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View Full Version : Risers...good or bad


SED
09-26-2004, 10:16 PM
What is the purpose of exhaust risers...how does this affect the motor..performance....are they good or bad..Thanks

SED
09-26-2004, 10:16 PM
What is the purpose of exhaust risers...how does this affect the motor..performance....are they good or bad..Thanks

DONCONVINCER
09-27-2004, 09:07 AM
The riser function is to allow cooling water to exit out the exhaust without allowing it to backup into the actual exhaust portion of the manifolds. The exhaust makes a U turn allowing gravity to keep water from flowing up.

SED
09-27-2004, 09:13 AM
Will risers change your RPMS..If so...will you have moer or less...Thanks DONCONVINCER

DONCONVINCER
09-27-2004, 10:31 AM
There are lots of different makers of manifolds and riser along with many styles for different applications. Depending on the manifold and riser combination, engine type, cam, intake system, ect ,preformance can be enhancer or diminished by the right or wrong combinations.

SED
09-27-2004, 01:52 PM
Its an all stock..454 MAG ...stock manifolds ...whats your opinion..Thanks

vinny p.
09-27-2004, 08:11 PM
I would always recommend ditching the factory Merc. exhaust manifolds and risers. They are more likely to leak and cost you a motor than aftermarket manifolds and risers. The gaskets between the risers and manifolds fail all the time. That is why I prefer Gil exhaust. They don't have any water passing through their gaskets, they use a by-pass hose. Works great.
What year is your motor? Do you run in salt or fresh water?

SED
09-27-2004, 10:03 PM
The motor is a 1997...and i run in fresh water only....Have any idea what Gil exhaust will cost

vinny p.
09-28-2004, 12:29 AM
About $2200 for Gil Wet Offshore.

overboard
09-28-2004, 10:29 AM
A friend of mine put stainless marine exhaust on his 95 261 persuader with a 454 mag carb. and lost 2 mph. I put gils on my 96 253 convincer with a 454 mag efi and gained 1 mph. I did lose about 75 lbs. over the stock manifolds. That might be the reason I picked up the extra mph. I'm sure now that I'm super charged the advantage of the gils over stock is much greater. I really like the fit and finnish of the gils. the brackets for the shifter, oil filter, ecu, are perfect. cp performance has good prices on all kinds of exhaust.