vtec-adykt

anybody know what would cause only runners 3 and 4 to change color so much? they almost look burned! its a thick stainless steel sls ramhorn manifold. on all others i've seen they stay the bronze color forever. i've only put about 500 miles on mine and it looks horrible.

d16sandrail

timing/tuning...those dark cylinders are running hotter.

vtec-adykt

oh ok. so no more gettn on it. lol! is there a way to make my manifold look pretty again?

Bailhatch

Have the individual cylinders trimmed for timing and fuel.

You can take it off and polish it or just scuff it up with scotchbrite pads while it's on the car, but that won't look since you can't get to all the spots with it bolted up. Having it media blasted with something somewhat mild (not sand) can give a nice finish or you could have it ceramic coated if you wanted.

FastEg6

Is it even tuned?

Boner_Ben

Or if those cylinders have an issue how bout figuring out what it is rather than putting a band aid on it?

averageJoe

could it be as simple as a problem with the air flow?

the discolored cylinders are behind the radiator, where the other 2 are not.

From the picture, even near the collector, the discolorations disappears on cylinders 3 and 4 due to them not being behind the radiator.

Looks like the air around runners 3 and 4 is hotter because it is going through the radiator and not cooling the runners as well as the unobstructed air cooling runners 1, 2, and the collector area.

Alfa Turbo

What Joe says. Chances you have two cylinder fuel trims off like that is low.

96 GSR-T

Every single person I know personally that has a ramhorn and a 1/2 size radiator does not have that discoloration on 3&4.... including myself.

jnv255

same here ^^^^

Bailhatch

good point. check valve lash, compression, spark plugs and injector flow to start..

turbociv910

i have that same SLS manifold, I ran with no hood and for awhile and the front two were that color, while the back two were that bronze. putting a hood on it made them all the same color