burned or whatever... and there was talk about "cold air hitting the hot valves"... maybe if you drive without headers :-) open heads!! maybe worth a shot one day, see how that goes! 

The valve damage is done when the engine is shut off. As the heat dissapates, the cold air is pulled into the open header
and up to the valves. With a complete exhaust, the pipes warm the air first so it becomes a non issue.