is the product crap or the whole theory of being able to dial in the optimum backpressure/exhaust velocity at the tail pipe with adjustable orifices and or different size tips?
How could they be bad - Jeremy Clarkson had four of them on his Buggy in the last episode of The Grand Tour?
The engines we are discussing do not benefit from backpressure. Sizing, velocity, wave reflection? Sure. Not looking to create conflict here, just bring the discussion 30 years forward. Not bashing any products either.
Ok, this thread seems to be working fine now. Deleting the other thread that pertained to this one being broken to eliminate clutter.
Also consider that a 2 cycle engine pulls the gasses through in a much different way than a 4 cycle engine does. First of all, NO VALVES and NO CAM...which means all the theories of back pressure and what's needed to help control the fuel/air moving through the engine that relate to 4 cycle engines is pretty much irrelevant. Back pressure can in fact control air flow and reduce detonation, as well as provide better moisture evacuation (among other, usually negative things). If people aren't worried about losing 25 hp over larger transmissions, but nickel and dime 10-15 hp here and there, including some lost from back pressure, spending 100's or even 1,000's of dollars to gain what a simple (and CHEAP) trans swap could offer, well where does one draw the line and keep from looking ridiculous? There will ALWAYS be some back pressure, even if it's just in the heads themselves (yes, it's there), and is relatively short lived, but when you work with it, it can be turned around to provide benefit depending on what you're talking about. Sometimes, there's a fine line between having optimal velocity and approaching too much back pressure.
this whole exhaust theory thread kind of goes up in smoke when you run a dragster with zoomie headers like me..........
A 2" exhaust with a 350 2bbl and a ST300 is all you need to beat the competition. Don't forget that stock cam. :moonu: Performance parts are overrated. Who needs that.
Fox, what car is this and how much does it weigh? 355 Buick 13.50@99 mph motor 13.31@100 best 11.81@114 mph 125 shot nitrous 12.42 @105 mph 75 shot 200-4r trans 3000 stall 373 gears H-O Racing suspension Mid 12 sec Nitrous run 80 hp shot https://youtu.be/49JqjgpygUQ With 350 trans 11.87@112, 125 shot nitrous 3500 stall With 200-4r trans 11.81 @ 114 Same shot 3000 stall w/lockup 417hp 463tq rwhp w/125 nitrous shot. On motor 284 hp 310 tq. rwp
I have been running a SuperTrapp on my 4 stroke Honda dirt bike for 15 years now. I like it just fine. Adding or removing discs will make it louder or quieter which I am sure will have an effect on power. Without dyno tests it would be hard to say exactly what the effect actually is. Another plus is that the design is a natural spark-arrestor which you need when you ride in certain off-road areas.
As you know a two stroke engine is a completely different animal. Custom tuning a "pipe" is considered an art. And most often dyno and track tuning don't correlate with "pipe" tuning. Manufactures purposely set up there exhaust systems on a conservative tune so the engine can survive time. Leaving a lot of hp on the table. In the not so far past, We've done a tremendous amount of testing for Ski-Doo at a factory level...to say the least. I've personally made runs down the track well over 10,00 times in my life, and every one was well recorded. In almost every situation on a stocker, we could gain a minimum two tenths in the 1/8th mile just by reducing the stinger size. That's huge! And by reducing the stinger size in diameter (and sometimes lengthening) creates more heat in the pipe, which helps draw more air through the cylinders, which makes more power. To a point of uncontrollable detonation. And by reducing that stinger or outlet size very well could be confused with more backpressure, if measured I would bet there is actually more air flowing through and coming out of the engine.
That was my point. Good info. Applying the lessons here to a multi-cylinder engine is valuable but difficult in threads like this without discussing header theory...which the board doesn't seem to support :laugh:
the problem I have with some of these theories threads is there is only a very limited audience that have anything to do with them. headers have been brought up before. how many different styles are there and for what purpose. the majority are only going to buy the regular headers that are available. nobody is going to develop(big dyno time) and sell tri-y headers for buicks. waste of type and time. zoomies are another waste of type and time because there is maybe 5 guys running a dragster in the usa. an example of what i suggest to read is on classracer.com. these are hard core racers and they don't use nasa style/cost parts. what most people build here is a low product of what the classracers do. you can learn a lot of basics from them. I suggest that a list of sites be listed for people to go to to see what others are doing, not key board jockey theorys. never seen a keyboard race down the 1/4 yet. cars yes, keyboards no. just my .02
My point in bringing this up is that people say things like "headers only add 5 hp" or whatever... When you apply the dimensions of those particular headers to their engine combos, miraculously the header's benefit is in a completely different range than the rpm range looked at. Geez, surprise. Who wouldn't want some easy tools to eliminate years of trial and error? Nobody is talking about any high dollar anything or fancy theories. Just using very basic engineering to clarify the anecdotal tales that mislead thread followers. If people want to ignore the actual methods used to engineer and create products and winning efforts, we might as well all comment on how pretty a color of a car is in an engine build thread on a performance forum. I support looking at what other racers do. Most won't quite spell out the what or why or even the details of their combos and why they work, but at least it opens people's minds to more ideas.
One of my friends back in high school had a TS185. His was a 73 like my Honda. He was the wheelie king of our school! He could wheelie that Suzuki in all five gears! Nobody believed he could get it to come up in fifth, but he did...
It is relatively simple isn't it? We have 1 5/8 Headers and we Have 1 3/4 Headers one for low end and one for high end. But I bet most people go down to Summit and buy the Hooker headers instead of TA's. My 1 3/4 headers looked bad a** 20 years ago and I had them Jet Hot inside and out, They are just now rusting and that is only because I don't drive the car as much. Could I have gone faster with smaller headers, who knows, Don't care, Car runs great.
Why do this? Are you wanting to start some ****, yet again? Your car isn't any faster than others' cars that have MUCH less done to them, and those are FACTS. Put that in your pipe and smoke it.
