Need exhaust welded... again :/

[FoxHondaRider]

Well my so called 2.5" exhaust is a tiny bit larger than 2.25" ID which sucks and with my new header it will be bottle necked being as it is a 2.5" ID collector. Probably going to order another eBay exhaust this time in the 3" figuring it probably won't be 3" lol. Then I need a flange welded on and 2 resonators welded. 1 as the test pipe and the other as just another resonator. I have the "2.5" that we can duplicate for length and all so no getting under the car or even needing a lift. Sooo any TR members want to help me out? I don't have a welder nor do I know how to weld.

[J@meson]

Well my so called 2.5" exhaust is a tiny bit larger than 2.25" ID which sucks and with my new header it will be bottle necked being as it is a 2.5" ID collector. Probably going to order another eBay exhaust this time in the 3" figuring it probably won't be 3" lol. Then I need a flange welded on and 2 resonators welded. 1 as the test pipe and the other as just another resonator. I have the "2.5" that we can duplicate for length and all so no getting under the car or even needing a lift. Sooo any TR members want to help me out? I don't have a welder nor do I know how to weld.

Um that is how exhaust tubing is measured, 2.5"OD as in Outer Diameter. And why the hell do you think that you need a 3in exhaust, Are you trying to breathe up and over 450hp?

You should really read up on how exhaust system works bc I think even a 2-1/4 will be sufficent to have a 4cyl breathe just fine. You lose all backpressure and venturi effect that how a performance exhaust works...

[zhillz]

I went to a muffler shop and got a exhaust from the header back 2.5" with muffler and new rubber hangers for $90 way cheaper then buying one on ebay and shipping. Of course it wasn't mandrel bent but it was on a NA Honda.

[The Hedgehog]

Well my so called 2.5" exhaust is a tiny bit larger than 2.25" ID which sucks and with my new header it will be bottle necked being as it is a 2.5" ID collector. Probably going to order another eBay exhaust this time in the 3" figuring it probably won't be 3" lol. Then I need a flange welded on and 2 resonators welded. 1 as the test pipe and the other as just another resonator. I have the "2.5" that we can duplicate for length and all so no getting under the car or even needing a lift. Sooo any TR members want to help me out? I don't have a welder nor do I know how to weld.

MMMMMMMMMMMMMMMMMMMMMMMMMMBBBBBBBBBBBBBBBBBBBBBBBA AAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH HHHHHHHH!!!!!!!!!!!!





























































You fucking ricer.

[FoxHondaRider]

Um that is how exhaust tubing is measured, 2.5"OD as in Outer Diameter. And why the hell do you think that you need a 3in exhaust, Are you trying to breathe up and over 450hp?

You should really read up on how exhaust system works bc I think even a 2-1/4 will be sufficent to have a 4cyl breathe just fine. You lose all backpressure and venturi effect that how a performance exhaust works...

Please tell me who taught you this. I will slap them with a stack of dyno sheets proving good gains on a 3" exhaust naturally aspirated on a 4 cylinder Honda. Everything after the header is a restriction. There is also no such thing as needing back pressure. Look it up, if not I will link you to all the research done to have your mind blown. Also the piping I have was claimed to be 2.5" but OD isn't even 2.5". It is more like 2.35" and the ID is like 2.25"

[SuburbanNoize]

Pretty sure fox is right. I used to think back pressure was needed but dyno graph after dyno graph shows a more open exhaust will yield gains, even NA. And fox I have the same piping as you have right now, its like 2.25 piping. I think its stock. It keeps my car quiet.

[J@meson]

Please tell me who taught you this. I will slap them with a stack of dyno sheets proving good gains on a 3" exhaust naturally aspirated on a 4 cylinder Honda. Everything after the header is a restriction. There is also no such thing as needing back pressure. Look it up, if not I will link you to all the research done to have your mind blown. Also the piping I have was claimed to be 2.5" but OD isn't even 2.5". It is more like 2.35" and the ID is like 2.25"

Lol I would love to see gains to a N/A 4cyl with 3in pipe.... There is no need on that motor to have that much pipe, So I would love to hear who taught you what you think you know about exhaust systems... And yes you do need backpressure for a engine to make all the power it can N/A, Hence if you look and see road race cars dont actually run open headers, or nascar, or F1 or anything other then Top Fuel... You make more power with 18-25in of pipe to the back of the header to create backpressure and proper scavaging.

But if you want to get techinical its actually called Delta pressure, Which describes the pressure drop through a component and is the difference in pressure between two points...

Scavenging: at the beginning of the intake stroke during cam overlap, the momentum of the exiting exhaust gasses creates a brief vacuum (positive delta P) in the header, pulling out the remaining exhaust gases from the combustion chamber, and allowing the new air/fuel charge to be full-strength.

Scavenging is also the reason for differently shaped headers (4-2-1, 4-1) and collectors. We use the momentum of exiting exhaust from one cylinder to scavenge exhaust from another that is next in the firing order! The different shapes allow for this to happen at different airflow velocities thus at different RPM bands.

Scavenging takes advantage of the momentum of the exiting gasses. In essence, the fast moving exhaust pulse pulls a vacuum behind it. Momentum is mass times velocity. So not only do we need to keep the velocity high to prevent reversion - but it greatly improves the scavenging effect.

Thus we have a balancing act. We want to minimize friction to lower the backpressure as much as possible - larger pipes have less friction because they have less surface area per unit volume. But we want to increase the delta P as much as possible to prevent reversion and increase scavenging effects - smaller pipes increase delta P because they increase velocity.


Now that my rant is over here is a quote from this link.... Exhaust Theory

Pipe Sizing
We've seen quiet a few "experienced" racers tell people that a bigger exhaust is a better exhaust. Hahaha… NOT.
As discussed earlier, exhaust gas is hot. And we'd like to keep it hot throughout the exhaust system. Why? The answer is simple. Cold air is dense air, and dense air is heavy air. We don't want our engine to be pushing a heavy mass of exhaust gas out of the tailpipe. An extremely large exhaust pipe will cause a slow exhaust flow, which will in turn give the gas plenty of time to cool off en route. Overlarge piping will also allow our exhaust pulses to achieve a higher level of entropy, which will take all of our header tuning and throw it out the window, as pulses will not have the same tendency to line up as they would in a smaller pipe. Coating the entire exhaust system with an insulative material, such as header wrap or a ceramic thermal barrier coating reduces this effect somewhat, but unless you have lots of cash burning a hole in your pocket, is probably not worth the expense on a street driven car.
Unfortunately, we know of no accurate way to calculate optimal exhaust pipe diameter. This is mainly due to the random nature of an exhaust system -- things like bends or kinks in the piping, temperature fluctuations, differences in muffler design, and the lot, make selecting a pipe diameter little more than a guessing game. For engines making 250 to 350 horsepower, the generally accepted pipe diameter is 3 to 3 � inches. Over that amount, you'd be best off going to 4 inches. If you have an engine making over 400 to 500 horsepower, you'd better be happy capping off the fun with a 4 inch exhaust. Ah, the drawbacks of horsepower. The best alternative here would probably be to just run open
exhaust!

[FoxHondaRider]

My B piping is just a serious bottle neck in the system. My axle back is 2.38" ID and my header collector is 2.5" ID. I rather the axle back being the bottle neck. I considered a T1R B pipe but that is $450 and then I still would need a flange for my test pipe or to have it welded onto the T1R. I figure eBay $140 for claimed 3" more like 2.75", then $80 for another resonator, then having someone weld the other resonator I have as the test pipe again max $200 for a total of $420. Then sell the fart can shit that comes with the eBay exhaust for hopefully $40 lol. Or keep it bottle necked and spend the money elsewhere, IDK?

[FoxHondaRider]

Your little article makes me lol. If the car comes stock with 2.25" piping, and that motor is stock, you are going to tell me that the motor modded will not benefit from a larger exhaust? Even with an untouched motor just bolt ons there are gains with a 3" exhaust. Even on the 1.6L DOHC motors they gained more HP and torque over the whole RPM range.

[senor honda]

Gentlemen, I am sincerely greatful that we don't all think alike.
Thanks for posting up what you believe to be true.-Bob

[Ls_[eg]hatch]

jameson - K-series run 3 inch exhaust all day & MAKE MORE POWER its been proven, i know op doesn't have a k but you called out any NA 4 cylinder.

[Thaking]

Bob you fucking grave digger. STFU