Do ya love yer sidepipes???

[decooney]

Originally Posted by bremillard

I've got a 540 Chevy motor that engine dynoed at over 700 h.p. When I installed it in my car using Shell Valley supplied sidepipes the motor would barely run. I cut open the sidepipes and removed everything. I welded in some 3 1/2" CarChemestry baffles and welded the sidepipes back together. This mod allows the motor to breathe but it is much noisier. There really is no free lunch with mufflers. It will either flow real well and be noisy or not flow as well and be quieter. Each person has to weigh what is right for them. I opted for maximizing power in my application. -Bob

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Bob,
There are some hi-flow (straight-through, non louvered, non-baffle type) sidepipe muffler designs that are quieter than others at lower rpms purely based on entry/exit chamber design, length, etc. My previous factory pipes were much louder at lower rpms, and 30% less freeflow as compared to my current ones; so it in fact was not a give-take situation for me.

Which mufflers/cores did you choose from Car Chemistry, I see mostly baffle design inserts on their website?

[bremillard]

"Which mufflers/cores did you choose from Car Chemistry, I see mostly baffle design inserts on their website?"


I used the 3 disc weld-in baffles. -Bob
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[Rare Iron]

Originally Posted by undy

Well.. I dyno'd the Cobra the first of the week. There's good and bad.. I'll talk about the good first. I gained around 70 rwhp by going from the Spiral Turbo inserts to the 3" Chambered Exhaust inserts, no other change. Temperatures were similar (within 5 degrees) and the same dyno was used. I dyno'd 370 with the Spirals and 440 with the Classics. Kudo's to Eric @ Classic Chamber for providing a quality product and the customer service to back it up!

Now for the bad... Even at 440 rwhp the motor's developing much less than it should. I can only assume that it due to my restrictive heads. I had Keith supply me with valves and springs but I had a local shop accomplish the port job and assembly on a set of Eboks that I already had. The port work looks great but I honestly believe that they flow no where near Keith's stage 2 or 3s.. There's just no other logical explantion. Now ..... do I want to spend another $3K for a set of stage 3 heads or just accept what I have now??

Dave

Dave I have to ask you, did you have the center tube uncapped at both ends of the spiral inserts? This would permit significantly more flow through the sidepipe than if one end was capped from what I understand.

-Eric

[undy]

Originally Posted by Rare Iron

Dave I have to ask you, did you have the center tube uncapped at both ends of the spiral inserts? This would permit significantly more flow through the sidepipe than if one end was capped from what I understand.

-Eric

Eric,

No, the caps were in place with 1/2" holes in them. I'm sure if I removed the caps my rwhp would have been higher though. In retrospect I probably should have removed them first and re-dyno'd. I might have been able to save myself some money.

Dave

[rblong]

Mine were open on one end and a 3/4 nch hole in the other - that may be why I got 430 RWHP out of mine.

[undy]

Originally Posted by rblong

Mine were open on one end and a 3/4 nch hole in the other - that may be why I got 430 RWHP out of mine.

Hey Bruce,

Yea, a 3/4" hole will flow quite a bit more than my 1/2". I'll probably remove the cap entirely and dyno again just to see. My initial blurb might have given the spiral turbos an undeserved bumb wrap. I'd feel bad if they lost sales due to a skewed report from me.

Dave


BTW... check the new toy in my sig.

[rblong]

Look at you! I mentioned I just bought a new 06 Viper last time we talked and next thing you got a new Vette - well I won't hold that against you since you still got your Cobra

I already have a list of "upgrades" I wanna do to the Vip - I can't keep nothin stock

Congrats!!!