BNR StageIII Wastegate
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Locust of the apocalypse
Joined: Apr 2003
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From: Directly above the center of the earth (York, PA)
BNR StageIII Wastegate
Well... found out why my BNR stageIII will hold any boost I want it to with no boost spikes or creep.......
LOOK at the size of this flapper!!!!!!! (this is MY turbo BTW)

Here is a layout of the various sizes of flappers Bryan puts in... Stage III and IV are definately the ones to go for!!! Stock is on top, StageI/II in middle, Stage III/IV on bottom

Now i see why there is a bump up in price for the III/IV... more machining on the housing required
Talked to Bryan the other day.... This is also the reason when he liked S4 manifolds better..... you can do more with the wastegate... He said you can't really do much with the outer hole on the S5, and because of the angle it has to take to get back to the downpipe... its pretty usless under higher boost..
something to chaw on if your thinking about sending a turbo to BNR and wondering if you should send your S4 or buy an S5 and send that......
A note on Boost..... I've hit 17PSI with my stage III.... But I've yet to be able to do it RELIABLY, i can hit it in third and fourth, but only over a small portion of the RPM range.. 15PSI however.. I have the boost controller High setting dialed in to keep it at 15 PSI.. its dead on from about 4K through the Powerband in third and 4th... (yes it hits it in second.... but that also smokes my stock tires... SO i usually keep the boost on low till third,,, but even then, its hard to keep the *** end in line.... getting bigger rollers and sticky tires, will solve that problem soon!!)
I think that because I run 2.5" IC piping and have a big FMIC (not QUITE as large as the greedy) the total VOLUME in the system is more that the turbo can compress to 17 PSI over its intended design capacity. Still.... I ran 118 MPH with this setup and the datalog showed 17PSI in 3rd and 4th, Bryan says that shold be 360HP at the wheels.....
LOOK at the size of this flapper!!!!!!! (this is MY turbo BTW)

Here is a layout of the various sizes of flappers Bryan puts in... Stage III and IV are definately the ones to go for!!! Stock is on top, StageI/II in middle, Stage III/IV on bottom

Now i see why there is a bump up in price for the III/IV... more machining on the housing required
Talked to Bryan the other day.... This is also the reason when he liked S4 manifolds better..... you can do more with the wastegate... He said you can't really do much with the outer hole on the S5, and because of the angle it has to take to get back to the downpipe... its pretty usless under higher boost..
something to chaw on if your thinking about sending a turbo to BNR and wondering if you should send your S4 or buy an S5 and send that......
A note on Boost..... I've hit 17PSI with my stage III.... But I've yet to be able to do it RELIABLY, i can hit it in third and fourth, but only over a small portion of the RPM range.. 15PSI however.. I have the boost controller High setting dialed in to keep it at 15 PSI.. its dead on from about 4K through the Powerband in third and 4th... (yes it hits it in second.... but that also smokes my stock tires... SO i usually keep the boost on low till third,,, but even then, its hard to keep the *** end in line.... getting bigger rollers and sticky tires, will solve that problem soon!!)
I think that because I run 2.5" IC piping and have a big FMIC (not QUITE as large as the greedy) the total VOLUME in the system is more that the turbo can compress to 17 PSI over its intended design capacity. Still.... I ran 118 MPH with this setup and the datalog showed 17PSI in 3rd and 4th, Bryan says that shold be 360HP at the wheels.....
Last edited by YearsOfDecay; Dec 25, 2004 at 06:36 PM.
If the s4 turbo has better options/possibilities for the wastegate than s5, then why do the s4 upgrades only go to stage III when s5 turbos go to IV? I mean, if the wastegate was so hard to work with on s5's you'd think he wouldn't go to an even higher stage would you? I don't think it's that big of a deal honestly.
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