Possible Detonation?

A

AquamanCHS

New Member

Sep 17, 2003

122

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0

N. VA

Sep 27, 2004

#1

• Sep 27, 2004

• #1

I recently did a whole slew of mods (PI headswap, VT stage I cams, BBK LT headers, BBK X, magnaflow catback) and got a mailorder tune via SCT microtuner from Tim at Modular Ford Powerhouse. Now, when I'm driving and I punch it in second gear at low RPMs (2k or so), I sometimes hear a low garbled gurgly noise momentarily that seems to come from right under my feet (I can feel it in the floor pan). Is this something that's normal for my setup or could it be detonation? I don't hear any loud rattles, either.. I don't experience the "marbles in a can" sound. Anyone have any ideas?

EDIT: I'm also running 93 octane gas

 

A

AquamanCHS

New Member

Sep 17, 2003

122

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0

N. VA

Sep 27, 2004

#2

• Sep 27, 2004

• #2

Anyone?

 

J

jbrown

New Member

Aug 5, 2003

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Tallahassee, FL

Sep 28, 2004

#3

• Sep 28, 2004

• #3

to me it sounds like your new exhaust

 

bierbelly

Dirty Old Men Need Love Too

Founding Member

Oct 17, 2001

1,598

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58

Sterling, VA

Sep 28, 2004

#4

• Sep 28, 2004

• #4

You know, with all the stuff you did, you may be running lean and causing backfiring. You'd hear this in your exhaust system, but it would be muffled by the mufflers. Have you checked your A/F ratio?

 

stang976

New Member

Apr 13, 2004

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Westchester, NY

Sep 28, 2004

#5

• Sep 28, 2004

• #5

bierbelly said:

You know, with all the stuff you did, you may be running lean and causing backfiring. You'd hear this in your exhaust system, but it would be muffled by the mufflers. Have you checked your A/F ratio?

Click to expand...

 

nickthegenius

Active Member

Dec 23, 2002

1,631

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38

Elwood, IN

Sep 28, 2004

#6

• Sep 28, 2004

• #6

My guess is the X-pipe. They make odd sounds under your seat that sometimes could be mistaken for detonation. My UPR pipe with the stock manifolds and my Trubendz (big POS by the way) pipe with my Mac LTs both make similar sounds to what you describe.

 

A

AquamanCHS

New Member

Sep 17, 2003

122

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N. VA

Sep 28, 2004

#7

• Sep 28, 2004

• #7

I got a tune from Tim at Modular Ford Powerhouse, I assumed he knew what he was doing . I plan on getting a few dyno runs but I haven't had the time.

 

bierbelly

Dirty Old Men Need Love Too

Founding Member

Oct 17, 2001

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58

Sterling, VA

Sep 28, 2004

#8

• Sep 28, 2004

• #8

Any mail order tune is at best an educated guess. But if you were running lean, I'd expect that you'd be hearing pinging under hard acceleration too.

 

Red35th

Member

Apr 18, 2003

609

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Houston, TX

Sep 28, 2004

#9

• Sep 28, 2004

• #9

Like bierbelly said, even the best tuner can't get a mail order tune perfect.

Put it on a dyn or borrow a wideband from a friend and check your a/f. If your a/f is good it's either an exhaust deal or the timing is too high.

Try putting in some 103 or 110 and see if it still makes the noise. No way you'd ping with that high an octane unless your a/f was WAY off.