Chase910

Sorry to confuse, I'm not saying E-Tops don't flow better than stock, they obviously do, but they seem to be on the same plane as EMI, IMCO, ect. I wish I could find that issue, but I think all those exhaust systems increase hp around 20. The Eickert and CMI, not the E-Top, increased hp to the tune of 40hp or so. At least that is what my memory wants to tell me. Basically double the hp. Its only $100 for the reprogram. I don't think any of the headers, CMI, Lightning will allow the use of your Stock silent choice, so you will be limited right there to probably the Cast Alum manifolds. If the CMI E-Tops hook up to your stock exhaust that would be a good option, but at $2500 you could get Lightning with silent choice and the reprogram ecu and brackets, then sell your stock silent choice, which seems to be the best bang for the buck.
I think you'll only see 1-2 max with the best flowing exhaust, 5-6 will require head work along with a cam swap, but if you do head down that road it would be nice to know you that the exhaust system you choose doesn't end up being a restriction.

evelkevin

I am considering the exact same install on my stock 502/415 with corsa captains call. Looking at revolution, stainless, and imcos. It seems like everyone has their own favorites. I think it will come down to price and ease of installation. Let me know what you find. Peace, D

blackhawk

Chase910, I know what your saying and I appreciate all your info. I am confusing myself cause there are so many options. And I have heard of a lot of people spending $3000+ on exhaust for a stock EFI motor and get very small gains. I realize that a good exhaust system is nice for future mods but if I ever do any mods they will be minor.

I guess right now I am leaning toward the Revolutions. They seem to be in the same ball park as EMIs, Imcos, etc and have a lower price. They have also answered all my questions promptly.

kaama82

iTrader: (1)

I just happen to be one of those guys running Lightnings at Monroe Boat Club. Totally happy with them, no problems at all.

Chase910

I would agree with your findings. The Revolutions seem every bit as good as Imco, EMI, ect. but a much lower price. I bet they perform as well also.
If we say the best flowing exhaust on a stock 502 mag only gives a 40hp increase, this is about 20hp or less to the prop so yes min. gain. without changing things in the engine.

Chase910

I've met several people here who have Lightning as well and all have no problems and some have run them over 10yrs. They are with out a doubt the best bang for the buck in headers.
They will be my next choice if and when I buy headers again, unless I end up in Florida, then it will have to probably be Stainless Gen-III's.

Chase910

There is one other exhaust option I just thought of. You could just replace the most restrictive part of the stock exhaust...the riser. IMCO makes a replacement riser for the stock unit which is a full 4" flow, where the stock riser is actually a little over 2". A local dealer installed a set on a 26' sport boat w/454mag mpi. They also gasket matched ported the stock manifold. Don't know the exact gain, but that boat ran the same speed as an identical hull that had a 502mag mpi. The gain is probably the same as a EMI, IMCO complete header, but only $500 or so. Of course you would not see the same weight savings, but is a inexpensive way for some improvement and you get a nice shiney stainless riser for some bling, bling.

cobra marty

In the end you will wish you would have spent the little bit extra for the CMI's.

Chase910

Why? and Which CMI's? The E-Tops don't seem to offer any real big performance improvement, and it seems Mercury Racing agreed. The Sport tube and 2 piece Tube Top are very pricey, like 4-6K?

blackhawk

formulaz583, that is the logic I am using. The money I am saving could come in handy down the road if I do a little head and cam work and I don't think there will be a big difference between a $1200 system and a $4000 system in my application.