as the snow settles in, here in Wisconsin, and SEMA winds up it is time to scan the interesting new turbo landscape. warning... there may be numbers involved, but that's what makes it interesting to some. others feel free to move on.

two new turbos have arrived that catch my interest. i will use a few other turbos for comparison.

the new items are the Garrett GTX4088r and the Borg Warner S300 series 63 with a billet Fully Machined (compressor) Wheel. otherwise known as a FMW.

to get an idea of how the billet wheel compares to cast let's look at the normal GT4088r and the BW S363. i will also throw in the GT4094r and the BW EFR9180.

i am aware there are other brands besides the above but i haven't seen compressor maps and therefore am unable to compare.

the comparison is a bit different since i have elected to use just the 65% efficiency flow numbers. some compressor maps use 60 and some don't so to get apples to apples i am looking at 65%. of course all the turbos do flow 60% and the gross pounds per minute number will be larger than 65% but we are just comparing relative performance here.

let's first zero in on the size of the wheels. i use average area in square inches. pls see my sticky "Turbo Comparison" thread for the details.

............................compressor............ .turbine.......hot to cold ratio.........material

GT4088r.................7.167..................... 6.423...............89%..................cast alu

GTX4088r...............7.167.....................6 .423................89%.................billet alu

BW S363................7.06.......................6.3 1..................89%..................cast alu

BWS363 FMW.........7.06.......................6.31....... ...........89%..................billet alu

GT4094r.................8.175..................... .6.423................79%.................cast alu

BW EFR 9180.........7.974......................7.189..... ...........90%...............billet alu


as you can see, the Garrett GT4088 and BW S363 are pretty close and the GT4094 and EFR are a touch larger. also, the two new billet entries are the same outer dimension as their cast predecessors.


FLOW

here we get to the rubber meeting the road. do remember that my flow number is at 65% which is not quite max flow pounds per minute-wise. we are looking for relative comparisons here.

i do flow at one pressure ratio (14.7), 20 PSI and Max... (at 65%).

........................(14.7)..........(20)...... ...........(Max and PSI)............(Surge at 2.2 P R)

GT4088r..............62.............65............ ..........67@24 psi..........................23

GTX4088r............69.............77............. .........80@ 32 psi.........................25

BW S363.............59.............67................ ......72@ 42...............................27

BW S363FMW......57............66..................... .76@ 39...............................20

GT4094r...............69............77............ ..........78@ 29...............................25

BW EFR 9180.......64............74....................... 87@ 37..............................22

note the difference in flow between the GT4088r and the GTX4088r as well as the much higher boost level which favors the more stout billet alu material. it is worth knowing that the GT4094r, being a Garrett hybrid is the same outer dimension as the GT4088 series. it does not appear that the BW FMW carries much advantage til higher boost levels at the 65% efficiency level. finally, the EFR 9180 really puts out on the topend.

surge numbers are worth a look. the lower (further to the left on the compressor map) the better.


EFFICIENCY

the table relates compressor (average sq inches) size to flow at 65%

................................Compressor area........Flow................relationship

GTX4088r........................7.167............. .......80........................11.16

BW EFR 9180..................7.974.....................87 ........................10.93

BW S363 FMW................7.06......................76... ......................10.76

BW S363........................7.06.................. ......72.........................10.19

GT4094r..........................8.175............ .........78..........................9.54

GT4088r..........................7.167............ .........67..........................9.35


What's it Co$t?

............................Price

GT4088r..............$1699

GTX4088r.............$2600 (est)

BW S363...............$950 (includes 3 inch V band option)

BW S363 FMW.......$1250 (estimate.... thru the grapevine FWIW)

GT4094r...............$1752

BW EFR 9189........$2418

(prices from Turbosource and Full-Race)



price per pound of flow @65% efficiency:

BW S363.......................................$13

BW S363 FMW...............................$16

GT4094r.........................................$2 2

GT4088r........................................$25

BW EFR 9180.................................$27

GTX4088r......................................$32

all of the above turbos have the T4 footprint and should work on most manifolds. there's something for everyone looking for 500+ hp both from a price and efficiency aspect.



howard

 

The GTX4088R is probably not going to be out til after summer, and in the $2600 range...

 

None of the baller turbos are worth a hot damn unless you're pushing the envelope and have thick pockets.
Get a journal bearing t4 with two cast wheels and never look back.
Early adopters get the shaft. Ask Obamacare.

 

I plan on only running 15 psi, on 93 octane looking for 400+whp with a wide powerband (hopefully). Geoff recently recommended the S300SX FMW turbo (61.4mm), which is smaller than the 363, but should spool quicker. Using the forged milled "billet" compressor wheel to deliver the same amount of top end flow as well.

 

I think you're highly overrating a journal bearing turbo's neglihable spool difference, lower price, and ability to be rebuilt in your own garage (inexpensively too).

 

Is there any info on the new 64.5mm FMW? Diesel guy are already testing it. Turbo like it would be a great fit for a rotary.

 

"Is there any info on the new 64.5mm FMW?"

when i received the compressor map for the BW S363 FMW i believe it had the cold side wheel dimensions and they were 64.5 X 87.36. it is this wheel and turbo that appears in my post (one) in this thread. this makes the area 7.17 sq inches V 7.06 of the S363.

this would line it up w the turbo that you are referencing re "Diesel guy."

hc

 

We've got the GTX4088Rs in stock, who wants to try one out ?

Garrett GTX4088R

 

You donate one and I'll e85 my car and push it til it can't breathe anymore on your old manifold setup lol

 

The EFR9180's seem to work great. A local shop fitted one to an FD circuit race car running a 13B half bridgeport on E85. The car is currently beating everything else in it's class and seems to do so with ease. The EFR spools 1000rpm earlier than the T70 turbo it replaced and has much improved transient response. Making 520-540rwhp on 18psi from memory. In one race the fuel filter blocked and afrs got as high as 15.0 but somehow the engine didn't detonate. God knows what the egt's got up to but the GammaTi turbine wheel didn't seem to mind either way.



The 64.5FMW 300SX3 is going to be an awesome turbo for the $ I think!


"The new S30064SH67XX Super Core, which will have an all-new, O.E. 64.5/87.4mm FMW compressor, and these have actually been developed to match the peak flow of the cast 66/91mm wheel, while providing quicker response.

They will be, essentially, identical to the 62FMW for fitment, and will also include the 6-pad thrust upgrade."

 

This will be my next turbo

 

My s362 keeps leaking oil after i rebuilt it and i noticed the shaft was scored. I cant find any info where to find a new shaft, so this is leading me to get a new turbo for 2014. Power goals are 500-550hp

1.00a/r is best? Im looking for quick spool but not sacrifice the top end.

 

"Power goals are 500-550hp"

you have a lot of choices in the 500-550 area... you are looking for a turbo w an approx 7 sq inch average compressor area. see my Turbo Comparisons thread in this section for a list.

some of the smaller turbos might just make (or not) 500 but they would be really straining.

one of the cheapest routes would be the BW 177283 w a 177209 turbine housing. around $800 with an additional $150 for a 3 inch v band

an uprate of that turbo would be the new BW S300 64 mm FMW. upgraded are the compressor wheel (billet and slightly larger than the 177283) and the bearing assembly... although the 177283 bearing assembly works well. around $1300

other turbos such as the Garrett GT4088r would also be in the same power area.

the new GTX4088r and the GT4094r are both excellent options but are 600 hp turbos.

i am not very familiar w the Precision line so others might want to chime in.

howard

 

Howard- do you have a p/n to that s300 64mm fmw? Really would like to stay in the lower $1k price range on turbo's

 

i don't (yet) know the PN but i do have a currently confidential compressor map for the 177283 V the S300 64 FMW.

the two wheels make the same net (taking into consideration efficiency) air at one pressure ratio at the 72% efficiency area but as the output rises the FMW pulls away to a 7% margin.

that's around 35 rotary rwhp. increased efficiency also helps engine life as cooler air passes by the throttle body.

given the 177283 is an excellent turbo, the 7% increase in output along w a better bearing assembly makes the S300 64 FMW an attractive rotary option.

i note the smaller (GT35 competitor) S300 62 FMW is being offered around $800 which does include the uprated bearing.

maybe the S300 64 FMW will price in the 62 neighborhood which would be welcome.

hc

 

Any info on how a Turbonetics T-66 would compare to an S363? I found a T-66 (1.00 exhuast housing) for $500 whereas the S363 is probably in the $800 range. I'm thinking the S363 would be the preferred turbo, but I'm not certain. Also not familiar with Turbonetics, but any insight would be much appreciated.

 

T66

compressor area 7.65 sq inches so it is bigger than a midrange turbo but not as big as the large 8 inch 80 pound 600 rotary rwhp class. it makes 74 pounds at 25 psi which is good for approx 557 max.

the T66 uses a P trim hot side wheel which is 5.89 sq inches and is small (77%) in relation to the compressor which will result in higher retained internal engine heat and backpressure.

the BW midsize cast comp turbo (PN 177283) offers a 7.06 compressor with a large 6.31 hot wheel.... hot wheel is 89% of cold wheel.

airflow is good for 550 rotary max.

get it w the optional 177209 hot side housing and a 3 inch V band mod.

a few hundred over the T66 but will pay dividends going forward.


howard

 

and you can buy NEW s360s & s366 from the boost lab for $600 or 650 with the marmon flange

http://www.ebay.com/itm/Borg-Warner-S360-T4-91-A-R-Turbocharger-83-75-Extended-Tip-/321387112890?pt=Motors_Car_Truck_Parts_Accessories&hash=item4ad42a29ba

 

when considering a Borg Warner Airwerks (non EFR) turbo do understand they come w a funky 4.21 inch turbine V band. that means you will have to butcher your downpipe and it will be expensive and may not be pretty.

the other consideration is they generally come w not an optimal hotside housing.

when you are doing a cost on such a turbo do consider these factors.

for instance Boost Lab is showing the S300 60 for $728.18. that is w a .88 hotside. the recommended hotside is .91. Boost Lab shows a price of $177.85 for the .91 housing.

$906.03 and you have a 4.21 inch back end with which to deal. $$.

Full Race sell the turbo for $799.80 with a .91. they will convert the back end to 3 inch for $150.

$949.80 and you are good to go.

of course all the prices are off the website and YRMV.

part number for the .91 is 177207 works really well on the S300 60
part number for the 1.0 is 177209 works really well on the S300 63

i don't sell turbos, i guess i buy turbos... Turbosource is a well regarded vendor on this site and it would be great if they offered rear housing swaps and a 3 inch option.

howard

 

or if you consider my link and buy the turbo .91 ar s300 83/75 AND the marmon flange adapter for $660.

you will save $289.80 and will only have to buy the raw material to tig up a downpipe.

vs. $150 for the vband service and a $50 vband clamp.

 

Yeah I was really worried about the small hot side as far as back pressure and EGTs. Not to mention old wheel technology. In your opinion do you think it is necessarily a poor turbo selection for an REW and the BW is worth the extra $300 or so? I was heading that way before the T-66 popped up but I wasn't comfortable buying it as I know very little about Turbonetics as a whole let alone on rotary applications. It was pushed to me as a Garret equivalent to an S366, but I'd seen members of the forum claim the S366 was a bit lazy for their liking so I had my goals set on an S363.



Also curious as to what may drive spool characteristics. Is it the size of the exhaust wheel or the size of both? I was figuring that the S363 would outspool and hopefully provide more power under the curve until peak, but would the small exhaust wheel make it the better performer? From what I've seen of your turbo comparisons the older Garret wheels offer relatively small increases in you examples of.

If it because the the wheel designs take advantage of certain boost ranges? It's interesting that in 10 psi on the GT4088R, you only have a flow difference of 5 pounds yet it has a difference of 8 lbs of flow in just 5.3psi on the GTX4088R. Is that a result of wheel style? Is area or wheel styles also applicable to the exhaust wheel? My only concern with the BWs was that the exhaust side might be too large since all their turbos seem to max out close to the 40 psi range and the designs are pushed towards maximizing output towards that region. Perhaps the high boost rating of the turbos is just a side effect of having a sufficient rotary friendly hotside?

It seems like a lot of the BW numbers max out at astronomical psi ranges (for most of us mere mortal RX-7 owners). When you say that an S363 is a 550HP do you go by max flow rating or max flow rating that you will see on your RX7's target boost range. I'm also curious as you how you figured out the above numbers on flow at 14.7 and 20 psi.

My builder/tuner and friends hate me because I over research/think/analyze everything and it takes me forever to pull a trigger, but it just makes me more comfortable. You seem to be like to do the same thing but are much more intelligent and experienced than me and whereas I go into the rabbit hole with all the numbers, I can never seem to find my way back out with any information that I'm confident in which is where you seem to shine. Sorry. You should be getting paid for this type of insight, but just trying to learn and make sense of it and see as best as numbers and theory-crafting can bring me to.


Thanks again Howard for sharing your time and knowledge when you can. Sorry if it's kind of rude to bombard you with questions.

 

T66 is old school technology.

Go with the BW

 

its both. the turbines job is to provide power to drive the compressor. the compressor then takes this power and moves air.

so spool time is somewhere around where the turbine provides enough power to drive the compressor into desired boost.

how much power the compressor takes, depends on the wheel size and design, and how much power the turbine delivers depends on its size and design, and then of course how much energy is coming out of the engine matters too, along with a whole bunch of other things...

 

Talking about the complex relationship of what affects turbo spool...

One thing that really caught my interest is the difference in spool between the EFRs and "regular" Garrett GT, GTX turbos.

It seems like a small difference on piston engine cars in the dyno charts I have seen with direct comparisons.

On the extreme example of a Subaru with its long exhaust path to turbo there is barely any difference in spool (~250rpm).

It seems like a HUGE difference in spool on rotary cars (~1,000rpm or more).

I mean, nothing comes close to spooling as fast on a rotary, not even choking it down with a tiny turbo.

I think it must be due to a relationship of exhaust velocity. The lighter exhaust wheel really seems to magnify the affects of high exhaust velocity.

I think it is because the traditional way of trying to get spool with exhaust velocity in tighter AR housings and smaller exhaust wheels- while it works with the rotary- it is also somewhat counterproductive.

It is counter productive on the rotary because it causes more exhaust manifold pressure which in turn limits exhaust velocity out the exhaust port.

Higher exhaust velocity out the port means its also pulling more intake/fuel into the exhaust during "overlap" (there is more to this dynamic on a rotary than just port timing)- which means more exhaust energy and higher exhaust velocity downstream of the port.

The downside of increased mass of turbine wheel has been greatly diminished with the EFR turbos and so the rotary "overlap" effect (as noted above) has been greatly magnified.

This is my theory on why EFR turbos spool so fast on rotaries compared to piston engines.

I first noticed this affect on a rotary when putting larger exhaust wheels (O trim, P trim) into the same S5 based (~T25 size) exhaust housing. The rate of spool actually improved (despite the increased mass).

Whatever the case is, its nice that a development in the automotive field shows more improvement for rotaries than piston engine cars for once.

 

Thanks for the info.

Thanks for bringing the EFR results to my attention. They look really impressive. The GTX4088 look amazing at the boost levels that I think the majority of us see. I've noted the relatively high levels that Borg Warners get their lbs/min figures (generally in the 40-psi range). Looking at Howard's post it would seem the GTX4088 would be the hot ticket having a 5 lb/min advatage @ 14.7psi and 3lb/min @ 20psi over the EFR 9180 which seems like it would be an amazing pump gas turbo, but if I'm correct that isn't a reflection of how fast a turbo may or may not spool. I'm just curious if the Borg Warner wheels are designed too much with higher boost levels in mind and as a result more sacrifices than necessary are made at sub 30 psi levels

I'm not the smartest guy when it comes to this stuff, but I am in the market. after your comment I went searching around and didn't find much on the EFR 9180 other than this chart from the Turbosource Blog.



It's certainly looks like a solid turbo, but I wonder if the parameters are reflective of their point. The MPH seems to show that it will out perform a S366 flat out, but does it show response or is it a marketing angle. Now I would just like to make clear that this isn't a shot at Turbosource, I just really do not know.

I was looking into an S366 and many people on the forum seem to be of the opinion that it is lazy, where as my tuner and friend this isn't super responsive. Friends tell me I'm over thinking it and grasping at minuscule amount of differences (which I may be), but if I can have something just a smidgen better due to some research I figure, why not?

The 8374 vs the 6262 response was interesting and did seem drastic, but the 12 psi mark felt like it wasn't quite reflective of what I would be doing. On the one hand I'm really appreciative of the businesses that share their findings, but also skeptical at the same time of how the info might be presented in a way that might mislead someone who doesn't have the broadest of knowledge on the subject (like me) into seeing something being larger, more beneficial, than they are. I feel like I'm learning, but I'm not sure I'm comprehending it properly if that makes sense. Perhaps random forum members aren't the best place to seek advice, but I think this forum's is quite exceptional and intelligent in areas that I lack and has a hell of a lot more practical experience.