classic roadster II sidepipes

cobraman428 · #1 (**permalink**) 06-04-2009, 12:41 PM

I bought my sidepipes from Don of CRII - sometime in 2006. Would anyone know if these are considered to be the "restrictive" type with considerable backpressure or the non-restrictive type??
Thanks

jdean · #2 (**permalink**) 06-04-2009, 03:49 PM

Get a flashlight and mirror and see if you can look inside the tail pipe. Then you can see how big the hole is in the muffler.

Double Venom · #3 (**permalink**) 06-05-2009, 04:25 AM

cobraman,
The way these are made it is almost, if not impossible to see the innards of the CR pipes but, thse should NOT be the restrictive type! First thing that Don did when he took over was to change the 'guts' of the sidepipes.
DV

James Stern · #4 (**permalink**) 06-05-2009, 04:31 AM

DV, My car was purchased in 1999. Would your statement hold true for this year?

Jim

FUNFER2 · #5 (**permalink**) 06-05-2009, 05:55 AM

I have made new 304 highly polished stainless side pipes.
From the header flange to the turn out with custom hangers.
Click on this like below. I can make these for you, so send me a PM or email.

http://clubcobra.com/forums/showthread.php?t=97010

undy · #6 (**permalink**) 06-05-2009, 08:42 AM

I hear that those polished stainless steel sidepipe are very suceptible to cracking, especially when installed on Lone Star Cobras...

FUNFER2 · #7 (**permalink**) 06-05-2009, 10:12 AM

The cracking is only because people don't support them properly with a hanger. The three guys I've talked to said the did not use the hanger at all !

The only time my LSC would crack them, is because it's so,oooo fast !

Here's a pic of mine.

HI Cobra · #8 (**permalink**) 06-05-2009, 01:36 PM

I have a '99 vintage CR and those pipes were restrictive. About three years
ago I got the unrestricted pipes from Don. Big difference. I used a small mirror and a bright flashlight and could easily see the baffle with an 1 1/2"
hole. The new pipes are the same diameter as the outlet and had an open
mesh wall instead of solid pipe inside - plenty of room to breathe. They
were louder than the others but if you were easy on the pedal no problem
with too much noise in town - just sounds mean.

jdean · #9 (**permalink**) 06-05-2009, 01:53 PM

I hear you Flip.... I just bought some new sidepipes recently and looked down into them with the mirror/flashlight. Saw a narrow tunnel in the muffler and immediately ordered replacements from Classic Chambered. Eric does a great job and offers lots of options.

In my opinion getting good flowing mufflers translates to one of the best "horsepower per dollar" investments you can make on these cars.

undy · #10 (**permalink**) 06-05-2009, 01:56 PM

Quote:

Originally Posted by FUNFER2

The cracking is only because people don't support them properly with a hanger. The three guys I've talked to said the did not use the hanger at all !

The only time my LSC would crack them, is because it's so,oooo fast !

Here's a pic of mine.

....look closely, is that a hairline fracture I see developing aft of the merge collector??

FUNFER2 · #11 (**permalink**) 06-05-2009, 02:17 PM

lol,...no. That's where the collector slides into the muffler, and is welded. You can see in the pic below what I mean. No cracks or problems at all. The sound is incredable. Love it. !!!

My buddy says it sounds like a Pro-Stock.

Double Venom · #12 (**permalink**) 06-06-2009, 08:36 AM

Funfer,
Well done! That is exactly how I built my first custom pipes, when I started to build them similarly! Had you done a pre/post dyno you would have seen at least 35 rear wheel hp gain, to well over 50 hp if a big block!
DV
PS..YES, the "rumble" is awesome and NO it isn't that loud!

FUNFER2 · #13 (**permalink**) 06-06-2009, 11:38 AM

Thank you !
I did make a before and after chassis dyno run.

I'll post several photo's of the pipes and dyno sheets on a new thread but, here's a preview. I'll mark the numbers with a pen as where the increases were at different rpm's on the new thread. It's around 12 hp at the lower and 30 + up higher. The old mufflers were surprisingly open, with the same type louvers, just smaller.

I wanted to enlarge the sheets but man, how did I do the bottom?

Still learning my new printer/copier.

MaSnaka · #14 (**permalink**) 06-06-2009, 01:29 PM

I have the dyno numbers with the old pipes circa 1997 and am installing Classic Chambered's 2 1/2" core x 30" mufflers this week. I should have 'em coated and back at the dyno in another week or so, so stand by and I'll have some comparison numbers for you guys. I replaced the Performer 390 with a Performer RPM intake as well. Stay tuned...

John

undy · #15 (**permalink**) 06-07-2009, 06:26 AM

Kev,

...a little confused here. I thought you had already put down 400 rwhp with the old combo?? You never made it to 350 rwhp on either run here. Am I sorta thick and missing sumpin'?

FWIW, I made 470 rwhp with the Pond 482. That's with a smaller cam than I think you're planning on running. As soon as I figure out all the plumbing etc I'm looking at a installing a 300 hp progressive Nitrous fogger system in the car. That should help with it's lethargic behavior..

Dave

cobraduke · #16 (**permalink**) 06-10-2009, 07:16 AM

Dave,
You're going to shoot your eye out with that thing.

Mike

FUNFER2 · #17 (**permalink**) 06-14-2009, 01:54 PM

Hey Dave, that 400 was on the Dynojet chassis dyno. It measures and calculates differently. I won't get into it on this thread but, the Mustang dyno will give you real true to the street numbers than the Dynojet. What I've heard is, if you want bragging rights go to them, if you want street and track proven results, go with the mustang.

I think your mind,........is foggy Dave !

undy · #18 (**permalink**) 06-14-2009, 02:54 PM

Quote:

Originally Posted by FUNFER2

Hey Dave, that 400 was on the Dynojet chassis dyno. It measures and calculates differently. I won't get into it on this thread but, the Mustang dyno will give you real true to the street numbers than the Dynojet. What I've heard is, if you want bragging rights go to them, if you want street and track proven results, go with the mustang.

I think your mind,........is foggy Dave !

Mind's clear as a bell and the dynojet's closer to the real deal, much research done on the latter.

FUNFER2 · #19 (**permalink**) 06-14-2009, 03:03 PM

lol,.....I beg to differ, and that can be debated for the next 100 years Dave.

MaSnaka · #20 (**permalink**) 06-14-2009, 09:29 PM

Progress report...I had Classic Chambered's 2 1/2" x 30" Cobrapacks installed onto my original 3" CR LTD side pipes. The muffler/exhaust shop, Fast Intentions, located in The San Fernando Valley, Southern California recomended the louvers be open to the rear not the front. Anyway I installed the newly assembled sidepipes back on the car to make sure I wouldn't need to make any changes before the new ceramic coating goes on. They fit perfectly, tig welded, they cleared all the ridges and edges on the inside that would impede airflow and did some very precision work IMO. I am happy. Well I figure as long as they are on, just tighten the flange bolts and take her out for a drive. The car fires right up, revs easily and now has a new personality. Loud screaming monster with a new deep throated growl. Performance was up significantly although I was taking it easy. Now my neighbors will hear me coming and going. Pipes come back off and get their new coating, dark gray. Hopefully back together this week and over to the dyno (JET) tuner for some super tuning. I am truley excited and can't wait to get it all back together. As promised I will have comparison numbers and pictures. On the downside I find it unbelievable that a company manufacturing a so called high performance kit car would design and build such a restrictive muffler/sidepipe combination. The only reason I can think to justify this is noise level. I guess thats why race cars are loud. It's a shame it had to be redone.

John