mrsteve

iTrader: (1)

So this is odd...

When I'm at the track or on the street (although I rarely get up to these speeds on the street) and I hit 95+ MPH I start to hear an odd sound from the exhaust. It sounds like a metalic ticking. It is definitely not coming from the engine bay. It definitely is coming from around the b-pipe/muffler area. It only happens at WOT at 95+MPH. It doesn't happen while cruising at 95+ on the highway while I'm at lower RPMs. And it doesn't happen at higher RPMs at lower MPHs.

So around 6000-6500 RPM in 3rd gear, at 95 MPH+ this sound occurs. I get no vibration or anything else abnormal, just this sound. If my dealer's service tech who installs everything on my car is at the track next time I go (he probably will be) I'll ask him to ride along and listen (they allow that). Any suggestions from you guys?


EDIT: The sound isn't a constant buzzing, but more of a ticking.

darrinb

they will let ya guys ride together

mrsteve

iTrader: (1)

mrsteve

iTrader: (1)

^^^^ Any ideas?

scalbert

The location wouldn't suggest it but that sounds like knock.

As for the location and that sound, could there be somehting loose?? The catalytic converter could make some noice if it were block but you would be noticing that.

mrsteve

iTrader: (1)

If it was knock wouldn't it happen in 1st and 2nd gear as well?

scalbert

Not nessesarily. There is a higher load on the car in the upper gears which will promote knock sooner.

scalbert

Just to be sure, pull the Unichip and see if this is present.

mrsteve

iTrader: (1)

Okay i'll do that... don't know when i'll be able to wind it up into the top of 3rd any time soon unless I head out to a back road.

I'll report back

mrsteve

iTrader: (1)

One more thing, if it was knock wouldn't I be seeing a loss in performance from the ECU retarding timing? I'm running faster than ever at the track lately, just trapped at 100.68 on Sunday.

scalbert

Yes and no. I saw the most power before the IC with audible knock present. I made 323 WHP with audible knock and 315 WHP without it.

It just depends on the degree and IMO, the Honda knock control system seems to be a little deaf.

mlb585

P.S....you can actually ride together at the track as long as you are not breaking 13.99 or less

mrsteve

iTrader: (1)

With a passenger you can go as long as both driver and passenger have helmets and other needed safety equipment. I've seen it done a few times.

mrsteve

iTrader: (1)

I probably won't have time to mess with the UniChip till the weekend, i've got a funeral to deal with plus the regular load from class and work.

I'm going to get the car up on jack stands and take a look over the weekend.

We dyno tuned the UniChip in 3rd gear and even at 14.5 A/F we didn't have any knock, its down to around 13.2-13.5 now.

I did however drive around with a dead primary O2 sensor for close to a month. I know that can't be good for the catalytic converter, maybe I messed it up in the process.

sixgearcl

a ticking sound under your car....

do you have problems with the mob????




j/k

darrinb

it might be a exhaust leak, or a crank in the headers....

Dan

Have had the same problem with 2001 for59,000 miles. I notice it in highway crusing at light throttle openings at about 75-85mph. Had the same thing on a 1985 Toyota MR-2, and it did it for 185,000 miles with no problems. Sure as hell seems like a light knock to me. If it is making the sound and you get into the throttle, it goes away.

mrsteve

iTrader: (1)

It only makes the sound at WOT. I'll have to check it out this weekend.

momentum3.2

I'm more concerned with what you're doing behind your CL when it's moving at 95+ mph! j/k

mrsteve

iTrader: (1)

The track

mrsteve

iTrader: (1)

UPDATE:

I went to the track last weekend and made 7 passes or so, never heard the sound once. Haven't got it up above 80 on the street since then either except for a quick run to 110 on the highway home that afternoon. Still no sound.