I did a search for headers here on the hamb and really didn't find anything. So I am looking for input on design and build tips. I am building a set for my current project and want sound and performance. Performance as in the car will only see the track. Sound as I know that headers with collectors perform better, but because the car is for nostalgia racing, I will sacrifice some performance for the sound of Zoomies. I found a couple calculators on the internet: http://www.wallaceracing.com/header_length.php http://www.thedirtforum.com/headercalc.htm What is the theory of bigger vs. smaller primary tubes. What about the length of the tubes. How about the gains or benifits for "stepping" the pipes at the end. What about pointing up, out, or down? Any difference. How about tricks for cuting and figuring out angles for the pipes. Set up, etc....share your expertise for all the hamb....or just point me to a similar thread that I missed while searching!
Don, Have you flowed the heads? Head/intake flow port size length, cam rpm it all counts on a real set of tuned Zoomies. Generally a longer/ smaller tube is more torque-midrange while shorter larger tubes are for higher rpm with no back pressure. To make a real difference you need a base line to go off of. It's one of those things that sometimes the engine likes something other than you think it would too... You can also step them both ways and testing of a similar engine helps. Maybe someone with a similar combo would be helpful?
Good how to here http://www.maxracesoftware.com/pipemax36xp2.htm Also look around on 'net for pipemax1. Used to be out there for free.
What engine? naturally aspirated? What body, enclosed or open engine bay? Not quite enough info. Here's my door car w/sbc, fuel injected, 4 steps (1 7/8 to 2 1/4)
Zoomies give you that cackel sound as each piston has it's own tube, you don't get the crossover/feedback of headers with a collector. You might make some adjustable baffels to tune the engine to what it likes as Algon mentioned in his post. I say make some and run them, after all you said you were going for the nostalgia look.
I'll say this, with the set I'm building right now based off of other combinations, dyno pulls and everything listed above the first calculator is almost identical to the set I am currently building,the second is two inches longer on the primary... Why can you not run Zoomies on the street? Outside of preference that is, you can tune baffles to them for sound and correct pressure?
my bud made a set of zoomies and has 8 small baffles slid into them. Looks wicked mean and tolerable.
Come on Don... What are you working on? Besides why does "Mr p***ing guy's while still standing on the back bumper" need help any way?
I am working on Mikey Harts old 33 Willys. (Pure Determination) I am running a BBC with Crower injection right now. I plan to later to go blown with it... nice car! how do the steps work?
Weedburners would be more nostalgic than zoomies for that Willys, and like Murcury Bill said, if it's not one heck of an engine, they do sound like ****. I'd go furhter and say if it's not a blown mill they'll sound like carp. But it's your car, so have fun!
Don, blown alky? Gas? If it's blown, probably all you need to be concerned with is keeping the flames off your pantlegs. Oh, BTW, is that stool on the other side for visitors? Lippy
I've been going the opposite direction. Zoomies just don't sound right to me unless the engine has a blower on it or injected nitro. After running zoomies for the past 14 years we just built a set of conventional collector headers. I'm either lazy or a slow learner. The motor sounds much happier now. Zoomies do have the "look" if built right though. Good luck. Have you tried headerdesign.com?
To me, zoomies are for blown or nitro engines that simply need exhaust out quickly...but I'm uneducated on them, so that doesn't mean much...I'm used to building collector style tuned headers, and I'm happy with staying in that realm for my personal projects...but I love learning new things, and hadn't ever thought of zoomies as being tuneable...good luck with the car Don, even if it is Chevy powered
It is funny how you guys think that zoomies will sound like ****? My other car sounds really good, and that amc motor is not that crazy...and Littlemans truck and coupe also sound pretty damn good....but I think weed burners might be the look I am going for...I will look and a couple of the sites suggested tonight. The car had zoomies on it back in the day, but I want to be able to fit the car in the front of my trailer and the zoomies would cause a problem with that...
Yeah, we're curious too. Making some fuel system changes and if it picks up I expect that will have a lot to do with it. I'll miss the look of the zoomies and blowing the hats off of peoples heads on the burnout. You'll have fun with yours. Should be quieter inside the car than collector headers too. It does sound better.
I will say that higher compression and blower motors sound better through zoomies than your buddy's stock 305 SBC does... lower compression motors with smaller diameter tubing can sound half-***ed decent through zoomies...but it'll never beat the real ground shaking sound of a built motor pushing big HP...
Run em if you want, ilike em also, gonna put em on my 31, of course i thought i was wrong once but i was mistaken................
Sure, your welcome any time Lippy...if it looks uncomfortable, that is because there is a Honda 10 inch wheel sitting on it...
As a historic car it would be a shame to alter it... what if the lower step section was removable if nothing else? I can't see you going wrong with the same design with a 2-1/4" tube... You probably want to keep the engine under wraps but what are we talking about 800-1,000hp give or take? Being blown the header is usually considered less critical unless you are building a serious mountian motor or running Nitro. It's your stack injector that would really come alive by splitting hairs but here as long as it's not choked up you won't see a major loss or gain the way you do naturally aspirated.
You're giving up quite a bit of power. A collector system is also far easier to tune on the car. BTW: fastest tuned length system for a single pipe is a megaphone - the original Ramcharger Plymouth used them. some adjustable baffels to tune the engine: Baffles in to shut the motor off. Baffles out whenever the motor is running. Correct amount of pressure for a race engine: none, not one, never, ever.
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