RotorMotor

iTrader: (5)

ok im seeing $50 (for an 18 that needs a rebuild, to $500 for one thats just been rebuilt)

now

iTrader: (1)

Ill take the one that needs the rebuild

matt

j9fd3s

iTrader: (3)

yah you only need the wheels and shaft

mike

RotorMotor

iTrader: (5)

its in the FC parts section...search for turbo

RotorMotor

iTrader: (5)

ok i sent an email to BNR...this is what they wrote back (by the way check the top...they state that the 20b turbos are an ht-12, and an ht-18? mike said they were a 10 & 15... frankly i have no idea now???? i thought pettit *upgraded* to the 12 and 18...maybe that information is false and they are actually using the stockers??? if anyone has the inside scoop on any of this (come on 20b gurus i know your out there please enlighten the rest of us cause im confused!!!!) id also like to find out exactly what pettit does to their turbos since there seems to be some disagreement now...so if anyone works for, has worked with pettit on a 20b pleeease chime in!! heres what BNR sent me: (i will ask them about flow rates for the stage 1 & 2 options so we have actual figures to compare to)

//
Hey Heath.
_
We_can upgrade these turbos for you._ Here is what_we offer.
_
Bryan
www.bnrsupercars.com
_
20B Cosmo Twin Turbocharger Upgrades
_
The 20B Cosmo turbochargers have 2 different types of turbochargers, one turbocharger being an HT18, and the other being an HT12._ Although these turbos perform well from the factory, there is room for some power improvement._ BNR offers 3 stages of upgrades for your 20B powerplant!
_
_
Stage 1:___________ The stage 1 consists of a secondary compressor wheel upgrade._ The compressor cover is machined to fit the upgraded compressor wheel._ The primary remains factory._ Both assemblies are inspected very carefully and they are each balanced/blueprinted to spec._ The wastegate is ported to 30-35mm. All bearings, collars, and piston rings are replaced._ All housings are very carefully inspected before used._ All tolerances are checked before assembly assuring you quality in the work performed by BNR.__ RECOMMENDED FOR SEQUENTIAL OPERATION ONLY!
_
Price:_ $1250 with a rebuildable core
_
_
_
Stage 2:___________ The stage 2 consists of both compressor wheel upgrades._ Both compressor covers are machined to fit the upgraded compressor wheels._ Both rotating assemblies are inspected very carefully and they are each balanced/blueprinted to spec._ The wastegate is ported to 30-35mm._ All bearings, collars, and piston rings are replaced._ All housings are very carefully inspected before used._ All tolerances are checked before assembly assuring you quality in the work performed by BNR._ RECOMMENDED FOR SEQUENTIAL OPERATION ONLY!
_
Stage 2 price:_ $1600 with rebuildable core
_
_
_
Stage 3:___________ The new stage 3 consists of the replacement of the factory CHRA (Center Housing Rotating Assemblies) or otherwise known as a “cartridgeâ€? for the secondary turbocharger._ The secondary cartridge is modified and adapted to fit the factory turbine and compressor housings which is a very difficult task!_ The shaft is Â1/4â€? in diameter while the stock shaft is 5mm in diameter._ The upgraded compressor wheel flows a calculated 500 CFM.__ The primary turbocharger is upgraded with a t04B compressor wheel and is machined to fit the factory compressor cover, while the turbine side of the primary turbocharger is clipped to spec._ Both rotating assemblies are inspected very carefully and they are each balanced/blueprinted to spec._ All bearings, collars, carbon seal, and piston ring are replaced in the primary turbocharger while the secondary turbocharger comes with a new CHRA.
_
Stage 3 price:_ $2100 with rebuildable core
//

RotorMotor

iTrader: (5)

also can someone knoledgable explain whats going on in the stage 3 upgrade? its starting to get a little over my head

last question...how does 500cfm compare to the flow rates of the popular singles (for all you single 20b guys ) thanks again, and please read the thread above this one too! -heath

RotorMotor

iTrader: (5)

haha im gonna be single if i put any more time into this 20b....... beat ya to it

Evil Aviator

Some common compressor maps:
http://www.majesticturbo.com/compression.html
How to use them (simplified):
http://www.turbosaturns.net/articles...r%20maps_2.htm
How to use them (expanded):
http://www.gnttype.org/techarea/turbo/turboflow.html

BTW, you need to double a rotary engine's rated displacement when using formulas made for crummy 4-stroke piston engines that only fire half as often as rotaries.

Cam has never mentioned the 20B turbo upgrade to anybody down here in Florida. It doesn't mean that it doesn't exist, but I have only heard about it through the internet. I would call them to find out, but Cam is never there, and the other people who work there don't know jack about anything except the standard Pettit products.

Neither of the 20B turbos look like an HT-18 to me.
https://www.rx7club.com/photo/showph...cat=500&page=1

t-von

iTrader: (8)

You know its about time someone got some info on stage 3 upgrades for the 20b. I was curious about this last year when I asked BNR if it was possible to upgrade them. I didn't get much info back then. Anyways ROTORMOTOR, since they have already responded to your e-mail, could you ask them if the stage 3's can be run non-seq? Also whats the max rwhp they produce, and the max boost they can handle? Thx

RotorMotor

iTrader: (5)

im already on it.... waiting for a reply

also, do any of pettits 20b coustomers belong to the forum...ive got some q's for them.

t-von

iTrader: (8)

Not sure about the customers. You know I'm hoping for some good results out of these turbos because if the Pettit car can make 550hp at 1 bar with their upgraded twins, I would think that maybe the BNR stage 3's (with their dynamic seals) could make a little more at a higher boost. I was hoping for maybe 650 rwhp max. This way I wouldn't have to go single and spend extra money.

RotorMotor

iTrader: (5)

same thought here....and then i could run sequential haha (dont yell at me...i know simpler is better....and ive had tons of problems with leaking vacuum lines in my FD.... but i must say i really like it when its running properly)
tvon: by the way what is a dynamic seal?

now

iTrader: (1)

well i had a chance to play around with the turbo's
today, i started by pinching off the hoses to the waste
gate took it for a run and found that nothing had
changed, so wondering if i had the correct hoses blocked
i did the next best thing i put vice grips on the waste gate
rod so that it couldn't move at all, took it for another
run and same thing, i guess i have some work to do on
making the ic lines more efficient!
next I am going to put a pressure gauge on the turbo
side of the ic and see what the pressure is before the ic
i am guessing that the pressure on the turbo side
is as high as the little stock turbo's can make it.

matt

t-von

iTrader: (8)

I believe those are the special bearing seals BNR uses for the stage 3's on the Fd. They are suppose to allow for lower friction and the turbos to spool really quick(so quick that running seq isn't necessary). Also, less friction means less heat buildup. A major plus when dealing with the 20b "GoodfellasFd3s" has a set for his 13b. Ask him how much he likes them.

RotorMotor

iTrader: (5)

thanks t-von. ill let everyone know when i get a reply from BNR...either way, from what matt says he is finding, we can all see that the turbos WILL need some sort of modification (be that something by BNR, or if its possible, swapping to larger compressors our selfs).

hey matt, i was wondering about how you proposed to measure the pressure that the turbos are actually putting out. is it true that through a restricted pipe you will gradually see lower pressure as you move farther down the pipe? or would it be that the pressure is constant through a certain configuration of pipe due to restrictions? i havent thought it through, but if that is the case you would not be able to detect a difference in pressure using your method. heath

now

iTrader: (1)

I am going to T into one of the hoses on the primary
turbo, the one that is taped into the compressor housing
then connect the boost gauge to that and see what i get,
probably a broken boost gauge

matt

j9fd3s

iTrader: (3)

i did that on mine, i got a 4psi difference. with the new setup i need to check it again, but it feels better, i'm hoping for 2ish

mike

now

iTrader: (1)

woops

now

iTrader: (1)

I have been told by a couple cosmo owners that
16 psi boost is possible on the stock setup, so i am
guessing that my ic and pipes are nfg

matt

t-von

iTrader: (8)

16 psi on stockers? Wow did they tell you how much power they were putting down?

now

iTrader: (1)

stock cosmo with 3 " exhaust and intake,
with the modded stock computer that i am
testing they say 450+hp.
sure find it hard to understand why i can even get close
to 12 psi with the stock turbo's never mind 16 psi!
doing some more testing tonight to see if i cant get
more boost.
matt

RotorMotor

iTrader: (5)

ok, i finally recieved an email from BNR. i asked him a good number of questions about the different stages that they offered, and what model turbos actually come stock on the 20b. most of my questions were not answered and the responses that he did give were vague to say the least. im not sure i feel any more convinced to use them than i did before. i asked a bunch of direct questions, sent him the link to this thread, and told him that there would be a good market for him seeing all the 20b conversions that are/will be going on. basically i wanted him to do a comprehensive write up on his products/conversions so all of us could make our decisions accordingly.....anyway this is all he wrote back->

//Hey Heath.

Stage 3 is geared for both sequential and non sequential. The problem with the HT10/12 is the shaft is 5mm thick. The shaft cant take the Load that the larger turbo puts on it. Since the stage 3 has a replacement cartridge, it will be able to handle the abuse.

The 20B shouldn't have to be ported until you reach 550 RWHP. Then it will restrict flow.

I will have to set down and make some HP figues. If you have any qestions, feel free to call.

Bryan
www.bnrsupercars.com
205 790 2514//

now

iTrader: (1)

ok here i am after some more testing to answer my own
question.
the reason that i cant get more than 10 psi boost is
because it would appear, this is as much boost as
the stock unit will make (on my car).
I put a boost gauge on both sides of the intercooler
and this is what i found.

at 2200 rpm the boost jumps quickly to 10 psi on both
sides of the ic, at about 4000 rpm both the intake side
and the turbo side drop while the 2nd turbo comes to
life, once it is up to speed the turbo side jumps to the
10 psi mark, as the rpm's rise the intake side boost
drops, at 7500 rpm in 3rd gear ( yes i was going a little fast)
the boost on the turbo side is a solid 10 to 11 psi and the
intake side has dropped to 3 psi. All this testing was done
while the waste gate was clamped shut.

conclusion, the stock turbo's seem to top out at 10 to 11
psi and flow about what the engine does at higher rpm.
if my ic pipes and ic itself were better flowing i might gain
a little more on the top end. either way i feel that the
turbo needs to make much higher pressures to deliver
the needed flow through the little openings of the stock
turbo housings.

I am working on a source to supply upgrade parts, will
have to see what he comes up with.

matt

RotorMotor

iTrader: (5)

thank you matt!!!! i, as well as everyone else really appreciate all the testing that you are doing, so thanks again. if we all work together i believe we can find a cost effective solution to raise boost pressure on the stock turbos. im still working on getting info from BNR, pettit and a few other sources. ill share info as i find it...

the one question i need answered before i can go any further is about the turbo models that come stock. since i have gotten conflicting info from the forum, and BNR i wanted to check the turbos myself for the models. ok, heres my question: does anyone know if there are model #'s or serial numbers on the turbos that would tell me exactly what they are?? if so, where on the turbos would this identification be? thanks guys, and good luck to everyone!

ps mike, just curious... do you have any idea how much horsepower you are putting down with your current configuration @ 10 psi or whatever you are getting?

j9fd3s

iTrader: (3)

now: hmm maybe your ic setup stops flowing, mine kinda felt like that, now that i have removed the 270degree ic pipe is a lot better.

rotormotor: it did 220rwhp with the 270pipe at 10psi, now with the better coils, and ic piping it feels a lot better, i'm going to say like 240-250rwhp@7psi.
we do have a stock ecu 20b running around to dyno too, so we can see where we are supposed to be