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Turbo confusion

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Old 04-05-11, 10:06 AM
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Turbo confusion

as i was exchanging PMs w a potential engine customer he disclosed that he was seriously thinking of going w a BW EFR 67 mm...

previously he had bought a GTX35... given the GTX35's map (around mid 70 pounds per minute) i figured he liked the lighter hotside wheel and some of the neat features and that he was trading one turbo for something of approx equal, or perhaps a touch more, output.

i have a feeling he did too.

i wanted to check out the trim on it and a few other details so i visited the site and started looking thru the 120+ page document.

http://www.full-race.com/articles/efrturbotechbrief.pdf

as most know the EFR series turbos do have lots and lots of neat new age features and truly there are 112 pages of yummy reading re the details.

of course then there are the numbers and on page 113 forward my eyes opened wide.

there are a series of compressor maps and on each map the inducer exducer sizes are disclosed.

so map 2 (page 114) is the "67 MM EFR"................ o k, here's the turbo my guy wants to trade his GTX35 for. let's take a closer look at the details.

inducer 53.9 mm
exducer 67 mm

max air? 44 pounds.

and here "TURBO CONFUSION" re-emerges.

when we think 67 mm turbos... we think of the A-Spec GT500r, we think of the TO4r and the TO4Z and the PT67.

these 67 mm turbos have 67 MM inducers, not exducers and they make mid 70 pounds per minute+, not mid 40s.

this is not a knock on BW, which i like, nor Full Race, it is merely an attempt to draw your attention to the continuing confusion re turbo nomenclature.

that's why i did my stickied thread entitled turbo comparisons... using a better comparative yardstick.

so if you are looking at the new line of BW EFR turbos do reference pages 113 to 118. check out the actual compressor inducer and exducer sizing.

another item that many of us are aware of but it justifies repeating... take the hp numbers and divide by 1.3 for the rotary.

changing over piston hp to rotary and using BW's figures:

62mm (T3) 450 piston 346 rotary
67mm 500 piston 384 rotary
70mm 550 piston 423 rotary
76mm 650 piston 550 rotary
83mm 750 piston 577 rotary
91mm 1000 piston 770 rotary

this post is not to paint the new turbos negatively (or positively) but to point out that given the unusual method of referencing the compressor sizing board members will need to make the correct decisions.

i will be updating my turbo comparison thread w the apples to apples.

it will of course be interesting to see how they perform. i will say i am not overly impressed w the comp maps but the maps are not necessarily the definitive statement and there are some very neat (esp the lowered turbine mass) aspects.

howard
Old 04-05-11, 02:29 PM
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Subscribed as I have already ordered the twin scroll 9180 1.05.
Old 04-05-11, 06:17 PM
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Borg Warner has always referred to their turbos using the larger end of the compressor/turbine wheel. I think this was more of an internal way they labeled things but i agree for the consumer its not the easiest.
Old 04-19-11, 04:51 PM
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Howard,
A slip of the calculator.

76mm 650 piston 550 rotary (500 rotary)

Good job,
Barry

Originally Posted by Howard Coleman CPR
as i was exchanging PMs w a potential engine customer he disclosed that he was seriously thinking of going w a BW EFR 67 mm...

previously he had bought a GTX35... given the GTX35's map (around mid 70 pounds per minute) i figured he liked the lighter hotside wheel and some of the neat features and that he was trading one turbo for something of approx equal, or perhaps a touch more, output.

i have a feeling he did too.

i wanted to check out the trim on it and a few other details so i visited the site and started looking thru the 120+ page document.

http://www.full-race.com/articles/efrturbotechbrief.pdf

as most know the EFR series turbos do have lots and lots of neat new age features and truly there are 112 pages of yummy reading re the details.

of course then there are the numbers and on page 113 forward my eyes opened wide.

there are a series of compressor maps and on each map the inducer exducer sizes are disclosed.

so map 2 (page 114) is the "67 MM EFR"................ o k, here's the turbo my guy wants to trade his GTX35 for. let's take a closer look at the details.

inducer 53.9 mm
exducer 67 mm

max air? 44 pounds.

and here "TURBO CONFUSION" re-emerges.

when we think 67 mm turbos... we think of the A-Spec GT500r, we think of the TO4r and the TO4Z and the PT67.

these 67 mm turbos have 67 MM inducers, not exducers and they make mid 70 pounds per minute+, not mid 40s.

this is not a knock on BW, which i like, nor Full Race, it is merely an attempt to draw your attention to the continuing confusion re turbo nomenclature.

that's why i did my stickied thread entitled turbo comparisons... using a better comparative yardstick.

so if you are looking at the new line of BW EFR turbos do reference pages 113 to 118. check out the actual compressor inducer and exducer sizing.

another item that many of us are aware of but it justifies repeating... take the hp numbers and divide by 1.3 for the rotary.

changing over piston hp to rotary and using BW's figures:

62mm (T3) 450 piston 346 rotary
67mm 500 piston 384 rotary
70mm 550 piston 423 rotary
76mm 650 piston 550 rotary (500 rotary)
83mm 750 piston 577 rotary
91mm 1000 piston 770 rotary

this post is not to paint the new turbos negatively (or positively) but to point out that given the unusual method of referencing the compressor sizing board members will need to make the correct decisions.

i will be updating my turbo comparison thread w the apples to apples.

it will of course be interesting to see how they perform. i will say i am not overly impressed w the comp maps but the maps are not necessarily the definitive statement and there are some very neat (esp the lowered turbine mass) aspects.

howard
Old 04-19-11, 06:01 PM
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Reminds me of when AMD start labling CPU's at an "efffective" clock speed. while intel just labled them all by the exact mhz/ghz. shame. yet another thing thats long been needing a standardization. right?
Old 04-19-11, 08:02 PM
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53.9mm comp inducers work great on an FD.......


If you have two of them
Old 04-21-11, 11:43 AM
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Originally Posted by lastphaseofthis
Reminds me of when AMD start labling CPU's at an "efffective" clock speed. while intel just labled them all by the exact mhz/ghz. shame. yet another thing thats long been needing a standardization. right?
I take it you never compared the speed of a Barton Core Althlon XP @ 2800MHz to an Intel P4 Extreme Edition at 3.6GHz.

Guess which was faster
Old 04-21-11, 03:57 PM
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As always a great post Howard.

Have u had any chance to look at the new Comp turbos that came out a few years ago?

Turbochargers Comp Turbo - Turbocharger, Rebuilds, Turbo Kits

They are showing great results here in norway the last year.

JT
Old 04-22-11, 08:34 AM
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ya it's confusing

I posted a snap shot of when i compared the 35 vs the 83 a while back.
Attached Thumbnails Turbo confusion-gtx-vs-efr.jpg  
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