No collector = No power, Huh? Options

[bd1308]

I know nothing about exhausts. Ive never had to mess with them.

I wanna HEAR my engine, so I'm building a exhaust.

I have a design that has backpressure, but no collector.

Is a system with matched length the best type of system, as shown in the figure?

And Is the use of a collector correctly used?

Hope its not too crude.

[Jake Raby]

You are walking on ground that seems simple, but is the most scientific in the entire engine combo. It is always considered least by builders, when it is the second most important part of the combo!!

Without proper exhaust you have nothing, all the work and money that went into the intake and mechanical aspects can be totally wasted- what goes in must come back out, or at least about 80% of it! If this doesn't happen the engine will run rich, be untunable, run hot and not make any power. Exhaust selection should be made FIRST before chosing cam or heads!!

It looks like you plan a 4-2-1 system by the drawing, those are the most sdifficult to do because you have both primary and secondary lengths and diameters to worry about as well as collector lengths, tapers and goilets to consider. With a 4-1 system you have ONE collector, with a 4-2-1 system you have two collectors and collectors are an integral link in the chain!

if you do this right, as equally lengthed as possible you will quickly see why a Tangerine 4-2-1 arrangement is so expensive. If you goof up you won't know till you drive it and the engine runs uncontrollably rich.

See this page on my site, its from an exhaust shootout I did in 2005, all with production units for our conversion engines. Look at the power differences, over 20HP on the same engine with two different, similarly priced exhaust systems.
http://www.aircooledtechnology.com/r_d_exhaust.htm

Thats how much it matters.

Don't base an exhaust on sound or looks primarily, doing so is certain demise from the day the first tube is bent.