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pros and cons of bnr turbos

Old 08-16-13, 10:08 AM
  #26  
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Originally Posted by BLUE TII View Post
I think a S5 ('89-91) based BNR Stage II is a really good turbo for 250-300RWHP.
I agree as well based on the experience of others with the S5 based unit. While I've not tuned it myself, the better design of the S5 hot side and wastegate would support the positive experience of others.

I wouldn't stick a S4 based turbo on anything by choice.
Bingo. And that's why it would be so much better if Brian would just document the issues on his website. Like being very clear that the turbo comes with a wussy wastegate actuator (even the "upgraded" actuator he sells, which my friend originally purchased, is a bloody 6 PSI spring) and boost issues may result.

Originally Posted by IAN View Post
Well came across this thread. Trying to get my car to pass emissions legally. I have a fully built TO4B 60-1 turbo and can not bear to think of driving a stock powered FC. So I bought a new harness and have a brand new stock Cat converter to install. I was going to try to run everything stock emissions wise with a P1000 ECU with a patch harness or Rtek with my big turbo or a Stage 4 BNR. I've read a few times of boost control issue with BNR. Now I'm not so sure what to do.
I don't think there is a proper turbo manifold out there that fits a single turbo with full emissions including air pump.
What about the Rising RPM billet manifold? With the larger compressor housing you may have to tweak the air pump brackets, and I would have no idea whether the ACV would fit. However they claim it will:
Rising RPM


Originally Posted by bumpstart View Post
keeping the 7 psi rated stock can and trying to control it with a boost bleed
( even with electronic solenoid control )
is always going to end up at some point where delivery down the pipe to the can will defeat the amount being bled and you end up with a bell shaped boost curve as it falls back to the spring rating
Yes, and that's my issue with the BNR hybrids as shipped. A wussy 6 PSI spring which is easily overpowered by backpressure, and then because of high backpressure, even a much higher PSI spring eventually being pushed away. If he had included a double diaphragm actuator or made it an option, this would be far less of an issue.

adding a helper spring is in no way dodgy.. isnt cheating anything .. and is in fact the most correct mechanical correction for the task
its also bloody easy to do// i have one on mine.. have done for years . and i have the HKS adjustable arm can
One person's opinion on what is a bodge vs. another's will differ. I consider it completely dodgy and that the most correct mechanical solution is a double diaphragm actuator. Sadly it seems that the helper spring will remain on my friend's car for the time being because it basically works, and he can move onto other things rather than **** around with wastegates.

The unfortunate part of the whole thing is that the "easy bolt on" turbo upgrade has become more of a hassle than a full upgrade would have been. Time wise, we could have made a simple manifold for an internally gated 3076R.
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Old 06-25-16, 08:36 PM
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Same problem, even tho i asked for 12psi.
How many lbs for the helper spring to achieve 12 or 15 psi?
If anyone doesnt need his helper spring anymore I would gladly buy it off of you if you are willing to send it to Italy
Thanks in advance
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Old 06-26-16, 10:57 AM
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I don't recall the specs of the helper spring, unfortunately. We just tried springs until we found one that would do the job.

While the spring works initially I'd suggest just getting a double diaphragm wastegate actuator or one designed for high pressure with a 12 PSI or so spring (ATP turbo carries them for under $100). These turbos need to be around 15 PSI to see their efficiency.
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Old 06-26-16, 03:25 PM
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Thanks a ton for your help and input. Going to heed your advice and try with the double diaphragm wastgate actuator.
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Old 07-05-16, 07:06 PM
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Been running but stage 3 with Profec b spec 2. No problem maintaining boost. Slightly lagging than stock turbo, but power gains were immense.

Easy enough and they go for cheap enough on this forum...

Change your mind and resell it for the same price you paid used for it. Then upgrade to a gtx
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Old 07-06-16, 09:41 PM
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For me, Bryan agreed to bolt up a Turbonetics dual port actuator (part 30326), which I sent him with my core. It required some welding because when he bent the rod, it snapped.



The dual port actuator is letting me run an AMS-500 controller, which applies pressure to the opposing port. It is a stronger wastegate spring on-demand. Overall, it is working well, and I like the BNR.

My boost curve still looks like this, with a distinct drop off. I am fighting the stock intake, AFM, snorkel, TMIC, and stock catback. I'm also using a TA-34 turbine, which might matter. Most folks get more than 7 PSI near redline.

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Old 07-06-16, 09:52 PM
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boost drop is common with these hybrids unless you add supporting mods to allow them to breathe, and they need alot of breathing room compared to properly balanced wheel size turbos.
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