how to work out if its any good?
Turbo Mini Forums

how do i work out if this new turbo i have bought will be any good on my motor?

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

Forts thing to do is find the a/r ratios of the snails. On Garrett's they are usually cast or stamped somewhere.

This will give you a rough idea. The next thing is to try and find a compressor map. Then do some maths. There is a great guide on the Garrett website on how to choose a turbo.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Work out what your estimated power will be in air flow, Lb/Min. Then find a compressor map for the turbo you have, and if you cannot find one, find the next nearest for a gestimation. See if the air flow your engine needs falls somewhere into that map. this will also tell you how much boost you will likely need to run.

For example, I cannot find a map for the GT1549, but there is one for the 1548. The GT1548 map indicates that at around 2.3 pressure ratio (boost of 19psi) it could flow 20 lb/min at 65% efficiency which is roughly 200hp and probibly at the very limit. In reality though it might be nearer 180hp.

Depending on what you are after, it might be a bit small. In the main most choose either the larger 52 or 56 compressor wheel, for example GT1752, GT2052, GT2056. Your GT1549 has a 49mm compressor wheel.

Thats not the end of it though as the housing A/R for both turbine and compressor affect the operating RPM range of the turbocharger, IE how soon or late it comes on boost.

I'd think the GT1549 would be really good for ~150hp at 10psi, but that is just a best estimate based on a GT1548 map

how do you work out lb/min airflow?

one day boost will be mine!

There are several 'calculators' available on the internet, but you do need to know a few basic things about your intended engine combination.

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

Not straight forward then, I'll try and get my head round it and have a google as well, cheers

one day boost will be mine!

http://www.engineeringtoolbox.com/flow-uni...rter-d_405.html

i JUSt found this, did some calcs on it and im confused haha

http://www.lovehorsepower.com/joomla/index...&id=4&Itemid=88

give it a go. looks like its useful

If you want to do the compressor maths, then this may help:

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=213848

However, the turbine has a greater impact on the engine performance than the compressor, yet there is no easy way to do any calculations, mainly due to the lack of actual data. Garrett publish some data but it is a simplistic approximation that is only useful for comparative purposes.

As a rule, I would never use a turbo from a diesel as the turbines tend to be small relative to the size of the compressor to give a quick spool up for granny drivers.

If you pick a turbo from the Garrett range or a petrol turbo engine car, ie R5GTT or Saab 93/95 then you can be fairly confident that the turbine will match the compressor better.

The GT1549 will spool up well, but will start to strangle the engine before the head and cam start to get into their stride.

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."

hmmmm. that doesnt sound good. especially as quick engine spec is morspeed head with 24cc chambers, 1330cc, roller tip rockers, cast omega 11cc dish pistons, lightened crank, sw5 cam, s/c box and drops, xpin diff and 3.44 fd. was kind of hoping this would be ok. especially as all the ports on it seemed to face the right way.

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

bearing in mind, i only want about 150bhp si i can actually use it and drive the bloody thing rather than it be sat in the garage for another 3 years.

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

if its the 452283-0003 ,then its off a 135 bhp diesel .using roberts 2/3rds diesel rule ,that will work up to 202.5 bhp .
it runs as stock at 19.9 psi in the mg zr .on the rover 25 it runs around 17.5 psi stock .

FIT IT !

Edited by robert on 7th May, 2012.

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

yeah it is the 452283-3 one. the advert says rover 25 but the part number is 452283-3.

http://www.ebay.co.uk/itm/170822431972?ssP...984.m1423.l2649

thats the advert on the bay.

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

I like this rule. Lets hope you don't want 202.6bhp though!

Edited for spaz spelling.

Edited by wil_h on 7th May, 2012.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

er.....nope. 150ish will do me fine. lol

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops

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'm not sure I follow this diesel vs petrol arguement.

Ignoring the materials differences for the moment, modern diesels produce their boost, and power, at much lower RPMs.

That isn't just the "granny" arguement but simply because diesels have a much higher thermal efficiency so can produce their power at lower RPMs but wind their boost pressure up at lower RPMs to achieve this.

Mass air flow (m (dot)) should therefore be lower ???

Am I missing something ???

Schrödinger's cat - so which one am I ???

hmmm. something doesn't add up. just looking at the turbo, the shell and compressor all looks shiney and new but i look into the exhaust end and there is definatly signs of carbon and use. sold in the advert as brand new never fitted to a vehicle!!

balls to the blower!!!



1330,stage3 head, gt1549, canems ecu, S/C box and drops