The OEM configuration with tweaks, such as trimmed exhaust wheels, bigger compressor wheels and cleaning up the exhaust manifold, port matching and grinding down and smoothing things out is good for 125mph in the quarter. I don't know anything about the BNR's but the layout has the potential for 400hp without doubt.

Kevin T. Wyum

 

ya but how many people out there have made such numbers? without the turbos going out a few months down the road?

 

Which turbos are you talking about? On stock twins, you can't. Not for very long. 125mph traps and 400rwhp on a street car on stock twins is a pipe dream, as has been beaten to death already in this thread

 

im talking about the bnr turbos. from what i have read they dont hold up well to high boost.

 

/\ where did you read that a bathroom stall? unless your idea of high boost is like 25psi

 

lol, nicely said. Unless you are looking to run race gas all the time (not feasible for a street car) the turbos can handle more boost than the motor can on pump gas.

 

Curious myself, and too damn lazy to go through the entire post, does or will BNR be doing any of the rebuilds with ball bearings? Like the M2s Mahjik told me about?

 

I don't think he will. Call him and ask.

 

so whats the best rwh that anyone has pulled out of these turbos?

 

david garfinkle has a set on his car. its up and running. hes doing preliminary tuning all the time. im not sure if hes going to be in birmingham this time around or not. he WILL get dyno numbers up when its all said and done. hes very much ready for this project to be done as he has a lot of other projects to move on to. so. . . count on dyno numbers from him soon. . . and im sure theyll be impressive.

another thing to note is the fact that his twins spooled up faster than my single turbo did. . . he went to 17psi REALLY fast. fast enough for me to be afraid to look. . . i just shut up and looked forward hoping his brakes worked. . . and his car is only getting faster by the day!!! everyday he messes with something and the car seems to take off more aggressively.

i think the turbos are worth it if the fit right. they are much more reliable and the spool up like no other. rather impressive piece.

paul

 

Paul,

Is the set Garfinkle has on his car the same standard set Bryan of BNR sells? Cuz I was under the impression Garfinkle's set was larger, and required some modification to fit? Or was that just the whole y-pipe modification thing Bryan was talking about?

 

davids are not the same. the comp housings are larger so a spacer had to be made to move them away from the LIM.

davids still need the spacer as do all of the stage 3s. bryan welds one in. david made one that fits in with an enterage (sp) of orings. . . that thing isnt leaking anytime soon. hahaha. he wanted to be able to go back to stockers if he needed to.

paul

 

what kind of trap speeds are people getting and at what boost level?

 

in the 1/4?

 

Just wondering if the compressors have been flow tested in the stock modified compressor housing? Also, something to consider are the turbine housings flow with the new turbine wheels. Finally, how about the flow as a system that combines the new compressors with the stock comp housings, the new turbine wheels, with the stock turbine housings?

Whilst the compressor wheels may flow 38 lbs/min in its proper compressor housing, the flow may be far less in a bored housing. Efficiency also typically suffers. Ditto for the turbine wheels and housings. If the comp wheels require a larger comp housing than the stock comp housing, lower rpm (compressor) flow will be generally higher, with the top end suffering, and usually poor efficiency.

Something else to consider: the flow pattern of the stock exducers leaves a lot to be desired when high flow is considered. Normally, the flow of two masses of gasses do not like to oppose each other, then change direction orthogonally. This will limit mass flow considerably. Perhaps this is where the 420whp "limit" is derived from? A divider should help considerably, and may be a near requirement for a mass flow above what the stock configuration intended. Do these turbos have the divider in place?

If the compressors indeed flow 38lbs/min each, then there should be no problem developing >500whp conservatively.

 

I plan on pushing the limits when we dyno to see what these twins are capable of. I have a fresh aggressively ported motor and all the bolt ons. I will be very happy with anything over 400 (safely) on 93 octane, and who knows what will happen on c16? 450 would be great, but not sure if that will happen. I can tell you that 300zx Z32 guys have been making over 500 rwhp on pump gas with turbos similar to these for a few yrs now.

Rich

 

On the old style BNRs, SPOautos trapped 125mph at around 17-18 psi. He can come in and give more details.

 

The 420rwhp limit is derived from the turbine design, there are a few things about it that are restrictive, one being the pulses crashing together as you mentioned before entering the downpipe.

The turbos would make much much more with different turbine housings and a custom turbo manifold. After I get done dynoing this set I might be adapting them to a custom manifold to see what they will do. Cant decide if I want to spend the money take a chance on that or just jump on a GT42R.

The should be fine for 420rw and maybe more, the other stage 3's made 412rwhp and there are some turbine side changes that Bryan says should help reduce back pressure.

 

With a good launch that should be in high 10's in the 1/4 mile

 

what was the best time that SPOautos traped?

 

Um, I already told you.

 

Rich, I think he wants the 1/4 time, not just the trap speed.

 

lol, thanks ramy. Been looking at this stuff for too long, time for bed. Best time, your guess is as good as mine.