Compound turbo build and other updates

tall boy said:
I would have used a 95mm or even 98mm inducer size on the secondary compressor to get some more RPM out of this engine. They came from 1200Hp @ 2200Rpm and calculated 1500Hp max, Fuel system per stroke is maxed out so 1442Hp is max @2400RPm but they have some more homework to get it all on the track as during testing they get 0,7sec of there 80 meter time but unable to perform this during the last dragrace event and only get 0,3sec faster than all previous runs. The way I look @ things is get data and make improvements and make the next step work. It’s not al about Hp but what works best.:blahblah1:
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Do you have the high pressure compressor shaft speed you can throw up in a log?
 
Joesixpack said:
Do you have the high pressure compressor shaft speed you can throw up in a log?
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I like to but the reading for this sensor is not reading correct as on no load it reads more RPM than under load. EGT I can show.

Foto540-TW7BLVHG.jpg
 
That's exactly what I want to show, most will be surprised that the HP compressor speed actually slows down from low load to high load while the work is shifting more towards the LP side.
 
Joesixpack said:
That's exactly what I want to show, most will be surprised that the HP compressor speed actually slows down from low load to high load while the work is shifting more towards the LP side.
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....but isn't that because the gate is diverting a lot of the hot gases directly to the primary when under a heavy load?
More drive to the primary=more low pressure boost.
Same, or maintained drive pressure to the secondary=same compressor speed unless a high load is sent...then it has no option but to slow down...kinda like just holding the throttle at a steady spot and hit a steep hill...the throttle is still in the same spot, but there's more load, and the truck slows down. (Dodges anyways...:poke:)
 
Its more to do with whats happening on the compressor side and just how much work can be done there. As the LP side doubles, triples+ the density or more it gets harder and harder for the HP compressor to do the same.
 
OK I manage to recover some data but the speed of the hi pressure is reading way to low.

On the bottom of the chard there are the two turbo speed indications and yes it’s slowing down due to low press dif on the hi stage compressor and more air mass moving as well as the air get denser. So Extended Power hit this one spot on for this set-up as the hi pressure is only there for low RPM boost and than the big brother will take over. Also when the turbine speed goes down the swallow rate of the turbo goes down as well creating more drive pressure on the hi end side.
Still the hi pressure is taking a lot more energy than I would expect as the EGT after the hi stage is a lot lower indicating a lot expansion on exhaust gasses but I would like some verification as the low stage EGT probe is just in front of the low stage turbine so is it the pressure drop over the turbo or WG???

On any compound set-up the low pressure is the most critical one as this is the one that’s needs to stay in the compressor flowmap and depending of the comp flowmap you have to move it up in pressure to get the max out of this charger so turbo RPM and pres differential are a good tool to run it to the max I think.

Foto540-XEFKRG4Q.jpg
 
LOL....Your data is showing exactly what I'm talking about but its cut off on the left side. The HP compressor speed creeping up is likely from intercooler loading up.


Sorry to the OP getting off of topic. Gotta keep our interest up...LOL
 
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Joesixpack said:
LOL....Your data is showing exactly what I'm talking about but its cut off on the left side. The HP compressor speed creeping up is likely from intercooler loading up.


Sorry to the OP getting off of topic. Gotta keep our interest up...LOL
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Yes to bad they pressed data logging only from part load starting @ 1,7Bar boost pressure.

The HP compressor speed creeping up is likely from intercooler loading up. Don’t think so as it getting in with dry ice cooled coolant @ 7 degrees centigrade and getting out with 16 and air temp is 33 degrees centigrade on the end of the run and both stages are after cooled as well.
 
So you want to say charge air temp is actually cooler at the end of the run as compared to the start of the run?
 
LOL yall can go off topic all ya want, I dont care. :) I'm at a standstill anyway till I get the rear axle fixed. Think I might try to clean up the old .83 housing I have laying around and throw it on for giggles.
 
Hey, before you stick that .83 housing on, if it is a true T4, could you measure the overall length of the housing for me?
 
Joesixpack said:
So you want to say charge air temp is actually cooler at the end of the run as compared to the start of the run?
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Yep way of topic here. Yes we seen that happen as controlling the dry ice box between runs can be hard getting the coolant down to a level that ice crystals start forming slowing the coolant flow down to almost nil so you start a run with +5 ending is with sub zero intake temp as the coolant flow get up and after the run going down to minus 20 even.

On the last picture the is a light bleu line called MAP (Kpa) effort an this is the wastegate control for the low stage and if the wastegate opens up the hi stage turbo RPM goes up as well and why is this? If a wastegate is used between the exhaust manifold and the down flow of the WG is fed into the low-pressure turbocharger as well and it’s constructed like a Y shape the flow of the wastegate can create a pressure drop on the discard side of the hi stage turbine making a bigger pressure differential over the turbine and things will speed up when pressure is drop on the down flow part so a wastegate on the low stage side will effect the hi stage as well.
 
Joesixpack said:
LOL....Your data is showing exactly what I'm talking about but its cut off on the left side. The HP compressor speed creeping up is likely from intercooler loading up.


Sorry to the OP getting off of topic. Gotta keep our interest up...LOL
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So by running the LP turbo at a higher pressure it is causing the manifold turbo to work harder? Wouldnt this possibly cause issues when trying to get the wastegate set properly on the manifold turbo?
 
12vCumminsFTW said:
Its a John Deere s200 housing. It has the t3 size volutes.
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Ok...that's the same one I have.

image-28.jpg


I'm trying to find a true T4 x .83 or even a T4 x .91 that is close to the same length for fitment.


This is what the ports look like after I port matched them to the T4 flange, and had it ceramic coated.

imagejpg1-21.jpg
 
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12vCumminsFTW said:
LOL yall can go off topic all ya want, I dont care. :) I'm at a standstill anyway till I get the rear axle fixed. Think I might try to clean up the old .83 housing I have laying around and throw it on for giggles.
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You want long outlet or short outlet measurements? I have both sitting on a shelf
 
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