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help? by 88 fiero formula
Started on: 05-09-2015 11:56 AM
Replies: 4 (128 views)
Last post by: 88 fiero formula on 05-10-2015 09:36 PM
88 fiero formula
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Report this Post05-09-2015 11:56 AM Click Here to See the Profile for 88 fiero formulaClick Here to Email 88 fiero formulaSend a Private Message to 88 fiero formulaEdit/Delete MessageReply w/QuoteDirect Link to This Post
I ordered a thrush welded muffler part number 17638 and everything is right but the muffler is large and obviously made for a much larger engine. Im worried the fieros 2.8 will not push the air that I need and it will sound ricey. Opinions? Also the cost of getting this larger muffler out on at a shop? yhe ins and outs are a quarter inch bigger than the fiero pipes and the tips will have to be adjusted.
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f85gtron
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Report this Post05-09-2015 01:01 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
You'll have to worry about losses of velocity with larger diameter plumbing. Too much increase in volume too fast leads to loss in pressure, which slows down scavenging, which is what is needed to evacuate the exhaust from the system to make way for the next push. This usually is mostly a problem at the headers and a few feet. As long as you have factory diameters up to 2.5 inch all the way to the muffler, you'll probably be ok. The higher end mufflers have walls and baffles in place to help keep velocity up and engineered tones too. 3" kills performance, unless you're pushing more liters or a turbo.
Disclaimer:
I only have limited experience and shade tree understanding to back up my theory. Someone else will have to disprove, or backup to complete rounded advise.
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Neils88
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Report this Post05-09-2015 02:53 PM Click Here to See the Profile for Neils88Click Here to Email Neils88Send a Private Message to Neils88Edit/Delete MessageReply w/QuoteDirect Link to This Post
From a performance point of view, these mufflers will be fine. I disagree with f85gtron with respect to the backpressure. There is a reason that many high performance engines run with open exhaust...backpressure reduces scavenging. f85gtron is correct about the reduction of velocity, however, this won't be an issue with the Thrush muffler. A bigger concern will be whether or not you can fit this muffler into the stock location. I can't recall what is the maximum size that fits.
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Lou6t4gto
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Report this Post05-10-2015 02:21 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
25" long, 2" IN - 2" OUT is what fits correctly in place of the converter. Those thrush mufflers are only $25 at advance or auto zone.
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88 fiero formula
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Report this Post05-10-2015 09:36 PM Click Here to See the Profile for 88 fiero formulaClick Here to Email 88 fiero formulaSend a Private Message to 88 fiero formulaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Thanks for replying guys. Also does anybody know if a thrush welded on a 2.8 will be overbearingly obnoxious? I havnt been able to find anything about the sound of this muffler just that it can be put onto a fiero. any advice before I put it on?
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