I have noticed that under my seats there are like 8x8 cut out that allow a lot of heat and noise into the cab. But i did not dare to cover with the fear of over heating. When you did your insulating did you cover these?I am running only the bottom part of the windshield and the Cab top. When the outside temp reached 90 it was getting awful uncomfortable. I just made these changes and it helped the noise and heat both a lot. Take the seats, floor pan, and the cover behind the floor pan by your heel out. The water lines run next to the drive shaft, I put a piece of black air conditioning tubing insulation
1 inch thick over these to get rid of the floor heat. Under the seats and behind your heel I used the duct board material that heat and air contractors use to contain the heat and noise, 1 side has foil on it and I used the foil barrier material put under metal roofs as a heat barrier to cover the other sides. U can by a foil tape that contractors use on duct work to hold all this together. Any place where there was room I insulated it to keep the noise and heat out of the drivers compartment, Be careful not to get any foil close to any electrical sources, and on the top of the engine I had a piece of high temp barrier material that is used in racing applications because of the high temp there, It came from Earl's who sell steel braided fuel lines. All these changes made a huge difference. The duct board was 1 inch thick I cut it a little big and squeezed it I to a lot of places or held it in with Ty wraps.
Thanks for all the replies! Well I have cut down the noise level a lot, and I just ordered this exhaust silencer so I think I'm done.I purchased a device you slip on the tailpipe of you factory muffler, it's called The Silent Rider. Cuts noise down by 60% maybe when you are running high RPM's you might get 40% reduction. I paid 186.00 but it's worth cutting the engine noise down. When I get my cab I will still try some additional sound proofing material. The device is made my Quad Fab, quality product.
I started piecing together a full cab and could imagine how noisy it would be. I found a site that seems to have high end sound proofing material. If I could resolve the noisy muffler I would be completely happy with my new RSX 850i
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