Recent Stage 3 Installs, others too--Catalytic Converter question: Boostd, Ed, ReyHey-TIA
04-10-2001, 04:24 PM
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Recent Stage 3 Installs, others too--Catalytic Converter question: Boostd, Ed, ReyHey-TIA
I'm having a truly annoying vibration, hum at 4100-4300 rpm. We have been over every inch of the exhaust (Borla). I think it is the heat shield next to the CAT hitting the CAT. So I went to Dynospot and put it up on a lift, they tried to bend it a bit out of the way, there just is not much room. So, we got it to stop doing it on the lift (actually a dyno, so there was weight on the wheels etc.) , but then when I got back on the road, sure as ****, there it was again. There is just no clearance there. Now, I don't think this was an issue on earlier stage 3's b/c I think that the CAT has changed (as evidenced by the 02 sensor not threading properly in this version). So are any of you newly improved 3's out there getting this, and if so how have you dealt? It seems to me that the only way to deal is to remove the cat, cut some heat shield away and/or reconfigure the heat shielding. I can't live with this noise.
Afraid to hit 41-4300 rpm, but happy afterwards. .
seth
Afraid to hit 41-4300 rpm, but happy afterwards. .
seth
04-10-2001, 04:36 PM
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no cat troubles here....it is a narrow tunnel, but mine isn't hitting.
The heat shield is probably the culprit. I would try tweaking it a bit. Has it always done this since you got the kit installed? I haven't heard this complaint before.
04-10-2001, 04:38 PM
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Yeah, it has always done it, But I always figured it was the Exhaust
b/c we've had our share of exhaust troubles with vibrations (even melted the bumper!).
P.S.--I go in for reprogramming tomorrow.
P.S.--I go in for reprogramming tomorrow.
04-10-2001, 04:44 PM
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I know what you mean.... I had a minor one at that range...
but it's been gone since I got the version 2 of the exhaust. One thing to check/try is the spring bolt at the end of the downtube if it's TOO tight, it will radiate vibrations from the engine to the cabin - and is dependent on the natural resonance.. Happens to BE 4100-4300 
I also noticed that there is more room now between the cat-flange that goes to the pipe and the adjacent heatshield.
I also noticed that there is more room now between the cat-flange that goes to the pipe and the adjacent heatshield.
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04-10-2001, 05:08 PM
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Geez, I pay $2.13 for 92, I cant imagine how expensive Race is.
Besides, I'm not sure if Brett is gonna give me that program or if I'm gonna buy it if not--I'm just talking about updated Stage 3 software.
04-10-2001, 05:16 PM
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Thanks Ed, at least I know I'm not going insane here. I sent an edited
version of your email to my wrench to see what he thought of that as a possible issue. I may end up upgrading to APR v.2 exhaust from Borla (depending on future software hp increases) so that might be an opportune time to closely look into this issue and resolve it.