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4" Downpipe with re-routed wastegate


jevansio
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I'm wanting to replumb my screamer into my downpipe for trackdays. Got it booked in today but having 2nd thoughts.

 

There doesn't look like a lot of room and removing the downpipe with reroute looks like it is going to be a massive PITA compared with the unmodified downpipe.

 

As I don't have access to a ramp I don't want to make it impossible to remove the downpipe in my garage on my own.

 

Any of you guys with this setup care to share your thoughts?

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Just make sure you get it done properly, I lost over 50hp when my wastegate was routed back into the exhaust badly.

 

The first attempt worked really well but cost well over £500 to get done as I also included another centre box, I was trying to quieten down a Veilside Ti. That worked fine until I pulled the exhaust off going over a speed bump.

 

The replacement which was around another £500 was rubbish, the routing was bad and caused a massive loss in power, in the end I settled on a open silenced wastegate pipe and a Tannabe exhaust :D

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My exhaust on normal checks is around 86db thanks to the Tanabe and I havent been kicked off yet for a drive by pass.

 

I dont have a pic sadly, my screamer pipe is basically a small muffler with a V band on one end for the wastegate connection.

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I thought that may be the case mate :( There is a lot of room down there with a cast manifold which makes certain jobs very easy.

Yip, I think this is why Wez muffled screamer is a better idea for me :)

 

Get a log manifold?

I don't think it'd be any good if I went 74mm+ turbo :(

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Get a log manifold?

 

That would mean changes to intake, IC pipes, and downpipe though. Plus I would recommend a lot of porting to get the manifold to flow well and I suspect Jay won't be interested in all this effort to quiten the wastegate down.

 

Also, I'm not sure whether you'd see any power loss from the cast manifold up at 700hp+ :shrug: I'd put mine against any other car on the RR running same cams, turbo and let's say 1.7bar boost and would be confident there'd be no loss of power up until the 620 kind of area. Above that I wouldn't be so sure :D

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That would mean changes to intake, IC pipes, and downpipe though. Plus I would recommend a lot of porting to get the manifold to flow well and I suspect Jay won't be interested in all this effort to quiten the wastegate down.

 

Also, I'm not sure whether you'd see any power loss from the cast manifold up at 700hp+ :shrug: I'd put mine against any other car on the RR running same cams, turbo and let's say 1.7bar boost and would be confident there'd be no loss of power up until the 620 kind of area. Above that I wouldn't be so sure :D

Yip, spot on Dan, it's a lot of work just to quieten things down

 

I'd have no quarms on putting a log on a T67, hell I was going to get one before I bought my HKS tubular :D

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Read post 29 http://www.supraforums.com/forum/showthread.php?t=445445&highlight=arnout&page=2

This is of course if your using a Arnout log mani.

816 rwhp is ok with me even if it is US of A horsepower.

 

That would mean changes to intake, IC pipes, and downpipe though. Plus I would recommend a lot of porting to get the manifold to flow well and I suspect Jay won't be interested in all this effort to quiten the wastegate down.

 

Also, I'm not sure whether you'd see any power loss from the cast manifold up at 700hp+ :shrug: I'd put mine against any other car on the RR running same cams, turbo and let's say 1.7bar boost and would be confident there'd be no loss of power up until the 620 kind of area. Above that I wouldn't be so sure :D

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