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Old 11-16-2004, 02:25 AM   #1
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Default Size of Bonneville DP?

When i got my tips put on today, i asked the muffler shop for a quote on a 3" DP. He went over and told me I already had a 3" DP. This is measuring with his hand, so he could be wrong, but anyone have info on this? I think the Series 2 L67 might be different, but I am not sure.
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Old 11-16-2004, 03:05 AM   #2
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Is a downpipe the thing that goes from the headers to the cat or whatever is there?
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Old 11-16-2004, 11:32 AM   #3
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Glasuan your stock downpipe should only be 2.5" if im not mistaken. Allmachtige or Foghorn should know for sure though.
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Old 11-16-2004, 02:29 PM   #4
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Quote:
Originally Posted by jr's3800
On the 95 Vin K and the 96 in1'*, I think they all have a 3" DP... I know my 95 has a lot lrger DP than does my 91...
Are you sure it'* not 2.5" for the 95 vin k?
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Old 11-16-2004, 02:36 PM   #5
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mine is 2.5 but then again mine is a series one N/A
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Old 11-16-2004, 07:40 PM   #6
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The DP is the pipe going from the crossover, to the cat. The pipe after it is called the flex pipe. All of that should preferably be 3".
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Old 11-16-2004, 09:05 PM   #7
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Well, on my 1998 L36 it WAS 2.5" stoock, but I had it cut out and a 3" DP put in -well worth the $45 I paid for it and the installation.
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Old 11-17-2004, 10:04 AM   #8
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I would go to a different exhaust shop, cause your downpipe should be 2.5", oh also, most exhaust shops can do the 3" downpipe but it will be press bent or worse wrinkle bent, i plan on doing a 3" downpipe in the future and im gonna buy two 45* mandrel bends from summit or jc whitney and have them welded together and have a very similar setup to the m&* downpipe that sol has
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Old 11-17-2004, 06:42 PM   #9
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Quote:
Originally Posted by jgs11
I would go to a different exhaust shop, cause your downpipe should be 2.5", oh also, most exhaust shops can do the 3" downpipe but it will be press bent or worse wrinkle bent, i plan on doing a 3" downpipe in the future and im gonna buy two 45* mandrel bends from summit or jc whitney and have them welded together and have a very similar setup to the m&* downpipe that sol has
The stock 2.5" DP is crimp bent, so a 3" crimp bent DP will still be a benefit. but if you can get a mandrel bent 3" DP made, for under $100 I say go for it. Then get a 2.5" or 3" Magnaflow/Carsound high flow catalytic convertor to go with it from www.justmagnaflow.com or ebay (both places have free shipping on purchases over $50). The cat will cost less than $65 including shipping, and with the install (recommend having it installed at the same time as new DP) the total cost of the new 3" mandrel DP, new cat and installation should be around $210 or less.
With the crimp bent DP everything should cost under $150.
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Old 11-19-2004, 12:51 AM   #10
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I had my cataclysmic perverter replaced with a high flow unit. They didn't weld it back in quiet right. I purchased a 3 inch exhaust clamp to rememedy the slight tick noise and it was about 1/2 inch to big. I then went and purchased a 2.5 inch and it was dead on . My year model is different however .

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