[14nce]

http://www.squirrelp...ocalc/index.php

thought this might be usefull to some people. You still have to some what understand a compressor map but plots your load on there for you.

Great tool in selecting turbos/what can be achieved with your turbo.

[Scott]

Note: PR or pressure ratio is not BOOST!


PR = Atmospheric + BOOST + Cooler Loss / atmospheric pressure

[Scott]

w00t - 1000hp = super effecient. Im set.

[mattyk]

Whats the BSFC

[Robby]

i dont get how to set everything! fuck it

[14nce]

i dont know wether it is engine hp or wheel hp...

turbo we got yesterday is awesome if its wheel, but the old one also works but we know it wont get the power...

Im assuming now its engine

Matty, If you click more it will give catagories for the BSFC... i used .51 as its moden lightly modified.

This post has been edited by 14nce: 16 January 2009 - 09:37 AM

[14nce]

Robby, on Jan 16 2009, 09:35 AM, said:

i dont get how to set everything! fuck it

this is a GT3076R on a 2.5, making full boost at 3800, max power at 7500 with 7800 limiter. 500hp

Attached thumbnail(s)

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[Scott]

14nce, on Jan 16 2009, 09:37 AM, said:

i dont know wether it is engine hp or wheel hp...

turbo we got yesterday is awesome if its wheel, but the old one also works but we know it wont get the power...

Im assuming now its engine

Matty, If you click more it will give catagories for the BSFC... i used .51 as its moden lightly modified.

.6 - .65 is more on a turbocharged multi valve engine.



And yer, its engine.

[Scott]

14nce, on Jan 16 2009, 09:40 AM, said:

Robby, on Jan 16 2009, 09:35 AM, said:

i dont get how to set everything! fuck it

this is a GT3076R on a 2.5, making full boost at 3800, max power at 7500 with 7800 limiter. 500hp

Car would be faster with smaller turbo

[Scott]

mattyk, on Jan 16 2009, 09:34 AM, said:

Whats the BSFC

Brake Specific Fuel Consumption


How much fuel per hp per hour.

For a Healthy NA engine - you will use half a pound of fuel, per horsepower, per hour. BSFC of 0.5 - Generally a Turbocharged engine will use more fuel to make the same power. 0.6 - 0.65 is the industry excepted norm for working out compressor maps / injector sizing etc

[Robby]

lol did specs on the turbo i have scott

Comp:
- Exducer: 58.1mm
- Inducer: 84mm
- Housing: 0.50

Exhaust:
- Exducer: 56mm
- Inducer: 61.5mm
- Housing: 0.63

new one is 30/82 basically

This post has been edited by Robby: 16 January 2009 - 09:54 AM

[Scott]

Interesting topic - Might start seeing some cars perform now Believe it or not 99% of performance shops wouldnt have a clue what a compressor map is, or how to read it - they simply "guess" or use a turbo thats known to work on X engine.

Myself and a few mates have built engines on paper before building - and all 3 of our engines - have performed almost exactly as we "estimated" they would - Good theory understanding is what seperates the pro's from the amateurs... Sure, Trial and error works as well - but takes longer, costs more and pisses people off.

I like the direction some of the forum is starting to take, theory tech in my opinion is the most important part about building reliable performing engines.

[Scott]

Robby, on Jan 16 2009, 09:52 AM, said:

lol did specs on the turbo i have scott

Comp:
- Exducer: 58.1mm
- Inducer: 84mm
- Housing: 0.50

Exhaust:
- Exducer: 56mm
- Inducer: 61.5mm
- Housing: 0.63

new one is 30/82 basically

Problem with ur turbo is, the compressor cover flow is unknown - as is the wheel design. Do they have a compressor map for it?

[Robby]

your right scott!

Both trent (mechanical engineer) and our tuner are the tech knowledge in this place, i am learning but it takes time! i lean on them alot! for advice when selling and doing quotes, for what package works, and trent often sits down and does all calculations and shit like that.

my poor white board in my office is constantly covered in drawings of how things work etc etc

[14nce]

Id dont like .6/65 as BSFC lol telling me its going to run out of puff at redline...

not that its a real concern, turbo choice was about midrange which sits right in effciency optimum.

[CUBES]

i can see the benefits of this for people that run an auto (selecting stall speed, lock up or hi) and need to select cam/s as well

This post has been edited by CUBES: 16 January 2009 - 10:07 AM
Reason for edit: topic pinned, good find

[Scott]

14nce, on Jan 16 2009, 10:00 AM, said:

Id dont like .6/65 as BSFC lol telling me its going to run out of puff at redline...

not that its a real concern, turbo choice was about midrange which sits right in effciency optimum.

Turbo's will still work when into choke - (right side of map), keeping them outta surge is the key to a quick car...


my last turbo sat basically in choke the entire rev range - yet still performed well

[14nce]

Scott, on Jan 16 2009, 11:43 AM, said:

Turbo's will still work when into choke - (right side of map), keeping them outta surge is the key to a quick car...


my last turbo sat basically in choke the entire rev range - yet still performed well

Thats what i though. is it correct to say surge is caused by using a turbo too large for your application?

eg. not letting the turbo stretch its legs enough, like trying to get you car to idle and run at 200rpm

[Scott]

14nce, on Jan 16 2009, 03:54 PM, said:

Scott, on Jan 16 2009, 11:43 AM, said:

Turbo's will still work when into choke - (right side of map), keeping them outta surge is the key to a quick car...


my last turbo sat basically in choke the entire rev range - yet still performed well

Thats what i though. is it correct to say surge is caused by using a turbo too large for your application?

eg. not letting the turbo stretch its legs enough, like trying to get you car to idle and run at 200rpm

yer basically - surging is cuased by not enough restriction against the wheel and it trys to chop the air instead of compressor it

[EV1LR8]

this looks kool will have to have a play when i work out how to use it