The Stovebolt Site Forums The Shop Area Engine Shop Raptor muffler

Has anyone ever put one of these on their 235 or in-line 6? They are on sale for $24 at Kraigen.

Does it matter which end you connect from the manifold to muffler pipe?

Raptor

Oh really?
I have a 2-1/4 with adaptors to make it a 2"
My truck already has a 2 inch exhaust pipe. What kind of problems would result?

Billy...I have to agree with AD-52. Without backpressure no engine runs as well as it will with some. If your running a split or dual exhaust manifold keep your exhaust to 1.75 into the muffler. Dual 1.75 or 2" outlets work OK on a one-in two-out muffler. IMO 2.25" is quite large for most Chevy inlines. Why don't you check out Flowmaster and/or Gibson websites and see what they have to say about it.

Bigger isn't always better.

I have a stock single manifold with one out. With 2" pipe

?????

Then why do folks put headers on V-8's to get more "scavenging"? Is there back pressure on top fuelers with the straight pipes?? You've peaked my curiousity. Is it a difference between a high horsepower motor and a low horsepower inliner. Apple and oranges? Would an inliner run worse with a straight pipe and no muffler ( and louder?) I know big diesels use the blower and turbo to blow out the burnt mixture and to pack in a high compression mix for combustion.

MN SMITH I agree with you, The only exception is 2 cycle engines cuz they actuallly suckback in the exhaust pipe. tuning the pipe is critical I found after racing sleds at different altitudes.

With the straight pipe the engine ran strong and sounded very good. When I put on the Muffler is ran worse and not as strong.

This is a little long on explanation and will not use words like "pulse" or "reversion". Do NOT mean to insinuate any contributers are not sharp but as a professor once told his class--if I use words or examples some don't understand then both persons time has been wasted. The exhaust should be sized so the "ball" of exhaust traveling out the pipe will fit the inside of the pipe like the piston in an old time suction gun. This leaves an suction behind the ball that helps pull any unburned gasses out of the cylinder AND pulls a new fuel/air charge into the cylinder when the intake valve valve starts to open. It's called the "scavaging" effect. When the pipe is too large the ball fits too loose and has no suction. Of course, as usual, there are exceptions, such as a very high rpm engine where there are many more pulses(balls) so that even though there is less suction to each one there are so many more it results in a net gain. Also on super/turbo charged engines the incoming charge is under boost(pressure) so a very low restriction exhaust is desired. I can hear the guys with a background in fluid dynamics laughing their hineys off at this explanation but I hope it does show why proper sizing on the exhaust does have an effect.

I'm running split headers on my 292 with Cherry Bomb glasspacks and 2" pipes from the header bell to the mufflers and then the same size out the sides. Runs fine. Much better than with the little bitty strangulation pipe that was stock on it.

I agree about 2-strokes (and rotary motors) needing backpressure, but on conventional 4-stroke, normally aspirated motors, I think it's pretty much academic until you get to things like tuned exhaust with equal length tubes and measuring flow rates to evaluate for maximum efficiency, especially with valve timing that has a lot of overlap where scavenging becomes critical. I'm sure the F1 guys have all sorts of computer models to design this, but on our trucks, I think it's a little over the top.

Granted, I wouldn't put 4" duals on my 292, but as long as I have a relatively mild motor, anywhere from 1.75 to 2.5 should function about the same.

Now if anyone has done extensive research or knows of any that refutes this, I'd love to investigate it.

That muffler sounds pretty good to me, no gurgly noises like a Flowmaster (they sound like an out of tune Quadrajunk to me). I have 2" duals on my 235, all stainless, with a pair of CJ 7 mufflers and don't have any power problems. But I don't think that you would want want to run any larger than that on a 6 or even a mild v-8. Wild smallblock or big block maybe a larger pipe would be ok. If you want to make a big pipe look put a tip on the tailpipe the size you want.
By the way, a guy I work with who's int the import thing put a low restriction , no muffler, fart can exhaust on his '91 Accord, now he has a burnt valve on #3 and the engine has no power. Didn't have this problem until he did the exhaust.

What I did with my '53 6500 was to weld end caps on a piece of 4 inch box tube about three foot long for a collector.I rubber mounted it(for vibration insulation)side to side behind the cab.I then cut two holes for the two inch ID 304 stainless stacks and welded in three bolt flanges for each(with stainless acorn nuts).I cut an inlet on the bottom again with a three bolt flange.I added two rain caps on the top and it sounds so sweet especially pulling under load.

I just installed two Raptor mufflers about a month ago on my 51 with a 235 engine. I am pretty happy with them, sound and performance. Like someone said earlier, 2 inches is a little big for the engine, but with the amount of power its making, I think the difference is going to be minimal. They are a great price though. Figured anything was better than the previous owners system. One rusted out glasspack, cuts out mid chasis, and one huge modern muffler with a tailpipe exiting in the back. I was running straight pipes, awesome idle, full throttle was embarassing, making all kinds of noise, and hardly moving.

MNSmith - I thought this would require a lot more explanation than I can offer so I was hoping an expert might jump in. About your question as to a long straight pipe and no muffler I used to see this years ago on school buses w/ inline sixes and they sounded great. It wasn't too loud however or uncomfortable. So I guess that works OK too but I believe the length of the pipe more or less acts somewhat like a muffler. But yes I do think it's apples and oranges on a high HP engine vs an old straight six.
I don't pretend to understand all of this and it's why I suggest we ask the experts at Gibson or Flowmaster or others. I'm sure they can explain it all properly in terms most could understand.
I hope this string stays alive for a while as it seems to be of interest to many.

I think coilover did a great job of making sense of it all.

I'm putting a small block TPI in my 'burb, so I have been looking for headers. My favorite maker, which I have used before, is Sanderson Headers. Their web site has some good tech info, basically the same stuff coilover was talking about.

http://www.sandersonheaders.com/tech_get_technical.php

Also, some neat stuff there regarding changing pipe sizes midstream ( creates turbulance and backpressure.)

http://www.sandersonheaders.com/tech_complete_performance_exhaust.php

If I read that correctly then I can run my straight pipe without a muffler. At least for a little while.
What's the worst that can happen besides being loud and a possible ticket.

So does anyone want to buy my Raptor muffler for $10.00 only been ran for 10 min.
I suppose I have to buy a new one that has 2" in and out lets.

MNSmith, good Sanderson sites. I'm running a '56 235, 848 head, Fentons, 2" pipes to 2-26" glasspacks and I'm ready to place an 'x-pipe' in the mix. I've been thinking I'd like to try the 'X' with NO mufflers, anybody ever tried this?