Welp, I have a friend who is part of the SE-R community named Rob Cadle. He is a lead engineer for Garrett. Yes, he designs these things for a living. Rob is super cool and EXTREMELY smart in regards to all things turbo. (Hell he designs them for a living)

From what I have learned over the years from him and seen him write about, that combo is NO good. The compresso and turbine mismatched in a big way. There are many things that affect turbo performance. It's not just like "hey this is small that's big" etc.

If you want to do some reading of his "notes" and "replies" on the SE-R mailing list archive you can go to this link http://www.se-r-list.org/archives/ and type in "rob cadle turbo" or whatever want to search on with his name. It's an education in itself.

 

Stage 2 or stage 3 T3 wheel is not exactly small wheels IMO. RDKRT has a BR-57. I think it's a stage 3 hot side and Buschur ran 10s with that.

 

Just because something makes power doesn't mean it's not hurting the engine, or has the potential to hurt the engine

IMO StageIII T3 IS small in the world of high hp turbos. A stage-III housing with a big .82 A/R with a 76 trim wheel will only support about 400whp comfortably. (Ask me how I know. ) Stage-V is the housing you want for 500whp. The trim of the wheel has a lot to do with power production as well. There are many "back door" ways to make power but it's retarded IMO. In other words, small housing, small wheel, clipped big time. Yea the clipping will allow airflow, but the turbo is now about .55 points efficient because it's all screwed up vs 75-81% for a properly designed turbo for said hp application.

Then again, I guess size is all relative.

 

so what you're saying the that a t3/t4 is pretty much a waste of time? Or just a t3/t4 with too much of a difference in size on each side? I'm thinking of installing a t3/t4 and I have read that the mismatch isn't good. Maybe I should just get a t4 and be done with it.

 

No no no...the T3\T4 hybrid is a kick ass turbo! I'm simply saying you have to match your hot and cold sides properly.

Here is a quote from the SE-R mailing list where Rob is doing a general over view of turbo's for the SR20 crowd. Most will apply for the 4G63 as well. It's good reading if nothing else.

For the record:

OEM:

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

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

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

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

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

HKS:

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

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

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

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

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

Turbonetics:

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

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

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

Now, my opinions:

Stock:

The T-25 seems to be OK up to around 1 bar of boost with a 3" exhaust and no
cat. This can support about 240 whp with no cat. With a cat, I would run
no more than 10-12 psi. 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. I'd say 240-260 or so wheel hp max. You can
get more power by running more boost, buy you do so at the risk of breaking
things.

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

HKS:

GT2510 is expensive and only has marginally better performance than the
Bluebird and S13/14 standard turbos. 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. I would personally buy something else first. 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. This with the larger
turbine housing will outperform a GTi-R turbo. 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. This is my opinion as I
haven't tried one. 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. There is too big of a
size mismatch between the 53.8mm turbine and the 76mm compressor. Also, it
is insane to run a .64A/R on the turbine given the flow capacity of the
compressor. This turbine and this compressor are both really good on their
own, but they are worthless together. Total mismatch. 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. Get the 56 trim
compressor wheel and the 90 trim turbine wheel with a .86 A/R turbine
housing. 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. Get the 52 trim compressor and
.73 A/R turbine housing for good streetability and ~400-425 or so whp. Get
the 56 trim compressor and .89 A/R turbine housing is you can live with a
little more lag and want ~475+ hp.

Turbonetics:

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

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

Stage 5 T3/T-04E hybrid. Only run the .82 A/R turbine housing. If you want
less lag, get a smaller wheel. Run the 60 trim compressor wheel. Don't run
a 60-1 wheel (shit) or the smaller trim T-04E wheels. This turbo will
support about 475-525 whp (don't know on the top end--we haven't maxed one
out yet!). Expect soggy boost repsonse below 4500-5000 RPM.

As an aside, many of the HKS turbos are available from INCON for
significantly less money. They are also a little more flexible about
housing configuration. The guys at INCON disagree with me typically when it
comes to matching on small displacment motors. In fact, many people do. You
can take or leave my advice. 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". I have heard it all before. Those turbos are what I recommend,
and you can either listen to me or listen to them. I don't want to play a
game of 'he said/she said'.

Told you he was smart as hell.

 

Well what made me think about this initially was this headline at www.dsm-performance.com

"Congrats to Mark Botto and his 1G AWD automatic! Mark is running an ETE42 with 6cm2 turbine housing on his Diamond Star. On a stock engine and full 3 inch exhaust with hi-flow cat, Mark was able to run a super-quick AND fast 6.98 @ 99mph in the 1/8 mile (no N2O)! He is currently building the bottom end and plans to find a 1/4 mile track as soon as it's completed. Low 11s? Possibly 10s? We'll see. Stay tuned for pics and slips from Mark... "

That ETE42 is a big ass turbo. Basically a 60 trim comressor wheel in the T04E housing. However, the 6cm2 turbine housing is tiny! It's about the equivalent of a .45 A/R or less. It seems to have worked beautifully for Mark Botto though, as that is one of the fastest times out there for an automatic. I'm not saying that what everyone is saying is wrong, but it seems alot of the people who think it won't work on paper, haven't actually tried it.. they merely think it won't work on paper.

 

Yes, but you have no idea what his inlet temps, exhaust manifold backpressure, combustion temps, cylinder pressure and lots of other areas were.

You can also toss a 350hp shot of juice on a Mustang and go 10's. It won't last very long, but you can do it. In fact I can even make a web page selling the kits so guys can post them on message forums!

They HAD to modify that housing in some form. Not to mention they stick a T3 wheel in there. I highly doubt it's factory issue 6cm housing, nevermind a TD05 wheel.

Basically what I see in the DSM camp in regards to turbos is meatball engineering. Just tossing shit together based on crude mathematical calculations and hoping for the best.

The info I posted above came from a veteran lead Garrett engineer. Not some monkey in a shop down in Mississippi, or a counter jockey at the "turbo shop".

What he writes on paper HAS to translate...if not he wouldn't have a job. You think OEMs are going to say "oh it's okay that the run of 500,000 turbos you made for us don't shake out, just redesign it and make another run"

I personally watched Rob calculate on his fucking WRIST WATCH what he thought an SE-R with a certain combination and turbo would put down to the rollers. He said "497" Guess what it laid down 5 minutes later? They guy knows his shit.

I presented the facts do with them what you like.

 

Hey Jay,

Can you give me Rob's email address? I have a few questions for him

mkii91@yahoo.com

Thanx

 

RE: Poster

Don't forget that turbo has to flow more and more with RPM raising to keep the boost. Even with large WG most of the exhaust will go thru the turbine. T4(57)/T3(stage3) is a good proven combo on DSMs. 57trim matches very well 2.0@7500@25psi. Playing with A/R of the turbine housing you can change the torque curve. 48 should be good enough for high 200hp; after that it will start to create too much back pressure and push the exhaust back into the combustion (that's how they ran some mad boost on the early Mutts). I would go with 63 or 82 to free up some flow. If the spoolup is a problem - you might look into tang divided housings.

Basically what I see in the DSM camp in regards to turbos is meatball engineering.

And again : there are some turbos that look good on paper, and there are some that turn in the E.T.s With the availability of Garrett parts, it's possible to play around (just don't forget to balance the turbo) and find what works the best for you. Unfortunatelly Mitsu turbo parts are very limited.

 

Yup, a true proffessional speaking! Keep up the good work!

It was on a private mailing list. Sorry if he rattled your cage somehow.

Doesn't matter what you think, I know Rob, I know where he works, (His email addy is allied signal) and I've actually used a turbo he spec'd and it made 409whp and spooled at 3200rpm with very low inlet temps.

The guy is extremely knowledgable, and a decent person to boot.

I posted this information for people to be educated. Not so "kiddies" could make snide remarks like your self.

Grow up.

Tondar, I don't want to give his addy out publicly. Email me privately and I'll see if I can hook you up. jay@<nospam>ctwd.net

 

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

I don't doubt that he is very knowledgeable. I just find it hard to believe that with the .63 A/R housing, it would only yield 320whp. This is a very similar turbo to the green with 8cm2 housing, and we all know that makes way more than 320whp.

 

The point that Jay is trying to make is, sure you can make huge amounts of horsepower with say an ETE6907 with a puny 6cm housing. HOWEVER, you can make just as much hp, with LOWER inlet temps, LOWER EGTs, and LOWER pressure in your exhaust manifold with a properly speced turbo. It's not always JUST about making power. It's making power RELIABLY. Just because X turbo puts down 600hp doesn't mean it can't be improved. Thinking that is again "meatball engineering."

Jay as soon as I saw this thread I was gonna email you, I'm glad you found it first

Weren't we just talking about this stuff on sunday? LOL

 

I don't doubt that he is very knowledgeable. I just find it hard to believe that with the .63 A/R housing, it would only yield 320whp. This is a very similar turbo to the green with 8cm2 housing, and we all know that makes way more than 320whp.

I watched the car with this turbo lay down 317hp @20psi on the dyno myself...and I also watched it gain 80hp with nothing more than a change to a .82 AR housing. Same boost, same conditions, same dyno everything.

It's not bullsh*t.

The 8cm is more like a .7X housing. Besides you don't know what trim wheel is in there.

 

in the green? That's a 50 trim for sure..

The 7cm2 housing is approximately .50
The 8cm2 housing is defenitely not a .7x it's around .6

Maybe the car wasn't tuned too well..

 

How are you calculating the A/R conversion?

In the green you are saying it's a 50 trim exhaust wheel? That doesn't sound right.

The car was tuned by Jim Wolf Technology...you know the guys who have been reprogramming Nissan ECU's for oh, 20 years. It was further tweaked by Mike Kojima (Yes Mike Kojima from SCC) who is also a Nissan Engineer and had a Nissan consult there to make changes on the fly. The car had C16 fuel in it as well. BTW that extra 80hp in the .82 housing make it 397whp and mine made 409whp. Right where Rob said it would.

Would you like to see the dyno charts?

 

Weren't we just talking about this stuff on sunday? LOL

 

no i meant 50 trim compressor wheel. I believe it uses a clipped TD06 exhaust wheel.

No need to see dyno charts, I believe you. Maybe he could have tried turning up the boost some. The compressor map for the 50trim shows efficiency up to 28psi on our 2.0L engines. Most people who go fast on the green are running way more than 20psi anyways. I do see your point that the exhaust restriction makes a huge difference.

 

Ah okay well there's your answer the TD06 does flow more than a 76 trim T3 wheel. If you clip it you get more flow as well (but lose efficiency in a big way)

The T04E 50trim *compressor* will support 460hp no problem, but the turbine side has just as much influence on power production.

A certain company the makes "dog like" turbos likes to rate their turbo hp by the compressor side only. I guess it does influence some people into thinking that is what it will actually produce...I just hope they don't actually believe that.

I watched a green put down 360whp and another 375whp. I don't think there is too much actual dyno numbers for a lot of DSM turbos, just guesses. It's not like there are AWD dyno's all over the place and not everyone wants to swap in a welded center diff and drop the t-case.

These cars may not be making the power we all think after all. My Nissan weighed 2750lbs and went 116mph with 330whp for reference sake.

A 2800-2900lb Eclipse should pull 120mph with NO problem at 375-400whp.

 

I watched a green put down 360whp and another 375whp. I don't think there is too much actual dyno numbers for a lot of DSM turbos, just guesses. It's not like there are AWD dyno's all over the place and not everyone wants to swap in a welded center diff and drop the t-case.

True, but then again - this is not a supra forum. There are not so many dyno numbers but there plenty 1/4 mile times - with times there is no guessing involved.

 

Yes but when you derive hp from trap speeds you have to have your race weight SPOT on. That's a big variable...especially considering scales vary pretty bad from track to track unless they are NHRA certified.

 

Maybe he could have tried turning up the boost some.

Forgot to address that part. Sorry.

It was tried, but with no real gain. The turbine section was out of flow. 4.5 more psi gained like 2hp.

 

Again: HP .... traps ....who cares? Times (and that's what I said, times) win races. With DSMs you can get repeatalbe times on a turbo. There are some freaks out there - but in general we know what to expect from a turbo. If you are not hitting low 13s with 14B - there is something wrong, if you are not going mid 12s with s16G - there is something wrong, etc.
It's true, 14B is not efficient above 17psi - netting mid 13s, but again, who cares. People have ran 24psi and low 12s on 14B. Is it efficient - NO, is making power - YES!

 

And now you know why DSMs break so much.

Meatball engineering.

 

So do you also prefer burnt valves, blown head gaskets and spending thousands of dollars in repairs you don't have to?

The turbo's Rob talks about are real, and they work. How dare you say it's BS.

My SE-R went 11.5@124mph with a lousy 2.0 60' on the stock 9.5:1 cast piston non turbo longblock for over three years without a much as a fouled spark plug. NOT ONE BROKEN PART. Can you say the same? NO you can not. That's REAL WORLD not BS.

He DID the R&D, don't be a fool. Why WOULDN't you want lower inlet times, better spool, and more reliability with the same power? I bet you would be one of the people who argued the world was flat with Columbus too.

Whatever...enjoy 300* inlet temps and crazy backpressure in your exhaust manifold. Don't cry when you blow up...after all you'll have your 11.0 timeslip.

 

What's the difference between turbo and non-turbo Sr20?
How many passes have you got on the car?

The car had a lot of abuse on it I've got a file folder full of timeslips. But that only tells half the story. As Formz can probably attest to, the car was BEAT just about ever single weekend at our local cruise scene. That was the routine. Take it out Friday night, waste 5 gallons of race fuel getting into about 5-10 races...park it, clean it up nice nice on Sat, repeat abuse seen on Friday night. Park car, maybe hit up a test and tune the following wednesday, park it again until Friday and repeat. The car had nitrous from 7K to 30K and the turbo from 30K to 50K. Another car just like it had nitrous up to 60K, then the turbo went on and it now has over 120K on it and it won't blow up. (<==That car was actually the test mule for the "kit" and was run pretty hard)

The difference between the DE and bluebird DET isn't that much.

DET = 8.5:1, sodium filled valves, oil squirters. That's about it.

The DE still has the FAT rods, strong crank, deep skirted pistons, main bearing girdle, timing chain, webbed block etc etc.

Mo, I'm sorry if you felt like that was a personal attack, I just didn't understand why you had to come off so cocky and sarcastic.

Rob clearly stated that he had not tried that turbo, but from a *garrett engineer's* standpoint it was a piece of crap. If you didn't know HKS turbo's are Garrett GT series turbo's rebadged..