Exhaust question

[newkidwithsol]

 

Now dont make fun of the drawing! LOL but this is what im planning on for an exhasut.... Right now i have manifold and piping going to the straight thru design can at the back.. And that is loud.. I wouldnt mind being a little quieter... Should i run a CAT? high flow or oem? I do plan on running a turbo in the future so I would want the exhaust to be good for now and then.. any ideas?

[zimmy709]

the cat would depend on emissions in your state... however it is still a good idea on a street naturally aspirated engine for the same reason that it is a good idea to go a bit smaller in pipe diameter on an NA engine. you need some back pressure. however you don't want any restriction in a turbo exhaust system. so it's gonna be hard to build an exhaust good for both. i would stick with what you have and maybe ad a high flow cat, or even just a resonator after your manifold. then when you turbo build a 3inch turbo back.

[James Matteu]

Bernoulli's principle says that "x or h pipe" will be filled with dead space, a low pressure system where moisture and exhaust particles will settle and work toward accelerating the rusting process.

[newkidwithsol]

So if I put on a cat and a resonator with 3in piping... that would be good while i dont have a turbo.. then when i do get one i can just take it off, right? Or no.. i dont know much about exhaust if u cant tell! LOL And the pipe that connects the two sides makes sense... but will both pipes flow equal without it?

[Hatch92]

2.5" exhaust is good for N/A and 3" is good for turbo. you can run 2.5" with a turbo but you will make a little more power with a 3".

[TS John]

Don't run dual exhaust on a 4 cylinder. It will lose power and most likely not sound very good. You'll prolly regret it if you go through with any serious build.

[newkidwithsol]

I dont think this sounds bad.

http://youtube.com/watch?v=VRGQfm_zcnU

 

not too sure bout this one http://youtube.com/watch?v=VV3oDxAUvdQ

http://youtube.com/watch?v=NuU3_jjzzpA&feature=related

[Hatch92]

yea um no

[airjordan223]

yeah man seriously dont run a dual exhaust on a del sol...please

[newkidwithsol]

I still dont exactly see why I shouldnt.... but if I were to just do a single out of the back, could I run three inch and put in a cat and a resonator while I dont have a turbo for the back pressure? and then just take them out when I get a turbo? Will that work? What type of material should I run on either set up? SS or anodized Aluminum? Anything else material wise I should look into?

[Kegger]

You don't want to run a 3 inch exhaust unless a turbo is in your very near future. Just stick with a good 2.5 inch exhaust, and when you boost, sell it and get a custom 3 inch made for ya.

 

And always go SS, and dual exhaust on a honda, minus the S2000 of course, just looks gay and does nothing at all for the motor except rob power. Look into flow dynamics and velocity, you'll see.

[cranny]

2.5 is too big for D or B series engines. 2" is plenty , 2 1/4 tops. i run 2 1/4 on my K20.

[CleanGSR]

It sounds like the thread starter needs to do some research to proper exhuast design.

 

Duel exhaust is only necessary on a car that runs more than one header, i.e. V styled engine

 

Think of it like this. Blow through a straw and you can get faster (but less) air than if you blow through a 2" pvc pipe.

 

You want a happy medium of the speed of air and the amount (size of pipe) of air flowing. There's a reason that people don't run 5" piping all the way back on a stock 4 banger.....it would kill your power. 2 1/4" is plenty big on a D series and 2.5-3" if your boosted. Do some research about exhausts and you'll understand better. Either that or say screw it and do 5" piping all the way back if you don't give a crap about the performance.

 

Splitting the exhaust into duals is the same as running bigger pipe. Hell even on the S2000, some of the better exhaust designs switch it to a single pipe.

[newkidwithsol]

That would be the reason why i posted it on here first.... I have better things to do besides get upset on the design of an exhaust on my car.... So instead of learning about exhaust design, I can continue what im doing in school.

2 1/4" is plenty big on a D series and 2.5-3" if your boosted.

And what about the B-series?

[CleanGSR]

I wouldn't go bigger than 2.5" on a B series and 3" if boosted.

 

My point is that if you are unwilling to do the research, then you need to take the advice that you are getting here and follow that advice. YOu say "I still don't understand....." but if you are unwilling to do the research, then you never will understand. So, bottom line is you don't have the time to do what's needed to understand why a dual exhaust on a 4 banger is a bad idea, you'd be better off just taking the advice here and being done with the topic.

[newkidwithsol]

Do research on what? The only thing im getting is that the flow... Which can't that be controled by pipe size? Everyone keeps saying to put up an exahust for N/A then just replace it when i get a turbo. Is there no way i can use the same exhaut? For N/A add some restriction, and when its turboed remove the restriction? I dont have the money to just buy a new one when i want.... Either way i need a new one now, so keeping the one I have is outa question.

[CleanGSR]

If you did the research on proper exhaust designs you'd understand.

 

No...you can't add restriction, because it's the overall flow through the pipe that determines the gain in hp/tq. If you take a 3" exhaust that doesn't flow well for n/a, then add more restriction, you now have a pipe that doesn't flow well and an added restriction in the pipe. 2.5" exhaust will flow faster and being n/a you won't produce enough exhaust gases to push through a 3" exhaust fast enough. The exhaust will move too slowly and hurt performance.

 

So, you can either get an exhaust that will hurt performance now and help performance once boosted or you can get one that helps now, but will be restrictive once boosted. Bottom line is you can't have it both ways....just not possible due to the way exhaust flows.

 

Oh and the flow is determined by engine and pipe size. The problem is that your engine doesn't produce enough n/a to flow through a larger pipe well.