borg warner s300-66 (s366) Feedback
 

Im looking into getting a borg warner s366 turbo to replace my recent precison 6765 turbo. I enjoyed the precision response it offered but was not fond of the turbine wheel size for high boost applications. I know that the borg warner turbo has a considerably larger more rotary friendly wheel. I ran a .96 turbine housing on the precision turbo but would the 1.0 be necessary for they borg warner since the turbine wheel flow more? Id like to have good response and good flow for high boost like 30 psi on my street ported REW. Im also aware that I might be asking for too much and in order to have response I sacrifice flow or vise versa. But i figure its a shot in the dark. Any feedback from anyone with experience with the s366 would be greatly appreciated. thanks

Street port
.88 AR.... Love mines. You have already seen some of my videos. FC3S1991 has the same turbo maybe he can chime in on what he thinks also.

pretty happy with my S366, i have the divided .91 housing and this thing spools pretty quick, im still running a rough tune at 15 psi on the car.

Hmm im still curious if .91 is big enough for 30psi and keep the backpressure down

The S366 XL has the option turbine housing. 1.00, 1.10, 1.25 a/r

Do you have the FMW?

Flat tip or cupped turbine?

At what rpm do you start spooling?

yes i seen that. but with a bigger wheel they 1.0 might be laggy where the 1.0 on a 6766 precision might stop flowing

i have no direct experience w the S366. i do have some dyno time on the 366's sister turbo, the S363.

if you go to Borg Warner's site, go to AirWerks and S300 you will find compressor maps for both turbos.

while the S363 is a 7.0 sq inch compressor wheel, the S366 is 7.7 sq inches... you would think it would flow around 10% more air... which is 10% more potential hp.

BW says NO.

both the 63 and the 66 flow 77 pounds per minute. the 63 at 35 PSI boost and the 66 at 41 PSI.

77 pounds of air is 580 rw rotary SAE hp max.

this is backed up by a PFS dyno sheet for an S366 which made 610 rwhp. this, however is Standard not SAE so the SAE number is 597. dynos of course vary a bit and my estimate is an estimate and can vary + or - a touch.

so is the 366 a better choice than the 363???

i found the 363 to work very well at higher rpms as evidenced by the lowest egts over 20 psi i have recorded... a stable 1540 F from 4500 to 8600. generally egts rise w RPM as backpressure/heat accumulates preturbo.

i attribute this to the large (in relation to the compressor) turbine wheel and 1.0 A/R on the hotside.

i don't see an advantage in going w the 66 over the 63 as you are swinging bigger wheels and getting no more air.

BTW, anything BW oriented... ScorpionT has the correct answer for you.

howard

That is pretty good egt's.
Thanks for the info Howard but dont you mena the s362 (s300 series turbo)?
I also have another problem. I built my manifold off of a precision 6765 and im wondering if the bw would sit any different on the manifold and have fitment issues?

i am no expert on BW nomenclature. they win the award for zillions of "different" turbos if you just look at the tags. and they all vary a zillionth. i think the problem is marketing and doesn't lie w BW, rather the dealers attempting to gain a proprietary foothold. (which i do not condemn, it is good old american capitalism but does muddy the water)

anyway, if you go to the source.... BW...

you will find they have a series of turbos that share the same general frame/size.

in the S300 category you have the 62, 63 and 66. (inducer size)

so you can call one of them an S300/63, or a S363. each do have different wheel dimensions.

my BW is the S300/63 or if you want to get technical BW PN 177283. 1.00 T4 divided hotside. V band back end.

it will bolt to any T4 manifold and you will need to alter your downpipe, as it has a larger than 3 inch V band.

if your P is a T3, of course, you would need to swap in a T4 flange.

howard

i don't know about the turbo fitment, i think the s366 is a little bigger than the precision.

but your down pipe wont work with it, the BW turbos have a special exhaust housing outlet that uses 20 degree taper "marmon" style V-Band flanges also the size of this V-band is 3.5"

I apreciate the input and great info. I will put all into consideration before choosing

The S363 is a great turbo with excellent response. For what its worth the 62mm FMW will flow 71lb max, and the 60mm cast (S360) 68lb. As mentioned above the 63mm cast wheel will do 77lb, very similar to the 66mm cast.

I just bought a BW s366, the vband that comes with it does it make it 3'? or do you need a reducer from 3 1/2 to 3'?

some people insert their 3" pipe inside the 3.5 flange and fill the gap when they weld it, or you could get a reducer. I went with a full 3.5 downpipe and reduce it at the midpipe.

Ok, i ended up picking up a reducer just in case, thanks

Most exhaust benders has a tubing flare tool on it so just flare the 3" to fit tight into the 3.5" and you save your self money on a reducer and a cleaner more professional look.

On a side note Ive been talking to Turboblown Engineering and comp turbo is going to make me a custom turbo. A 6771 with a ct43 compressor 1.0 turbine housing. Not sure if i want ball bearing or not yet :scratch:

if your going custom, might as well and spend the extra money for ball bearing setup.

Elliot will build you a nice turbo and you will be very happy with it.

Ball bearing costs more and ive never had a laggy turbo that was jb so in a sense I dont think i really need a bb turbo.
We will see what happens.

We just installed my BW s366 and I can tell you that it is a great turbo, has a awesome whine right when it comes out of vacuum. It fits a bit tight in there though.

mine fits perfect.

Attachment 718480

Mine is a tight fit, due to my manifold apparantly.

Attachment 718481

What manifolds are you guys running?

Modified Ebay manifold for now. New sturdy manifold being built..

Attachment 718482

Damn, those compressor covers are freaking huge.

Mazdaspeed Dan, that oil feed setup looks er, less than ideal.