Necking down a down pipe
#62
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I dont think that k-memeber will help as the downpipe hits the body, manifold, and sparkplug. K-member would help down below I believe, where I dont have a problem. 3.5" is about as big as its going to get, especially after I wrap the pipe cause its so close to everything.
Here is a 5" split to 2 3.5"
![](http://i27.photobucket.com/albums/c174/zapp109/turboexhaust_zps15b32a6c.jpg)
here is a 4"
![](http://i27.photobucket.com/albums/c174/zapp109/t1_zpsaf8fbf95.jpg)
![](http://i27.photobucket.com/albums/c174/zapp109/t2_zpseff69d12.jpg)
#64
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Im a complete novice as well. But i know I want mine to go out the back so Im going to be doing the 4" setup. However ill have a 5" cutout upfront. If you feel you cant do this id just run the dp out the front fender
#66
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For his situation if he were to use a turbo with a 75mm turbine yes, are you done? It doesn't matter as much as you think.
Depending which borg warner 400 series turbo you have all the turbine exits are closer to 3.5 inch so a 4 inch dp will suit your needs no matter what. Like you pointed out tho clearly I wasnt speaking about a s475 anymore.
One persons results compared to another really dont mean ****. There could be many reasons why change in dp size made such a difference in before and after hp numbers or track times.
One guy sees no change and the other sees pretty large change. It's obvious it has more to do with his whole setup more than simply just the dp being too "small"
Depending which borg warner 400 series turbo you have all the turbine exits are closer to 3.5 inch so a 4 inch dp will suit your needs no matter what. Like you pointed out tho clearly I wasnt speaking about a s475 anymore.
One persons results compared to another really dont mean ****. There could be many reasons why change in dp size made such a difference in before and after hp numbers or track times.
One guy sees no change and the other sees pretty large change. It's obvious it has more to do with his whole setup more than simply just the dp being too "small"
#71
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I dont think that k-memeber will help as the downpipe hits the body, manifold, and sparkplug. K-member would help down below I believe, where I dont have a problem. 3.5" is about as big as its going to get, especially after I wrap the pipe cause its so close to everything.
![](http://i134.photobucket.com/albums/q116/VGIORDANO_2007/ae32ad29-1d66-45ef-9e6d-805ba75a24d2_zps8a3593e1.jpg)
![](http://i134.photobucket.com/albums/q116/VGIORDANO_2007/ae32ad29-1d66-45ef-9e6d-805ba75a24d2_zps8a3593e1.jpg)
#72
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I just got of the phone with the great Jose at FI, he suggested the s475 t4 1.10 AR, he didnt like necking down the t6's to a 3.5 either. The t4's 4" to 3.5" via a smooth transition is much more ideal. I just had to cough-up the extra 200.00 for it.
That may of been the most expensive 1" I ever paid for (200.00 an inch)!!!
Last edited by 69-chvl; 03-19-2013 at 09:32 AM.
#74
#78
TECH Senior Member
iTrader: (59)
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at 1300 hp, likely.
...for a ''mostly stock 5.3'' per thread topic nooooooooooooooope
wouldn't have done it on my car no matter how much hp it cost because streetcar
anybody want to start a 'best downpipe for 1300+hp' thread i'll stay out of it. until then ill keep fighting for you professionals to not confuse the poor guy.
...for a ''mostly stock 5.3'' per thread topic nooooooooooooooope
wouldn't have done it on my car no matter how much hp it cost because streetcar
anybody want to start a 'best downpipe for 1300+hp' thread i'll stay out of it. until then ill keep fighting for you professionals to not confuse the poor guy.
![Gruffy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_gruffy.gif)
#79
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at 1300 hp, likely.
...for a ''mostly stock 5.3'' per thread topic nooooooooooooooope
wouldn't have done it on my car no matter how much hp it cost because streetcar
anybody want to start a 'best downpipe for 1300+hp' thread i'll stay out of it. until then ill keep fighting for you professionals to not confuse the poor guy.![Gruffy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_gruffy.gif)
...for a ''mostly stock 5.3'' per thread topic nooooooooooooooope
wouldn't have done it on my car no matter how much hp it cost because streetcar
anybody want to start a 'best downpipe for 1300+hp' thread i'll stay out of it. until then ill keep fighting for you professionals to not confuse the poor guy.
![Gruffy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_gruffy.gif)
I may of missed it, but what its the exit size of your turbo to your current 3.5" d-pipe?