Review: SuperSprint Twin tube (2x 2.5") Section 2

[Thoglan]

You are way off on your numbers

pi/4 * 3.375^2 = 8.84sqin
pi/4 * 2.375^2 *2 = 8.85

You're off as well. Splitting hairs at that point though
8.95 for 3.375
8.86 for 2.375

Both rounded to 2dp

3.5" is 1% larger in area and 100% worse in sound

[digger]

Redid and got 16.59 in² for the 3.5in pipe.

The 2.5 in twin pipes are at 23.29 in² which is 40% larger overall.

I actually used the radius this time. I was excited to change my mind but ultimately the twin pipes seem to flow a significant amount more when comparing apples to apples.

According to math, stock pipes have like 30% more area than a single 3.5

You are way off on your numbers

pi/4 * 3.375^2 = 8.84sqin
pi/4 * 2.375^2 *2 = 8.85

[Arith2]

Edit: This is also wrong.
Redid and got 16.59 in² for the 3.5in pipe.

The 2.5 in twin pipes are at 23.29 in² which is 40% larger overall.

I actually used the radius this time. I was excited to change my mind but ultimately the twin pipes seem to flow a significant amount more when comparing apples to apples.

According to math, stock pipes have like 30% more area than a single 3.5

[SQ13]

Anyone here have V1 headers, catted sec 1, twin resonated sec 1, and SS Race muffler? Curious what your thoughts are on tone and volume.

I’ve used AP, Euro, and CPI headers with stock US midpipes and Race muffler, and I loved how it sounded with AP headers. Hoping the tone would be somewhat similar with the full SS setup. Don’t mind it being a little quieter tho with the larger piping, cats, and resonator.

Edit: The closest setup I can find on YouTube is V1 headers, catted sec 1, twin resonated sec 2, and Sport muffler. Sounds good.

https://youtu.be/x3Jl2IC5M-M

[SQ13]

You’ll scrape everywhere with 3.5” piping. It was pretty annoying when I had the BW exhaust.

[F1Dryvr]

I believe its 3.5". It definitely was a dumptruck below 4500rpm, was able to get some back by adding a SS twin pipe section 1, and the rest is the BW Race. I wonder what the result of adding a section 2 twin and then single pipe at the exit would do?

[Obioban]

Idk what Bimmerworld’s track pipe is size wise, but it 100% does ruin the bottom of the powerband (which, to be fair, is fine for it’s intended (race) use… but terrible for a car that sees any street use).

[Arith2]

I think your area calculations way off (looks like you did Pi d^2 instead of pi R^2). I don’t know of any 3.5” section 2s sold for this car, anyway (the OG SS single tube is 3”, and they still had to compress it to make it fit between the V brave and chassis). Also, the lack of H pipe is detrimental to the powerband— guts the bottom end.

I did do diameter, not radius

I'll redo it and see what happens. It sucks my job doesn't involve math everyday because I've gotten sloppy. Bimmerworlds pipe is 3.5 if I'm not mistaken. I don't know if they have something for a stock sec 3 though.

[Obioban]

Just did the math and the available area in a twin 2.5" with a 2.36" ID has an area of 34.98 in². The 3.5", assuming the Pipe is the same thickness at a 3.36" ID has an available area of 35.44 in². There is about 35% less diameter in the 3.5" than the twin pipes which gives less drag or chances of turbulence. There is also no need for a crossover which creates turbulence. There may be a little at the merger but it'll be much smoother than a straight 90 degree bend at the H pipe. I'm not sure about how much better or worse and X pipe would be, flow wise, over a single pipe. I do know the less turns and curves, the better.

Until I went back through this thread tonight, I always brushed off single pipe exhausts, but in theory, the single 3.5" flows more and better than the twin pipes. I don't have time to dive into dyno results tonight but I think my mind has been changed so far. How can we scientifically test this? Dynos are not the answer and are too inconsistent. What I mean is a real science experiment with sensors and crap.

I think your area calculations way off (looks like you did Pi d^2 instead of pi R^2). I don’t know of any 3.5” section 2s sold for this car, anyway (the OG SS single tube is 3”, and they still had to compress it to make it fit between the V brave and chassis). Also, the lack of H pipe is detrimental to the powerband— guts the bottom end.

[Cubieman]

Would love to see the guys on the show engine masters test different exhaust combos on the engine dyno, maybe if we all write in they would throw an S54 on the stand instead of the big block chevys they usually test

The last few episodes were very interesting, they were all about exhaust combos, dual/single, muffler types, mandrel bent pipe vs muffler shop stuff etc.

I really am considering getting a Twin Tube Sec. 2 this GB but just don't know if it would be of any benefit at all with my mods, not to mention it may quite my exhaust and/or change tone for the worse.

This is the time to get it though, just thinking w/o cams my stock Sec. 2 is likely just fine. What could I possibly gain, 5HP way up top? I need to stop chasing power on this car, just not worth it to me at this point, but I can't stop thinking about it.

[Arith2]

Hey guys, Done a lot of researching on both the Internet and talking to other members about section 2 and which one works best.

The 3 section 2's that I'm comparing are stock section 2, Supersprint resonated single pipe section 2, and SS resonated twin pipe section 2. I haven't used my stock section 2 since I put my SS Street section 3 on and then my Dixis Spirit section 3 so I haven't compared the sound/powerband of stock vs the SS resonated single pipe. A couple of people have told me the twin tube makes the exhaust sound bad, which would suck because the car sounds amazing right now, but I do also need to increase the exhaust diameter once I install SS v1 headers and section 1.

Has anyone compared stock vs SS single pipe vs SS twin pipe using a similar setup? I'm considering doing a comparison test between all three just to see which one feels AND sounds best.

If there's any interest, I can make a thread and try to dyno the differences between the 3.

Just did the math and the available area in a twin 2.5" with a 2.36" ID has an area of 34.98 in². The 3.5", assuming the Pipe is the same thickness at a 3.36" ID has an available area of 35.44 in². There is about 35% less diameter in the 3.5" than the twin pipes which gives less drag or chances of turbulence. There is also no need for a crossover which creates turbulence. There may be a little at the merger but it'll be much smoother than a straight 90 degree bend at the H pipe. I'm not sure about how much better or worse and X pipe would be, flow wise, over a single pipe. I do know the less turns and curves, the better.

Until I went back through this thread tonight, I always brushed off single pipe exhausts, but in theory, the single 3.5" flows more and better than the twin pipes. I don't have time to dive into dyno results tonight but I think my mind has been changed so far. How can we scientifically test this? Dynos are not the answer and are too inconsistent. What I mean is a real science experiment with sensors and crap.

Edit: I was dumb and used diameter, not radius. The math is bad.

[EthanolTurbo]

Hey guys, Done a lot of researching on both the Internet and talking to other members about section 2 and which one works best.

The 3 section 2's that I'm comparing are stock section 2, Supersprint resonated single pipe section 2, and SS resonated twin pipe section 2. I haven't used my stock section 2 since I put my SS Street section 3 on and then my Dixis Spirit section 3 so I haven't compared the sound/powerband of stock vs the SS resonated single pipe. A couple of people have told me the twin tube makes the exhaust sound bad, which would suck because the car sounds amazing right now, but I do also need to increase the exhaust diameter once I install SS v1 headers and section 1.

Has anyone compared stock vs SS single pipe vs SS twin pipe using a similar setup? I'm considering doing a comparison test between all three just to see which one feels AND sounds best.

If there's any interest, I can make a thread and try to dyno the differences between the 3.

[x Spades x]

You can use the same one, but I would check that it doesn't interfere/impede air flow, maybe folks are trimming the gaskets down on the inside to fit the larger piping.

I think the inner rung of the oem gasket is metal. There is a slight lip

[Cubieman]

I'm about to install this and have a question regarding the flat gasket. This is the same one from the smaller oem piping... is there a 2.5 inch 3 bolt gasket everyone is using?

You can use the same one, but I would check that it doesn't interfere/impede air flow, maybe folks are trimming the gaskets down on the inside to fit the larger piping.

[x Spades x]

I'm about to install this and have a question regarding the flat gasket. This is the same one from the smaller oem piping... is there a 2.5 inch 3 bolt gasket everyone is using?