turbo cfm comparison chart

[scottm1978]

OK I did many many search's but could not find it.

so could some one post the info with the turbo comparison with the cfm.

thanks guys

EDIT: I found it but can anyone expand on this chart with more turbos.

Stock Turbo
360CFM at 14.7PSI

IHI VF-22
435CFM at 18.0PSI

Small 16G
505CFM at 14.7PSI

Large 16G
550CFM at 14.7PSI

20G
650CFM at 14.7PSI

AVO 450HP
630CFM at 20.0PSI

AVO 500HP
740CFM at 23.0PSI



Straight from wrxworld.com (Jeff Sponaugle).
Ajay

* Registered users of the site do not see these ads.

[STEALTH-WRX]

nicks

60-1
stage 5
.58 a/r

900 cfm

how much.

$680 brand new from turbonetics.

[hotrod]

These are the numbers I've been able to capture so far. There is a little variability from different sources so these include some interpolation on my part.

Notice that turbos that list outputs that are within 1-2% should be considered equal, as there are small variations on how vendors flow test turbos, and interpolating flow off of a small gif image of a compressor map has potential for error, as many on the web are very hard to read, and some are of questionable source.

These numbers do not consider issues about compressor effeciency with great precision. When faced with a turbo that was obviously operating at the very edge of its envelope I tended to round down flow numbers.

You might have one turbo flowing x CFM at 70% effeciency and another flowing x+y CFM at 60% effeciency. The difference in outlet temps could easily negate the apparent advantage of the high flow number. By the same token a modern turbo design that scarcely flows more CFM than an older turbo could easily be running at high to mid 70% efficiencies so the actual mass flow would be much higher than an older turbo running at choke flow and 60% effeciency. Some of these numbers are harvested from manufactures sales literture/advertisement illustrations on the web, with no compressor map to reference.

Last two turbo's that have identical compressor flow characteristics could yield different performance in the real world due to differences in the hot side of the turbochargers. If compressor performance is identical, the exhaust back pressure required to achieve the flow becomes a major determining factor.

High exhaust backpressure reduces the value of boost achieved as the engine looses effeciency because it cannot breath as well against the backpressure. Unfortunately exhaust backpressure data is nearly impossible to find.

Larry

Last updated 12/28/02

Turbo Type      Approx flow @ pressure 
13G turbo         360 CFM at 14.7 PSI ( NOT used as the stock WRX turbo compressor )
IHI VF 25         370 CFM at 14.7 PSI  <--- estimated
Stock 13T Turbo   390 CFM at 14.7 PSI  <--- the stock turbo is actually a 13T compressor 
IHI VF 26         390 CFM at 14.7 PSI  <--- estimated
T3  60 trim       400 CFM at 14.7 PSI
IHI VF 27         400 CFM at 14.7 PSI  <--- estimated

IHI VF 24/28/29   410 CFM at 14.7 PSI  <--- estimated
========= 422 CFM max flow for a 2 Liter at .85 VE pressure ratio 2.0 (14.7 PSI) 7000 RPM =======
IHI VF 23         423 CFM at 14.7 PSI
FP STOCK  HYBRID  430 CFM at 14.7 PSI  <--- derived from HP potential listed on web
IHI VF-30         435 CFM at 14.7 PSI  <--- estimated
SR 30	          435 CFM at 14.7 PSI
IHI VF-22         440 CFM at 14.7 PSI  <--- refigured
T04E 40 trim      460 CFM at 14.7 PSI
========= 464 CFM max flow for a 2.2 Liter at .85 VE pressure ratio 2.0 (14.7 PSI) 7000 rpm =======
PE1818            490 CFM at 14.7 PSI  <--- estimated from max flow numbers
Small 16G         505 CFM at 14.7 PSI
ION Spec (stg 0)  525 CFM at 14.7 PSI  <--- per vendor post 12-27-2002
========= 526 CFM max flow for a 2.5 Liter at .85 VE pressure ratio 2.0 (14.7 PSI) 7000 RPM =======
Large 16G         550 CFM at 14.7 PSI
SR 40	          595 CFM at 14.7 PSI
18G               600 CFM at 14.7 PSI
PE 1820           630 CFM at 14.7 PSI  <--- estimated from max flow numbers
20G               650 CFM at 14.7 PSI
SR 50             710 CFM at 14.7 PSI
GT-30             725 CFM at 14.7 PSI
60-1              725 CFM at 14.7 PSI
GT-35R            820 CFM at 14.7 PSI
T72               920 CFM at 14.7 PSI  <--- Note you would have to spin a 2.0 L
                                           engine at about 14,000 rpm to flow this much air.

IHI VF 25         395 CFM at 18   PSI  <--- estimated
IHI VF 26         400 CFM at 18   PSI  <--- estimated
stock turbo 13T   ~410 cfm at 16 psi <--- estimated
T3 60 trim        410 CFM at 20   PSI
IHI VF 27         420 CFM at 18   PSI  <--- estimated
IHI VF 24/28/29   425 CFM at 18   PSI  <--- estimated
IHI VF 23         430 CFM at 18   PSI  <--- estimated
IHI VF-30         460 CFM at 18.0 PSI  <--- estimate based on trap speeds of cars running this turbo
AVO 320HP         465 CFM at 17.5 PSI
T04E 40 trim      465 CFM at 22   PSI
FP STOCK  HYBRID  490 CFM at 18.0 PSI
IHI VF-22         490 CFM at 18.0 PSI  <--- refigured
SR 30             490 CFM at 22   PSI
Small 16G         490 CFM at 22   PSI
ION Spec (stg 0)  500 CFM at 19   PSI  <--- per vendor post 12-27-2002
PE1818            515 CFM at 22   PSI  <--- estimated from manufactures rated max power 
Large 16G         520 CFM at 22   PSI  <---  upgraded flow some on review of compressor map
========= 526 CFM max flow for a 2 Liter at .85 VE pressure ratio 2.5 (22 PSI) 7000 rpm =======

========= 578 CFM max flow for a 2.2 Liter at .85 VE pressure ratio 2.5 (22 PSI) 7000 rpm =======
HKS GT2835 400 hp 580 CFM at 22   PSI
MRT 400           580 CFM at 16   PSI  <--- added
AVO 400HP         580 CFM at 17.5 PSI
MRT 450           650 CFM at 19   PSI  <--- added
AVO 450HP         650 CFM at 20.0 PSI
SR 40             650 CFM at 22   PSI  <--- added, got lost some how in editing
========= 658 CFM max flow for a 2.5 Liter at .85 VE pressure ratio 2.5 (22 PSI) 7000 rpm =======
HKS GT3037 460 hp 670 CFM at 22   PSI
PE 1820           680 CFM at 22   PSI  <--- estimated from manufactures rated max power
20G               695 CFM at 20.0 PSI  <--- added
HKS GT3040 490 hp 710 CFM at 22   PSI
AVO 500HP         725 CFM at 23.0 PSI
SR 50             770 CFM at 22   PSI
GT-30             790 CFM at 22   PSI
60-1              800 CFM at 22   PSI
HKS GT3240 570 hp 830 CFM at 22   PSI
GT-35R            880 CFM at 22   PSI
T72              1000 CFM at 22   PSI  <--- note you would have to run a 2.0 L engine
                                           at >40 PSI boost to flow this much air









Conversions used where I had control over conversion factors:

1 HP    approx equals   1.45 CFM
1 CFM   approx equals   0.0745 lb of air/min
0.108 Lb/min  approx equals 1 hp
1 Meter cubed/sec   =   35.314 CFS  = 2118.867 CFM
1 KG/sec = 132 lbs/min  approx equals 1771.812 CFM



power coversions:
1 PS = 0.9859 HP  = 75 Kgf m/sec
1.3405 HP = 1 KW    <-- edited to fix stupid typo
1 HP = 746 watts     <-- edited to fix stupid typo

If any of the pros here on the board want to give some add'l info or recommend tweeks to these numbers I'm sure everyone would appreciate it. Some of you may be bound by confidentiality agreements and can't release the actual compressor maps for some of these, but I suspect it would be okay to provide your "professional opinion" regarding these numbers.

Edit log -- uprated orginal estimates of PE1820 per info from AZScoobie. Used compressor map located at http://forums.nasioc.com/forums/atta...postid=1882312

changed VF 24 listings to VF 23/24 as turbos have essentially indentical compressor performance

Corrected backwards conversion statement for horsepower and watts

Added high pressure ratio info on 20G mitubishi turbo

In review of comments to question about flow of 16g large vs 16g small, I decided I probably miss-read the flow map on the 16g large and under rated it too much. It's difference in effeciency at Pressure ratio 2.5 is about 3% due to increased heating, so I am uprating it back to a corrected value.

added SR 40 in high pressure list, got lost somehow during editing

added estimates of IHI VF-xx series, ranking derived from compressor inlet size and exhaust housing / AR ratios. some based on trap speeds reported by users.

PE1818 1820 flows derived from both official rated power output potential 450 PS - 1820, 350 PS- 1818 and individual drag strip performances and a compressor map of unknown reliability.

added 18 psi value for FP stock hybrid based on post by fastburro 12/25/02

Moved HKS turbos into main list following private communication advising test pressure for their ratings is 1.5 bar from protocol_droid 12/26/02

Add flow data for ION Spec OE upgrade stage 0 per vendor post

added maximum usable flow for various engine sizes

5/11/06 Fixed rated flow of stock 13T at 390 CFM, to see compressor map view post :
http://forums.nasioc.com/forums/showthread.php?t=988825

Given how abruptly the turbocompressor rpm lines fall at the right side of the map, I'm using a peak flow at PR=2.0 of .185 M^3/sec as the basis for the flow of 390 CFM. I think 400 CFM is a bit optimistic. This uprates its output from the original estimated value of 360 CFM for the 13G compressor that was believed used on the WRX. )



EDIT to add a note that the stock turbo on the 2.0 L wrx measures out to be a 13T compressor not a 13G as is widely believed. This uprates its max flow from 360 CFM to approximately 385-410 CFM. This gives a max power output of about 280 hp which is slightly below the best power numbers that have been achieved with this turbo. This flow rate is on an estimate based on emphirical evidence like diameter of the inducer and such.

easyfind search key = turbo rank list

[AZScoobie]

Originally posted by hotrod
These are the numbers I've been able to capture so far. There is a little variability from different sources so these include some interpolation on my part.

Notice that turbos that list outputs that are within 1-2% should be considered equal, as there are small variations on how vendors flow test turbos, and interpolating flow off of a small gif image of a compressor map has potential for error, as many on the web are very hard to read, and some are of questionable source.

These numbers do not consider issues about compressor effeciency with great precision. When faced with a turbo that was obviously operating at the very edge of its envelope I tended to round down flow numbers.

You might have one turbo flowing x CFM at 70% effeciency and another flowing x+y CFM at 60% effeciency. The difference in outlet temps could easily negate the apparent advantage of the high flow number. By the same token a modern turbo design that scarcely flows more CFM than an older turbo could easily be running at high to mid 70% efficiencies so the actual mass flow would be much higher than an older turbo running at choke flow and 60% effeciency. Some of these numbers are harvested from manufactures sales literture/advertisement illustrations on the web, with no compressor map to reference.

Larry

Stock Turbo       360 CFM at 14.7 PSI
T3  60 trim       400 CFM at 14.7 PSI
IHI VF 24         423 CFM at 14.7 PSI
STOCK  HYBRID     430 CFM at 14.7 PSI
IHI VF-22         435 CFM at 14.7 PSI
SR 30	          435 CFM at 14.7 PSI
T04E 40 trim      460 CFM at 14.7 PSI
Small 16G         505 CFM at 14.7 PSI
PE 1820           510 CFM at 14.7 PSI
Large 16G         550 CFM at 14.7 PSI
SR 40	          595 CFM at 14.7 PSI
18G               600 CFM at 14.7 PSI
20G               650 CFM at 14.7 PSI
SR 50             710 CFM at 14.7 PSI
GT-30             725 CFM at 14.7 PSI
60-1              725 CFM at 14.7 PSI
GT-35R            820 CFM at 14.7 PSI
T72               920 CFM at 14.7 PSI  <-- Note you would have to spin a 2.0 L
                                           engine at about 14,000 rpm to flow this much air.

IHI VF 24         388 CFM at 18   PSI
T3 60 trim        410 CFM at 20   PSI
IHI VF-22         460 CFM at 18.0 PSI
AVO 320HP         465 CFM at 17.5 PSI
T04E 40 trim      465 CFM at 22   PSI
Large 16G         470 CFM at 22   PSI
SR 30             490 CFM at 22   PSI
Small 16G         490 CFM at 22   PSI
AVO 400HP         580 CFM at 17.5 PSI
PE 1820           580 CFM at 22   PSI
AVO 450HP         650 CFM at 20.0 PSI
AVO 500HP         725 CFM at 23.0 PSI
SR 50             770 CFM at 22   PSI
GT-30             790 CFM at 22   PSI
60-1              800 CFM at 22   PSI
GT-35R            880 CFM at 22   PSI
T72              1000 CFM at 22   PSI  <-- note you would have to run a 2.0 L engine
                                           at >40 PSI boost to flow this much air


HKS GT2835 Turbo about 400 hp approx 580 CFM, pressure not specified
HKS GT3037 Turbo about 460 hp approx 670 CFM, pressure not specified
HKS GT3040 Turbo about 490 hp approx 710 CFM, pressure not specified
HKS GT3240 Turbo about 570 hp approx 830 CFM, pressure not specified



Conversions used where I had control over conversion factors:

1 HP    approx equals   1.45 CFM
1 CFM   approx equals   0.0745 lb of air/min
0.108 Lb/min  approx equals 1 hp
1 Meter cubed/sec   =   35.314 CFS  = 2118.867 CFM
1 KG/sec = 132 lbs/min  approx equals 1771.812 CFM



power coversions:
1 PS = 0.9859 HP
1 HP = 1.3405 KW

If any of the pros here on the board want to give some add'l info or recommend tweeks to these numbers I'm sure everyone would appreciate it. Some of you may be bound by confidentiality agreements and can't release the actual compressor maps for some of these, but I suspect it would be okay to provide your "professional opinion" regarding these numbers.


easyfind search key = turbo rank list

1820 is 695CFM as per the Compressor map from PE. Which is about in line with PE's rating of 450hp.



CT

[scottm1978]

Thanks guys ver informitive.

1 HP = 1.3405 KW I thought 1hp was less than one 1 kw.

Cause over seas people talk about 300 kw being a lot of horse power. but this would covert to only 223 hp

[jlevy]

Actually I believe it's 1kw = 1.34hp



Hotrod,

That's some great reference info.

-JL

[hotrod]

Sorry guys but 1.34 is correct. I am off just a tiny bit as I should have used 1.341022038 KW = 1 Hp but hey who cares about .000522038 KW.

In the other direction it is as below from the National Institute of Science and Technology which is the standards agency for the U.S.


http://physics.nist.gov/Pubs/SP811/appenB8.html#K

horsepower (550 ft · lbf/s) (hp) watt (W) 7.456 999 E+02



Thanks for the info on the PE1820 CT.

Larry

[driggity]

Originally posted by hotrod
Sorry guys but 1.34 is correct. I am off just a tiny bit as I should have used 1.341022038 KW = 1 Hp but hey who cares about .000522038 KW.

In the other direction it is as below from the National Institute of Science and Technology which is the standards agency for the U.S.


http://physics.nist.gov/Pubs/SP811/appenB8.html#K

horsepower (550 ft · lbf/s) (hp) watt (W) 7.456 999 E+02



Thanks for the info on the PE1820 CT.

Larry

Uhm you're reading that wrong. It says to convert from hp to watts multiply by 7.456999E+02 (or 745.6999). That means 1 Hp equals ~ 746 Watts or .746 KW.

[scottm1978]

Thats what I thought but still great info.

[hotrod]

Just goes to show what happens when your working at 3:00 am, then re-read in haste. I knew what I ment but didn't read what I wrote --- duh

Right conversion is miss stated on orginal, will edit now. Thanks guys, proof reading is much appreciated.

Larry

[mlambert]

small 16g outflows a large 16g at 22psi, is that a typo?

sounds like a good turbo if not

[thebusiness999]

Lots of good info, but I'm curious about the HKS GT2835.

Are those numbers based on the 70mm inlet or the 100mm inlet? Since the CFM is similar to that of the PE1820, does that mean one would have similar spool-up times? By how much will the dual ball bearings of the HKS turbo spool the turbo faster than the PE1820?

I read in another post that the 2835 offered similar to stock spool up times, but with much more power, which is great. But looking at these charts makes me wonder a little bit. Anyone willing to school the ignorant (me)?

[hotrod]

mlambert:

small 16g outflows a large 16g at 22psi, is that a typo?

sounds like a good turbo if not

Nope its not a typo. This is an example why it is so stupid for the manufactures to make it so hard to find compressor maps.

The large 16G compressor map is much narrower than the small 16G. In its sweet flow area it will go to higher pressure ratios, but at high flow numbers you fall off the right side of the compressor map.

You could actually get the flow numbers probably, but it would be hot enough that the actual mass flow would be the same or less.

You'll also note that the 16G large has much lower effeciency (71%) compared to the effeciency of the 16g small (77%) so in terms of mass flow the 16g small CFM's are at any given flow rate, probably cooler and more dense than the 16G large.

See the below links for the maps.

http://www.stealth316.com/images/td05h-16gsmall-cfm.gif
http://www.stealth316.com/images/td05h-16glarge-cfm.gif

begin rant

Anyway after beating my head against a wall for over a year trying to put together this info, and seeing some of the interesting details like noted above, I have made a decision.

I will not buy a turbo that does not have a readily availble compressor map in the industry standard form.

I refuse to spend hours down loading third party software to view the cartoon flow maps on the APS site only to find it won't run on my system, and I refuse to be a beta tester for them.

If we all did the same more of these maps would be available.

As far as the argument that the average consumer won't understand them --- I'm not an average consumer and I dislike being forced to do business on the assumption I am an idiot.

Would you buy a car if when you asked the sales person what the cubic inch displacement was or if it was a 4 valve overhead cam engine and he responded, sorry I can't tell you that !

I'm afraid you won't understand.

Can you name any other industry that makes a federal case out of getting technical info ?

You can go to docs.sun.com and get any technical manual published by Sun Microsystems on any of their servers by free down load. That in my opinion is the way it should be with Turbo compressor maps. You can get more detail technical specifications and info for a $200 Radio Shack stereo amplifier than you can for a $1800 turbo.

So for now I will only be buying turbo's where I can be an informed consumer. I've just heard way too many stories from folks that spent major league money on the "hot setup" turbo only to find it didn't fit their needs. Some of them wouldn't have been able to determine that from the maps, but they deserve the opportunity, and access to the necessary information if they choose to be an informed consumer.

The only turbo manufacture that I know of, that is open about its products and freely publishes its compressor maps is Turbonetics
http://www.turboneticsinc.com/

To a lesser degree Mitsubishi is also open with its product specs in that there are maps for most of their turbo's available online. Not sure if that is a spin off of the association with Chrysler or just due to the diligence of the the DSM folks, but in any case these two vendors will be the first I go to. At least with them I can make sensible design decisions independently from any sales rep who is focused on pushing his particular favorite product.

In any other industry this top secret map crap would be viewed as a restraint of trade, and a conspiricy to fix prices. The same issues apply to much of the after market automotive indurstry, but turbo chargers seem to be at the top of the list for intentionally deceptive advertising.

/ end of rant


thebusiness999:

Lots of good info, but I'm curious about the HKS GT2835.

Are those numbers based on the 70mm inlet or the 100mm inlet?

Can't really say, I think I pulled those numbers off an advertisement/product info web page, not sure of the exact unit specs sorry.

Larry

[hotrod]

thebusiness999:

That info in the chart was for the 70mm inlet --
HKS GT2835 - 380/400/410 PS Output
http://www.hksusa.com/products/?id=709

100 mm inlet--
HKS GT2835 Pro S - 420 PS Output
http://www.hksusa.com/products/?id=1670

HKS GT2835R - 420 PS Output
http://www.hksusa.com/products/?id=711


Hope that helps?

Larry

[Z1 Performance]

Great Post Larry

[nmyeti]

Originally posted by hotrod

I refuse to spend hours down loading third party software to view the cartoon flow maps on the APS site only to find it won't run on my system, and I refuse to be a beta tester for them.

Larry

You could always just pull the compressor cover off and measure.

The APS turbo chargers are GT centers in their cast housings. It's not as if APS got out the grinder and made their own compressor wheels

By the way the maps for these are not easy to get, but if you know where to look, you can find them. All it takes is some digging and some good measurements of the actual wheels.


-Nathan
www.turboxs.com

[scottm1978]

Care to share this info

This has turned out to be a very good thread. Keep the info comming guys.

Originally posted by nmyeti


You could always just pull the compressor cover off and measure.

The APS turbo chargers are GT centers in their cast housings. It's not as if APS got out the grinder and made their own compressor wheels

By the way the maps for these are not easy to get, but if you know where to look, you can find them. All it takes is some digging and some good measurements of the actual wheels.


-Nathan
www.turboxs.com

[angus]

anybody have the compressor map for the VF30?

[hotrod]

Nathan:

By the way the maps for these are not easy to get, but if you know where to look, you can find them. All it takes is some digging and some good measurements of the actual wheels.

I realize your suggestion was made in good faith, but really think about what you said -- that is a totally unacceptable option.

You just need to take the cover off and make some careful measurments ??

Like I have $6000 dollars worth of turbochargers laying on the floor at the foot of my bed, or were you suggesting I just drive to Utah and on some dark and stormy night help myself to some of Cobbs stock ?


As far as knowing where to look and some digging. I've spent litterally 100's of hours viewing 1000's of web pages, so I think I've already done some digging.

You forget you have some inside the industry information that is not readily availible to the average Joe. You have physical access to the units, you have a complete understanding on how the industry does business.

Are you alluding to industrial supply avenues ? or sending dozens of letters to the marketing and engineering departments or, doing patent searchs ??
Or spending a few hundred hours at a major library looking for initial product announcements in trade magazines, or SAE transaction papers ??, or do I only need to take a few days off work fly out to the SEMA show and pickup every product data sheet I can find ??

Yes I realize that the info is probably out there (some place), but you shouldn't need the search resources of a major crime investigation to find it

The bottom line is the turbo manufacturers are holding close fundamental product information that is absolutely critical to an informed purchase by the user.

I shouldn't have to take an engineer from Allied Signal out to lunch to get basic specifications of a product that are essential for the most basic purchase decisions.

The other option is to start stirring the pot at the consumer protection level about all the money that is being spent by well meaning consumers on after market performance products that in essence are being fraudlently marketed as suitable to perform a task when in fact they were not.

In time that would result in mandated information requirements like food content labels on your groceries, or major increase in market share by the vendors that are consumer friendly and have nothing to hide.

Larry

ps -- when I worked as a machinist, I could call up an industrial supply house and get every detail specification you could ask for on bearings and other basic building block commodities at the cost of a phone call or two. A few days later I'd get about 3 pounds of product data sheets and catalogues with detail instructions on how to spec a bearing and useful product application information. The turbo industry could learn a lot from the industrial supply industry in that regard. Because the bearing manufacturers learned a long time ago that happy customers that buy the right bearing the first time, will come back for more at a later date. The good will created by good product information is priceless.

[nmyeti]

Originally posted by hotrod
Nathan:


I shouldn't have to take an engineer from Allied Signal out to lunch to get basic specifications of a product that are essential for the most basic purchase decisions.

I totally agree with you. I think it's a shame that APS is unwilling to release standard compressor maps, or even discuss the actual "trim" of the GT25 and GT30 compressors they are using.

I'll throw a few bones out to you guys though.

www.turbobygarrett.com

Compressor trim = [(inducer diameter)^2 / (exducer diameter)^2]100

For reference the compressor trim of the SR30 is not listed in that catalog, so Garrett isn't giving everything away, but at least there is some useful information there.

If you were to say come up with a GT25 .63 trim compressor map you'd have a very good idea what was going on with the SR30.

I've pointed you in the right direction, the GT maps are out there, but Garrett is a little touchy about them being given away to people outside of their engineering houses. I don't always agree with things like this, but it's how the "turbo business" works.

The move Garrett has made to post some of the GT compressor and turbine maps is pretty major, but they have a long way to go before you can expect them to give all this information away.

-Nathan

[hotrod]

Thanks Nathan !!

Now an extension on what you said in the earlier post regarding careful measurement of compressors etc.

Here's a general request to the turbo community.

If you have a turbo that is not well documented, setting on the floor while you are waiting for other parts.

Could you do as nathan suggested, measure the key dimensions of the compressor, count the blades on both the compressor and turbine wheels, capture casting numbers etc. and if possible make a clear picture of the wheels.

With a little effort as a group we can dig out the key info on these things like the DSM folks did with the mitsubishi series xxG turbos.

In the long run it will save us all a lot of money.

One of two things will happen. We will figure out what they are and can make informed decisions, or we will force the vendors to correct misinformation by releasing the basic data they should have in the first place.



Larry

ps -- I just down loaded the Garrett Performance Products pdf catalog, based on the info included I am adding Garrett products to my approved vendor list thanks to their willingness to make reasonable disclosure of basic product information.

I would suggest others do the same. They will determine the success of this public domain information based on their perceived interest in it. Be sure and register as well. If we don't support vendors that support us, we deserve the service we get.

[hotrod]

I spent some time reconsidering my original assignment of flow to the 16G large compressor, and my response to mlambert.

After much head scratching I felt I must have miss read the hard copy compressor map I printed out on the 16G large ( I did most of this work at 2:00 - 3:00 in the morning) and under rated it.

My observation about its effeciency difference with the 16G small still stands, it would have a lower density ratio at the same boost pressure of about .96% or so, and that brings its effective flow down to essentially the same as the 16G at this pressure ratio.

It would take a boost pressure (here at altitude) of 21.35 PSI on the big 16G to achieve the same density ratio as the small 16G achieves at 19.52 psi. The discharge would be 375 deg on the large wheel at this boost vs 338 deg on the small 16G, so you also are stressing the IC slightly more and would be slightly more prone to detonation as the temp out of the IC would also be hotter.

It would how ever handle higher pressure ratios than the 16G small. These higher pressures would over speed the compressor on the small 16G.

Sorry for any confusion, but this is still a work in progress.

Larry

[gossamer_monster]

Cool thread, great info.

bump to keep it alive for those who might have missed this


Bill

[tdxflex]

where does the VF30 stand in this comparison?

[Sunrise City Rider]

You will never find this kind of info from any other enthusiast website...Bump for intelligent car enthusiasts...

Zee