CK5
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The Willomet Charger
- Thread starter AgDieseler
- Start date
A desecration to Mopar nuts everywhere, this is my protouring, LS-powered, 1970 Dodge Charger; built at my shop, Willomet Motor & Fabrication.
Another thing to ponder. Are the cutouts for sound or performance? For your engine I would recommend a dual 3.5" exhaust with high flow mufflers for full performance potential. If this is done, cutouts will likely not increase performance, they may hurt it if you loose smooth laminar like flow of a mandrel exhaust.
If you can't fit that, or it's too loud, then cutouts make sense. But for maximum performance when the cutouts are open, it's best to have a straight shot from the collector through the full 3.5" cutout, then a curved dump or something after that. zThe exhaust can then turn inward as a smaller diameter before the cutout, but not in a way that restricts flow through the cutout. This way, when the cutouts are open, they give full performance like open headers. You will not have laminar flow when they are shut, but at least it will be quieter when shut and full performance when open.
I see too many cutouts installed incorrectly or without full flow, and then just add noise and not performance. I had a friend with a mild BBC, had a full dual 3" exhaust, and he put some cutouts that were not ideal and not an ideal location(exhaust had to make a curve then a 90 degree turn to exit the cutout, whereas straight went through the muffler), I warned him. He dynoed it and the difference was less than 1 HP. Also, because if was half muffled and half open, it does not sound good. He never opens them.
If you give a straight shot full collector diameter, then at least it will sound good when loud and give full performance. And it will be quieter when closed. At that point you could run a dual 2.5 or dual 3" exhaust that either would be quieter than a dual 3.5". You could have a different tune for the open headers at the track.
I just run the correct size exhaust without cutouts. For my regal, that meant dual 4.5", I used oval 5" (had the same flow area as 4.5 round) which I split into four 3" borlas in parallel(2 per bank), for mufflers without restriction. But even so, it is not that quiet.
Nice, did you end up with that carbon fiber intake we spoke of or which one?
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On Instagram I thought it looked like an ash tray.
IN highschool I took ceramics, dad always laughed and said well if it doesn’t turn out good you can always make an ashtray.
I'm thinking 70/30 sound/flow. The dual 3" needs to be pretty quiet for running around town, and to get Erika to join me for any of these road trips. I have two ideas for a cutout - one is boom-tube-esque ahead of the rear axle, or a simple muffler bypass that still goes to the same rear exit. I have a whole pallet of 3" 304 and CP1 from Vibrant. Plenty of time to noodle on where the cutouts go and how it routes.
No, just a placeholder cathedral port intake from MSD. I still like the Harrop ITB setup.
David
Collector mounts. Last step is to print a bunch of mockup elbows.
David
David
Nice...what size is the collector outlet, 3.5"?
4”. It’s the only size they had at the time they shipped the order. I can swap out for a 3.5. The 2” side was what was important.
David
Throttle body cover.
Started fitting a trimmed 120 in #4. There’s basically one way this whole thing CAN work without intruding on the passenger space, and I have a decently clear idea how to get it done.
But I could be wrong.
Also, steering rack and new bungs arrived, so Rev3 final goes together soon.
David
Started fitting a trimmed 120 in #4. There’s basically one way this whole thing CAN work without intruding on the passenger space, and I have a decently clear idea how to get it done.
But I could be wrong.
Also, steering rack and new bungs arrived, so Rev3 final goes together soon.
David
Getting to #7 and 8 plugs looks like it will be fun, maybe make an access panel in the firewall 
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What mufflers do you plan to run?
So here is a hand diagram for prioritizing max performance when open, and muffled when shut...
Also another option if you can fit 3.5" halfway back is to put the cutouts ahead of the rear axle before the mufflers, inline with the exhaust tube again but further back, but max performance would require a longer run of the larger pipe.
These options do not help flow when shut, you may get pressure waves bouncing back off the closed cutout, which is why I don't use cutouts. You may need different tunes for open/closed.
Just throwing out ideal open performance options. It's your car, so if you are prioritizing something else, have at it. I like your idea of just bypassing the muffler and back into the tailpipe, that could make a lot of sense if it's a restrictive quiet muffler, could be quiet then increase flow while adding sound that still sounds good if that is the goal.
Keep in mind if you don't keep a full 3.5" dual exit as an option you will likely sacrifice some ponies you can't get back. Which is fine if you are good with that.
Also, I've seen a lot of road grime under cars that dump the exhaust under the car, black grime with pump gas and gray grime with race gas. Your tune can be great but over time it still happens.
Another option is dual 3.5" all the way back, with 2 mufflers in series on each side, may be quiet enough without needing cutouts. But it may be hard to fit them.
Lots of compromises...ease of maintenance, sound, performance, looks, cleanliness, cost, etc. I am just arming you with more information that you likely already knew so you can decide exactly how you want to build it. I look forward to your results.
You may be able to get to them from under the car but the starter might make that a little more difficult?
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Both Vibrant and Ticon have some large volume Ti mufflers and resonators. The area in the back corners have loads of room.
I’ll have to noodle on the rest of the exhaust. I already have a boatload of 3” from Vibrant, and I might be able to swap it for 3.5, but I’m not sure.
Unloading this guy today. 1939 Atlas lathe. Barely used. The 1925 South Bend is going back on a pallet.
Planning to put it immediately to work.
David
I think that is a good location as I think short tailpipes sound better and the weight is further back.
Nice! I thought my 57 lathe was an antique.
I use it more often than I ever thought I would.
Got this guy all setup, lubricated, and running.
Came with a good amount of holders and tooling.
Immediately turned down these inserts ti become power steering rack mounts.
David
Came with a good amount of holders and tooling.
Immediately turned down these inserts ti become power steering rack mounts.
David
Rev3 steering rack mount works.
David
David
Mr Ackerman is in the building.
The original power steering rack mount forfeited about 5° of steering angle, and put the rack way down low, where bump steer would have been difficult to tune out.
That’s a good enough routine for the shaft for now.
David
The original power steering rack mount forfeited about 5° of steering angle, and put the rack way down low, where bump steer would have been difficult to tune out.
That’s a good enough routine for the shaft for now.
David
That’s a good amount of angle, what’s the degree of turning radius? Almost looks like a drift car!
Should be 33ish, which is a normal range for the autocross crowd. It’s a major improvement from what came with the suspension kit.
David
My friend found and printed some 2” and 4” CLR mockups. Free-99 (nearly).
All the 2” from Vibrant are in CLRs that naturally nest - 2/4/6.
David
All the 2” from Vibrant are in CLRs that naturally nest - 2/4/6.
David
Can you get to them from underneath?
