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t3/t4 bigger exhaust?

787 Views 6 Replies 5 Participants Last post by  superfly676
Anyone have any thoughts on running a 4" exhaust with the t3/t4 setup?
Will be a full custom with a side exit, after looking closely under my car and taking some measurements I think it may be possible. Would there be any benefits?
I know the Dp couldn't really be any bigger than 3" though maybe 3.5 might just squeeze in there.
Just an idea.......
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Re: t3/t4 bigger exhaust? (StevenH)

It's true that if you go too big you loose power, especially in the lower rpm's. With respect to making horse power, the exhausts job is to produce the minimum back pressure. if you go too big, the exaust gas expands too much and as a result, cools off too much therefore increasing resistance to flow and also back pressure which robs power. The extra surface area of an over sized pipe also contributes to the problem of cooling the egt.
That being said I think a 3inch is about perfect for the t3/t4 making around 300hp or a bit more. The idea of making the exhaust shorter via a side exit is a good plan for power if it doesn't get crushed.
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