Garrett PDF catalogue

[Mark Halligan]

Aha I have found the link to the performance catalogue this is the one that list all the GTR's seperately.

http://stealth316.com/misc/garrett-performance-catalog.pdf

[S2central.net]

Anyway If someone were to use the GT35R on a heavily worked upon one of our engines there are two choices of A/R for the hot side housing, the smaller is I think 0.82 and the larger is 1.06, I take it the larger housing will give more top end but more lag then?

Aye - that's as I understand it....

I love the way Garrett actually publish this info - for compressors & turbines (though I don't understand turbine maps yet). I wish we had similar data for the KKK turbos... I only have compressor maps for K24 and RS2.



Paul

[S2central.net]

I completely and utterly agree with Mihnea on surging concerns with the GT30R and larger - you cannot get into maximum boost until 4000-4500rpm.

My calculations are bang on target with the known capability of K24 & RS2 turbo.

On the GT30R I can see ~450bhp at 7000 rpm assuming a hefty amount of boost (1.8bar). I'm also assuming the same IAT, for this configuration which might not be realisable without a much more efficient intercooler. The RS2 IC might not be good enough for this configuration, plus I reckon a very good hot side will be needed to spin the turbine sufficiently to generate the 1.8bar required.

There are two choices of hotside I know of for the GT30R... and the little one may not be capable of 450bhp. It also depends on camshafts, exhasut manifolds etc etc

The calculations don't lie, but the assumptions do !!!!!!!


Paul

Well on paper the GT35R can make ~540bhp but it requires significant head modification to get VE into 95% territory. Also needs a mighty good intercooler for IAT below 40 celsius... and a hot side man enough to spool the sucker.

Attached ZIP explodes to a protected Excel file showing the theoretical power & torque figures for the GT35R.

Only a flowbench will give us accurate VE info. Pi & Pf are approximate. All of these provide an error introduction for the CE figure we get from the compressor map... And then another assumption gets us to IAT values.

I've shown that a better intercooler and air filter can reduce the PR. This, coupled with higher VE keeps us further away from the surge region and generally provides for better compressor efficiency. Add to that a better intercooler and you can see how the paper numbers for the GT35R are much better on a modified engine.

The graphs speak for themselves...



Paul

[Jeffer]

K27/27/30 (same spec as Doug's and Tom's but with K27#7 hot side) (must be above 500 crank HP)
xxx (??HP°

Soon you can tell how much HP it pumps Mihnea. :mischeif:

[Dutch_RsBlueS2]

Soon you can tell how much HP it pumps Mihnea. :mischeif:

[Mark Halligan]

GT35R??? (???)

Mihnea, maybe I will get one then with the 1.06 A/R hotside, and see if we can fill in the spaces where those question marks are, all in the name of science of course :mischeif: .

Mark.

[S2 Ant]

And to better everyone else

Looks like the tubular EM is a v gd investment as well!!

[Doug_RS2]

Soon you can tell how much HP it pumps Mihnea. :mischeif:

Jeffer - is yours the k27, no7 hotside? I'll be very interested in hearing what yours does, as that is my next thing to change - along with a better EM - hopefully beginning of next year

[4WheelDrifter]

I thought you were giving it a rest Doug.

[Mark Halligan]

I thought you were giving it a rest Doug.

whoever it was who started all this tuning lark off has a lot to answer for.

[auditude]

Mihnea, maybe I will get one then with the 1.06 A/R hotside, and see if we can fill in the spaces where those question marks are, all in the name of science of course :mischeif: .

Mark.

Yeah, Hap here in the States is going to be running a GT35R on an AAN with an RS Tuning EM and some serious modifications to whole car/engine. I want to see what his actual results are before I buy the turbo for my project.

Looking at the .pdf in the second link, if you believe what Garrett has to say about where the GT30R fits, it would seem to put our motors, or at least a 2.5liter version which I'm probably going to go with, right in the middle of its application range,2.0-3.0 liters and 350-500hp. (that's a lot of commas, huh?)

You know what I've seen done is to have the rpm points of our motors plotted onto the compressor map for a given turbo, with the idea that we'd want them to be to the right of the surge line. That would be pretty cool to see for these turbos (personally, I'd like to see a 2.5l version too). I'm still too ignorant to be able to figure out how to do that myself.

I'll be looking for a turbo for this motor:

2.5l stroker block*
custom rods/pistons (still need to choose c/r)
mildly(?) ported head (will mild be enough? otherwise I'd prefer a pro do mine )
both 7A cams*
RS Tuning EM w/Garrett flange*
Wagner intake*
still need to choose IC

*I have these parts already

My project is somewhat long term, as I have to complete an RS2 upgrade on my 200q20v first, and another project. But the topic is here now so I'm asking.

My fear is that there is a trend for people to get overly large turbos, and perhaps a less impressive smaller turbo might work better for a car that will not only be for the dragstrip.

My only targets for the power level is that it is low enough that it doesn't blow up or need to be rebuilt every year, and high enough that I am not wasting the custom internals and special parts like the header. So, from about 450hp to as high as will hold together without an annual rebuild/replacement. I do want to minimize lag (which I thought would be possible using the GT series products), but I'll take whatever lag I get for those power targets.

I guess I don't want to have a dog below 5k and then just get insane power from 5k to 7k, if I can avoid it. If it must be, that's ok. I know it's a backwards way to plan a project, but that's what I'm gonna do.

Hey, while I'm posting, have you guys seen this 200q20v? Watch the videos:

http://www.ttstuning.de/

Supposedly it's running an RS2 motor. I was impressed.

[S2central.net]

, huh?)

You know what I've seen done is to have the rpm points of our motors plotted onto the compressor map for a given turbo, with the idea that we'd want them to be to the right of the surge line. That would be pretty cool to see for these turbos (personally, I'd like to see a 2.5l version too). I'm still too ignorant to be able to figure out how to do that myself.

You CAN do this with info from my Turbo Calculator.

Simply plug in the ambient conditions and desired boost levels for given engine speeds. Make plots on the compressor map for PR (from Step 2) and Corrected AirFlow (from Step 5). The trick is keeping between the surge and choke lines.

Easy enough when something like Excel does the hard work.

Paul

[auditude]

You CAN do this with info from my Turbo Calculator.

Simply plug in the ambient conditions and desired boost levels for given engine speeds. Make plots on the compressor map for PR (from Step 2) and Corrected AirFlow (from Step 5). The trick is keeping between the surge and choke lines.

Easy enough when something like Excel does the hard work.

Paul

How do I know the desired boost levels for engine speeds? I thought the possible boost levels were dictated by the compressor map for a given motor. Not quite knowing what I'm talking about, I think I want the maximum boost possible at every rpm, no? How do I determine those values to enter?

[S2central.net]

Thats the trick - you have to play with the desired boost levels to generate the combination of PR and airflow that fits the map !

Too much boost at low revs can cause the compressor to surge... Just play with the data in the calculator and do some plots. You'll see how.

[Doug_RS2]

I thought you were giving it a rest Doug.

I have rested - I haven't driven my car fast for 2 weeks now. (not been allowed to fix it)

whoever it was who started all this tuning lark off has a lot to answer for.

Yeah - he's taken me to the point of bankruptcy

Roll on the 500bhp