More Power Without The Exhaust

Yes there is a definite power difference, but the main reason we don't keep stock exhaust on is because of the rules. The main reason we have stacks is honestly for crowd entertainment. Loud v8s + big crashes = Awesome

But yes, there is definitely a difference in power having stacks come out the hood. There is a theory that having 4 into 1 stacks actually may produce a couple more horsepower than 4 in a row as each "Wind stream" for lack of a better term helps pull the other wind streams to help the air come out of the stacks faster.

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Also true about the heat. The main part about the stacks is for crowd entertainment though

 

That's because it creates more back pressure...
4 into 1 restricts the exhaust more than each
having their own or none at all.

Like putting your thumb on the top of a
champagne bottle and shaking, or garden hose.
Sort of...

The engine has a little force to work against
instead of just dumping power into nothing.
Back pressure is good for the engine.

 

This thread turned out well I just have to hope that one of the devs sees it

 

removing a complete exhaust system will in most cases decrease the engine performence because you loose back presure. only thing that mostly works to have a bit more power is to remove the cat.
or install headers. only if you put a turbo or a bigger turbo or other kind of forced induction you need to increase the diameter of the exhaust.

 

Its that careful balance. Having a full exhaust system can restrict performance, but so can no exhaust at all, got to get it just right for optimal performance and frankly most cars lean towards the too much backpressure end of the scale.

 

That's actually a pretty good explanation of it haha. I see now. But at the same time... I can't imagine the exhaust on the cars we use does much more than restrict air flow...

 

I like how you tried to act like a know it all and at the same time talk down to us, but you have failed so much.

Exhaust GIVES power.

 

...anyway, exhaust does change the amount of power, a car has, so that should be implemented

 

I think the primary purpose for exhaust is to move the toxic gas
to the rear of the car so we don't breathe it, and engines do run
better with exhaust so it does have it's purpose.

Essentially there's all types of "tricks" to gain horsepower by removing
this or that, and some may work but those actual gains could be
measured in single digits. Not even worth it.

Real horsepower gains can only be achieved by real hardware.

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Not enough to make a noticeable difference so, I wouldn't hold my breath if I were you.

 

You're simplifying it too much man, you don't get it.
Some back pressure is good because IN SOME CASES it allows the gasses exhausting from the cylinders to help pull each other along (since not all cylinders exhaust at once, obviously). I think that in a lot of cases this is achieved just fine with the exhaust manifolds alone, and that having the exhaust pipes on only increases the backpressure past the point of usefulness, but there is no end-all-be-all answer for every engine in the world.

It's just stupid to say "EXHAUST GIVES POWER" because it's not specific enough to mean anything. Every single internal combustion engine exhausts things because that is a fundamental part of their working. Even without the exhaust manifolds, engines still have exhaust strokes. It's like saying "GAS GIVES POWER" even though it's very possible for the mixture to be too rich (fuel heavy).

http://www.autozine.org/technical_school/engine/Intake_exhaust.html#Variable-exhaust

 

If you remove the exhaust it might make the car a tiny bit lighter meaning it might become a fraction faster but as far as I know it makes no difference engine-wise.

 

exhaust. some back pressure is good. balance is key, and you do gain hp. but not very much. if you think otherwise, look it up and research it. prove most of us wrong. look up dyno tests of before and after.

 

running no exhaust at all MAY give you more power than a complete (cat+muffler) exhaust system, key word "MAY". the correct amount of back pressure IS GOOD for an engine, but it is possible to have to much or to little back pressure. that being said, to little back pressure should yield more HP than to much back pressure, but your still talking about a couple of HP on a stock engine. nothing that you would notice. and ofcourse an engine with no exhaust at all WILL burn valves.

then there are some engines that work better with more back pressure than you would think they need, example : a ford 302ci v8 will get a small bump in HP (and torque) if you run, say 3inch pipes with no cat. but if you did the same thing to fords 300ci I6, you would actually LOSE POWER compared to the factory exhaust system. more specificly, you would lose low end torque (and a lot of it) if you were to dump the pipes on a 300, and this decrease in torque would be so great that it would not be offset by the (small) increase in HP, in witch case your performance would be slightly worse. it depends on the engine really.

 

Alright, what if you only removed the pipe, leaving the manifold? That would work, right?

 

IF they are long tube headders, the short answer is yes. but a short stock manifold or shorty headders will get you burnt valves. allow me to explain, open headers that are too short (say, stubbs right off the cyl head) will burn and or warp a valve, the reason for this is because, sence they are so short, they can actually draw cold air into the engine, where it makes contact with the hot valve so it warps. but why would it draw cold air in? glad you asked lol. now we get to talk about scavenging, scavenging is where one exhaust pulse creates a vacuum to the point where it helps in pull the exhaust gasses out of the next cylinder. So instead of just the piston pushing the gasses out of the exhaust valve, it also has suction coming from the primary tube that actually draws it out too.

now if your talking STRICTLY from a power standpoint, with no concerns whatsoever about reliability/longevity, then yes you COULD run open manifolds. hell, you could run NO manifolds. however the power increase/decrease would vary greatly depending on the engine, like I said in my last post about the 302ci V8 vs 300ci I6. the engine MAY gain power, or in some cases it may LOSE power, depending on how well the original exhaust system was designed. and even if your particular engine did get a power increase from removing the entire exhaust system (save the headders/manifolds) the increase in power would not be marginal. seriously were talking like 10HP MAX on a STOCK NON-forced induction engine. ofcourse if the engine were turbocharged/supercharged then large gains MAY be possible, but that's another story...

 

I'm involved in modified Hondas. When people run open headers you can loose power. I've also seen people gain 1 or 2 hp up top and kill their midrange. At the very least you need to add fuel to keep the AFR. I ran open headers for 2 weeks after an engine swap and after I got the new exhaust welded up I noticed more power from 2500 to 5000 rpm. A lot of modern cars will barley run of you take the exhaust off. I worked at a Porsche shop and someone brought in a v8 cayenne that needed an exhaust. The car barley ran until we put the new one on. Just food for thought.

 

Tuning tuning tuning... Any back-pressure is lost power. Uncorked headers still create backpressure, but much less than the cat, muffler, and piping in a full exhaust. If you want an exhaust that makes the best power you need to reduce the backpressure to as close to zero as possible. The first thing that jumps to mind is the biggest possible exhaust with no cat or muffler, but oversized exhausts can cause the exhaust to get backed up trying to expand and fill it's new "container", thus creating backpressure.

Old carbureted cars could be tuned at home with a screwdriver and a wrench to achieve their maximum power for the parts, but EFI cars need new fuel and spark maps to do the same. You would also need to make sure that the O2 is getting the info it needs to work properly, and stock O2s are inadequate for power tuning. There is no car in the world that needs more back-pressure (excluding turbocharged cars before the dump pipe) to perform better.

also, M-M-M-Mega-bump

 

Yes tuning is essential. You have very little to gain by pulling your exhaust off without a tune. When hardware is 20 times faster maybe we can see a full model of the cylinders and airflow and design our own intakes and exhausts and play with ignition timing and fuel mapping. I'd love to see beamng head in that direction way down the road.

 

They wouldn't really need to simulate that in real time per-se, but an (OPTIONAL) mode or menu to tune that indicates AFR, spark-knock, back-pressure, EGT, boost, and IAT, as well at the ability to alter timing, fuel, and boost would be pretty neat for those who understood how to use it. That to me has more to do with engine damage than performance, as the only thing you gain with such a system is the ability to destroy your engine, wimpify it, or squeeze milage, all with varying life expectancies. As for on-the-fly uncorking from an accident, I'd like to see dynamic exhaust notes more than dynamic backpressure.

Also, try to look at the date of the oldest post in the thread before replying to it next time. In this case, the topic still hasn't been addressed in the game, thus making it arguably still relevant, but people frown upon bumping none-the-less. I'm not ripping on you, just giving a heads up.

 

If this was ever implemented into BNG, I would be so impressed with this simulator. to date there is not vehicle game/sim that lets you do this.. The only "game" that lets you sort of tune is automation and its very "dumb'ed" down with only sliders AFR and timing and boost are only available also, automation is geared towards building your own car company (tycoon) and "sort of" engine design, nothing else.