GTX housings (compressor and turbine)

[Trev Vaa 1,185]

hey guys, just wondering whos played around with the garrett GTXs?

 

reason i ask, friend of mine was looking at getting a GTX3076 to put on a CA18. however heres what we were looking at doing

 

ported compressor shroud, an a .78 A/R t3 twinscroll turbine housing, just wondering whos put these things together and who i can get some advice from to make it work, wondering about the boost tapering off over the .63 t3 housing

 

hoping that going the 76mm wheel over the 71mm will yeild an extra 20rwhp without loosing too much on the lag side of things.

 

this is a pretty serious little CA, tomie procams 260* high lifts, arias forged pistons, pauter x rods, ported head etc

as far as boost goes, hoping to push it to 2bar. looks to be comfortable in the compressor map and have seen them run up at 1.8 bar on pump fuel, which may very well be the limit on pulp, which will suck. but only with the .63 A/R t3 standard turbine housing.

 

 

another quicky, whats the garrett number for the BA XR6T gt35/40 (or is the actual name GT3540?)? need to get some parts and i don't have it written down anywhere, if we have to send it off to get rebuilt we're up for a grand, which means, fuck that, we're gunna upgrade instead.

[PSI_LTD 37]

when sizing up your compressor wheel, don't just look at the peak power figure, also plot where you expect to come onto full boost.

 

eg: @ 4K rpm you may be moving xx lb/min of air x 2 bar boost. that's your first point on the map.

[matt_lamb_160 252]

^{The GT35/40 is a GT3582R.}

[Trev Vaa 1,185]

when sizing up your compressor wheel, don't just look at the peak power figure, also plot where you expect to come onto full boost.

 

eg: @ 4K rpm you may be moving xx lb/min of air x 2 bar boost. that's your first point on the map.

hey mate how are you? how do i plot a graph properly? i've never 100% understood how to pick a turbo correctly, i've just looked into what others are using and how it performs and then based my plannings upon that (in as much detail as possible, inc cam positions, turbine sizes, housing mods, as well as engine internals), hoping for full boost by 4500rpm and to hold to 7500 and taper off a bit up to 8000,  expecting peak power to be about 6500-7000rpm

 

^{The GT35/40 is a GT3582R.}

shit... i put one of those on an R33 GTR! thanks dude, might look into an upgrade then me thinks. now time to convince the owner.

[PSI_LTD 37]

hey mate, i'd say one way of doing it could be like this:

1. estimate when your turbo should hit full boost (power balance equation - how much power the compressor requires to achieve a certain pressure = when the turbine is able to provide such power)

2. for that rpm point, factor in volumetric efficiency, intake density (off temp @ given pressure), and displacement, and you should get the mass flowrate.plot that point against target boost pressure.

3. plot your second point @ max power figure using same technique as above (you can do another at a halfway point, if you wanted)

... this gives you the efficiency range of the compressor. if the first point is too close to surge line, the turbo will have a harder time of making full boost at that point.

 

from my research, ideal condition is where the efficiency range is on the either side of the max efficiency island on the map

[Trev Vaa 1,185]

ok i get you so plot it off exhaust pressure and air volume that the exhaust would move, and how fast that would spin the turbine, is that correct?

 

i've got a bit of time, so if you can link me to a website or send me a file you have that is in depth in explination and understanding how to make the equations properly and accurately i would greatly appreciate it.

 

from what i have read, the GTX3076 will spool better than the GT3071R with a twin scroll on both, but in saying that the GTX3071R should spool the same as the GT2871R, from what i have read on back to back comparisions though it should outpower the GT3071r by a long shot.

thus your aforementioned calculations will be required.

 

tell you what though, this CA really is gunna be the CA from hell.... looking like it should shit in 500hp with ease.... most likely a lot more.

[PSI_LTD 37]

that sounds awesome..

 

good luck finding info on turbine sizing (learned that when I was at ford from the turbo engineers) - dont remember the maths involved.

 

but the compressor side is explained over at turbobygarrett.com.

 

keep us posted!