Currently, I have a Drag 3 on my '00 GS-R, but I'm doing a little research for my next project -- a '94 GS-R swap into my '93 Civic hatch and have a few questions.

Basically, I plan to run about 18 psi (max) on a built motor (ie. GE sleeved motor, rods, pistons, EMS, full 3" exhaust, etc.).
I understand how to find the proper sized compressor. I've checked out several compressor maps, and contrary to popular demand, it looks like I'll be going with a T3/T04E "50" trim compressor wheel with a .63 A/R stage 3 turbine. A few things I don't understand are:
1) How do you determine which would be the "ideal" turbine wheel/housing for a particular setup? I understand a .48 A/R would spool quickly, but fall off in the upper rev range , and a .82 A/R would give awesome topend, but won't reach full boost early enough , so I think the .63 A/R would be the one for me. Keep in mind that I'm shooting for approximately 18 psi max with a stock GS-R redline.

2) Are there any turbine maps out there for us? To my knowlege, there aren't. If so, please help with any formulas necessary to figure out the "ideal" exhaust setup.

3) There are a few Honda-Tech members that have quoted certain turbos to be good for x amount of horsepower (ie. this turbo is good for 375-400 whp). Can any of you point me in the right direction to find out how to arrive at these estimates? I've checked out several turbo calculators that do this for you, but I'd like to understand how to do this with my calculator. Any info on this would be great!

4) Not really related, but a question none the less...
The T04E "50" trim compressor apparently has a 4" inlet. Do any of you have a link to a place that sells the silicone hose couplings in 4"? All the ones I've seen usually only go up to 3".
This place has something 3 3/4" I.D. "Nitrile/SBR Rubber Hose". Maybe that'll work if I stretchhhhhhhh it.

As always, thanks for your help!
Take care,
Mick

 

3) Multiply the lbs per minute a turbo flows by ~9 to get an estimate of its max
Horsepower.


So if it flows 44 lbs per minute, it should flow enough air to give you around 400 HP, but I don't know if it's Bhp or Whp

HTH

 

Thanks for the info, John.

Anyone else?

 

There was a guy that just made a "Turbo Calculator"...some where on this board.

I wonder if you could find it with a search?

I don't think it will really tell you WHEN the turbo will spool though, but will show if the turbo is too big, or too small for your engine/HP.

Plug in your boost you want to run, and the specs on your engine... then gives you the #'s to graph on your compressor map's



[Modified by Bryson, 2:13 PM 7/24/2002]

 

https://honda-tech.com/zerothread?id=233598

 

Thanks Bryson, I saw that a few nights ago... but, I have no problem plotting the points on compressor maps to find the one which suits my needs. I'm mainly looking for any and all info I can get dealing with the exhaust side of the turbo. I'm pretty sure the T3 A/R .63 stage 3 wheel will be good for me, but I'm trying to learn as much as possible here before I make any decisions.
L'il help from the gurus... please.
Hello --- hello ...
Is this thing on --- on?
<crickets chirp>
Y'all take care,

 

So, nobody knows this... or nobody's tellin'.

Come on all you gurus. Share the knowledge.

 

Thats the one they sell with the drag 3 kit. We took one off and measure it and it was a 50-trimT04e comp wheeland a .63 a/r turbine housing with a stage 3 turbine wheel.That turbo on a ls integra tune to 240whp@8psi Ran 12.6 1/4mile on a good track with slicks

Elite Autosport
95 civic coupe B20T vtec 360whp@10psi (on pump gas half tune)with a custom turbo

 

I measured the compressor and turbine wheels on my Drag 3 kit for a GS-R, and mine came with a 54 trim T04E compressor and a T3 .63 A/R turbine housing with a stage 3 wheel.

 

So no one ever answered .......

I am also curious to know the answer.... I was thinking about the .82 a/r turbine housing, but agree boost is gonna come way late... I dont know ... Id like an answer .......

And also wondering why some drag kits come with a 50 trim compessor wheel and some with a 54 trim wheel

 

Standard answer on turbine sizing is "trial and error" or "knowledge from experience".

There are just way too many variables in exhaust flow to even HALF accurately model the turbine side; the only way to go is by trying things or talking to people who have. Even with HARD core finite element CFD analysis I think it would be beyond the capabilities of most modeling systems.

 

 

Anyone knows of a way to calculate this?

 

At least one formula exists to calculate compressor size. It is fairly accurate. However, I have not seen any formula to calculate turbine size. The only info I have ever seen on selecting a turbine uses the exducer bore to estimate it's flow capacity.

 

Wow! You brought this one back from the dead. Anybody else wanna chip in?
I'm still lookin' for answers. Thanks.

 

I would agree. compressor maps exhaust plot graphs can get u close but real world is the only way to really found out how good this and that combination is gonna work.

 

Anyone else? It's been a few years, but I'm still curious about this topic.
Thanks again fellas.
Mick

 

One more time...

 

To the top...

 

I'll bring this one back from the dead in a few more years... maybe.

 

You can plot exhaust gas flow in a similar way to how you plot a compressor map. Unfortunately, few turbo manufacturers provide this information. I do believe Garrett does for the GT series stuff.

This helps, but it isn't a complete picture. You can use a compressor map and turbine map together (by using the common shaft speed I believe) to determine approximately how much exhaust gas the turbine can flow at a given point, and then you need to determine what kind of exhaust dynamics you have going on (headers) and whether you are making more or less exhaust than the turbine can flow, and if you are making more exhaust than it can flow if you can bypass that much via wastegate or whether you are fucked.

Hope that helps a little, I understand enough to be dangerous but probably not enough to be really helpful.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Hope that helps a little, I understand enough to be dangerous but probably not enough to be really helpful.</TD></TR></TABLE>

I know exactly what you mean here.

I appreciate you taking the time to reply.
Take care,
Mick

 

Here we go again...
This post is ~7.16 years old. Any new ideas on this?
Thanks,
Mick

 

Umm. there are entire writeups on this on http://www.turbobygarrett.com, as well as turbo professionals available that understand your application on what you're trying to do with the car. The best thing to do is base your needs on power level, and how you want that power delivery, not just a pressure ratio. They are located in the FAQs section of the forum.

Things have changed since '02, you can find this stuff now.