Reading Comp Flow Maps

[Guest INASNT]

I need some help on how to read the comp flow map for this T04 60-1 Trim i might be buying.

It has 0.60 A/R comp and either 0.84 or 0.63 A/R exhaust housing.

How Good will this run on a internally stock RB25DET with adj cam gears. Dont worry about injectors and fuel pump etc coz they r getting done 2.

[Sydneykid]

Hi INASNT, very quickly .........

At 1.1 bar of boost, it is going to be doing 96,400 shaft rpm and producing 55 lbs of air per minute. I can't tell you the efficiency as it has no calibrations on the islands, but it looks to be around 65% to 70 %, which is good. That's enough air for around 550 bhp.

It has good efficient airflow of 25 lbs per minute using 69,600 rpm at 0.5 bar. Efficiency drops off sharply over 105,500 rpm and using more than 1.5 bar of boost would be waste of time. It is going to need careful tuning and matching of the exhaust turbine and housing to stay above the surge limit.

In summary, a pretty good compressor to use with an RB25DET provided it has at least forged pistons and preferably forged rods as well.

Hope that helps

[Steve]

INASNT - compressor maps arent too difficult to read - airflow along the bottom and bar up the side. thing to remeber is that at sea level you already have 1 bar - so subtract 1.0 from the vertical axis and you will have boost pressure.

With turbine housing size, one theory (the one I am trying:)) is to use a smaller housing with large wastegate - this will build the boost earlier, and keep you away from the surge limit. I am using a 0.61 A/R ratio turbine housing on the 3037 I am fitting - I hope it will be done and tuned in about 2-3 weeks (the wait is killing me) so I will let you know how it goes.

That turbo should be sweet with 0.8 to 1.0 bar on stock internals (and a good tune) - after that start thinking about a head gasket to drop the compression ratio

***ducks for cover waiting for sydneykid to throw something***

[sidewaymambo]

INASNT...you might want have fun here..

http://www.turbofast.com.au/turbomap.html

and

http://www.rapidline.com/calc/turbo/pctcmap.htm

[Guest INASNT]

thanks for the replies!

I want to make around 260rwkw at not much more than 1 bar of boost without forged psiton or short penned rods for the time being, but not have a lag monster either coz of driving to and from work. So will this provide the goods?

[Steve]

Yes it should - purely off the map anyways:)

sidewaymambo, the t04E 57 trim looks nice

[sidewaymambo]

yes....and joe from here has one on hos RB20det...

[Guest INASNT]

More info on the turbo.

Exhaust housing has a T03 flange, although A/R .84 housing is to suit an external wastegate. The A/R .63 housing is internally gated which is also available if required.

It is a bush-bearing Garrett T03 turbo which actually has a 360 degree competition (screwed-down) thrust bearing also (forgot to mention).

But it is a design from the 70's and a twin ball bearing would be more efficient and spool up quicker wouldnt it??

damn i dont know what to do!!!

[Steve]

If the bearing was from the 70s, I would definately replace it with a new one before fitting it:p But seriously, bush bearings today are catching up with ball bearings. Subaru use them on the WRX.

If you are not sure - go with what you really want, not what is cheapest - remeber, the glow of a cheaper unit will wear off quickly - the added cost of a better unit will be forgotten when you are driving. I would definately go the smaller A/R ratio as it will make boost quicker, just make sure the internal gate is a good size, which it should be if its designed for use with that turbo. If you are buying it from a shop, ask if they have fitted them to anybody elses car, and if you can get in contact with them to find out how it went?

sidewaymambo - any details on joe's turbo, performance wise and what turbine AR did he use? - that map is just so nice and fat!

[Guest INASNT]

its coming off a ford cosworth. I aint gonna buy sumthing cheap as i have forked out lots of $$ of the good other parts 2!!

[Steve]

Why not buy a new garrett GT turbo then? Get the specs you want and it costs less than 2.5k? That T04E 57T does look pretty good Go on, you know you want to...

[Guest INASNT]

here r some pics of it

[Guest INASNT]

[Guest INASNT]

[Guest INASNT]

your thoughts?

[Steve]

Looks perdy, that inducer is a bit on the small side though - do you know what size it is?

What has made you lean toward this particular turbo out of interest?

[Guest INASNT]

coz sum1 is selling it at a good price and it has a t3 exhaust flange so easy fitment!

how much was your 3037, manifold, ext gate and all the oil and water lines just out of interest

[Steve]

Less than 5K

[Guest INASNT]

yes alot less! its not 100% new, its got about 2000kms on it

[Guest INASNT]

sydneykid/steve

how can u work out at what rpm u will het say 1 bar of boost from the comp flow map?