gt17 latest thinking .
Turbo Mini Forums

thought id put up my latest on this pesky little critttur ..

gt1752 specs ,


part no ----------dia-----inducer------tip ht--shaft dia ----trim

436131-0002-- 52,00--- 38,55------ 4,10------ 5,00---------55

so i did a bit of a research ,and thought , i wonder if i can find a comp map that , whilst not identical ,has as similar measurements on the wheel as possible ..

so i found this ..

---dia-----inducer------tip ht--shaft dia ----trim

- 51,00--- 38,25------- 4,25--- 4,90--------- 56

which gives this map ..




and calcs to around 268 bhp max flow .




now , looking at my last rr stuff .heres a graph of my best quiet exhaust run ,peaking at around 19 psi and dropping to 17 ,versus my side pipe run ,on 21 psi dropping to 17 again .



(note :the wobbly bit is a 16:1 air fuel mix missfire ,due to me not pulling out the choke fast enough .so imagine the green line shape but higher there.also ,the green line is 200 rpm low ,so should move over to sit on the other line ,and bhp would then have been 245 odd.)

while i personally feel the numbers are a touch high , i think the trend is suggesting a compressor that thrives on boost .the jump in power as the boost rises is very marked ,especially if you think of the increase in rpm should be making more bhp .it responded far more to a couple more pounds of boost ,than a few more hundred rpm .

it will be intersting to see this at 23 psi all the way to 7k rpm ,if itll do it .

regards
robert.

ps , i know how much paulS and demon offspring love a puzzle ..i give them oohh 28.5 minutes before they figure out what map it is ..

Edited by robert on 20th Oct, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

As always Robert, very interesting information :)

Edited by Sprocket on 20th Oct, 2010.

That's a TD04 or a TD05 probably a 15T.

Some one has doctored the flow scale but is hard to tell.

Same as Nic runs....... ?

Edited by Paul S on 20th Oct, 2010.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

just had a little more of a look at that comp map. 28lb of air is awfully close to the stonewall

Found this whilst checking out the above:

http://www.pittsburghsaab.com/upgrades.html

Cheeky buggers have pinched our Gt1752 map.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The problem with the above map is that it flows as much as the GT2056 which is known to be a considerably bigger and faster wheel.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

GT22? the 59.4mm wheel (gt2259?)

Edited by Brett on 20th Oct, 2010.

Yes i moved to the darkside

Instagram @jdm_brett

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

yeah i just looked up its specs,

its a td04 13t of an early impreza and you converted it to lb/min

Edited by Brett on 20th Oct, 2010.

Yes i moved to the darkside

Instagram @jdm_brett

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

robert you should write a book "turbos for dummies" even i understood that .......... i think

Never mind the tip speed, has your oil in the gearbox gone supersonic yet?

Robert :
audi rtdi as the same compressor wheel as the 1752.


fab

Edited by fab on 23rd Oct, 2010.

On 20th Oct, 2010 robert said:

ill rewrite this for the senile over 50 's lol..

the 56 flows around 30 lbs /min
this flows around 27.5lb/min ... this is therefore LESS .

the 56 wheel is 56 mm diameter .this is 4 mm bigger than a 52 mm wheel ,and 5 mm bigger than a 51 mm wheel .so its SMALLER .

a smaller wheel ,at the same revs as a bigger wheel is moving slower at the tip .so for the same tip speed ,a 52 is going proportionaly faster .
if you look at wheels diameter versus rpm ,youll see at smaller wheels are specced to run fast on the maps .

so ..a 52 mm wheel will run safely to a higher rpm than a 56mm wheel . all things being equal .

in this case ,a 190 000rpm 56mm wheel ,has the same tip speed as a 204,615 rpm 52mm wheel.(unless this bottle of apple juice has clouded my thinking )

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Right, affinity laws determine the relationship between geometrically similar centrifugal devices.

http://en.wikipedia.org/wiki/Affinity_laws

So, we know that the GT1752 compressor wheel is a 92.8% scale model of the GT2056, based on the published data.

From that you can determine the map of the Gt1752 from the published map of the Gt2056.

That Mitsubishi map just does not fit if the wheel data is right.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Ha Ha

http://www.evocoupe.net/forum/viewtopic.php?f=2&p=38780

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

On 21st Oct, 2010 fab said:
Robert :
audi rtdi as the same compressor wheel as the 1752.



fab

Edited by robert on 21st Oct, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

i think these quotes from gt17... sort of sum up my point here ..


[quote =robert ] On 26th of Feb, 2007 at 08:08pm robert said:

3.4mm and 4.3 mm are the two different tip heights for the 55 trim 56mm wheel

4.1 and 3mm are the tip heights for the 55 trim 52mm gt17 wheel ,

i think it may be that these dimensions are going to affect the characteristics of the maps ,
i know that the wheel in mine is the 4.1mm but unless we know the tip hieght for the 56 mm wheel map can they really be compared like that axel , it may be the map your looking at is the 3.4mm ...



[quote =paul] What I am trying
to say is that if the 2056 56mm map was 3.5mm tips, then the 1752 at 4.1mm tip would flow considerably more than the 2056.

Edited by robert on 21st Oct, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

This is the official version of the map:

http://img280.imageshack.us/f/13tcompressormapsn2.jpg/

The specs for the TD04H-13T are a little muddled. There seems to be some confusion over the 13g and 13t. Most recent data sources now quote the wheel size as 55.9mm.

But if you compare the performance of the above with the GT2056 (56mm wheel), just along the 170,000 rpm line then you will see that they are near identical.

Hence, that curve must be for a 55.9mm wheel version.

Following the affinity laws, the flow from a 52mm wheel of the same trim would be around 15% lower.

Edited by Paul S on 21st Oct, 2010.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

FFS can some one please just phone, pester annoy Garrett for the GT17 data. Garrett must have it on file some where!!

FFS can some one please just phone, pester annoy Garrett for the GT17 data. Garrett must have it on file some where!!