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Does your engine get "raspy" over 5000 RPM's?

1040 Views 6 Replies 7 Participants Last post by  mwojton
Just curious...with the cooler air...I have been doing some good practice take off's and *especially with cooler air (below 60 deg) I feel/hear a certain raspy Honda fart can sorta rasp going on...It sounds deeper than Honda so it is a good rasp type of sound...just wonder if this is common among the group???
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Pay close attention since it could be detonation or spark knock. A quick way to test that is to up the octane and listen for it.
Um, if you up the octane you would make predetonation go away. Unless that was your point -- that the sound, whatever it is, would stop with higher octane fuel.
I believe that was his point, if it goes away then there is a problem.
Sounds to me like hes talken bout the exhuast sounds. The cams kick over at 4k so that in combo with cooler air might be what you are hearing...
I had issues with knock or pinging on the dyno with 87 octane after about the 4rth or 5th run. Tech suggested higher octane but i remember seeing posts about timing retardation with higher octane and hence a loss of HP so i never tried it. Let me know if it works for you.
Sounds to me like hes talken bout the exhuast sounds.[/b]
I think it's entirely possible that the exhaust is raspy. IMO, any small displacement engine (and a 3.0 v6 is relatively small) will sound raspy once it gets into the higher rpm's. Four-bangers are the worst, but I've heard v6's do it to. I come from the SHO world, and the 3.0 Yamaha engine was raspy right about the time the secodaries kicked in. Both of my cars did it. The trick to helping to reduce it was to replace the resonator with a different type. The stock resonators were just a slightly larger section of pipe with some perforated metal inside. Replacing it with a fiberglass packed muffler helped quite a bit. It also lowered the tone of the exhaust.

On my first SHO I had an aftermarket y-pipe installed. I also had them replace the resonator, and it ended up sounding pretty good. My last car I had a Dynomax catback installed. I wanted the shop to replace the resonator but they said they didn't have enough room to fit it. I think the y-pipe gave them room to finagle it around to get it to fit. Anyways, the car with the Dynomax was a little raspy.

I haven't been under my 6 yet to see how the exhaust is designed, but it could be possible that this trick would work on it also.
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