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.

I'd be interested to see the 0.91 vs. 1.10 EGT temps.

Unfortunately I'm not able to log egt's yet. The egt's I'm using have a 5 volt out for data logging but the FD series 1 AEM box is hard wired for AEM egt sensors. There is usually a jumper to switch between the AEM sensor or a 5 volt input.

So the 1.10 is the way to go at the sacrifice of 200 rpms?

At least for my set up it is a no brainier. Once i get a half way decent IC core, I can at least get a better idea of the top end benefits.

That is unreal boost response!

20psi gauge at 4100rpm from the 0.91 A/R 9180 aka 366?
20psi gauge at 4375rpm from the 1.10 A/R 9180 aka 366?

I have to ask the question are we talking about the same turbo 66mm compressor inducer 91.4mm exducer? Basically that is a T66 wheel of old on a massive turbine wheel in a tighter housing than normal.

That turbo is meant to have a 73mm turbine exducer, 80mm turbine exducer. A full GT4202 uses a 75mm / 82mm wheel.

That wheel is a good 8mm larger than the modern aggressive p-trim on a T04Z. How on earth are you achieving the same boost threshold rpm.

I have quality plots I've found online from 1.0 A/R T04Zs doing similar tests and they typically achieve similar boost at 4000rpm as to what you are getting at 4000 with your 0.91A/R, but your turbine is massive in comparison.

I must admit I am skeptical. Are you sure you aren't using the 3.0" inducer 2.66" exducer turbine (basically a Q-trim)?

This is the standard out of the box S366 purchased from Turblown along with his latest manifold design. Turbine is the 80mm inducer and 73mm exducer. This is the only S366 Elliot from Turblown sells. E85 has a little to do with it. Maybe 200rpm or so. The rest is the manifold design, thermal coating and ports. Honestly response may improve when it cools down. It was really hot out during my tuning session. August in Arizona is no joke!

The only problem with switching to the 1.10A/R is it is not a 100% direct swap. If you already have fabricated the DP then work will need to be done. The discharge tube is much longer on the 1.10A/R, similar to the EFR line. The one good thing is the housing is very inexpensive. I found mine for $150 brand new.

Here is what the housing looks like S366 1.10A/R . This is the same vendor that sold me just the housing for $150 as well.

That is very good value. Does your one have the back cut / /clipped / cupped turbine wheel?

I'm not into back cut wheels.

I'm not sure. The turbine wheel is just how it came from the factory. I don't think so.

The S300SX 9180 aka 's366' in question is an outstanding turbo, incredible bang-for-the-buck. We actually had this turbo with 1.10 a/r on the 2nd place car at World Time Attack 2012 last year.. 2.3L motor at 35psi boost, it was by far the simplest and least expensive turbo in the field but the performance speaks for itself.

BorgWarner turbos have some of the best turbine wheel aerodynamics in the world. This particular 80mm turbine is an excellent unit which uses their 'J-type' turbine wheel blade shape and that was actually carried over to the EFR series. This is a very large and high flowing wheel design, yet it has high efficiency (especially in twinscroll config) so it spools like a much smaller turbine wheel - definitely a nice match for rotary 13B engines.

FYI - the old p-trim T04Z turbine wheel is an antiquated 11blade design, good for its time (early 1990s) but definitely not modern tech any more. much better turbine wheel selections available now IMHO

There is no "one-size-fits-all" answer for this, that's why we (Full-Race) offers all the different housings (0.88, 0.91, 1.00 and 1.10). Even though it only shows up as 200rpm on a steady state dyno plot (or drag race application) - the larger A/R can feel lazier especially during transient driving conditions experienced (during real world driving or road course/time attacks stuff). for a high power street car the 1.00 could be a good in between.

thats because youre using the wrong 1.10!! it works and obviously you found it inexpensively, but it is not the one we recommend for plug-and-play-fitment

the borgwarner J-type turbine wheels ALL are machined on the outlet, but it is not a clip!!

Hi Geoff, just curious but would you prefer the FMW design to say a BatMoWheel design? Also do you see a benefit to running the billet wheel on your standard rotary application (~16-22 lbs)?


My apologies on my comment earlier as I didn't realize that I was looking at a s366 and thought I was looking at an S362 which is more along the lines of what I'm in the market for. Did we conclude that he was having issues with his boost controller and it wasn't compressor surge? I recall on someones s362 setup that you recommended a .91 AR for them and it sounded like a lot of fun to me - being a stock port car. Would you still suggest the .91 on the s362? Do the other turbine housing have the same dimensions (as far as downpipe fitment is concerned)?



Just curious but going by your site:

Perhaps it was just that guys application, but on these turbos would you suggest a 1.10 for most of the rotary guys on a smaller turbo?

And this Marmon flange?

Is there a real benefit to V-band vs Marmon for your average car owner who doesn't plan to swap turbos for years down the road? And if not do you guys sell the Marmon adapters?


-Sorry for the barrage of questions, but they've been building up for quite awhile and a lot of people have just look at me puzzled when I ask them about it or they give me answers in theory without actually looking at the product (or perhaps thinking of an older product by the name name). Thank again Geoff you've been so helpful through the years and between you and Tony I don't know who is out there on multiple forums more. :lol::icon_tup:

Forgot to mention that the compressor surge is completely gone now. We also had a boost control issue as well which is what I was experiencing on the street after my initial tune. There was a little surge on the dyno with the .91 that is not there any more.

wow those are some questions! ok, ill try to knock them out:

FMW vs batmowheel: FMW is 100% genuine OE borgwarner. This is the way to go IMHO. Top quality usa made turbos by actual engineers. on the other hand, bullseye buys BW turbos from distributors then installs their own compressor wheels... these comp wheels are not gas stand tested or compressor mapped nor are they burst tested. In my experience they do not perform as advertised, and i prefer to keep it 100% bw.

billet vs cast: borgwarner's latest generation compressor wheels are billet, and they do offer a performance improvement (due to blade aero) over the older cast compressors. The 61.4mm inducer "S300sx fmw" is a great turbo and it's compressor map fits the 13b nicely up to 500-550hp level The billet wheels do have a price increase and the older cast models still hold the "bang-for-the-buck" crown

The most significant thing to consider outside of compwheel is that the OE Borgwarner Airwerks turbos with billet compressor wheels also have their latest 6-pad "severe duty" bearing system - which is not seen on any of the other cast wheel bw turbos nor any aftermarket company turbos

which size compressor? If you need more airflow than the 61.4mm FMW can deliver, my opinion agrees with howard coleman ... For the best value and performance in an off-the-shelf turbo, the S300SX 88-75 is probably the single best fit to the 13B for sub600whp range. This is not a billet nor is it a 6pad, but it hauls the mail, at a great price

which size turbine housing? This depends on how much boost you plan to run and what is your power target and intended use for the vehicle? If its a street only car yes id suggest 0.91 a/r. If its street/track 1.00 a.r is a good spot and if its just to go really fast then 1.10 a/r... 13B's like to exhale, and that means a big turbine housing. The cupped tip turbine wheel comes standard on the 8875 and is what i recommend on the FMW so thats a given to use here. 0.91 will spool a tiny bit quicker but higher rpm and higher boost levels will drop power. the 1.10 a/r might spool only 200rpm later on the dyno comparison attached but every application is different and a steady state dyno is not always a true representation of the real world.

marmon vs vband -- marmon works well and keeps cost down. Vband is faster, more convenient, more precise and easily allows you to swap turbos in the future. I personally prefer vband and recommend it when its an option - but it is not necessary. We can supply you with the marmon flange and clamp no problem at all. If you plan to stay with the BW turbos there are a LOT of different turbos that use the identical housing (no changes) ie: 83-75, FMW, 88-75, and the upcoming FMW2. you could use the same turbine housing and only swap the center sections and comp cover..

lots of options with the bw :icon_tup: hope this helps


that is good to hear your setup is running so well with the larger 1.10 a/r turbine housing. I suspect you may be correct, that 0.91 spooled the 66mm compressor just a little quicker. Its unlikely to surge in real world driving conditions as you noted, but UMS has dynapack dynos which can really load the engine up, and get the turbo spooled earlier than realistically... its almost impossible to duplicate the load and spool that the dynapacks can generate in the real world (without a load like a trailer or long, steep incline hill)

Hi, im looking at BW turbos for my mild-extended-turbo-port 13b, im chasing maximum spool up and mid range, and id be happy with 400 - 450 rwhp, on an engine that is fresh, and has a decent 3" exhaust, large fmic, plenty of fuel ect, ie its pretty efficient. Would the 83-75 with 1.00 housing be sufficient? And would I be better off with a t4 divided or sticking with my t3 manifold? And what effective advantages would I see using an FMW? Please be gentle, I need some insight. Thanks in advance!

And how would a cupped tip .91 compare to a flat tip 1.00? Thanks!

Your time and knowledge is always appreciated! I was really impressed with your products when I had a friends make 493 whp on a stock block RSX using the Full-Race turbo kit. I've been a fan ever since! I notive your FD manifolds slowly creeping down in price. Hopefully I'll be able to save up enough for it eventually. :lol:

Just read your link to the turbo diesel website on these on SupraForums and will not be going this route now or ever.

Perfect.

The only reason I've been following these turbos at all is due to the high praises spoken of it on the Full-Race website. I've been scouring RX7Club ever since to try to see some other people's results. I was really looking more towards the PT 6266/6766 :lol:

It is a 6-pad is it not? Perhaps you mean ball-bearing?

Intended use:

Power Target: as close to 500 as I can get on e85 :lol: 93 octane and water the rest of the time.



fmw2? Now I'm intrigued. Haha, no but I'm really appreciative of you taking the time to answer my questions. You've always been super helpful to all communities and have been enjoying your continued participation in the RX7 world. :icon_tup:

Now time to start saving up for a Full-Race manifold. :lol:

the 83-75 is definitely a good fit for the <450whp range 13B. 0.91 a/r would be a great match for the 400-420ish level and then for 450+ the 1.00 would be the call.

I encourage you to use a twinscroll T4 manifold with dual WG, this generates the fastest spool, broadest powerband and most area-under-the-curve. Twinscroll also has the best selection of turbine housing A/R's to choose from. Of course you can use the t3 turbine housing and your current manifold to keep things simple.

the FMW is basically the updated S300sx 83/75. It features an EFR style compressor wheel with a slightly better fitting compressor housing and more robust bearing assembly. the same selection of turbine wheels and housings as the other s300sx's applies

http://www.full-race.com/img/article...stinpawlak.jpg
^^We had really good results with justin pawlak running the s300sx 8375 turbo @450whp on his FormulaD / falken tire FC rx7, it lasted the entire season and never skipped a beat. (We were planning to test the FMW on his car but he got sponsored by Ford to drive a v8 mustang and then the car+trailer got stolen in california, sad deal)



a cupped tip 0.91 is pretty comparable to the flat tip 1.00. I tend to favor cupped tip for the rotary engines, because there is so much exhaust energy compared to a traditional piston motor


this power target is pretty much a perfect fit to the S300SX FMW... and you could go either way on the 0.91 or 1.00 - just figure out which fuel youre using the most and what boost level to optimize for and work backwards. feel free to post up ideas i can add my 2 cents and hopefully it helps someone else too

Thanks for that geoff

Is the 1.0 and 1.10 direct fit or would I have o modify my downpipe ?

there are 3 different fitments available for these housings

a) standard borgwarner S300SX 'marmon flange': this comes standard on most airwerks turbos. The marmon is the least expensive and easiest to swap between with best availability. http://www.full-race.com/store/image...-content-8.jpg and
http://www.full-race.com/store/image...content-18.jpg

b) Extended snout s300sx: The extended snout is the hardest to fit for most applications but depending on your manifold may work on the 13B
http://www.full-race.com/store/image...mw-turbo-1.jpg

c) Full-Race Vband: Full-Race machines the standard s300sx housings marmon to a locating nub then we preheat and perform a special tig weld between the cast housing and the steel vband. This makes the BW share the same fitment and footprint to garrett andrecision turbos like GT40R or T04Z... or blown up PTEs that dont want to change the DP or anything else - just turbo swap and go
http://www.full-race.com/store/image...-content-7.jpg

Hi guys I'm in the market for a new turbo and have been looking at the s366 for quite some time now but have been hesitant on pulling the trigge for one reason. A friend of mine has a gt4088r and I've fallen in love with it. The response and low end is insanely quick and pull very hard all the way to the top end. The car is specifically set up as a street car with occasional track use (drag).

My goal is upper 500s to mid 600s with half bridge and e85. Would the s366 or s363 be able to achieve this? How would either of these turbos compare to the gt4088r? What a/r would you recommend? Obviously the 1.10 would seem to be the right choice but I don't want it to be laggy.

Thanks in advance.

ive got years of experience with the gt4088R, ran it on my personal car for 2.5 years in fact. It is a good turbo, reliable, spools well. It was ahead of its time especially for 2000-2004 but there are a lot better turbo choices now IMHO. When you 'fell in love' with your friend's car - did it have a 'twinscroll' divided exhaust manifold? -- Combining the right manifold with the right turbine housing makes a huge improvement on these engines (especially on the GT40R turbine wheel, undivided it is lagggy!)

here are my suggestions:

-borgwarner's 'S300' answer to gt4088R killer is the S300SX FMW: BorgWarner S300SX FMW Turbo - Full-Race.com -- both turbos flow the same 75lb/min airflow however the BW spools earlier, responds quicker and makes more power than a gt4088R due to the 83mm od compressor wheel (lower inertia) and J-type 'cupped tip' turbine wheel. below is a customers fully built STI with both of these turbos, back to back comparison (solid line = FMW, dotted line = GT)

http://www.full-race.com/store/image...content-14.jpg

*neither the BW turbo nor the gt4088R will be able to get to a true mid-600hp target (which requires ~80+lb/min airflow on the 13B)

--the S363: BorgWarner S300SX 8875 Turbo S362 - Full-Race.com 88mm OD compressor wheel -same diameter as the GT4088R - so it has comparable inertia, but is higher flowing. This is the turbo howard coleman is experimenting with and many <600hp 13B's use as a "bang-for-the-buck" turbo. When i took my gt4088R off, this turbo went on. Same spool, much more power I loved it... however soon after i got spool hungry and went to EFR8374

-- the S366 BorgWarner S300SX 9180 Turbo S366 - Full-Race.com spools remarkably well and is about the same as the GT4088R. really impressive.


all that being said... Im a turbo engineer and work with ford and BW on many different projects. The latest generation BW turbos are their EFR series, if you are considering a gt40R dual ball bearing turbo, i strongly encourage you to do some research on the EFR turbos - they truly are THAT good. We usually have a long backlog, but currently all EFR are in stock (first time in 3 years)

EFR 8374 1.05 a/r : BorgWarner EFR 8374 Turbo - Full-Race.com -- this turbo makes S363 power with spool and response comparable to a small t3/t4

and EFR 9180 1.05 a/r: BorgWarner EFR 9180 Turbo - Full-Race.com -- this turbo makes more power than the S366 and S467 but spools like an S360

i hope this helps lmk if you have any other questions

How good are the wastegate and bov on the efr turbos? Are they effective on a rotary engine?

I was considering getting a wastegated EFR as it would work out fairly cost effective not having to also buy a wastegate and BOV and also a little bit less fab work, plus making it all a bit more "legal" looking to the "powers that be", not to mention the amazing spool and flow claims.

+1

Pm sent on the 1.0 -1.10 back housing

the CRV (compressor recirc valve) aka 'BOV' works extremely well. the simple design vents charge air (high pressure) directly to the compressor's inlet (low pressure). I have not seen any issues or failures. there are already aftermarket options available but Im dubious of any benefit

the internal WG also works very well. It is the largest diameter internal WG ever used in a production turbo. Keep in mind the restriction for you guys is the turbine housing A/R size, not the WG. I like divided twinscroll exhaust manifolds for 13B rotary engines and the 0.92 a/r is a little bit small if you plan on boost levels above 28+ psi. In some instances people blame the dropoff in performance on the IWG but its usually backpressure and A/R related. I asked BW to make a larger A/R IWG housing but they said no, larger housings would be ewg only for maximum performance

compared to traditional turbo kits with wastegates, dumps/flanges/clamps, external bov, etc ... the engine bay looks clean and uncluttered with the EFR in place. here is a photo of the EFR install just completed on the nemo racing time attack evo

https://fbcdn-sphotos-f-a.akamaihd.n...43641126_o.jpg