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Discussion Starter #1
So how good is this kit?

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:laugh: :laugh: :laugh:

Serious question though, I am researching their methods for choosing turbos for different applications and I have come up empty. I have no idea what turbos they use with which kits, what trim, etc. If I can figure at least that much out, I can extrapolate how they pick proper turbo size for remote mount.
 

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There's not that much magic to it. They use a smaller turbine housing and/or a smaller AR ratio so that the cooler exhaust still spools the turbo in a decent amount of time. They also use dual ball bearing turbos to aid in spooling time also. The compressor section is the same no matter how far away that it is from the engine. If you are shooting for 400HP, you will need a compressor that flows 40lb/min before it falls off the map.

Have you ever plotted a compressor map before? I can explain it but it will be a good sized post.

BP
 

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For instance, here's a GT3071. I've plotted it for a healthy 3.0L that puts out 250HP at the crank at redline with no boost...



The first thing that you'll notice is that not all of the lines are on the "island." That is bad. In this particular case, it means that the turbo is a little too small.

The different colored lines are RPM of the engine. Going from left to right they are 2k, 3k, 4k, 5, 6, 6.5k, and 7k. On the left had side of the graph, is PR or pressure ratio. That is a multiple of the incoming air. If it is a single turbo, it will just be sucking in air through a filter at atmospheric pressure or about 14.7psi. On a vacuum or boost gauge, this is 0psi or no boost. Now if you follow the PR line up to 2.0, that is twice atmospheric pressure. On a gauge, it will be 14.7psi. With a PR of 2.0 your engine will be taking in twice as much air as it would without a turbo. In a perfect world, that also means that your engine would be making double the power.

The plot above therefore shows 500HP or 50lb/min at 7000rpm with a PR of 2.0. If you continued the 7k line down to a PR of 1.0, it would be 25lb/min or 250HP. The other RPM ranges are best guesses made looking at stock engine dyno graphs.

The compressor map looks like an island. The closer that you get to the center blob on the island, the more efficient that the turbo is. In our case it would be a little over 4,000rpm. The will also be where the most torque is produced. As you get towards the outer edge of the compressor map, the turbo is less efficient and just heats the air. That is bad. Hot air equals detonation. That's why this turbo is too small. Over 6500rpm, we have fallen off the map.

I should also mention that the horizontal line on the graph is flow in lb/min. That is pounds of air per minute. A good estimate is that 10lb/min equals 100HP. So 50lb/min equals 500HP. That is the quick and dirty way to see of a compressor is sized properly to your application. If you know that you are shooting for 500HP, and the island ends at 40lb/min, your turbo is too small. Now if you are shooting for 500HP and your island ends at 65lb/min, your turbo is probably too big.

If your turbo is too big, your lines will be plotted to the left of the "island." That is also bad. The left edge of the "island" is called the surge line. This is where the turbo is barely starting to compress and is VERY unstable. The air surges but doesn't come off of the compressor wheel in a fluid motion.

Now here's a turbo that'd be great for our 3.0L...



It would hit full boost between 2 and 3k rpms, the torque peak would be between 6 and 6500 rpms and you've got a little room to grow.

$1250 for dual ball bearings and it's all yours...

http://www.atpturbo.com/mm5/merchant.mvc?S...tegory_Code=GTB

This is a T3/T4 turbo. It has a smaller T3 turbine housing but the bigger T4 compressor. Perfect for a remote mount setup.

You can also see all of your turbine AR ratios in the above link. For a remote mount, a .63AR would be a good start. For more traction in the lower rpms, a 0.83AR would be a better choice because it would build boost slower.

You can also see all of the different turbine housing types. Personally, I'd go with an internal wastegate just to make life easier. For higher performance, an external wastegate is recommended.

I hope that some of that makes sense.

BP
 

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Thanks! Yeah, I used to do them all by hand but found this awesome spreadsheet that plots 80 different turbos at once. I'd attach it but it's 5.2MB. Doh!

One cold day this winter, I want to add more. I'd like to expand it to some larger turbos. After I turbo my Contour, my next project will be a 383 powered AWD Chevy Astro. 800HP AWD anyone? Bye bye WRX. See ya Evo. ;)

There was a 3,000HP blown methanol 4x4 S-10 pickup on Horsepower TV this last weekend. I was in awe. Seeing all four tires do a burnout was a-w-e-s-o-m-e.

BP
 

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QUOTE (ButtonPuncher @ Sep 29 2009, 12:18 AM) index.php?act=findpost&pid=1604714
Thanks! Yeah, I used to do them all by hand but found this awesome spreadsheet that plots 80 different turbos at once. I'd attach it but it's 5.2MB. Doh!

One cold day this winter, I want to add more. I'd like to expand it to some larger turbos. After I turbo my Contour, my next project will be a 383 powered AWD Chevy Astro. 800HP AWD anyone? Bye bye WRX. See ya Evo. ;)

There was a 3,000HP blown methanol 4x4 S-10 pickup on Horsepower TV this last weekend. I was in awe. Seeing all four tires do a burnout was a-w-e-s-o-m-e.

BP[/b]
You've got a PM coming your way.
 

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Discussion Starter #7
Awesome, thanks, I was actually thrown off by the fact that when STS first came on the scene they marketed themselves as professionals with the knowledge of picking the right turbo for a remote mount application, which led me to assume they were not using the same turbos.

What are your thoughts on a T3/T4 journal bearing turbo?

* T04E Compressor Housing with .60 AR
* T04E 57 or T04E 60 Trim Compressor Wheel
* Oil-Cooled only
* Stage 3 Turbine Wheel
* T3 Inlet Turbine Housings with 4-Bolt Outlet, Externally Wastegated, AR ratios .48, .63, .82, and 1.06 available
* Factory built, VSR balanced
* 57 trim wheel rated up to 450 HP
* 60 trim wheel rated up to 500 HP

Brand new for $700 each.

I was reading on one of the Corvette forums, where one or two of the guys with STS kits upgraded their journal bearing turbos to ball bearing and couldn't tell a difference in spool time or power. So is ball bearing really worth it in remote mount?
 

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On a huge displacement engine like a Corvette, journal or ball bearing won't matter. On our engine, I would definitely go with dual ball bearing.

Water cooling extends the life of your turbo and drops the compressor output temperature.

One thing that I didn't mention earlier with a remote mount turbo is that you will need an oil reservoir mounted to the bottom of the turbo and an oil scavenge pump to pump it back to the oilpan.

T04E compressors are too small. Check out the attached maps. You might be able to use the 60 trim, but that would be on a bone stock engine only making 220HP at the crank. You'd have no room for expansion. The 60 trim maxes out at 35lb/min at a PR of 2.0. So at it's absolute maximum, it will only make 350HP. Anything more and it's just hot air.

Also, here is the site that has the turbo calculator...

http://www.squirrelpf.com/site/?page_id=55

You want the "V1 Turbo Calculator." I've also attached the settings that I use. Click on the "setup" tab and enter in the same numbers. These numbers are for a healthy 3.0L that puts out 250HP at the crank naturally aspirated (no boost).

Make sure that all of the numbers in blue and maroon match mine. When they do, the "Corrected Air Flow and Pressure" graph will fill in with numbers identical to mine. I know that the Liter Displacement isn't exactly 3.0L and the Compression Ratio isn't exact. This spreadsheet was originally made for a 2.4L SOHC Turbo Dodge engine. I had to fudge the numbers a little to get the proper results.

If you don't have Microsoft Excel, don't worry. Download the free Open Office and use Calc to open and edit the xls file.

http://www.openoffice.org/


BTW, they also have an online calculator at...

http://www.squirrelpf.com/turbocalc/

I just noticed it now and I haven't used it before.

I hope that helps.

Later,
Ben
 

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you have to be careful using Ball Bearing turbos on our cars. or any car period. if you go ball bearing make sure you have the proper size orifice restrictor for otherwise you'll blow the seal on the turbo. BB turbos are very oil pressure/flow sensative.
 

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Discussion Starter #10
I get the numbers to match yours in the spreadsheet version, but for some reason the lines don't match. Tweaking the numbers on the online calculator, however, to match yours, gives me an even weirder result, it shows a pair of T3 50-trim turbos are the best match for TT. Yet the Noble uses a pair of T25s and produces a proven result.
 

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The numbers that I'm using are for a single turbo. If you are going twin turbo, you want half the power.

Instead of 3.25L, you would put in 1.6L. Check out the attached pics.

If you are going twin turbo, definitely check out mitsubishi turbos. The TD04-13G is absolutely PERFECT. Mits makes great turbos for small engines... Or half of our engine. ;)

The TD04H-15G would also be a good candidate. It's a bit on the large side but it's still at full boost by 2500rpms. If you were going forged everything and shooting for 500HP at the wheels, two of these turbos would get you there.

The T3 50trim is also dead on. Torque peak right at 4k rpms.

The GT25R is good but the map is funky. You don't hit peak efficiency/torque until higher in the RPM band.

Watch out because there is also the GT2540 which is WAY too big. You wouldn't hit full boost until 4k rpms which is horrible.

The nice thing about mitsubishi turbos is that they are cheap and plentiful. I used to have a site that rebuilt them. I'll see if I've still got the link somewhere.

I hope that helps.

BP
 

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Ooops. Forgot the GT25R...

The more that I look at it, the more I don't like it. The surge line swerves into the 3k rpm line, and peak efficiency isn't until 6500. Meh...
 

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Two Mits TD05H-14b turbos would also be a good with room for more power like the TD04H-15G. The efficiency/torque peak is getting up there...around 6k rpms. It'd pull like a supercharger.

Plus they are dirt cheap (as far as new turbos go)...

http://www.turbochargers.com/store/product...7c764208f4fcf84
 

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I know when I mapped out the super 60 they were fine. I'm building max boost between 2500-2800rpms all day and building power until I let off at just under rev limit.

I still think doing a remote mount on this car is not necesary. There is plenty of room so a singl turbo setup behind the motor
 

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I think most people aside from a select few won't be fully building their motor to boost so they will either have to sacrifice low end/faster spool by using a bigger turbo to make power up top or sacrifice top end and use a smaller turbo since they won't be able to go over 8psi to 10psi

Deppeneding on the turbo...8psi will be enough for some.
 

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QUOTE (The Great NY @ Oct 1 2009, 06:10 AM) index.php?act=findpost&pid=1605398
I still think doing a remote mount on this car is not necesary. There is plenty of room so a singl turbo setup behind the motor[/b]
I no longer have my 6, but this is for a Duratec project of mine. Instead of doing a V8 swap in the Mazda, I really like the idea of an AJ series Duratec, more than likely from an LS or S-Type since the water pump got moved to the front of the block and the exhaust manifolds are designed for RWD applications. Since I would be getting one out of a junkyard for around $500, building it up with new pistons, rods and bearings will be on tap.

Thank you ButtonPuncher, you have been a great help!
 

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QUOTE (The Great NY @ Oct 1 2009, 04:10 AM) index.php?act=findpost&pid=1605398
I still think doing a remote mount on this car is not necesary. There is plenty of room so a singl turbo setup behind the motor[/b]
There is definitely room, as you have shown with the twin setup and remote turbos aren't necessary for any application, really. The benefit I see with rear turbos is you don't have to mess around with an exhaust manifold being fabricated or any of the associated issues with that (just some piping--a lot easier) and you don't have any of that extra heat under the hood, as well as the double edged sword of having easier access to the turbo setup to work on it.

QUOTE (The Great NY @ Oct 1 2009, 04:15 AM) index.php?act=findpost&pid=1605399
I think most people aside from a select few won't be fully building their motor to boost so they will either have to sacrifice low end/faster spool by using a bigger turbo to make power up top or sacrifice top end and use a smaller turbo since they won't be able to go over 8psi to 10psi

Deppeneding on the turbo...8psi will be enough for some.[/b]
With remote turbos you don't need to set it up for boost at all. Since most naturally aspirated cars are at or above 10:1 compression, boost should hit in pretty quickly. As is obvious with reading this thread and having a basic understanding of turbos, matching the right size turbo to the application is crucial. I do like the idea of a rear turbo on the 6i, for instance, because it isn't a high compression motor by any means (9.7:1) but it isn't too low, either. That and I'm already single exhaust with mods, so I'd be into boost pretty quickly with a GT25 or similar turbo.

Typically, rear mounts are used to just have an even more cost effective way to gain 50-100hp than a traditional turbo setup, depending on the turbo and application. I'd love one for this altitude, that is for damn sure.
 

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Yea there is plenty space behind the motor. But in front of it between the radiator abd moree....there in not much at all, lol



The thing with remote mount is they usually work better on bigger notors because the turbos are so far away from the engine you lose some of the exhaust properties that is needed to spool a turbo.

Which is the heat.

Flow velocity doesn't change much if any. And if it does it would be too small to measure.

Heatwrapping the entire length of exhaust would help tho.
 
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