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Post by Buddyg - Forum Founder on Mar 9, 2014 7:21:13 GMT -5
Dana you have a 2500 series is there any chance SPF improved the Sidepipes from earlier models like mine at 1309?
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dana
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Post by dana on Mar 9, 2014 11:01:10 GMT -5
Dana you have a 2500 series is there any chance SPF improved the Sidepipes from earlier models like mine at 1309? Someone would need to cut open an early and later model pipe to see if there are any differences. The collector design looks the same. Build quality and materials could make a difference. The assembly of the muffler core to the collector on my pipes probably could have been better, but it didn't cost a huge amount of power. As far as someone bolting on a set of pipes to their SPF and picking up one hundred horsepower, it's not going to happen. Most people equate increased noise as an increase in power. Although some of these sidepipe builders refuse to believe my results, especially with the 2" flowpath GAS-N pipes at the 500 horsepower level, the results speak for themselves.
All in all, I'm very happy with my GAS-N pipes, especially for the price. They do offer a 3" core now.
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dutch
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Post by dutch on Mar 9, 2014 14:56:58 GMT -5
Thanks!
I remember a comparison I read a few years ago. but forgot about the details. They compared Firefly with the standard SPF pipes. It was something like this: under 3000 rpm the noise level is almost the same, but the Firefly pipes have a deeper sound. Above 3000 rpm the Firefly pipes have more dB, they sound louder, but make more HP, less restictive.
Does that make sense? Anyone with the same experience?
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Post by SPF131 on Mar 9, 2014 22:45:32 GMT -5
I get a kick out of these muffler threads. When I dynoed my 427W, I did some back to back tests with the stepped dyno headers with no mufflers, SPF headers with the stock SPF sidepipes and SPF headers with GAS-N Performance polished stainless steel sidepipes with only a 2" flowpath.
The Superformance mufflers are not near as bad a some would have you believe. I only saw a around a 20 horsepower loss between the dyno headers with no mufflers and the SPF exhaust at the horsepower peak. The GAS-N pipes, with a 2" flowpath were only a few horsepower behind the SPF pipes. This was on a low 500 horsepower 427W.
I have since replaced the GAS-N 2" flowpath pipes with a set of GAS-N 2 1/2" flowpath mufflers and I may have picked up a couple of horsepower. The 2 1/2" GAS-N mufflers have more of a deeper rumble at idle compared to the "crackle" at idle of the 2" GAS-N pipes. The GAS-N pipes aren't too loud at cruising speed-I don't need ear plugs, but you can definitely hear them at full throttle.
There may be a Cobra sidepipe out there that is so bad you might pick up a hundred horsepower, but it sure wasn't the pipes that came with my SPF. In speaking with the builder of the GAS-N pipes, there is a lot that goes into making a set of pipes that work-think collector design, muffler design, exhaust gas temperature and velocity. A loud 3" core muffler doesn't necessarily equate to more horsepower, just like a 427 big block needs a bigger muffler than a 427 small block.
Hmmm... That kinda sounds like what I wrote. @20 horsepower loss on a 500HP motor is almost 5%! That's a pretty big sacrifice considering how simple it is to not lose it. That and no-muffler dyno headers aren't necessarily the best for flow either. You are correct, bigger isn't always better in terms of pipe diameter and HP gains. A bit of backpressure is beneficial for flow and scavenge effects. On the SPF pipes, as Red Barchetta eludes to, they ARE a joke! Not just the muffler part either, the whole thing from the bend on back is surprisingly poor... In my stock pipes, where the 4 individual cylinder pipes came together in that simple larger tube they call a collector, the individual end curves converged directy at each other, and the gap in the middle where they converged not only didn't point to the rear at all, there was less space between the 4 converging individual pipes than the diameter of ONE of them... I laughed out loud when I saw it.. A 6" carbide cutting burr and an extended shaft die-grinder took care of that issue... Back to what Dutch asked about noise levels; talk to Ron at Firefly. From my past experienc with the Firefly pipes, yes, you can expect an increase in volume straight accross the RPM spectrum, but you do get HP increases that go with it. The Firefly pipes definitely have more of a "PoP" at idle. A WOT it's music to the ears, but it ain't "quiet"... I'm sure Ron can couple a quieter muffler with a real merge collector and keep it quieter if that's what you desire... |
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dana
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Post by dana on Mar 12, 2014 1:49:50 GMT -5
You missed my sarcasm there. 427 cubic inches is 427 cubic inches. The displacement is the same. A 427 big block is not going to displace more air than a 427 small block. At the same horsepower level, a big block will not need a bigger muffler than a small block. 4% actually. For me it's a small price to pay to not have to wear earplugs all the time. One's "butt dyno" isn't going to feel that 20 horsepower.What?? Maybe if the tubes were grossly undersized for the application they might not flow enough.If increasing backpressure would cause an increase in flow, horsepower should increase with some restrictive mufflers. I won't argue the design of the pipes could be better, but the funny thing is, the factory headers and sidepipes don't work that bad. The bottom line as I see it: you aren't going to pick up 100 horsepower, at the 500 horsepower level, with some bigger mufflers on a SPF.Back to what Dutch asked about noise levels; talk to Ron at Firefly. From my past experienc with the Firefly pipes, yes, you can expect an increase in volume straight accross the RPM spectrum, but you do get HP increases that go with it. The Firefly pipes definitely have more of a "PoP" at idle. A WOT it's music to the ears, but it ain't "quiet"... I'm sure Ron can couple a quieter muffler with a real merge collector and keep it quieter if that's what you desire... |
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Post by gramps on Mar 13, 2014 5:57:57 GMT -5
Dean and Pat,
We have seen pipe tryouts for the last 10 years, Yes the stock pipes are restrictive but all in all they work for most owners. When they fail the pipes can cost more than 100 horse power, this failure is due to the internal support members rotting out and causing a "cat eye" condition. The question of whether SPF pipes have improved over the years is yes. Original pipes back in the day had only a one and seven eights inch thru bore, the improved pipes have a 2" thru bore muffler insert.
One needs to understand, Carb, intake, heads, stub headers and cam have a lot to do with the gains to be expected. Example: I have had some small blocks that had no gain by changing pipes and other 427w's that had 38 rear wheel gain in horsepower. Big blocks all tested have had a rear wheel gain starting with 28 rear wheel to 69 rear wheel. On one car we were able to spool the dyno set up for a 3,000 pound car, the pull starting at 20 mph in 3rd gear to 120mph in 6.9 seconds (car has around 1,000hp).
Also, do not confuse engine dyno and chassis dyno numbers, they are very different.
Hope this helps,
Ron Roberts
Firefly Performance Products
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Post by clayboy on Mar 18, 2014 0:29:29 GMT -5
Red,
Is that 3" packed or unpacked?
Bob
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Post by RedBarchetta on Mar 21, 2014 11:55:09 GMT -5
Red, Is that 3" packed or unpacked? Bob Who me? 3" packed w louvers against the flow. Deafening at WOT. |
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Post by spf2932 on Mar 28, 2014 7:49:04 GMT -5
My car sounded like a sewing machine with the stock pipes, so I shoved a mirror into the tip and took a look. The inside diameter was less than 1 3/4"! WTF? Sent my pipes to Full Throttle in Sparks, Nevada and they exchanged them for a new set with 3" internals. Man, what a difference in sound, throttle performance and seat of the pants horsepower.
And yes, they are very loud. You can hear every cylinder fire. But they are worth every penny!
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Post by Buddyg - Forum Founder on Mar 28, 2014 7:50:28 GMT -5
My car sounded like a sewing machine with the stock pipes, so I shoved a mirror into the tip and took a look. The inside diameter was less than 1 3/4"! WTF? Sent my pipes to Full Throttle in Sparks, Nevada and they exchanged them for a new set with 3" internals. Man, what a difference in sound, throttle performance and seat of the pants horsepower. And yes, they are very loud. You can hear every cylinder fire. But they are worth every penny! Video please and thank you! |
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