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Discussion Starter · #1 ·
Hi guys,

Is it possible, with the Tech2 preferably, to reduce the engine acceleration when you hit the gas?

Or, alternative question, how would you go about reducing air intake noise?

Thanks,

Cédric
 

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Strange question. Kinda backwards from most other questions about performance. I don't think that a Tech-2 is capable of making permanent changes to anything that will reduce performance. And the intake noise thing........well, I've never thought how to make it quieter. Buy a Buick maybe, that would solve the acceleration problem as well.

But seriously, why this question? Is it about your son or daughter wanting to go cruising? Or......are you just pulling our legs?:D
 

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Discussion Starter · #3 ·
I need to meet European standards for noise in order to get a certificate from the equivalent of the DMV.

Vette has to be at 74dB in noise.

I failed the test and apparently the air intake is the thing that is making most noise.

They test the noise by flooring the accelerator on a road strip over 25 yards.

If I don't allow the engine to go up in revs real quick it can solve the issues, or I can noise insulate the air intake, or I can restrict the air intake.

I am not to sure if restricting the air intake will damage the engine, I don't think so because of the MAF, but I have doubts.


Thanks.
 

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Put a block of wood under the gas pedal? I would think that anything done to restrict airflow would throw a code...MAF, etc. Since you have to try something how about a 24"x24" foam furnace filter. Fold it a couple of times so that it fits inside the air cleaner housing or roll it up and put it just before your throttle body. Might want to put a piece of mesh in front of it so it doesn't get sucked into the engine. It may help diffuse the airflow enough to get you past this pesky problem. Kinda like a glasspack for the intake. Just a thought and it's cheap.
 

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Hi guys,

Is it possible, with the Tech2 preferably, to reduce the engine acceleration when you hit the gas?

Or, alternative question, how would you go about reducing air intake noise?

Thanks,

Cédric
What Air Intake do you have? Some are very quiet like the Callaway and some are very noisy like the Air Raid, Halltech and K&N.
 

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Via tuning the PCM, reduce timing, rev limiter and making AFR a bit richer would reduce the exhaust Dba level.
Also set at what angle TPS is to go into WOT higher.
 

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Discussion Starter · #8 ·
Via tuning the PCM, reduce timing, rev limiter and making AFR a bit richer would reduce the exhaust Dba level.
Also set at what angle TPS is to go into WOT higher.
I assume that this can't be done via the Tech2 but that I would need to get a something to program it?

I have put an insert in the exhaust and taken down the sound by 4dB

I can't reduce the rev limiter because they check for that, I can only change the program so that the engine doesn't increase in revs very quickly.

The noise test in acceleration is only over a distance of 24 yards.

Thanks.
 

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Using like LS2edit you can tune PCM to reduce rev limiter down some and they would not really know exactly what stock limiter is but by setting in the tune that engine will not go into WOT until 100% throttle along with lower timing would reduce flow
Also could set when engine goes into closed loop by raising the water temp trigger when PCM goes into closed loop

A X-pipe in exhaust up close to engine will also reduce Dba

I assume that this can't be done via the Tech2 but that I would need to get a something to program it?

I have put an insert in the exhaust and taken down the sound by 4dB

I can't reduce the rev limiter because they check for that, I can only change the program so that the engine doesn't increase in revs very quickly.

The noise test in acceleration is only over a distance of 24 yards.

Thanks.
 

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Discussion Starter · #10 ·
When you say reduce the timing I assume that you mean retarding the timing?

They know that the stock Corvette rev limiter is 4000 rpm in neutral and at that RPM that engine makes a lot of noise.

The test is that they arrive at 30 mph in 3rd gear (or Drive if auto tranny) and floor it for 20 meters (about 24 yards).

They measure max noise generated by car over the 24 yards, I'm at 82 dB with the exhaust inserts instead of 77 dB.

Which is a lot of noise to kill ...
 

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What if you sprayed lizard skin for noise reduction on the inside of the air bridge and air box. Maybe if you applied it thick it would have peaks and valleys to mess up the noise path. Maybe ?? you could give it a try.:partyon:

good luck

Paul
 

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why not just put on a 2005-2007 intake... its much quieter and then you can put on your regular intake after you pass the test. Since you have the 2008, do you have the NPP exhaust which is much noisier when the flaps open up.
 

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Discussion Starter · #13 ·
why not just put on a 2005-2007 intake... its much quieter and then you can put on your regular intake after you pass the test. Since you have the 2008, do you have the NPP exhaust which is much noisier when the flaps open up.
For the exhausts I put inserts and I also restricted the size of the exhaust to an inch and a half.

The car is stock except for the inserts and diameter restriction. Don't have the NPP exhaust, thankfully.

Why do you say that air intake for the LS2 is quieter than the LS3 air intake? I had the impression the intakes were the same.

What if you sprayed lizard skin for noise reduction on the inside of the air bridge and air box. Maybe if you applied it thick it would have peaks and valleys to mess up the noise path. Maybe ?? you could give it a try.:partyon:

good luck

Paul
I am thinking a doing some noise reduction around the air intake, but I'm also exploring other possibilities. 4 dB is a lot noise to kill.
 

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I would have to believe you're not the first to go through this. Are there no local dealers, clubs, C6 groups to talk with?

Good luck. :buhbye:
 

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Put a block of wood under the gas pedal? I would think that anything done to restrict airflow would throw a code...MAF, etc. Since you have to try something how about a 24"x24" foam furnace filter. Fold it a couple of times so that it fits inside the air cleaner housing or roll it up and put it just before your throttle body. Might want to put a piece of mesh in front of it so it doesn't get sucked into the engine. It may help diffuse the airflow enough to get you past this pesky problem. Kinda like a glasspack for the intake. Just a thought and it's cheap.
I ike the block of wood idea. I would hide it as best as you can and bring it to a different shop. They do this to the go-carts at some fairs to slow them down. I wouldn't make the wood to big then the guy will know something is up. It might take a few test runs to get it right. If that doesn't work, cant you just bribe them?
 
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