View Full Version : SR20det Turbo Guide

09-11-2002, 12:58 PM
We must all give props to the pioneers of the SR20det here in the states. The Se-R guys are way ahead of us!

DOH!  No external linking.  Hope Rob Cadle doesn't mind the reprint:

Geo, turbo sizing comes up a lot, so I think that this should be in the
expanded FAQ you are making.

Derek Greaser <[email protected]__.com> wrote:

>I've got an JDM S13 SR20DET in my 96 240sx. &nbsp;I've been using an HKS >GT2510
>turbo and was happy until i needed more than 300rwhp.

For the record:


S13 SR20DET: T-25, 60 trim 56mm BCI-1 compressor, 53.8mm 62 trim
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; T-25 turbine, .64 A/R turbine housing. &nbsp;Journal
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; bearings.

S14 SR20DET: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing,
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 62 trim 53.8mm T-25 turbine. &nbsp;.64 A/R turbine housing.
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Ball bearing center section.

S15 SR20DET: Same as S14, but with Inco turbine wheel (instead of
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; GMR), cast divider wall between turbine discharge and
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; wastegate.

Pulsar GTi-R: T-28, 60 trim 60 mm BCI-1 compressor in standard T-3
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;housing. &nbsp;79 trim 53.8mm Inco T-250 turbine wheel .86
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;A/R turbine housing. &nbsp;Journal bearings.

BB SR20DET: T-25. &nbsp;Basically, the same as the S13 Silvia.


GT2510: T-28, 63 trim 60 mm BCI-1 compressor in T-04B housing.
&nbsp; &nbsp; &nbsp; &nbsp;62 trim 53.8mm T-25 turbine. &nbsp;.64 A/R turbine housing.
&nbsp; &nbsp; &nbsp; &nbsp;ball bearing center section.

GT2530: T-28, 63 trim 60 mm BCI-1 compressor in T-04B housing.
&nbsp; &nbsp; &nbsp; &nbsp;76 trim 53.8mm NS-111 turbine. &nbsp;.64 A/R turbine housing.
&nbsp; &nbsp; &nbsp; &nbsp;Ball bearing center section.

GT2540: 46 trim 76.2mm BCI-8 compressor in T-04E housing. &nbsp;76 trim
&nbsp; &nbsp; &nbsp; &nbsp;53.8mm NS111 turbine. &nbsp;.64 A/R turbine housing. &nbsp;Ball
&nbsp; &nbsp; &nbsp; &nbsp;bearing center section.

GT2835: I believe that the following is the spec for this, but I could be
&nbsp; &nbsp; &nbsp; &nbsp;48,52, or 56 trim 71mm BCI-18C compressor in T-04E housing.
&nbsp; &nbsp; &nbsp; &nbsp;84 &nbsp;or 90 trim UHP turbine cut down from 60mm to 56.5 mm.
&nbsp; &nbsp; &nbsp; &nbsp;.64 or .86 A/R turbine housing. &nbsp;BB center section.

GT3037: 48,52, or 56 trim 76.2mm BCI-18C compressor in T-04E housing.
&nbsp; &nbsp; &nbsp; &nbsp;84 trim 60mm UHP turbine. &nbsp;.61, .73, .89, and 1.06 A/R
&nbsp; &nbsp; &nbsp; &nbsp;turbine housing. &nbsp;Ball bearing center section.


Super 60 T-3: This could be about anything, but is usually a 65 trim
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;60mm BCI-1 compressor wheel in either a standard T-3
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;or a T-04B compressor housing, with a 62 trim 58.x mm
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;T-3 turbine wheel in a .49 A/R turbine housing.

Stage 3 T3/T-04E hybrid turbo. &nbsp;40-60 trim 76mm BCI-4 or BCI-8
&nbsp; &nbsp; &nbsp; &nbsp;compressor wheel in T-04E housing. &nbsp;76 trim 65 mm T31
&nbsp; &nbsp; &nbsp; &nbsp;turbine in .49-.82 A/R housing.

Stage 5 T3/T-04E hybrid turbo. &nbsp;40-60 trim 76mm BCI-4 or BCI-8
&nbsp; &nbsp; &nbsp; &nbsp;compressor wheel in T-04E housing. &nbsp;76 trim 72 mm T350
&nbsp; &nbsp; &nbsp; &nbsp;turbine in .63 or .82 A/R housing.

Now, my opinions:


The T-25 seems to be OK up to around 1 bar of boost with a 3" exhaust and no
cat. &nbsp;This can support about 240 whp with no cat. &nbsp;With a cat, I would run
no more than 10-12 psi. &nbsp;Expect about 220 whp.

The S14 T-28 spools really nice, but has the same tiny turbine as the T-25.
It can't support much more hp. &nbsp;I'd say 240-260 or so wheel hp max. &nbsp;You can
get more power by running more boost, buy you do so at the risk of breaking

GTi-R T-28 is a really good turbo. &nbsp;I think that it is better if you lose
the T-3 compressor housing and get a housing off of the S14. &nbsp;This is a big
improvment. &nbsp;With the T-04B compressor housing, the GTi-R turbo can support
about 16 psi and 280+ wheel hp. &nbsp;Makes pretty good boost by 3500 RPM, too.


GT2510 is expensive and only has marginally better performance than the
Bluebird and S13/14 standard turbos. &nbsp;Yes, it has better transient response
because it is ball bearing, but it's not like a stock journal bearing T25 is
a spool dog. &nbsp;I would personally buy something else first. &nbsp;I don't think
you will be able to measure any improvment over a standard S14 turbo with
this one, and it costs a *LOT* more.

GT2530: This is a pretty good turbo, but I don't understand why HKS won't
offer it with the larger .86 A/R turbine housing. &nbsp;This with the larger
turbine housing will outperform a GTi-R turbo. &nbsp;This should be good for 300
whp and good response from 3000 RPM on up.

GT2540: IMO, this turbo is a big piece of shit. &nbsp;This is my opinion as I
haven't tried one. &nbsp;But, looking at the maps, it looks like a pile of shit.
I have heard annecdotal evidance from people I respect that it works pretty
well, but I wouldn't put one my car and find out. &nbsp;There is too big of a
size mismatch between the 53.8mm turbine and the 76mm compressor. &nbsp;Also, it
is insane to run a .64A/R on the turbine given the flow capacity of the
compressor. &nbsp;This turbine and this compressor are both really good on their
own, but they are worthless together. &nbsp;Total mismatch. &nbsp;Save your money.

GT2835: If this turbo is actually what I described above (check to make sure
before you buy), this should be a pretty good turbo. &nbsp;Get the 56 trim
compressor wheel and the 90 trim turbine wheel with a .86 A/R turbine
housing. &nbsp;This should make good boost by 3500 RPM and should support 375-400
or so wheel hp.

GT3037: This is the mother load of turbos. &nbsp;Get the 52 trim compressor and
.73 A/R turbine housing for good streetability and ~400-425 or so whp. &nbsp;Get
the 56 trim compressor and .89 A/R turbine housing is you can live with a
little more lag and want ~475+ hp.


Straight T3 is an OK 2.0L turbo. &nbsp;Gets good boost about 3k RPM, will make
about 250-275 whp. &nbsp;Cost and installation is the same as other, larger
turbos, though, so I'd just rather go bigger and take 500 RPM later

Stage 3 T3/T04E hybrid. &nbsp;Get the 50 trim compressor wheel, and only the 50
trim compressor wheel. &nbsp;Get the .63 A/R turbine housing for boost response
by 3500 RPM. &nbsp;This will support about 320 whp. &nbsp;Get the .82 A/R turbine
housing is you can live with full boost ~800 RPM later. &nbsp;This will support
~400 whp.

Stage 5 T3/T-04E hybrid. &nbsp;Only run the .82 A/R turbine housing. &nbsp;If you want
less lag, get a smaller wheel. &nbsp;Run the 60 trim compressor wheel. &nbsp;Don't run
a 60-1 wheel (shit) or the smaller trim T-04E wheels. &nbsp;This turbo will
support about 475-525 whp (don't know on the top end--we haven't maxed one
out yet!<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>. &nbsp;Expect soggy boost repsonse below 4500-5000 RPM.

As an aside, many of the HKS turbos are available from INCON for
significantly less money. &nbsp;They are also a little more flexible about
housing configuration. &nbsp;The guys at INCON disagree with me typically when it
comes to matching on small displacment motors. In fact, many people do. &nbsp;You
can take or leave my advice. &nbsp;Please don't contact me and say "person x at
company y told me the turbo you spec'd is no good and this other one is
better". &nbsp;I have heard it all before. &nbsp;Those turbos are what I recommend,
and you can either listen to me or listen to them. &nbsp;I don't want to play a
game of 'he said/she said'.