BNR Stage 4 worth it?
 

So do you all think the Stage 4 BNR turbo upgrade is worth it? Here's the link to it: www.bnrturbos.com/2ndGen.htm

Which one do you think would probably be the best decision?

i havn't really ever got much of an answer to this question but that is the route im going to go, the people i have talked to say its a good way to go. and you dont have to buy new turbo manifolds or anything.

Are you going to install a FMIC?

I'd hope he does. the TMIC isn't that great past 10, and this thing looks like it can haul some balls at a high boost range.

Where can I get a cheap FMIC? =]

already have a FMIC w/ my stock turbo..

im using a Ebay kit, Core and piping, got the pipes beaded, havn't had a single problem with it.

bnr's lose efficiancy past 14-15 psi. max they ever got out of them was 400HP. not bad, but for the price you can get some nice aftermarket turbos..

so should I just stick with BNR stage 2? or 3?

I was trying to decide the same for my 88 T2. Bryan at BNR actually talked me out of the stage 3 and into the stage 2 with the upgraded bearing. I had a best 1/4 mile of 12.8sec./108mph. All this was on a stock T2 block with only 65,000 miles on it. Pump gas 93oct.
I`m still on the top mount IC. The ECU is an Rtek stage 1 1.8 with new 750cc RC Engineering injectors, cone filter, Racingbeat turbo back exhaust and electronic boost controller. On a trip to the strip after the 12.8 run I ran one to many passes and cavitated the Walbro as I was just letting off the gas. The car had a miss after that, even with new plugs and flooded easy. My guy a the local Mazda dealer ran a proper rotary comp test. bottom line is low comp on the front rotor and border to "okay" on the rear. Funny thing is I had already booked dyno time, on a Dynomax dyno. before confirming low comp. I was blown away as I watched three runs all showing an average of 275RWHP, can't remember torque but same average on three pulls. All that with low compression front and rear. My goal was and still is 300 to 350 RWHP.


It has a date with Kevin Landers (not firm date) but I will be shipping with his approval in the next couple weeks. Having him rebuild, port, and going to 3mm apex seals.

While the motor is already out I have installed a manual rack (not de-powered power rack) and even found the A/C only bracket to keep my A/C in place and operating when I want it.

BNR stage 4 has a reputation among some for being laggy and lacking in durability. It still uses the stock hotside and clips the wheel, which reduces spool but gives a bit more topend. Some say hybrid turbos tend to brake more easily.

I'm just looking to make around 350rwhp. Do you think the BNR Stage 2 will be enough?

clipping the turbine wheel will increase turbo lag at lower RPMs & loads, but decreases backpressure at higher RPMs & loads. It shifts the peak efficiency of the unit towards higher flow rates, but at the expense of the overall value of that peak efficiency

You might get a nice turbo, but will you get the new manifold, custom water lines, custom oil lines and custom exhaust too? All will be required, increasing the price considerably. No doubt hybrids have their disadvantages, but their low cost is a considerable advantage over a full replacement turbo.

Isn't there a thread in the "dyno and timeslips" section about this already?

The only word that matters is Bryan @ BNR's

You'd probably need at least a stage 3 BNR for 350rwhp

My FC was the one that hit 332rwhp with that Stage2 turbo. Will be able to hit 350rwhp? You might be able to get close. Depends on what you are running with. So I don't know for sure. But you will need to run more boost than the turbo will be happy with. You'll be running on the bleeding edge and possible sacrificing longevity. Last I can recall is that it was about 16psi where that Stage2 seemed to max out at.

BTW, I haven't had that car in over 4 years. That dyno number was from a tuning session from about 5 years back. I wasn't chasing a hp number, but just adding fuel with the help of a dyno with a wideband.

If I ever get around to playing with my 'new' FC, I'll just go with a used T04E. Older sets are somewhat easy to find over here seeing as I don't mind used stuff. 350rwhp would be more than enough for me as I'm not much of a power hungry type.

BNR Stage 4 uses a larger than stock T04 "S" or even larger "P" trim exhaust wheel. It is the Stage 3 that uses a stock clipped exhaust wheel. That is the difference between Stage 3 and Stage 4.

Lag will depend on the rest of the set up. My S5 based Stage 4 is very responsive
with ~2psi by 2,000rpm and full 13psi boost at 3,200rpm in 5th gear.

I have had zero reliability issues with the BNR turbos. I have had to have Brian rebuild them after sending an apex seal through the exhaust wheel and he provided great service and turn around time.

I have put 35-40,000 miles daily driving and racing on my BNR turbo without any reliability problems at all.

Give Bryan a call and discuss what you want out of the car/ set up. He will NOT try to talk you into one of his hybrids. He will listen to your goals and let you know if you should consider a stock hybrid or a full large frame turbo set up.

^Thanks for the thread.

just a side note, the rtek 1.x was not meant as a standalone fuel solution when running an aftermarket turbo, you really need an safc or something too to add more fuel. I believe they take out 25% for the bigger injectors, but then that brings you back to stock fuel rates.. you are no better off than with the stock 550s. I would upgrade to the 2.x before putting the new motor in

This is the first to hear that durability is a problem... I have never had durability problems and if something happens I take care of the situation. I don't have many issues and haven't done much of any warranty work in several years b/c I take no short cuts. The stage 4 isn't stock on the hotside and I don't just "clip" the wheel. The stock turbine is removed and a Full T4 is machined to fit the stock 1.00 A/R turbine housing. All my stage 2 and greater all come standard with a 360 thrust package. Also if any parts are anywhere near questionable, I throw away and use new Garrett OE parts. Everything is balanced 6 times greater than OE specifications. Garrett T3/4 turbochargers are supposed to be balanced to 3 gram/in2. I balance to .5 gram/in2.

I have customers that are way happy with the response of the S5's, but I do tell people that the S4 turbine housing b/c of being undivided and the removal of the twin scroll, the spool up will be hindered. The power on a S4 is better up top b/c the housing flows a bit more than the S5 when it is opened up with the big valve assembly and inlet port work. Also what you have to consider is tuning. With tuning you can make response and take it away. Bump the timing, you get hotter EGT which is more energy. You take the timing away and it will be a lag monster.

I have been doing RX7 turbos for 10 years and never heard of "lacking in duriblity". Hybrids are for mild applications Sub 400 RWHP. If you want a drag car or more than 400 RWHP, go get you a Full T4, T6 or whatever with external gate...

Bryan@BNR

LOL, I said "S" trim, meant "O" trim. I must have had the BB TO4S w/ 60-1 HiFi comp housing in a stock turbo housing stuck in my head :P

I dunno Bryan, there was that time I forgot to supply ANY oil to the Stage 4 and only lasted a couple days. Then the time I sent 3 apex seals, one apex seal spring and a couple pieces of corner seal through the Stage 4 and had to have the exhaust wheel swapped out.

Not to mention the ~30,000 miles I have on the Stage 4 without any realiability problems besides my own bone headed-ness :P (four engines later-cough-)

At least when I did destroy the turbo with my own stupid mistakes Bryan went out of his way to get it fixed and back to me as fast as possible.

This is the first I have heard of any BNR reliability issues and you know how we forum boys like to talk, so I think that may have been a misunderstanding.

Just stick with gut feeling. What ever you feel is good and safe, go with that.

Me
fc3sdude
Shh, I don't wanna "wish I had a V8"... LOL