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My compound turbo set-up

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It hangs open and causes all kinds of problems, especially the trans overheating in the lanes. It's not wilson's fault specifically, it can be an issue with all of the giant throttle bodies on 4 cylinder engines. The problem is that we have to close the plate so far to get a normal idle speed, to a point where they just didn't design the plate to fit the bore properly at that angle. It rubs and hangs up and starts to wear itself out. A V8 would have it open much more at idle and they don't have issues. Wilson (IIRC) told a mustang friend of mine that they recommend building up some JB weld on the back side of the throttle plate so it can be left further open at idle. Not something I want to bother with on a 500 dollar TB! On my car I kept my trusty 75mm unit and made my own adapter plate for it.
 
^^Curious about the same. Was the throttle body a restriction in this setup?

Edit: gotcha.... I wouldn't want to put jbweld in the throttle body either unless there was some really good way to ensure it couldn't vibrate/break loose and get sucked into an expensive engine.
 
Yup, I would rather just run a smaller throttle body. TB diameter is the least of my worries. Here's an update on the car from this past weekend that I forgot to post here.



Here's a video of all of Kait's runs in the 2g at the SO.

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We took it out again yesterday and she ran it in the local NEDx275 class. The car is a full second too slow to compete but it's still a lot of fun. She beat my best 60 foot and 8th ET by a little bit, 1.33 and 5.97. Still unchanged from the SO aside from being back on E85. Just dragged it out of the woods again and headed up. This would be a fun car to loosen up the converter bit, nudge it into the 8s, and just go racing a couple times a month.

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Yes, individual cylinder widebands, back pressure compensated. I also have a normal one in the WG dump tube so I have something to look at going down the track.
 
It is a bit ridiculous. With this setup I can go from idle to 60 psi in a few seconds. I've logged 50 psi increase in 1.5 seconds. It also make full boost at full power at 50% throttle, still not sure what to make of that. :D

Most of that video is about 20% throttle. It's only WOT once it reaches 9k. When the vapor is pouring out the VC breather it's at WOT.
 
I have a question.... why is the magnus bracket upside down running the mechanical pump off the intake cam? Mine's "right side up" on the exhaust cam. Was there some thought behind this or was it just the way it had to be run to make things fit?

Also, is there no radiator in this car or is it somewhere else?
 
Nope, just had to flip it to make this setup fit better. :) I will eventually swap that bracket out for an EVO one so it looks right.

The radiator is way out in the nose as far forward as possible. It's a bar and plate core so most people think it's an intercooler. 21x7x3.5, works mint.

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Ah I see, makes sense. I've had a WAIC in my car going on 3 or so years now.... I will never go back. I'm impressed everytime I see someone with a large WAIC core in their car. It looks like yours has the icebox connected to the cores. Is there no water pump or heat exchanger?

on my car I used the stock a/c condensor in the stock location as my heat exchanger for the water to air setup. It returns to ambient after hard mexican highway pulls very quickly... and it doesn't heat up very much either during the pull.
 
Yup, ice water tank directly exposes to both cores. There is a bosch lightning style pump that draws (cold) water through the front core, and returns it through the rear core. In theory this is pretty ideal, but it reality it's not working that well. Like any centrifugal pump, it doesn't want any restriction on its inlet. There's a lot of cavitation and not a lot of flow. But it still kicks the shit out of an air to air. :) I'll probably add a second pump over the winter, have both draw from the bottom of the tank and each pump through its own core. That should be a massive improvement. The pump is ECU controlled and definitely makes a huge difference vs just using it as a heat sink.
 
I was thinking about putting AC back in my car and running two of the largest heat exchangers I could fit in both fog light wells. That might be a good solution to get some of the ambient air out front to cool your stuff down. Of course this will heat things up if you're running ice water as the ambient is hotter.... I had some clever ideas for valving that could intelligently fix that problem but I didn't want to over engineer a mess into my engine bay and engine control. It would work though to block the exchangers until the internal core water temp reached ambient outside temp then switch over to the exchangers. That's more for a daily driving setup as I'm sure your car is not ;).
 
No sir, I put 20 lbs of ice in this POS for a pass. Mathematically it should melt about 11 lbs on a 8.0 run.
 
It is a bit ridiculous. With this setup I can go from idle to 60 psi in a few seconds. I've logged 50 psi increase in 1.5 seconds. It also make full boost at full power at 50% throttle, still not sure what to make of that. :D

Most of that video is about 20% throttle. It's only WOT once it reaches 9k. When the vapor is pouring out the VC breather it's at WOT.
That turbo pairing is awesome! isnt it a 3582/4505?
 
Yes, that is the setup. Works very well. I wish I could go bigger than the GT45R turbine/1.44 T4 housing though. The 3582 is on a .63 housing, which I will likely raise to .82 consider how quickly it spools. But it's a great pair even as is.
 
Had to put compounding on hold so im not in the club yet :( Spooling a big turbo like that with no nitrous is incredible, would love an incar vid on the new setup!
 
I figured it's about time I share this project with everyone on this site. I've been tinkering with this since November of '08 and it's finally almost complete.

Cliff notes on function: Two turbos are used, one smaller than the other. The smaller turbo get exhaust first in the stream, and the smaller compressor receives compressed air from the larger turbo's compressor. Being that pressure ratios multiple, this type of set-up can yield a large amount of dense air very quickly. Translation = lots of boost and very quick spool. Another huge advantage to this type of set-up is that it's capable of running more boost than any single turbo. This is how tractor pulling guys achieve 200 psi boost.

For a more detailed explanation of it's function, read this article: Diesel Power Source - Articles - Turbos/Twin Turbos - Twin Turbos vs. Single Turbo

And for you visual people out there, here is a picture of a compound set-up on a Cummins diesel engine:

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These are pictures of the final product. Pics early 2010:

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Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.
that looks great, i cant wait see a video when you get it going
 
Belated update for this old thread. My car is still set up much the same as it was in 2016 above, but a few key changes.

I added a second Bosch pump to correct the problem I mentioned there. Both pumps pull from the ice water tank and pump into each core. That solved the pump cavitation issue and dropped IAT 50 degrees F.

I changed the cooling setup around again. It's amazing to me how finicky this stuff is. That pump is now also working better and really moving some water. Temp is back under control, as long as the head stays down. I changed the double pass "radiator" (it's a bar and plate IC core type heat exchanger from frozen boost) to single pas, and that was the main improvement. Some changes in line size and routing as well. I also got rid of the radiator pressure cap and put a sealed screw on cap on it. A 50 psi relief valve opens if it gets pressurized by head gasket leakage.

The 4505 had its compressor upgraded to an 80mm, but I wasn't using all of the 76 anyway most of the time. Same turbine size, same 3582 for the bottom turbo.

I added 3 BOVs (previously had none for many years). That's a long story.

And I switched out my trusty old torque converter for something a little stronger, and bolt together. I haven't spent any time optimizing it yet (I have a few stators to try) but it was an improvement right out of the box.

With these changes the car finally ran 7s on compound turbos and matched the performance of the single turbos. 7.96 at 173 I believe. It's really just down to the converter, the car should be much quicker for its power level. Luckily I bought a dyno a few years ago and do at least know it's making power. That was a mystery for a long time. I haven't dynoed it at full power yet but I know it always makes 10x airflow minus whatever buffer I leave on the table. Here's a video. Hard to believe even this was already a year ago. I'm not sure the fastest compound turbo claim was correct even at the time, I feel like someone I help out had gone quicker by then, but it's someone else's video. In any case we now have Jett Racing going 6.20s on compound turbos. The dyno pull here was 991 whp, that was probably already posted above somewhere, but the track run is after it. My previous best was a ton of 8.30s for years, and one random 8.29 it ran on a no prep street night, LOL.

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Hopefully I can find the time in 2019 to test some stators and get this thing sorted out. It really should go mid 7s on this setup, even with the stock ECU, pump e85, and other alleged handicaps.
 
Does anyone remember the 95 3000GT Twin Turbo... I'm wondering if you were able to find one if it could be transferred to the Eclipse...There is no sound in the video clip.
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Meanwhile 3/S guys are busy swapping to the 4G engine because 4G63 > 6G72. :)
 
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