Do ya love yer sidepipes???

[undy]

First, let me say that I've searched my butt off on this subject and I still don't have a warm fuzzy about what to buy for my 3rd set of side pipes.

I chassis dyno'd the new Pond S/O today and as countless before me I was disappointed with the results.. The short of a sort of long story is that I'm losing 100+ fwhp over my go@#*^amned side pipes. I was present at the dyno sessioned and witnessed the horror in progress. I dyno'd with and then without them. I've got the Spiral Turbo inserts in 4" pipes. They ain't cutting it..

What's everone running on high HP applications.. I see Howe mufflers and Classic Chambered Exhaust. Is there anything else worth a snot?

Dave

[rblong]

Undy - you are the man - I have not had time to test mine, but this tells me why I went from 580 FWHP at Keiths to 430 RWHP at the dyno. I will be calling you.

[lineslinger]

It is my understanding that the spiral inserts were meant to be used as a "volume" control while minimizing flow restriction, and that when they were removed (making things a lot louder) you could regain the lost hp for your immediate wants/needs say for track runs etc.
Are you talking about a sidepipe setup with reasonable DB output while still retaining optimal HP? I have always read that it is pretty much of a compromise, flow restriction equals a loss of HP and the best most can do is find a balance between restriction/volume as opposed to running open pipes which in many places will get you pulled over, ticketed, complaints from neighbors, accelerated hearing loss etc.
If there is an alteranative that won't get you arrested I would love to hear about it.

[ERA Chas]

My Stainless Specialties side pipes are within 5 HP of open headers. (Flanged connections allow interchangeability) And these are the older 2 5/8 inch cores. WHP = 462.

[undy]

The Spirals are not quiet at all, in spite of their excessive HP losses. I understand that I can't have my cake and eat it too when it comes to noise versus performance. At this point I want the performance, damn the noise... short of open sidepipes..

[BossCER]

Dave,
I don't have chassis dyno results yet, but I'll let you know when I do.

I had my Spiral Turbo's modified a bit. First we cut them almost in half (now about half as long) Then completely hogged out the center plug. Next step was to take and stratigically bore holes all over center section of auger and pipe that auger fits into (my augers are like 3 15/16" to fit into a 4" pipe). The last step was to fit the 4" pipe with auger in it into a 5" pipe and pack w/ stainless steel packing, taper at the ends and weld into place. All of this was done in stainless.
I can say that I'm very happy w/ the result as far as the sound goes, but like I said, I don't yet have any performance results. I've got a couple of pics in my gallery if you've got any interest.
Good luck,

Chris

[Jon Miller]

Here is a look down the length of the Stainless Specialties "Muffler". I've got mine the "quiet" direction, louvers forward, and they are plenty loud. Given the straight pipe with bumps design I can see why there is only a 5hp loss. I have not dynoed mine yet, I'm still in the tuning phase.....

-Jon

[wtm442]

Have your cake and eat it .....

http://www.pfyc.com/store/merchant.m...ory_Code=VTEXH

[Rare Iron]

With the minimal amount of exhaust system assy. on these cars, if you are going to achieve quiet, you are going to lose major HP. There are 2 effective ways to quiet down relatively short sidepipes: 1. Squeeze the flowpath diameter so small that flow is significantly reduced, & add soft packing material to absorb flow (current stock systems - 1-7/8" +- flowpath approx.). 2. Use a non straight-through muffler core inside the muffler cavity. Walker used to build a muffler that looked like a glasspack externally, yet had two (very small dia.) staggered flow tubes internally. These were called "Royal Scots." Flow on them? Terrible. Noise reduction? Yes.

Now, if you want sound attenuation qualities + good flow, you'll need at least a 2.5" (OD) flowpath & soft packing to absorb. If you are over 480 flywheel HP, run a 3" (OD) core muffler with soft packing. I believe this will give you the best of both worlds - as good as can be hoped for. Run as long of a muffler as you can fit - shorten the collector & shorten the exit spout.

There's no sense spending THOUSANDS of dollars on a high HP motor only to have your mufflers rob you of 100+ HP (not to mention torque) in the power band.

-The Powerstick/Cobrapack blacksmith.

[undy]

I talked to Classic Chambered Exhaust this evening, nice of them to call me back after hours too. I think I've pretty much made up my mind to replace the Spiral Turbo inserts in my 4" pipes with The custom made 3" flow path inserts by Classic. They'll custom make them to fit inside my existing 4" pipes and to the length I require. Howe also makes a killer 3 1/2" flow path but unfortunately it's not an insert. They would require entire new sidepipes, new ceramic job too. Howe's mufflers have the same OD as my sidepipes. I think Howe's muffler is significantly louder than Classic's is too. I don't think that they'll do custom lengths either. That, with what I know now, persuades me to give the nod to Classic.. They've some dyno results on their web site's that pretty impressive.

....any one have a better mouse trap??

Dave

[blykins]

Dave, what did she dyno at the tires?

[rblong]

Undy - just mneasured mine and they would need the 30". I am with Dave and have to come up with something else. I have been wanting to get mine in and have a before and after by pulling baffles and just have not had a chance - I will try next week I hope, but Dave was standing next to the dyno and what he saw - he saw. That is probably why I saw a 26% loss in FW dyno versus chassis dyno. Ran the FW dyno with open headers, chassis with baffles.

Bruce

[rblong]

Jon - the ones Dabe are talking about have the same interbnal works as your stainless specialties bufflers. Here is a Link http://www.classicchambered.com/

[rblong]

Hey Dave - when you talked to them - will they build the Cobrapack without the ends. In other words can we get the overall length to be 30 - all body - no ends? I guess we would always order the 36" and cut the 6 inches of ends off?

Bruce

[undy]

With the side pipes on she went to 374 rwhp and flattened out at 5300 rpms. We pulled the side pipes and she jumped to 451 rwhp @ 5400 before we shut here down. Horse power was really on the incline at 5400 when we pulled the plug on it. We weren't monitoring fuel pressure or A/F on that pull so we decided to be safe. I've no confidence in my fuel system as I'm still running the original Holley 110 gph electric pump w/ 3/8" fuel lines. My plan is to upgrade to the Holley "black" 140 gph pump and 8AN (1/2") fuel system. That should cure any potential lack of fuel woes. My cam should make peak HP around 6200, on the conservative side. There's probably some significant horse power left on the table. I think I'm going to do the fuel thing and the new inserts before I pay another visit to the dyno shop.

Dave

[undy]

Originally Posted by rblong

Hey Dave - when you talked to them - will they build the Cobrapack without the ends. In other words can we get the overall length to be 30 - all body - no ends? I guess we would always order the 36" and cut the 6 inches of ends off?

Bruce

Even without ends It'll still neck down to the 3" OD inner pipe. Why would you do that anyway? The custom inserts/Cobrapacks are identical internally and there's no new ceramic job either. Am I missing something??

[JRoss]

Hey Dave,

When you upgraded your sidepipes to run the spiral inserts did you start with the stock lone star pipes. The reason I ask is lone star side pipes have 1 7/8 primarys and there FE headers are 2''. That could be one bottle neck.

If quiet is not on your wish list, here is what I did.

I started with mandrel bent 2'' primarys. 4x2'' - 3 1/2" merge collector. Howe racing muffler 4'' od - 3 1/2'' id. 3 1/2'' turnout.

Loud yes, restrictive no. I am making 511hp at the rear wheels. There is a rear wheel dyno sheet in my gallery.

Good luck on you HP quest,
John

[undy]

John,

I had Lone Star's 1 7/8" primary "J" pipes replaced with 2" "J" pipes matched perfectly to the headers. They come into a 4" collector. No restriction there..

I think your Howe setup flows about the best...

[Unique 289_FIA]

I have a set of 26" 2.5" core Cobrapacks from Classic Chambered sitting in my shop waiting to be built into sidepipes. Real nice construction, a bit on the heavy side (probably due to the heavy duty build). I last dyno'd 352 rwhp with my 354" 302 stroker from Southern Automotive using stock sidepipes from Unique. My fabricator is going to build them on 12/04, will dyno and report on results!

[decooney]

undy,
FYI: This topic has been reviewed over and over at length here on CC over the last 2-3 years if you search around. If you have a healthy cam/compression and heads on that Pond motor, some 2-15/16 peforated core baffles, non-leuvered, 20.5 long canisters, with chambered entry/exit will do the trick and it will ROOOOOAAAAAAARRRRRRR!

To me, all these other turbo baffles, directional louvered units, cones, and every other flim-flam gadget out here inside the sidepipes are just different variations of restriction if you ask me and some are actually louder than a well designed chambered glasspack exhaust setup. I pretty much concluded last year that one could achieve the same results with a $8K 390 FE motor and improved sidepipes as compared to a $20K FE motor with factory sidepipes that come on many of these replicas/kits. This seems to be a repeated oversite with many of these high $$$ cars out there. A few Cobra folks in my neck of the woods with small blocks have picked up 40-60hp rwhp on the dyno with improved sidepipes and others have claimed more but I did not see the before/after dyno sheets myself. My stock mufflers are sitting out at the scrap metal yard or melted down somewhere by now

Good Luck.