Borg Warner S366 v S363: Bigger is Better?
 

caveat:

as a Garrett engineer told me a few years ago.... "compressor maps are not money."

if they aren't money they are pretty close.

something has been bugging me for a while so i thought i would finally lay it out for discussion.

executive summary:

the S366 has a 10% larger compressor wheel than the S363 yet delivers very close to the same airflow.

WHY would anyone pick the S366 over the S363?

here are the maps:

S366

http://img24.imageshack.us/img24/775...1177275177.jpg

S363

http://imageshack.us/a/img259/4154/bbws30063compmap.jpg

and here's my read:

.................................................. ..S366..........................................S3 63

14.7 PSI Boost...............66 pounds 497 rwhp....................64 pounds 482 rwhp

20 psi............................72.4 pounds 545 rwhp.................70.6 pounds 532 rwhp

max air at 62% eff.........76 pounds 573 rwhp...................76 pounds 573 rwhp

you may be thinking that the S366 has an edge so what is this thread about. i say that the hp diff between the two turbos is a jump ball.

what isn't a jump ball is that the S366 compressor wheel is 10% larger.

S366 compressor area is 7.743 square inches

S363 compressor area is 7.04 sq inches.

this isn't "jump ball." this is a major spool drag for the S366. a drag you feel all the time.

in addition, the heaviest part of the turbo by miles is the turbine wheel assembly. the S366 has a 7.151 sq inch turbine while the S363 has a 6.31 sq inch wheel. the S363 is much lighter which also promotes spool.

granted the rotary likes a larger hotside but the 6.31 S363 is plenty large...

compare it to the typical "big" Garrett P trim wheel at 5.89 sq inches.

so you have to swing a 10% larger compressor wheel and a 13% larger hotside w the S366 and just what do you get out of it V the S363?

both turbos are the same 9.19 inches in length and all other outer dimensions.

perhaps one of the reasons many end up w the S366 is that there is more of a settlement as to the name.... "S366"

just try to figure out what you are looking for w the S363 (my tag BTW)

it could be:

S300SX3- 63

BW S300SX8875

S362

i could go on.

what you want is a BW 177283 with a 177209 hotside (T4 divided 1.00 A/R)

the 177209 does not come w the turbo and is extra, around $170. Full-Race does sell the 177283 w the 177209 for the same price.

as always, shopping around pays dividends.

another nice option is a conversion of the weird 4.21 inch back end V band to a more friendly 3 inch. this is available from some vendors for $150 or so.

given the pricing, quality and configuration, this turbo is a great value for the FD owner looking to make around 500 at 20 or so psi.

as to mid-range... i run 295 rear tires at 27 psi and rolling into boost in 3rd i am on the edge of adhesion at 46% throttle at 14 psi. you will be happy w the midrange:)

favoring midrange on both turbos is a 52 trim on the compressor wheels. this compares to 63 trim on the Garrett/PT wheel of similar dimension to the 363. in spite of the 52 trim i found the 363 still delivering a lot of power at 8650 rpm...

Howard

howard can you do a comparison between a gt35R and a precision 6262? i would LOVE this.

Hi Howard, great comparision, is the HP you refer to flywheel or RW/HP,//////////////////RW...HC//////////////////////////
Our racecar is nearing completion, what would you expect the S362 FMW or 177283 turbo to happily achieve with a 13B REW full Bridgeport on E85, 2200x4 injectors, running 2x44 tial w/gates & 3.5" exhaust (side exit). sequential 6 speed trans. 280x650x18 Hankooks.
we are possibly looking to run 22-25psi, running haltech 1000 & dash.

Your input would be greatly appreciated.

Many Thanks in advance.

"what would you expect the S362 FMW or 177283 turbo"

the limit to power is all about how many oxygen molecules you can jam in a motor over a period of time.

at the margin, the turbo is the governor. the "restrictor plate" in NASCAR terms.

the compressor map tells the tale.

at 2.6 pressure ratios (see map above) or midway between your 22 and 25 numbers the turbo will make 71 pounds of air.

whether you burn the O2 w alcohol or gas you will make approx 535 rwhp tops. that's if all your systems and tuning etc are max.

71 pounds of air and a 10.9 AFR means 6.51 pounds of gasoline which is 1.02 gallons per minute which is 118,412 BTUs.

since you are running E85 which has 82,300 BTUs per gallon you need

118,412 / 82,300 = 1.44 gallons per minute or 5451 CC per minute net of IDC and lag.

to get to gross 5451 X 1.35 = 7358 gross injectors

you have 8800 and have done your homework...

good luck,

howard

"can you do a comparison between a gt35R and a precision 6262?"

compressor maps cost approx $15,000 each and last i checked are not available from Precision.

of course track and dyno results speak clearly. PT rates the turbo at 705 (max) piston hp which suggests the turbo makes approx 70-71 pounds of air.

this compares w 68 for the GT3582r, 76 for the Garrett GTX3582r and 69 for the BW.

all 4 of the turbos are approx the compressor size but have differing wheel design.

here's how the "small" category lines up:


.................................................. ....compressor average area sq inches

PT6262 CEA............................................... ...6.448

GT3582r........................................... .............6.386

GTX3582r.......................................... ............6.519

BW 177272/280.............................................6. 43


.................................................. ......turbine average area

PT6262 CEA...........................................5.40 8 (similar to T3 Stage 5)

GT3582r........................................... .....5.171

GTX3582r.......................................... ......5.171

BW 177272/280......................................6.31

among this group of turbos the two items that stand out to me are the impressive GTX3582r compressor map and the large BW hotside.

the GTX compressor map proves that there are gains to be made in wheel aero and this may also be duplicated w the PT offering as well as the BW FMW. i do really like large hotsides for the rotary having logged exhaust back pressure and EGTs.

decisions decisions


hc

W.w.h.c.d. ?

Lol

one of my favorite isms is....

"we can't all be divorced from the same woman."

in other words, more wife friendly, it depends on what you want to do w the turbo.

probably any of them would put a smile on your face if properly setup.

in the real world money sometimes is a factor...

the BW is around $700 while the GTX is around $2K. the GT35 si $1650, PT is $1075

one thing i like about the "small" category is they are.... small.

they sort of get lost in your engine compartment as opposed to beating out your inner fender for some of the monsters.

one thing i don't like about the "small" turbos are they are.... small

you have to wind the XXXX out of them to make major hp whereas the "medium" line is loafing and still have good spool. something to think about.

now if we could just put the GTX compressor on the BW w its super duper hotside.

decisions decisions

hc

weren't those guys from east tn putting 11 blade billet wheels on the BW turbos?

^^^ This.

I had the option of an 11 blade billet wheel installed on my turbo when I bought it.

You can buy them and install them yourself for under $250 - but would probably need a rebalance.

diesel guys are claming that swapping wheels wont need a rebalance. i would rebalance only if i could find someone local to balance them.

I have a question regarding compressor surge and the S366. I recently changed to the S366 with .91 A/R divided turbine housing. I am defiantly getting genuine compressor surge on the street pretty much any time I hit the throttle and roll into boost, low or high RPM. On the dyno this was happening only at low RPM hits. I am hitting 15 psi a little before 3800 rpm, 18psi at 4000rpm and 20psi at 4100rpm.

I am not 100% sure how Compressor surge works. I do know that is directly related to falling out of the far left hand side of the compressor map. I am not sure how to relate this area of the compressor map to what I am experiencing.

Everything that I have researched and from what my tuner has evaluated from data logs is that I may need to go to a bigger turbine housing.

I just do not understand how this could be possible as there are plenty of FD's that run the S366 and I have never seen this issue posted before. I have found 1.00 and 1.10 A/R divided housing available for the S366.

Any advise would be appreciated.

Diesel turbos are balanced differently.

Jason

How are the BW's so cheap and how do these two differ from the R85 Max Cooper had issues with. Yes, I know he also had issues with the RX6 so it may not have been the turbo.

BorgWarner is one of the largest turbo mfg's in the world, they supply audi/vw/porsche john deere, cat, ford, hyundai, many others. One of their biggest strengths from a performance standpoint is they some of the best turbine wheels and bearing assemblies in the industry - that is particularly important for high exhaust energy rotary engines

that's not entirely correct. there is no callout difference for balancing based on the fuel burned. instead there is component balancing or core balancing. both work well depending on turbo size and many other factors

the s300sx 9180 a.k.a. s366 is a tried and true unit, very solid and turbine wheel geometry is excellent.. it comes standard with 0.91 a/r so you are runinng it "straight outta the box"

getting 15psi before 3800rpm is very good I assume you are running a divided twinscroll manifold? one or two wastegates? Realistically surge is telling you that this compressor is trying to move more air than your engine can ingest and its running off the map. your best solution is to use a turbo with a broader LHS of the map something with a slightly smaller inducer might also be worth consideration. changing the turbine housing will slow the spool slightly and might help, but it also might not, id bet on not

Thanks for the info. I am running a Turblown divided twinscroll manifold with 2 Tial 38mm wastegates.

I am honestly not sure now if what I experienced on my way home from the tuner was compressor surge. We did have a issues with the boost solenoid when trying to raise boost. Erratic boost from 8 to 16psi before it smoothed out. My tuner specified that this function was turned off in the EMS but I am not sure it was. I honestly do not see how I could be getting surge hitting the throttle at a high RPM.

Either way, I finally found and ordered a 1.10 AR housing and I am going to give it a try. EGT's were much higher then my old GT4088 and I am sure this will help. Power was also taking a nose dive at 7K where this was not the case with my old turbo. The car still did 550 WHP at 7K running 23psi. I am pretty excited to give the bigger housing a try.

please post up after you get the 1.10 a/r installed with feedback. If you can log boost of the 0.91 and overlay the 1.10 against it, Id be grateful.

the power taking a nose dive at 7k probably means the 0.91 a/r is too small for your power target/ideal boost level so thats on the right track. erratic boost that eventually smooths out does seem similar. For example when I get surge in my 2.0L evo with the 62mm EFR8374: when floor it at 2000rpm, the turbo spools so fast its trying to make more boost than the engine can ingest - so the boost gauge is bouncing and the engine is "surging" you definitely know it. basically an 83mm turbo is too big to spool that early on a 2L motor, thats surge.

I certainly will. Later tonight I will post my current boost plot with the boost solenoid off and on. We had issues that made diagnosing problems tough. Turns out my AEM may have a bad internal ground which would explain the boost the boost solenoids odd behavior.

I can tell you from firsthand experience with compressor surge that it usually occurs at high boost & low rpm, as described above ^^. The boost will oscillate and if the surge is bad enough, you will hear a chug-chug-chug sound. It's common on 4 cylinder engines with fast spooling turbos.

Typical rotary setups tend not to run high boost at low rpm (instead using high flow at low boost) so compressor surge under load is rarely an issue.

Thanks. I am pretty positive now that the boost solenoid was what I was experiencing. I already sent my EMS into AEM. Wish I would of downloaded the map before I did. You can tell from the 2 charts which plots are with the boost solenoid on and off.

ohhhh YOU are the rx7 tony was asking me about last week :) did not put that together until now, small world. OK this makes sense, hopefully its solid once you get the box back from AEM

arghx - you are correct, and is in fact the reason that CT9A evo's never were offered with cruise control! The oemturbos are big for that little 2.0L and twinscroll spools early so stock they can surge

Yep, thats me. I'm sure Tony is going to be happy when my car is sorted out and he doesn't have to tune it anymore:)

yeah without electronic throttle and torque modeling it probably would have been a lot of trouble to stay out of surge in cruise control.

Well I have some results for the .91a/r vs. the 1.10a/r. All in all there is only about a 200 rpm difference between the .91 and 1.10. Unfortunately the heat and my super thin crappy eBay inter cooler core was holding back for seeing the full potential on the top end. Tony did say there is absolutely a difference on top at lower boost levels but at higher boost the air temp were just to hot. Mid 160's no matter how much we cooled down the car. At 27psi it still made 580whp at only 6700rpm before the heat really started to kill the power. Torque was almost 480 I believe but i will post the chart when I receive it. Left that one at the shop for some reason.

Attached is a comparison of a 24psi vs 24psi boost plot for the old .91 to the new 1.10. I also attached a boost plot of my current low and high boost settings. The 22psi run has an even better 15psi number then the 24psi run.