Popping and banging in noise tests - any way to stop it?

For discussing MicroSquirt (TM) configuration and tuning of fuel parameters (including idle valves, etc.).
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chris_g
MegaSquirt Newbie
Posts: 6
Joined: Tue Sep 13, 2005 1:31 pm
Location: Bristol, UK

Popping and banging in noise tests - any way to stop it?

Post by chris_g »

Hi all,

My tuning seems to be going pretty well but I'm having some probles with popping and banging in the exhaust during static noise tests which are causing me to get higher readings than I should and I'm concerned it may lead to being prevented from taking part on some track days.

I'm using a wideband lambda and have run Autotune during a simulated test (4500rpm) so my AFR is in the right region but still it pops and bangs quite a bit, is there any way of reducing this or some other settings that will help?

Cheers
Chris

PS I'm due on Castle Combe circuit on Saturday so it would be good to improve this for then :P
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jsmcortina
MegaSquirt Guru
Posts: 332
Joined: Mon May 03, 2004 12:34 am
Location: Birmingham, UK
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Post by jsmcortina »

That is misfires most likely. Try richening up at idle, check that your ignition is working correctly and that you don't have any exhaust leaks.
Without any setup details I cannot comment further.

James
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ZECAT
MegaSquirt Newbie
Posts: 6
Joined: Sun Feb 19, 2006 4:57 am
Location: dorset

Post by ZECAT »

Hi Chris mine is ok at 4500rpm so I will have a look at the mixture and the timing next time I have it running. I think you will need it rich what have you set it to?
I hope you have a good day at Castle Combe I am hoping to book another trackday with motorsport events soon.
Keith
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mops
Experienced Squirter
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Post by mops »

rtming can affect it aswell... I'm not sure what timing are you running at steaty no load 4500rpm, but i would imagine it should be in the vicinity of 40 degrees....
BMW, 1985, E30, 325i, 2-door, 5spd , 127k miles, short shift, MSII, V3/code 2.684/60-2 wheel/MT 2.25, LC-1 wbO2, ignitor module mod driving msd coil/, 3 pin Bosch PWC IAC mod
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ZECAT
MegaSquirt Newbie
Posts: 6
Joined: Sun Feb 19, 2006 4:57 am
Location: dorset

Post by ZECAT »

Chris I tested mine at 4500 rpm and the timing was 28 deg and the AFR was 13to1
I am not using fuel cut so it could be that you are not holding the throttle steady and cutting the fuel on and off?
I was think of having a go at using the fuel cut now I have the map set up for my smaller injectors, what setting have you used on yours?

Keith
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