Turbo Comparison... includes NEW 2023 GARRETT GBC & BW SX-R turbos/post one
 

exducer inducer trim GT say what?

as i initially approached understanding turbos things became more, not less, confusing... some referenced turbos by inducer size, some by exducer. of course they reverse when you are talking turbine wheel V compressor.

i felt there needed to be a better way of comparing turbos.

as you may know all wheels have a minor diameter size and a major diameter. they are often in inches or millimeters. i wanted something simple to help me with sizing them.

i settled on the following:

take the minor diameter and solve for the area.
take the major diameter and solve for the area.
add together, divide by two.

you now have the average area of the wheel.

do it for the compressor (coldside/intake) , do it for the turbine (hotside/exhaust).

you now have two understandable numbers that help a great deal when you seek to compare turbos. needless to say there is a major correlation between area and airflow.

the cold side area determines the airflow potential, the hotside must deliver the power to actualise the potential.

hot area V cold area is especially valuable w the rotary. the rotary places a premium on large hot V cold wheel relationships. you want something approaching 1 to 1 areawise.

EDIT NOTE: significant flow advances for newer turbos which are bolded



here's my list in square inches:...............cold.......................h ot....................relationship

GT2860RS (Disco Potato).....................3.549................. ..3.105.................... 87%
FC T2 (OEM).........................................3.57 9....................4.288................... 119
BW EFR "6255".......discontinued..........3.79........... ...........6.758....................178
TDO5H 18G..........................................4.375 ......................3.363....................77
BW EFR "6758"....................................4.498... .................5.229....................86
G30-660............................................... .4.50.......................4.02.................. ..89 (2021 Garrett)
BW EFR "7064"....................................4.632... .................5.229.....................88
GT3071R........................................... ....4.776....................4.019................ ... 84
GT3071R........................................... ....4.776....................3.683................ .... 77
G30-770............................................... ..5.1.........................4.02................ ....79 (2021 Garrett)
GT2876............................................ .....5.224.....................3.108.............. ..... 59
RX6 TCW 17..........................................5.29.. .....................4.315....................82
BW K27............................................... ..5.36.......................5.06................. .....94
TO4E 57 Trim........................................5.369. ....................5.408 (Stg 5)......... 100
GT3776............................................ .....5.374.....................5.441.............. ...... 101
BW S200SX...........................................5 .40......................5.24..................... ....97
TO4E 60 Trim.........................................5.476 ....................5.408...................... 98
GT3076R........................................... .....5.511...................4.019................ ....... 73
BW S300SXE 7670..................................5.52........ ............5.27........................95
BW EFR "7670"......................................5.524. ..................5.229.......................95
GBC 35-700............................................5.5 7.....................5.13........................ 92 (2023 Garrett)
GTW5857........................................... ....5.59......................4.52................ .......81 (2015 Garrett)
GTX3076R.......................................... .....5.614..................4.019................. ......71.5
RX6 TCW10............................................. 5.63....................4.315..................... ..77
HKS TO4S.............................................. .5.64.....................5.89.................... ....104
Turbonetics 60-1....................................5.647........ ...........5.89....................... 104
Turbonetics T61......................................5.79..... ............... 5.89......................101
TO4B 62-1..............................................5.8 7..................... 5.89...................... 100
G30-900............................................... ...5.87.....................4.02.................. ......69 (2021 Garrett)
G35-900............................................... ....5.87....................5.16.................. .......88 (2021 Garrett)
FD (OEM)............................................. ....5.972.................5.25.................... ..... 88
RX6 TCW 76.............................................6.0 3....................4.315......................72
Precision 6062.........................................6.27. ...................5.408......................86
RX6 TCW77............................................. .6.356..................4.315..................... .68
Borg Warner S300 60 PN177282 & 80.....6.383..................6.328............... ........99
GT3582R........................................... ........6.386..................5.171.............. ........81
HTA 3582R (Forced Performance)............ 6.386.................5.171....................... 81
GT3574 (A-Spec, Turblown TD61)..............6.386..................5.89.(P) .................92
GT3082R........................................... .........6.386.................smaller than GT35R..?
Precision 6262...........................................6.4 48..................5.408.....................84
Precision 6265........................................... 6.448.................5.885 (P)...............91
GTX3582R.......................................... .........6.519..................5.171............. .......79
BW S362 FMW (billet)................................6.53...... ...............6.35......................97
BW S300 SXE 62-76..............................6.54.............. .......6.31.....................96 (2015) PN 13009097056 my 500 hp value pick for 2015
BW S300 SXE 62-80..............................6.54.............. .......7.15..................109 (2015) PN 13009097053 hot wheel mis-matched IMO
BW EFR "8374"..........................................6. 626..................6.23....................94
BW, R85, TEC300...................................... 6.667...................6.93...................... 104
GTW6262........................................... ........6.69......................5.38............ .......80 (2015 Garrett)
GTW6265........................................... .........6.69....................5.88............. .......88 (2015 Garrett)
BW Bullseye S362.......................................6.69... .................6.31.....................94
GTX3582r GEN II........................................6.73.... ..................5.15....................76..(201 8 Garrett)
BW SX-R................................................. ....6.78......................6.31................ .....93 (2023 BW)
HTA 3586 (Forced Performance).................6.839................ ...5.171....................76
GTW6465........................................... ........6.84......................5.88............ ........86 (2015 Garrett)
Precision GEN2 6266..................................6.91........ .............6.........................87 (2015)
Borg W S300s 61/87(2010 catalog)...........6.946..................6.928... ..................100
Precision 6765............................................6. 997.................. 5.885 (P).............. 84
Precision 6768............................................6. 997..................6.652 (GTQ)........... 95
TO4Z, A Spec GT500 PT67...........................7.002.............. ....5.885 (P)...............87
GTX3584RS......................................... .........7.02.....................5.13............ .......73 (2016 Garrett)
GBC 37-900............................................... ....7.03....................5.81.................. ..83 (Garrett 2023)
G40-900............................................... .........7.04.....................6.58............ .........93 (2021 Garrett)
BW S300 SXE 63..........................................7.06.. ..................7.15.....................101 (2015)
Borg Warner S300 63 PN177283................ 7.06....................6.31....................89
Precision GEN2 6466.....................................7.07..... ..............6.........................85 (2015)
G35-1050.............................................. .........7.08.....................5.13............ .......72 (2021 Garrett)
GTW6765........................................... ............7.09....................5.88.......... .......83 (2015 Garrett)
BW EFR 8474.............................................. ..7.10....................5.91..................83 (2019)
GT3788R........................................... ........... 7.155................. 5.694...................80
GT4088R........................................... ........... 7.167................. 6.423...................90
GTX4088R...........................................7.167.. ................6.423.................90
Borg Warner S364 FMW...............................7.17............ ........6.31....................88
BW S300 SXE 64...........................................7.17. ...................7.15...................99 (2015)
GT4088............................................ ............ 7.26.................... 6.633..................91
Precision 6766...........................................7.5 1......................6......................80 (2016)
BW SX-R................................................. .....7.52.....................7.15................ ...95 (2023 BW)
T78............................................... ............... 7.584................... 5.903................. 78
T88 33D............................................... ........ 7.58..................... 7.577................. 100
T66............................................... ............... 7.657.................. 5.894.................77
Borg Warner S300X 9179............................ 7.691................... 5.885 (P)........... 77
BW S300 SXE 66..........................................7.74.. .....................7.15...................92 (2015)
Borg W S300sx 66/91(2010 catalog)............7.743....................7.151 .................92
Garrett G42-1200...........................................7.7 5.....................7.52..................97 (2018)
G40-1150.............................................. ..........7.76......................6.58.......... ........85 (2021 Garrett)
BW EFR 9180.............................................. ....7.84....................7.189................. 92
Borg Warner S366......................................... 7.88.....................7.15................... 91
BW S300 SXE 69...........................................7.99. ......................7.15..................89 (2015)
Precision GEN2 6870.....................................8.01..... .................6.77..................85 (2015)
Xona/Tial 6894 "XR 95-68 X3C"......................8.17.................... 6.34...................78 (2019)
GT4094R........................................... ........... 8.175................... 6.423..................79
BW S300 SXE 72..........................................8.18.. ................... 7.15......................87 (2019)
BW EFR 9274.............................................. ..8.18......................7.15.................. .....87 (2019)
G 42 COMPACT 1200...................................8.27....... ...............7.51.......................91 (2021 Garrett)
BW EFR 9280.............................................. ..8.36.....................7.15................... ..85 (2019)
GT4294, T51R.............................................. 8.384................... 7.527..................90
Borg W K29 Billet (2010 catalog)..................8.432................... .7.175..................85
T88 34D............................................... ........ 8.449................... 7.577.................. 90
MasterPower "GT42"................................... 8.658................... 6.871................. 79
T70............................................... ................ 8.725.................. 6.648.................. 76
Borg Warner S368.........................................9.1.. ......................7.49....................77
Borg W S400sx (2010 catalog)......................9.174............... .....7.62....................83
Borg Warner S372-80.................................. 9.456................... 7.173................... 76
Borg Warner S372-83.4............................... 9.456................... 7.593................... 80
Borg Warner S372-84.................................. 9.456................... 10.298................. 109
Borg Warner S475....................................... 9.49...................... 10.292.................108
T72............................................... ................. 9.549.................. 6.648 (Q)............. 69
GT4202............................................ ............. 9.726................... 7.527.................... 77
T51R Spl............................................... ......... 9.92..................... 7.194.................... 73
Borg W K29 Billet (2010 catalog)..................8.432................... .7.175..................85
Masterpower GT45................................... 10.082..................... 8.4739.................... 84
T88 34D............................................... ........ 8.449................... 7.577.................. 90
MasterPower "GT42"................................... 8.658................... 6.871................. 79
T70............................................... ................ 8.725.................. 6.648.................. 76
Borg Warner S368.........................................9.1.. ......................7.49....................77
Borg W S400sx (2010 catalog)......................9.174............... .....7.62....................83
Borg Warner S372-80.................................. 9.456................... 7.173................... 76
Borg Warner S372-83.4............................... 9.456................... 7.593................... 80
Borg Warner S372-84.................................. 9.456................... 10.298................. 109
Borg Warner S475....................................... 9.49...................... 10.292.................108
T72............................................... ................. 9.549.................. 6.648 (Q)............. 69
GT4202............................................ ............. 9.726................... 7.527.................... 77
T51R Spl............................................... ......... 9.92..................... 7.194.................... 73
Masterpower GT45................................... 10.082..................... 8.4739.................... 84%


i also have max flow numbers in pounds per minute for each turbo that has a compressor map. take the pounds per minute, multiply by 14.471 to get CFM and divide by 1.92 to get approx max rear wheel rotary hp. or take pounds per minute, multiply by 10 and divide by 1.3 to get to the same general vicinity.

for instance... the GT3582R puts a hair better than 60 pounds per minute between 2.3 and 2.9 pressure ratios. (19-28 psi).

so, 60 X 14.471 = 868 CFM/ 1.92 = 452 max rotary rwhp. if you will notice the compressor map at 60 pounds you will note the RPM lines are very close to vertical which means the compressor is not able to accelerate further... it is very close to stall mode. overdriven.

a turbo acts at this point as a restrictor plate ala NASCAR. no more air. so IF the compressor map is accurate that's about it. you can do the same for any of the turbos.

this thread should be read as a companion to my "Making the case for the (rotary) powered FD.. The Fix.

Making The Case For The Powered FD: The Fix - RX7Club.com

the Fix is AI.

and AI changes how we can fixture our cars. we can run larger turbos because alcohol and water cools the CCP.

so take a look at the above list and pick your poison. i like 550 as a max target as above that number the engine becomes a bit in need of some reconstruction. also, if you have ever been in a 500 hp FD you will quickly realise it is about all you can hope to hook up without different transmissions and rear driveline components.

most of the numbers above should be accurate. feel free to offer any corrections. some turbos above can be fixtured w different hotside wheels. also the new deal is the billet compressor wheel which may offer additional flow per diameter due to less hub/more fins. most of this addition happens at very high pressure ratios (boost) and we are all waiting to see what happens when billet meets rotary.

trim relationships also add or detract from low rpm V higher RPM but area numbers should, i hope, be helpful.

additional turbo discussion welcomed... especially considering the ability to run alot more airflow w AI.

howard coleman

I just want to add what we talked about Howard, regarding compressor aero. This formula applies primarily to cast wheels with larger center hubs, since billet wheels of similar diameter actually have greater wheel surface area than a similarly sized cast wheel. Cheers

Interesting information, but theory and practical application have a pretty wide variation. Nevertheless, useful information. However, its a great ballpark figure, and as you mentioned.. if the compressor maps are accurate, these results should be on par.

A friend mentioned pre-turbo AI, do you have any suggestions on pre versus post turbo AI?

Thanks for the post, I am going to crunch some numbers myself :)

Interesting about the 4202, only77%

I have a GT4202 compressor combined with a GT47 turbine wheel here (92.7mm 82trim), thats far closer to the ideal 100 mark isnt it?

I don't think that 100% is always ideal, I think there are limits to how big you want your turbine to be period, in order to maintain gas velocity and reduce mass. Obviously depending on engine, porting, etc.

Hey howard, thought id update this thread for you and did the figures for a masterpower MP4503(GT45)

Masterpower GT45....................... ......... 10.082..................... 8.4739.................... 84%


what do you think of that for a turbo for a rotary, seems better than a gt4202 from garrett.

Ive been thinking about getting one instead of a borgwarner as i might struggle to spool a 98mm exhaust wheel up

are these figures max pump gas horsepower?//////////////////////yes pump gas w AI///////////////////

In all the turbo research I've done since I bought into my first turbo car 7 months ago, this is the best source on usefull info I've found in one place.
thanx Howard Coleman

FIGURES, printers out of ink......

the GTX3076r and GTX3582R numbers have been added as well will be a number of new BE EFR 2010 turbos.

the new GTX35 looks like a legitimate 570 SAE rw rotary hp package... in the smallish GT35 frame... weighing only 18 pounds.

another turbo that has caught my eye is the Forced Performance billet version of the 80 pound per minute GT4094 in a GT35 frame. they are talking 90 pounds per minute!

it looks like a VERY exciting year for turbo advances.

howard

Great Info- very Helpful, thanks

a "your welcome" to all the thank youz :)

do the final numbers on the right directly relate to HP or are these just a efficiency number?? where can you find the map numbers for the individual turbos...

its efficiency, but my understanding is its a bell shaped curve with the peak of the bell being right at 100, you start to lose in one area or the other as you increase or decrease from 100

like I said, that's just my understanding, I could be wrong.

I'm not so sure. The GTX3582R is only a 79, but it's one of the most efficient turbos ever made. That may jus be a billet thing though...

updated w BW EFR info

Do u have any info on XS Engineering To4s?

Is there formula to work out on say a gtx35 how the different size A/R hotsides will affect the end power figure ?

Howard the
"BW EFR "83".......................................... ..6. 626..................7.938......................11 9"

Is in the wrong spot, it should be below the Gtx3582r

:)

//////////////////thanks, all fixed, Howard/////////////////////////////////////////////////

"Is there formula to work out on say a gtx35 how the different size A/R hotsides will affect the end power figure ?"

i don't think there is a formula but relatively soon i will be doing a dyno comparison between a GT35 w a 1.00 and 1.15 A/R so i do hope to have some data...

BTW, i do recognise the answer is a bit late... :)

howard

Haha all good i bought a GTX35 anyway with the Tial 1.03 rear

I'm stuck between the s366 & t04z...I'm not extra knowledgeable of turbos so I don't really know the significance of flanges & a/r's...guess I'd take I'd take the one with quicker spool
I need help choosing one

another question would be
 

the turbine and the compressor both have a/r numbers. I understand that the larger number on the exhaust side means a looser housing and a later spool able to run at higher rpm without overspeeding.

I think that's what I understand.

Can somebody break it down for me?

have you fot the T04R ???

Good stuff!