Im trying to decide whether to get a catback exhaust and a cutout or just the catback or just the cutout. What are your opinions? Im looking for a nice loud ear piercing roar whn i mash the gas. Also the best gains.


thanks

 

Cutout- VERY Loud, better performance.

Catback - specific sound, some performance, appearance reasons also.

If ur on a budget, just get a cutout for performance and loud sound purposes.

However, if u want something that sounds good and still give u performance when the cut-out is closed, u should get a catback.

 

how loud is VERY loud. Like Harley Davidson motorcycle loud?

 

Its not that bad, it will seem loud at first but you will get used to it. My daily driver has no cat and an open cutout and it doesnt seem that loud anymore to me.
Brandon

 

depends on your setup

on mine, hooker longtubes into a 4inch mufflex y-pipe, the cut out is loud enough to make grandma's cry and **** off the dead people in the cemetary.

get a hooker catback and a cutout so that when you don't want to attract attention to yourself (read: COPS) but still want to sound good and have good performance you can just cap the cutout.

 

I got a cutout and then bought the muffler of my choice for the sound when the cutout is closed.

 

Had a question about running your cutout open all the time. Will the lack of backpressure hurt anything in the long run? If not than would running an exhaust out the back without a muffler be ok on the valves?

 

no

yes

 

NO! any four stroke engine (with a properly tuned exhaust) can only benift from less backpressure (power wise). If you want the proof, I can email it to you, it's a very good explnation.

You valves will be fine.

 

Get the cut-out. I used to think that it was just a ghetto piece used to get your car sound ghetto, but after I heard a car with a cut out I knew I had to get one. It sounds even better when you have a cam.

 

Thanks for the replies and the info. GOT-Lt1, If you have that article I'd like to read it. thanks!

 

Hell I'll just post it:

~~"No, you absolutely cannot have too little backpressure. That is one of the biggest and dumbest fallacies that exist in relation to 4 stroke IC engines. Why? I'll tell you.

Pumping Losses --- The concept of backpressure means that there will be a high pressure area at the exhaust port. When the valve opens, the escaping exhaust gases have to push against that high pressure area. How can a parasitic loss be good for your engine? The only engines that NEED backpressure are various small engine designs, mostly 2 stroke. The problem with them is they have the tendency to be too effective at driving the exhaust out, loosing compression. I assure you that on a big 4 stroke engine such as an SBC you want the exhaust to have the free-est path possible. In fact, it would be ideal to have a low pressure zone at teh exhaust port. A low pressure area would help to pull the exhaust gases out. Freeing up more power that your engine would have wasted pushing the gases out...which brings up the next topic beautifully.

Scavenging --- We've heard this before, but what does it mean in relation to our discussion of exhaust. Easier for me to use an example. So your engine fires and now it's on the way up on the exhaust stroke. Exhaust doesn't come out at a consistent rate, it comes out in pulses. Each pulse is a high pressure area, and as it moves, it leaves alow pressure area behind it. Aha, there's our scavenging. You want that low pressure area to be at it's peak when the exhaust port opens on the next exhaust stroke. Thats another reason why headers make better power than manifolds. besides just flowing better, instead of all the pulses being dumped in a log fighting with each other, the tubular runners allow the exhaust pulses to stay seperate and create a nice low pressure area behind it. This is also where tuned and equal length headers come into play. Tuned headers are sized such that the length of the tube corresponds the speed of the exhaust pulses so that the low pressure area is maximized at certain rpms. No surprise that short headers are better for high rpms than longtubes.
Problems can surface if you use too large of a primary diameter, loss of torque. The morons are quick to spout 'you lost backpressure and thus torque.' Next time you hear that you will smile and know that that person failed physics in high school. The problem with using too large of a primary is this. The exhaust pulse only has so much gas and energy in it. If the tube is too large, the pulse expands to much, losing energy and thus velocity. When it loses velocity, it can potentially stall and stop moving in the tube, or at least slow down. aha! Too large of a header actually CAUSES backpressure, and thus lost power. We feel this power loss as a loss of torque because usually this effect is much more pronounced at low rpms as much less gas is moving.

The same principles apply to the entire exhaust system, from primaries to collectors to pipes to mufflers. I am too tired to explain it all, books have been written on these topics. I have just scratched the surface, but hopefully you all understand a little better why their is no such thing as good backpressure. I know some of this has been a little oversimplified, but it think it gets the message across.
thank you please drive through~~"

Makes sense.

 

Hey, thanks for clearing me up on backpressure, that info was very helpful!