EMI S.S. risers vs. alum.
 

I have EMI aluminum risers with silent choice on my procharged 502 and was wondering if the 4" s.s. riser with silent choice would make any more power than the cast alum. piece. anyone know the Id on each? Greg

I was wondering the same thing...when they sold me mine the said the cast ones were fine to 500hp......I think to make any gains we would have to get rid of the diverters....

Dyno I dont think the diverters are the bottleneck. I think the gains are from "drying" out the exhaust. In other words not adding water until later in the exhaust stream near the transom.
They told me the same thing, now with roller cam, brodix heads, and procharger I know Im at least 700hp. Greg

well my thinking is if we go to the larger SS risers without the diverters we would benifit the most....the stainless riser for silent choice does'nt look that much better than the cast...it mixes before the diverter.....looks almost as restrictive as the cast!!!!

A lot of the aftermarket manifolds come with the 2.5" dia. risers which may be adequate, but aren't the greatest when it comes to making power. They usually have a few 90% bends as well which further hurts breathing i.e, power. You'll benefit more with some manifolds that have a at least a 3.5" dia. riser or tailpipe---something with an elbow style type of riser and makes the exhaust gases easier to escape. Stainless Marine makes a well designed exhaust manifold and riser/tailpipe. There are others as well.

FYI. EMI cast risers are 2.5" and the EMI ss risers are 3.5" I.D. thats why I ask about the flow. Greg

When I talked to EMi about switching to s/s risers they said you probably won't even notice a diffreance with the s/s risers. They don't prevent reversion anymore then the aluminum ones do he mentioned too. I was surprised what the guy said. The guy admitted that if you already have the aluminum ones, don't bother switching its not worth it. and for $800 I could get alot more parts :D :D

just my .02


Travis

Thanks for the input Travis!!!!and are the SS risers for silent choice 3.5 inch????they didnt look thet big to me....