Garrett PDF catalogue

[Mark Halligan]

For those who are interested there is a nice catalogue of the Garrett turbos on offer including the GT - R series, along with comp maps, turbine maps, and other useful info HERE

Mark.

[audiman]

GT35 looks top trumps Mark, order one up!

[Mark Halligan]

GT35 looks top trumps Mark, order one up!

Yep I was just thinking along the same lines, I keep picturing one clamped to the end of one of Hackes nice exhaust manifolds .

[audiman]

Yes dude, that crappy thing you have now is not up to the job. It needs to be bigger. Why not go back to the KKK turbo?? K27 hotside would be good for over 500bhp. Thats my next trick once i have finsihed paying for this turbo!!!

[auditude]

Seems like the GT30R, or GT3071(R?), is missing from that catalog. Is it an older one or something?

Also, how are you guys justifying the GT35R since it's spec'ed for a 2.5 liter engine or larger? Is it because of the flow of the 2.22l 20vt?

[audiman]

30R isnt gonna do 500bhp, so the only way to get that is with bigger turbo, hence 35R

[audiman]

http://www.hksusa.com/categories/more.asp?id=1092

found that aswell, which may help someone?

[Mark Halligan]

Why not go back to the KKK turbo?? K27 hotside would be good for over 500bhp.

Don't like em

[audiman]

Fair enough

[Mark Halligan]

Also, how are you guys justifying the GT35R since it's spec'ed for a 2.5 liter engine or larger? Is it because of the flow of the 2.22l 20vt?

Actually it would be handy if someone a lot brainier than me (Marco etc. ) could tell us if the GT35R would work ok on our tuned engines, I suspect that the top end bhp would be high, but I am not sure how the torque figures would turn out. I tried getting my head around the comp maps stuff a long time ago, but I never really trusted the results I came up with.

[Jamo]

Actually it would be handy if someone a lot brainier than me (Marco etc. ) could tell us if the GT35R would work ok on our tuned engines, I suspect that the top end bhp would be high, but I am not sure how the torque figures would turn out. I tried getting my head around the comp maps stuff a long time ago, but I never really trusted the results I came up with.

I'm sure S2Central has already done this
somewhere on the forum, might be worth asking Paul.

[S2central.net]

It has been done... I'll post some estimated power/torque plots of the following :

K24
RS2
GT30R
GT35R

The GT30R isn't big enough for 500bhp, but the GT35R should be... But lets never forget the lag trade off and off-boost performance... We don't drive at WOT all day long !

FWIW - Mark's original choice of Garrett turbo (a T04e w 57 trim) is damn fine for 400-450bhp on the S2. I've been in the passenger seat enough times to know it is plenty quick enough and didn't suffer from lack of torque in the mid range either.

Bigger is not always better (said the actress to the bishop)


Paul

[Mihnea]

My 0.02 worth:

The order for turbos is:

K24 (280HP-400-430Nm)
RS2/GT30R (330-370 HP/500-600Nm)
GT35R??? (???)
K26/27/30 (same spec as Doug's and Tom's) (up to 480 crank HP and 580-600Nm)
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°
The problem with the Garrett turbos is boost threshold and compressor flow matching engine flow. On most of them, they are really nice for top-end power, but at low RPMs, they really suck because of surging (engine not flowing enough air for the turbo to flow compressed air), on a stock engine at least. For instance, Nickhey's GT30R would surge with 1.65 Bar at 3300 RPM, all the way to 4500 RPM. Backed boost off to 1.55 Bar and it pulls really nice with no surging. Now, I guess 2x7A cams and some porting job would help a lot with this problem.

On Tom's/Doug's cars, no problems with surging at low RPMs with the K26/27/30 hybrid turbos, 2.2 Bar hitting hard at 3600 RPM feels good and makes load of torque, and no signs of surging. Of course, their engines flow more than a stock one, but still, that turbo is good for anything above 380 crank and reliable HP, with very little lag...


Just my 0.02 worth of experience...

Mihnea

[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

[Mark Halligan]

Am I going mad, but I just clicked the link again to that catalogue, and it is definately different from the other day when I posted it, looks like its been edited the other one listed the GTR's seperately from the GT versions ???

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?