Exhaust pipe size for -se 6port 13b?
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Exhaust pipe size for -se 6port 13b?
Ok, so I'm getting close to installing my 13b w/48mm Weber DCOE and need some input on the size of my exhaust pipe.
I am using the Racing beat dual exhaust header and have the weld on flanges for a custom collector to go from 2x 2in to whatever size single pipe.
Should I use a 3in or should it be a larger size. ***No emissions required***
Going with MagnaFlow components, so I will adjust my choices based on the pipe size.
So give me some feed back on what would be a good size to go with.
Thanks!
I am using the Racing beat dual exhaust header and have the weld on flanges for a custom collector to go from 2x 2in to whatever size single pipe.
Should I use a 3in or should it be a larger size. ***No emissions required***
Going with MagnaFlow components, so I will adjust my choices based on the pipe size.
So give me some feed back on what would be a good size to go with.
Thanks!
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Just to make it clear, I am intending to collect "two" 2inch pipes together from the header into one larger one.
Are you saying it's not necessary to increase the size of the exhaust?
Interesting....
So Doc.....who's your evil twin in the first post? LOL!
Are you saying it's not necessary to increase the size of the exhaust?
Interesting....
So Doc.....who's your evil twin in the first post? LOL!
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#8
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Yes, But he is using a RB header, not a SDJ.
When RB designed their systems I'm sure that they took into consideration the maximum amount of HP gain with the matched pipe size. I'm sure that SDJ also did the same and that is why with their header they are using 2.5".
It would be interesting to show if there was a difference in HP gain on the RB header with 2.5" tubing.
When RB designed their systems I'm sure that they took into consideration the maximum amount of HP gain with the matched pipe size. I'm sure that SDJ also did the same and that is why with their header they are using 2.5".
It would be interesting to show if there was a difference in HP gain on the RB header with 2.5" tubing.
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This one
Vs this one
It's hard to say what the exact performance difference is going to be.
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This all helps, I currently run a RB header collected to 2in and then 2-1/4in the rest of the length on my existing 12a nikki carb setup, so I'm not going to go any smaller with a 13b. I already have a RB collector for the dual header now, I just checked the I.D of the RB header pipe and it's 1-7/8 per runner not 2in.
If I stick with a 2.5 all the way to the rear of the car I should not have any issues.
The problem is, do I want to run my port actuators or just wire them open all the time. If I go 2 inch I can make a pickup tube and have the pressure I need for proper operation(maybe). The magana flow components flow very freely and create little back pressure so do I give up the exhaust tone I like for port acutator performance? Hard choice, Magnaflow sounds sooooo good!
If I stick with a 2.5 all the way to the rear of the car I should not have any issues.
The problem is, do I want to run my port actuators or just wire them open all the time. If I go 2 inch I can make a pickup tube and have the pressure I need for proper operation(maybe). The magana flow components flow very freely and create little back pressure so do I give up the exhaust tone I like for port acutator performance? Hard choice, Magnaflow sounds sooooo good!
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I searched but I couldn't find it... it's in the archives, but someone dynoed his car with the 5&6th ports functioning perfectly and with them wired open, and he made more hp and tq across the entire RPM band with them wired open. The only thing functioning 5&6th ports improve is gas mileage...
Back on topic Lloyd you need to ditch that collector. It looks terrible. You're better off running the RB streetable header then running with that collector. It looks like more of a restriction than a collector. Something like this would be perfect
SDJ FTW...
since you can't buy 'em anymore why not try and make your system ad close to their design as possible. that's my plan...
Back on topic Lloyd you need to ditch that collector. It looks terrible. You're better off running the RB streetable header then running with that collector. It looks like more of a restriction than a collector. Something like this would be perfect
SDJ FTW...
since you can't buy 'em anymore why not try and make your system ad close to their design as possible. that's my plan...
Last edited by Hyper4mance2k; 05-19-08 at 03:11 PM.
#19
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I searched but I couldn't find it... it's in the archives, but someone dynoed his car with the 5&6th ports functioning perfectly and with them wired open, and he made more hp and tq across the entire RPM band with them wired open. The only thing functioning 5&6th ports improve is gas mileage...
Back on topic Lloyd you need to ditch that collector. It looks terrible. You're better off running the RB streetable header then running with that collector. It looks like more of a restriction than a collector. Something like this would be perfect
SDJ FTW...
since you can't buy 'em anymore why not try and make your system ad close to their design as possible. that's my plan...
Back on topic Lloyd you need to ditch that collector. It looks terrible. You're better off running the RB streetable header then running with that collector. It looks like more of a restriction than a collector. Something like this would be perfect
SDJ FTW...
since you can't buy 'em anymore why not try and make your system ad close to their design as possible. that's my plan...
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No worries, not using that design, close but it will not close like that.
Picture 2 funnels that are melded together, the smaller tapers will be the flange that connects to the dual header outlets, the wider part of the funnels at the top will be melded to a single pipe, that will be the desired diameter with no reduction.
Simple geometry
Picture 2 funnels that are melded together, the smaller tapers will be the flange that connects to the dual header outlets, the wider part of the funnels at the top will be melded to a single pipe, that will be the desired diameter with no reduction.
Simple geometry
#21
Does anyone in the states run twin pipes joining into one larger diameter pipe at the diff? I currently run a 13b large extend port with 2.5 inch extractors into 2 inch pipes joining into a 3 inch single at the diff with a stainless dumpy exhaust tip.
#22
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I believe he was asking about the H pipe in this pic
An H pipe has been used in the muscle car scean for years. It used to equalize pressure in the exhaust flow which in theory gives a much flater torque curve. SDJ Dyno sheets have proven that yet again. The few SDJ dyno sheets i have seen give IMO a 25% flatter torque curve than a RB exhaust.
An H pipe has been used in the muscle car scean for years. It used to equalize pressure in the exhaust flow which in theory gives a much flater torque curve. SDJ Dyno sheets have proven that yet again. The few SDJ dyno sheets i have seen give IMO a 25% flatter torque curve than a RB exhaust.
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I say 2" or 2.25" at most. I used 2" in my GLC with a large streetported 13B and the powerband went well beyond redline if I chose to rev it that high. However, I don't have dyno sheets to prove this.
Another thing to keep in mind: the larger the pipe diameter, the louder it'll be. You may be losing a lot of power just getting the noise down to acceptable levels. No way to know what's best without some real dyno time, though.
Another thing to keep in mind: the larger the pipe diameter, the louder it'll be. You may be losing a lot of power just getting the noise down to acceptable levels. No way to know what's best without some real dyno time, though.
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It's all about torque for a good streetable car. If you're more concerned with higher RPM HP and could care less about low end torque, then by all means run the biggest (or just big) pipe you can fit. I know that rotary engine's aren't known for their impressive low end torque, but I think I'm still going to stick with 2.25" and 2.5" max when I get around to adding my turbo. I want a car that'll perform in traffic when I need it to, at RPM levels that don't draw unnecessary attention...
Just plan out your mods and consider what the goal and main purpose of the car is. If it's going to be street-driven and is mostly stock under the hood you may want to keep the 2.25" or even go down to 2". The exhaust alone won't make the car-it's all the mods working together with each other...
Just plan out your mods and consider what the goal and main purpose of the car is. If it's going to be street-driven and is mostly stock under the hood you may want to keep the 2.25" or even go down to 2". The exhaust alone won't make the car-it's all the mods working together with each other...