Project "Baller"

[meminto]

It's all good lol...

It's a design I have been working on for a while now involving staged turbocharging..

The T67 now has an 8cm housing and will be the secondary stage..

A GT4718 will feed it in the primary stage.. I will hopefully order it next week..

In the meantime I have been honing my tig skills as I bought an ac/dc tig welder earlier this year..

[r34 gtr]

Sorry if I am being a little apprehensive, but isnt a GT 4718 (aka 4788R) a little on the big side for a CA? A 93mm wheel won't spin up particularly fast on a 1.8L, and I mean come on, its freaking huge! T6 flange and 5" V-band outlet?! Its not little.

What kind of TIG setup did you get? Im pretty jealous!

[meminto]

Your right it is a huge turbo, it would never spool on it's own..

But this is staged (compounded) not sequential which is a different kettle of fish..

Hence the 4718 .96 is first to see atmospheric, second to see exhaust..

These types of setups are specifc to the motor, luckily I know all the variables for mine so I have a good calculated starting point..

I may need to muck about with exhaust housings, but this should be close..

Some of your dsm enthusiasts across the pond are obtaining great results, with this type of setup..

[meminto]

A quick update, the 4718 is in the country..

It is a big mutha, its as big as a helmet lol..



And here is the T67 with the 8cm T25 style housing..





1600cc injectors have been sussed out..

Cheers

[float_6969]

Big Mama Jama

[Noxy]

Wow. I can't think of anything else to say other than that...

[r34 gtr]

That back housing on that 25g looks so adorable!

[NUTCSE]

You do realise thats a 1400hp turbo, right???

[r34 gtr]

Read. I asked the same question right above the pictures.

he is fully aware of how humongous it is.

[meminto]

That back housing on that 25g looks so adorable!

it does look cute doesn't it.. lol...

[meminto]

You do realise thats a 1400hp turbo, right???

Yeah mate fully aware..

Yes its a maximum 1400hp (or according to the map in the least of its efficiency range at 130-140 lb/min)

But I need 110 lb/min flow at a specific PR as efficient as possible.. 2.2 PR absolute (roughly 18psi gauge) but this turbo sees atmospheric pressure, the other does not..

Here is an extract of a response on ns.com of why these turbos..

"So why a 4718 and a T67-25G together?

I decided that with all the work that went into the motor, a thousand hp was likely to be achievable, so I used 1050 as the target hp..

Using a number of formulas, and knowing the variables in my motor such as Volumetric Efficiency, RPM I wanted to use, Displacement of the motor etc, I found out what my estimated normally aspirated cfm flow is.

I used this figure to calculate the flow and pressure ratio required to reach the 1050hp goal. I must stress for my motor only, other motors will be vastly different and as you move up in displacement requirements change..

1050hp @ 9200rpm = 110 lb/flow @ 5.5 PR (all in absolute pressure)- No big single turbo would do this efficiently, and if it could the powerband would be so insular that it would be useless anywhere but on a dyno or on a drag strip with a 6000rpm stalled up auto lol..

Remember this is peak, I also calcualted this in 2500rpm increments using a 10000rpm limit for all subsequent calculations.. and plotted oncompressor maps (and to a certain point turbine maps) accordingly..

So enter the compound turbo setup, I knew that I needed the 110 lb flow, but at what PR? Logic suggests and research backed it up, that with a compound setup you want to use each turbo in the best efficiency possible, sharing the pressure ratio not to far away from equally but in a high/low relationship. So I played around with multiplying the pressure ratio numbers until a came up with what I think is a good relationship. 2.2PR on the low and 2.5PR on the high...

The low pressure turbo was fairly straight forward, I needed a turbo that could produce 110 lb/min flow @ 2.2 PR, with relatively high efficiency (peak). I looked at several turbos and settled on the 4718, plotted out it fitted the requirement with 74-76% efficiency..

The high pressure turbo was a little more difficult to figure out, as I needed to claculate the mass airflow correction between the output of the low pressure turbo and the output of the high pressure turbo. Note that the density ratio of each turbocharger stays the same relative to the PR.

Running the claculations resulted in requiring a turbocharger that could produce 55 lb/min flow @ 2.5PR. Greddy do not provide compressor maps and I thought I may have to sell off the T67 for a different turbo, so I measured the specs of the wheels (both inducer and exducer on both wheels) and looked up the garrett site to find a turbocharger that would be closeish to the Greddy. Out of pure luck, the greddy turbo seemed to fit the requirement, but the 10cm housing was too big for a quicker spool and I opted for an 8cm housing.

As far as heat goes, as each turbo is highly efficient and with the correct use of intercooling, the egt's should not be any higher."

I haven't worked out wastegating yet, for the exhaust manifold, but at this stage two 38mm gates (primarily to reduce backpressure around the 8cm housing when the 4718 is ramping up to its nominated pr) is looking like the winner out of a couple of configurations..

The 4718 will be gated with a 50mm gate

[meminto]

I made a small vid of the two turbos together..

http://www.youtube.com/watch?v=VirpCxZU9mk

And a couple of pics..





This one illustrates the original T25 compressor on the very right, the greddy and the 4718.. Very cool ..



I am hoping to start positioning the turbos in the bay this weekend..

Cheers

[r34 gtr]

Fantastic. I cannot wait! Best of luck in achieving your goal, good sir!

[ca18detgabby]

always good stuff when I open this thread.

[meminto]

always good stuff when I open this thread.

Cheers gabby..


A couple of things going on, I am moving again, but at least I will have a much bigger garage to work in.. lol

Have all the steam pipe bits to make the manifold and I also received the mazworx harness bar..

With a bigger garage I can leave the car on stands again and work around it, will be more productive..


Sourcing 1800cc injectors at the moment.. But with the rising rate I have some flexibility in rail pressure..

Cheers

[Amays U G37S]

lol omg at this comparison and what you're about to stick on a ca!
can a CA even handle that?
Im sorry but that's extra scarry on that motor, I believe the motor is intimidated.

Loving the dash man, and the swap. That is most amazing.

Goodluck with the rest of the build.

[meminto]

lol.. cheers dude.. ill find out...

I believe my ca will handle it, a lot of research and dollars went into the build of the motor, if it doent ill find out why and go again

one thing I need to keep an eye on the intercooling efficiency and i may need to fab up a cooler between stages, but may not be necessary..

good thing is that both turbos will fit, maybe a pipe through the bonnet, but I loose conventional power steering...

Cheers

[Amays U G37S]

Power steering is only good at 5mph and less. Lol

Oh man, I cannot wait to see this thing in action. It is going to be a monster.

Goodluck man!!

[Amays U G37S]

update?

[meminto]

No progress recently, going through some personal circumstance issues that are still being worked out which has taken up time..

Committed to finish by christmas, solid work going in this weekend, will be mounting the 4718 and welding the manifold together....

Kicked off the patent process for my design of the gas acceleration chamber..

[Amays U G37S]

No progress recently, going through some personal circumstance issues that are still being worked out which has taken up time..

Committed to finish by christmas, solid work going in this weekend, will be mounting the 4718 and welding the manifold together....

Kicked off the patent process for my design of the gas acceleration chamber..

WOW! Sounds awesome! Pics are a must

I cannot wait to see this. I just wanna hug the little CA carrying that monster.


"Hey, I think your face is in the backseat"
This is going to be fantastic. Goodluck!

[Noxy]

Hah. Looking to get my CA running befoe christmas, too. Though its not even in the same league as yours! Good luck to you!

[nelson8708]

nastiest build on nico....bar none. I dont care about a turbo ls1 swapped s14, this build pwns all. I'm going to ask santa for a dyno vid of your setup....haha

[cheap_sticker05]

Any updates on this? I hope you didn't sell it.

[sjbsuperman1425]

I doubt he sold it haha. I dont know if anybody noticed but, this thread has 58,000 views lol

and Awesome build indeed. can't wait for a video!

[frftw]

ur putting THOSE on a CA? u just made my year...

[ks13]

bump

[ks13]

bump

[float_6969]

I'm thining he's MIA. Or he spent all his money. Or a Wallaby ate him.

[ks13]

single turbo it and call it good meminto.