dimitros
seems like you did it right. especially with noticible power increase.
i don't understand the "back pressure" thing i keep hearing about. i do not grock the idea of restricting exhaust flow to gain power.
seems like no restriction at all would be ideal?
i have put on a cheap pacesetter header to 29"glass pack to cherry bomb muffler- all 2 1/2" from header(too loud without muffler).
i've only test run so far and it seems to run easier(idle increased quite a bit), but can't feel much difference powerwise. sounds different.
i look forward to my next fish trip- see how it really goes.
richard

rascott

The back pressure thing helps to prevent air-fuel mixture to get blown out to exhaust while engine working on high rpms, cause there's such thing that inlet valve is already open and outlet one isn't shut completely yet, so you are loosing usable fuel. But if reduce exhaust diameter too much one might expirience other side of the coin, exhaust fumes will get into the ignition cahamber and ignite the gas inside before the inlet is shut causing detonation.

I know that normally atmospheric engines require back pressured exhaust systems.


 

I run 2 inch on every sammy, tracker I have wheeled.  Made a decent about of difference in power performance. 

Any "backpressure" is a loosing proposition in any engine.  Nowhere in any engine building or design criteria will you find a spec for "backpressure." It's flat bad for any power producing engine. Exhaust systems are all a compromise for sound restrictions. The best ones have NO restriction.

Any "backpressure" is a loosing proposition in any engine.  Nowhere in any engine building or design criteria will you find a spec for "backpressure." It's flat bad for any power producing engine. Exhaust systems are all a compromise for sound restrictions. The best ones have NO restriction.

Well, if you just keen to power, then it is so, no "backpressure" thing, but there's also fuel economy and efficiency + some ecology (maybe ) left.You see bentparts, we have here, in Ukraine, no sound restrictions (there are but none cares) and $5.5 for gallon, so I do mind about blowing my money away, they should fairly be burned in cylinders.

I wrote about "backpressure" considering only naturally aspirated gas feeded engines (atmospheric) but in case of turbocharger/supercharger one must have no restrictions in exhaust.

And again, if a car equipped with a catalytic converter then also no "backpressure" needed. Catalytic converter works itself as "backpressure".

i wanted to see what difference a header could make.
it was fun in the driveway, but way to loud to drive on the street, so i put a glass pack(29"cherry bomb) on it and ran pipe out the back. all 2 1/2".
drove that a little and realized i needed more muffling action or i was going to hate hwy driving.
i added a cherry bomb muffler.
certainly not a stealth vehicle.
i will see how it performs on the trail, 'cause i can't feel much difference on the street- mabe some improvement on hills.
bit of a hack job and obviously not well planned. my next one will be better.
mabe.
i will have to replace all this in 1year(smog).

I'm thinking of adding a turbo, and live in smog-nazzi california too *sigh*

Any "backpressure" is a loosing proposition in any engine.  Nowhere in any engine building or design criteria will you find a spec for "backpressure." It's flat bad for any power producing engine. Exhaust systems are all a compromise for sound restrictions. The best ones have NO restriction.

x2.

There is such a thing as a negative pressure pulse that helps extract the exhaust gasses at a certain rpm. However you don't need any restriction, you can get that from the end of an open exhaust. In a multi cylinder engine most of the tuning is done in the header anyway.
If you drive on the road then silencing is nice to have, a nice big silencer with little restriction is ideal.

I'm still a fain of QUIET. I want to enjoy the trail, not someone else's exhaust tone ON that trail.

I'm still a fain of QUIET. I want to enjoy the trail, not someone else's exhaust tone ON that trail.

  Me Too.   NO Problem, you can still have an unrestrictive exhaust system on a stock motored 16v. I think about a 2-2.25" exhaust with the LARGEST freeflowing  muffler you can fit should help quite a bit. Big volume in the muffler will reduce "backpressure" and noise, but allow it to flow. Drop in a good filter, K+N, or similar, and that's about as good as you can get with stock engine internals. I wouldn't mess with the airbox if your going to go off road. Those cone's don't like water. Some say a header on the 16v is not necessary as the stock system is very well designed, but before I did my turbo I ran a Calmini header, 2" exhaust with a large turbo muffler, and K+N Filter and the motor responded very well to that. Everything else you can throw on the outside of a motor is basicly wasted, except for a GOOD set of ignition components. my 2 cents.

I'm still a fain of QUIET. I want to enjoy the trail, not someone else's exhaust tone ON that trail.

i usually don't see a lot of people, but i don't like a lot of noise either.
my next one won't be using a glass pack. it'll have a cat also.

a free flow cat and a resingnator.will quiet the exhaust and still let it flow.

mine has a magnaflow muffler, hedman header,2 inch tube, free flow cat and res, nice sound but when open up it opens up

  Doug Thorley tri-Y header to cat to resonator to thrush welded muffler and out the back.  I have done 2 this way with 2.25 pipe (a sammy and sidekick).  Both sound great and definately add power.  I think next time (yeah I got another tracker) I will do the same combo only stay at 2" pipe.  The only issue with the 2.25 pipe seems that there is not enough speed in the exhaust at idle so it gets some humidity build up (read that as water dripping from tailpipe at idle).  I think going to 2" will help that and not lose anything. 

As was said before, some pics of my exhaust