So i decided to purchase one of these to put after my Y-pipe where it meets my I-pipe to quiet down my exhaust. (I/H/C with Long tubes,ORY and GMMG).

well it definetly did a somewhat decent job of quieting it down at idle.. and tammed it at WOT. So i was somewhat happy with it.

Until i decided to goto a local dyno day.

my previous best pull (SAE corrected) was 419.5 rwhp and 399.5 rwtq

so with nothing changed other then the addition of the moroso spiral flow (same dyno BTW)

first pull 371.7 RWHP 357.6 RWTQ!

WTF! where did all my power go... so i decided to undo my exhaust at the y-pipe and take off the moroso spiral flow and just run open y-pipe.

420 RWHP 386.6 RWTQ! (TQ is probably down due to the shorter exhaust length)

thats right... the moroso spiral flow robbed me of nearly 50RWHP!!!!!

the test was done on the same dyno... on the same day 1 hour apart (time it took to get that damn thing off)

sooo anyone considering this thing... beware!

i will post my dyno graph for all to see

 

Reall, i run one. thats crazy.

 

Heres the graph...

 

I run 'em in my duals. Weird. Interesting.

-J

 

weird thing is i didnt lose but 2hp when i had one.

 

sounds like you got a messed up spiral flow.

 

I dont know what to think. I love my exhaust and it sounds great, but I ma down on power and a friend of mine has said he has seen the muffler rob power as well. I have 3" TDs with 6" long resonators, dr. gas X, and spiral flows dumped at the axle. Granted the motor was brand new when I dynoed it with cheap conventional oil. I am going to put a couple hundred more miles on it and then dyno again with mobil 1 and see where it is. Then swap the heads, headers, exhaust, maf, and lid.

 

Spiral Flow mufflers are not for making power. Just a quieter bullet. You should look at the Dynatech split flow muffler. Should help you cut down on noise and not rob power.

 

I dont really see how they could rob that much HP. I mean, I can see a little restriction and added backpressure. But 50rwhp? Thats insane. Well, dual cutouts from the headers is always an option.

 

X2, a baffle probably came lose and is blocking it.

 

What size spiral flows are you guys using? I gained a little with my true duals and spiral flows over a y and lm1.

 

The dynatec split flow muffler is great. Used to love the sound with my 4" mufflex type setup. Pricey, but a good piece.

 

U probably lost power because the whole motor was exhaling thru 1 spiral flow as opposed to 2 on a set of duals.

 

x3. There's no reason a muffler should have a difference of that much hp. I had a pair of them on my cammed Z28 w/ true duals and loved them. They flowed pretty well.

 

are they directional? maybe the bitch is backwards? i dont know i dont remember how they go. just all the spiral **** inside.

 

If I was one to sig. quote posts, this would be one.

 

 

I hope thier not that bad! Before I bought mine I read up on them and they seemed to be the best that came with the TSP package Nothing was said about power loss...

 

nothing seemed to rattle inside after i took it off to indicate that one of the baffles were loose.. as the dyno day was the very next day after i put it on...

i think it was just to much flow for one... on a TD setup they may be fine since its one per side...

 

Was at the Dyno myself to witness this! Hell, we put it on the day before! haha

I must say.. it was quite interesting to see the difference.. and then the ride home with an open y-pipe... oh my!