:iagree:

Yes it is true, I made 483rwhp with open pipes and 477 with the spiral baffles without the caps. The caps make the car 4db's quieter at idle and 2500rpm free rev. The car ran 13.5:1a/f ratio with open pipes, about 11:1 with the baffles. I have no doubt that if I had leaned up the mixture I would make back all 6 lost horsepower.

My primary reason for preferring the side pipes is ground clearance. I have said numerous times in other posts that I really do prefer the discreet look of pipes that go under the car. BUT, I can't get anything that flows even close to the side pipes with the spiral baffles under the car without cutting up the frame or jacking the car up too high. I much prefer the lowered stance of a road racing C3. Keeping the heat away from the trans, differential, and passenger compartment is a great plus too.

Leg burns are no problem with Jim's heat shields. I got mine after my 10 year old daughter received 2nd degree burns on her first ride in the car! :sad: The sound is about the same as Flowmaster 40's or 50's I've heard which is not quiet; but, is passable if you don't flaunt it in front of the wrong people. But sound levels tend to be subjective. I used a db meter to measure mine. Roughly 92 db's from 15 feet away at the 2500rpm free revs without the caps. With open pipes, it was off the 120+db scale. The baffles do work!

 

I've read it a bunch here that under car exhaust gives more HP to side pipes. I'll agree with the latter posts that it's not side pipe design that costs HP, but the mufflers in them. If you put the exact same muffler in a under car system and in a side pipe system, they will produce the same HP.

 

Very true; but, 4" inch pipes under the car gives quite a clearance problem without cutting into the frame. Running 3" pipe which wouldn't be as good still causes a clearance problem. Running 5 feet through 2.5" pipe then through the baffles will cause greater loss; but, even so where can you stick a 3 foot long baffle?

Believe me, I have spent more than a few hours, even years thinking about how I could make such an under car system work. For me, the side pipes with Jim's baffles worked best.

Chuck

 

I think that your original Plan is best....Sidepipes look cool but they are not for me........I have friends that have them and they too think that the sound can be a bit much

 

And I'm banking on Chuck's experience...literally.

My '69 has 1 7/8" Hooker ceramic coated long tubes, 3" collector and from there 2.5" stainless steel all the way out back to 40-series Flowmasters. This set up will be for sale within a month. ;)

I just got my Hooker side-mounted pipes today. 2 1/8" primaries and a 4" collector. I'll be running the JCL baffles. I would hope this system will make as much, if not more, power than the one that's on the car now.

Ground clearance will improve and I'll be able to drop the car an 1" which will put it about the factory ride height.

Unless these baffles are just really, really restrictive (and I have no experience with any of the sidetube baffles), I would think there will be a power gain, not loss, from what I have now.

 

I agree. I was just answering why I thought Chevy went with the sidepipes instead of under car pipes. There is nothing better than sidepipes to run on a race car except for maybe open headers.

I'm about to purchase the Hooker sidepipes from Jet-Hot, and the JCL inserts from Spiral while the inserts are still on sale. Spiral's sale ends Dec. 2002 (hehehe), so hurry. You can get a 10% or so discount from Jet-Hot on the headers and sidepipes with their coating. $1014 shipped to your door. I hope this information doesn't get this posting blocked, but for anyone interested there you go! :cheers:

mark

 

Pulled them off mine. I personally like the look of the vette without them, minor hp differences on mine seemed like a moot issue, and most importantly - no burns on my son's legs.

The post above regarding emissions might be the key.