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I don't have much detail on the dyno session since I know little about.
BW362 sxe at 13-13.5 psi on DynoDynamics Dyno.
I need some water injection, though.
besides that, I put the engine together and everything worked great.. how long it will last? lol.....
the most important is that with the changes I made it picked up 40 whp.
from 350 to 393.. that os plenty for me.
I am super happy with it. I just wanted to share it..
I'm going to change .91 to .88 a / r turbing housing
I have Rx8 R3 6 speed transmission, differential 4.44 with 20” wheels. 4,500rpm spool.
I want Spool at 4,000rpm or close.
I'm going to try the .88a/r T4
Have you tried retarding the timing 5 degrees in the spool area (2,500-4,000 RPMs, at 0-7 psi) to try and get it to spool quicker? You could also add some fuel in those same VE cells...
I would play with tuning before spending money on a slightly different rear housing.
"I would play with tuning before spending money on a slightly different rear housing."
i agree.
there are so many things that greatly effect spool besides the hotside housing.
many in the "hardware" category but others in the "software."
software would be tuning.
before ripping into the hardware i would start the earlier spool project with tuning.
assuming your AFRs are in the ballpark, i would look at midrange timing. ideally you should have EGT data. many people just look at EGTs between peak torque and redline but EGTs are very important as soon as you get positive boost. you will probably find them to be on the cold side. using AFR and timing you want to see 1400/1500 F on gasoline. more heat, more drive to the turbine. my bet is tuning in this manner will help spool.
once you have proper low/mid range EGTs w a correct AFR it becomes about hardware which is a book and not able to be properly treated in the forum.
changing to a smaller A/R will not be helpful overall for you. it may slightly increase spool but it will greatly increase backpressure which is harmful, sometimes fatal, to your motor. the 88 is highly restrictive so exhaust heat and pressure piles up in front of the turbine wheel and part of it backs into the engine. since there is overlap (intake and exhaust both open) a portion of hot non oxygenated ends up in your INTAKE charge air. gasoline autoignites around 450 F so you want as little as possible of the exhaust in the charge air.
if, for example, you are at 20 psi boost and your exhaust backpressure is 45 psi which way will the flow go? to the extent your backpressure exceeds boost it is heading into the intake. it is also having a harder time getting out of the combustion stroke thus increasing temperature seen by the apex seal.
you have an awesome turbo. properly mated with the right tuning and hardware your car will perform as good as it looks.
"I would play with tuning before spending money on a slightly different rear housing."
i agree.
there are so many things that greatly effect spool besides the hotside housing.
many in the "hardware" category but others in the "software."
software would be tuning.
before ripping into the hardware i would start the earlier spool project with tuning.
assuming your AFRs are in the ballpark, i would look at midrange timing. ideally you should have EGT data. many people just look at EGTs between peak torque and redline but EGTs are very important as soon as you get positive boost. you will probably find them to be on the cold side. using AFR and timing you want to see 1400/1500 F on gasoline. more heat, more drive to the turbine. my bet is tuning in this manner will help spool.
once you have proper low/mid range EGTs w a correct AFR it becomes about hardware which is a book and not able to be properly treated in the forum.
changing to a smaller A/R will not be helpful overall for you. it may slightly increase spool but it will greatly increase backpressure which is harmful, sometimes fatal, to your motor. the 88 is highly restrictive so exhaust heat and pressure piles up in front of the turbine wheel and part of it backs into the engine. since there is overlap (intake and exhaust both open) a portion of hot non oxygenated ends up in your INTAKE charge air. gasoline autoignites around 450 F so you want as little as possible of the exhaust in the charge air.
if, for example, you are at 20 psi boost and your exhaust backpressure is 45 psi which way will the flow go? to the extent your backpressure exceeds boost it is heading into the intake. it is also having a harder time getting out of the combustion stroke thus increasing temperature seen by the apex seal.
you have an awesome turbo. properly mated with the right tuning and hardware your car will perform as good as it looks.
interesting observation.
with a 5-speed rx7 transmission and .91 turbine housing the results may be are different.
My car is a rx8. I am using the 6-speed Rx8 R3 transmission. with 20 inch wheels. This affects the fast spool. With the .91 turbine housing, spool at 4,500rpm and I didn't like that.
I been testing the .88 for 5 days. Spool Improved from 4,500 to 4,100rpm. Incredible change. I am very happy with the result, A rocket from 4,000 to 8,100rpm. I have to investigate more about my backpressure. For now street tunning 10.9afr ,12psi with conservative timing. Maybe dyno next month. I would like to know your opinion.
Last edited by Gamaliel31; Feb 12, 2020 at 12:45 PM.
I would be going to a larger housing and converting to a twin scroll maifold vs the single scroll you currently run ................best of both worlds .
I would be going to a larger housing and converting to a twin scroll maifold vs the single scroll you currently run ................best of both worlds .
I understand your point. Maybe then I bought a new manifold with those specifications. Right now I love how it feels. I have several friends with small turbine housing, one has .88 in a sxe366 450+ without problems. Another one in a fds with .81 / 72ar with 500+ without problems. But I would like to know more about my backpressure.
Welp may as well throw my lastest status with this turbo in the ring. I have the turbosource kit. Currently running it at 9 psi, budget slowed things down. Will 380 hp be safe to run on stock seals with this setup? Stock port, midpipe, Upgraded smic. Q2 Is the marmon flange a big enough liability to warrant switching over to v band? Boostlab has a turbine housing(twin scroll) that is v-band I've been eyeing.
"Will 380 hp be safe to run on stock seals with this setup?"
stock seals are fine as long as you don't have detonation. OE seals will generally chip/break if you have detonation. the broken parts often embed in the rotor, greatly gouge the rotor housing and take out the turbine wheel on their journey out of the motor.
most other aftermarket seals such as (in no particular order) Goopy, E & J, Rotary Specialties, RXParts, I Seals are more malleable and less likely to cause $$$ problems should you encounter knock.
a simple AEM water or water meth AI system should be of great help in decreasing detonation risk.
i may not be understanding Q2 however, there is nothing wrong with a Marmon flange. the I D of the turbine exit to the exhaust is the same 3 inches as non Marmon flanges.. the O D of the flange, which uses a V band, is simply a bit larger. there are adapters available to mate to the typical 3 inch downpipe.
"Will 380 hp be safe to run on stock seals with this setup?"
stock seals are fine as long as you don't have detonation. OE seals will generally chip/break if you have detonation. the broken parts often embed in the rotor, greatly gouge the rotor housing and take out the turbine wheel on their journey out of the motor.
most other aftermarket seals such as (in no particular order) Goopy, E & J, Rotary Specialties, RXParts, I Seals are more malleable and less likely to cause $$$ problems should you encounter knock.
a simple AEM water or water meth AI system should be of great help in decreasing detonation risk.
i may not be understanding Q2 however, there is nothing wrong with a Marmon flange. the I D of the turbine exit to the exhaust is the same 3 inches as non Marmon flanges.. the O D of the flange, which uses a V band, is simply a bit larger. there are adapters available to mate to the typical 3 inch downpipe.
There is nothing better than powerseal. The loquito killer with 20b engine, Rafaelito Racing 13b, Karma 13b, Professor 13b, all do 6sec on track and all with the powerseal (extreme version). For the street they have a version that holds more heat and is called powerseal street. That's what my engine has. They call: (the indestructible seal)
@Howard Coleman To add some more data to this old post are you able to post up any full RPM pulls showing EMAP vs boost? I see the cross over was 6100 on your 1.0 housing or a bit under 6000 for the 0.91 shown below.
I expect from 6500-7000rpm on the EMAP is skyrocketing from what the graph trend looks like below?
ack from San Diego and had a brief opportunity to do a run today. it is 33 degrees and the road surface doesn't have much traction so i did it in 4th.
i am in the process of switching back to gas w meth AI so my map is not finished in the upper boost levels but i do want to see what my SE 62 can do as far as spool.
the log shows a roll into the throttle:
i started at 22% throttle (TP) at 3240 and upped it to 47 to 50% at 3314. i was at peak boost (17.6 psi) at 3965 at 49.6% TP.
at peak boost of 17.6 my exhaust back pressure was 12.4 psi. back pressure crossover with the .91 hotside was at 5592. my previous data w a 1.0 places crossover with my manifold at 6100.
Thanks, is that with the S362 SX-E?
I think he has a 3" DP plumbed back and maybe the 0.91 turbine housing? But either way that's only 1.39 EMAP at 7500rpm at 19.6psi.
Much better than I thought it would be..
Finally tuned again
how long it will last? 
lol.....
I just wanted to share it.. 
