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Discussion Starter #1 (Edited)
Hey guys
Thought I would share my compound Rodeo
Isuzu 4Jb1t 2.8L
Turbos: td04L-15 for high pressure
Garrett gt2871r for atmospheric
Running around 34psi total. Turbo sizing is not perfect, but what I had available.
12mm ve pump
Cam regrind, lower compression ratio,
Head porting, ceramic coating
Water/meth injection
currently producing 210hp and 500nm
Waiting for some larger injectors for more fuel to make the most of the pump upgrade and compounds. Only had one run with the current setup on the drag strip, @14.7

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Recently did a video with a bit more explanation of the setup
 

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Discussion Starter #5
Where are you getting the injectors from? Would 4jh1 injectors work?
The later ones would allow a little more fuel but I have an earlier 4jb1 with square piston bowels. So anything other than a 4hole nozzle won’t work. Most the later injectors run a 5 or 6 hole nozzle so only suited to round bowel pistons. The injectors I am getting done are 4hole getting modified for around +30%
 

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The later ones would allow a little more fuel but I have an earlier 4jb1 with square piston bowels. So anything other than a 4hole nozzle won’t work. Most the later injectors run a 5 or 6 hole nozzle so only suited to round bowel pistons. The injectors I am getting done are 4hole getting modified for around +30%
Very nice, quality work for sure. Is it your daily driver?
 

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1989 Jeep Wagoneer, 360v8, 727, stock for now,
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Very professional build, looks factory.
 

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What caused the input shaft to break? I thought those gearboxes were quite strong.

Are you still running the 240mm clutch? The 4jg2 and 4jh1 had 250mm
 

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Discussion Starter #11
What caused the input shaft to break? I thought those gearboxes were quite strong.

Are you still running the 240mm clutch? The 4jg2 and 4jh1 had 250mm
The gearboxes are pretty strong, but the input shaft is the weak point.
Clutch is standard diameter, cushioned ceramic with double diaphragm spring. Had a heavy duty organic, cushioned ceramic, ceramic 5 puck clutch, before that and none would hold. Have over 2000kg clamp force now so input shaft was the next weakest link.
 

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Nice build, I haven't seen anyone run exhaust over the top like that before.

How does it run for noise, heat and fuel economy as a daily?
 

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Discussion Starter #13
Nice build, I haven't seen anyone run exhaust over the top like that before.

How does it run for noise, heat and fuel economy as a daily?
Routing it like that made it easier to make the turbos modular. I can remove either turbo with the other one still in place. Noise is not too bad, I have a small resonator in the 3inch exhaust, get a lot of turbo noise but the engine noise is pretty quiet. Runs about 8L-100km on the highway. Normally 9-10L-100km flogging it around town. Never been able to get it hot
 

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I presume your power figures are at the wheels? Because it looks a whole lot quicker than 212hp/500Nm.
 

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You might find this post interesting. It's a guy in NZ compound turbocharging a Toyota 5L engine. Yours is slightly smaller capacity and a lot tougher engine. I ran a line of turbo sizing for him:

Dougal said:
To get 530Nm with a BSFC (efficiency) of around 300g/kwh you'll need to inject around 110 cc/1000 shots (that's doable depending on your injection pump plunger size).
To burn that much fuel cleanly and safely (A/F 18:1) you'll need 45 lb/min of airflow. 600 CFM.
To fit that much air into a 3 litre engine with 80% VE and a decent intercooler you'll need about 45psi (PR 4).

I have a map for a 2009 GT2876R. It's close to tapped out at 45lb/min and you'll want to run it with a PR of about 2.5 to get decent efficiency from it. That pulls the little one down to a PR of 1.6

The turbo sizing I've only run one rpm on (because it's a full days work to do a complete engine rpm range) and that's 4000rpm for max power.
I've used a 0.86 housing on the big turbo and a 0.64 on the small.
Wastegate the big turbo to 22psi.
Wastegate the little turbo to 45psi (max boost).
Small turbo is generating 28kw of power. Big turbo is generating almost 46kw of power.
Your intercooler has to shed 55kw of heat to drop the intake temp to 60C.
Drive pressure should be around 63psi.
Net power around 187kw.

You can do better with a bigger big turbo. Especially on the turbine side. These two have turbines that are too close in flow numbers to work well in a compound set.
I haven't checked spool up. My preference is to go with a smaller small turbo. But that one shouldn't be horrible.

You'll need a decent sized air-filter with a good cold air feed.

Good luck.
You're both using GT2876 for the big turbo and that's I think the hold-up. For your application I think you'll drop drive pressure and pickup power if you wasteget the GT2876 to higher pressure (i.e. almost total boost) and use it to unload the small turbo more.
 

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Discussion Starter #19
You might find this post interesting. It's a guy in NZ compound turbocharging a Toyota 5L engine. Yours is slightly smaller capacity and a lot tougher engine. I ran a line of turbo sizing for him:



You're both using GT2876 for the big turbo and that's I think the hold-up. For your application I think you'll drop drive pressure and pickup power if you wasteget the GT2876 to higher pressure (i.e. almost total boost) and use it to unload the small turbo more.
Thanks for the link, I’ll have a read. I’m running the GT2871. there is probably a lot of room for improvement in my setup, never spent much time on the dyno with it to perfect as I was changing things regularly. I’ll give your suggestion a go when I put a Garrett back on it, not sure I want to push the one I’ve got on at the moment. What you’re saying is pretty much treating it like more of a sequential turbo setup. I’ll put some valving on my boost control lines for the HP turbo wastegate and see how it behaves with earlier bypassing.
 

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Discussion Starter #20
You might find this post interesting. It's a guy in NZ compound turbocharging a Toyota 5L engine. Yours is slightly smaller capacity and a lot tougher engine. I ran a line of turbo sizing for him:



You're both using GT2876 for the big turbo and that's I think the hold-up. For your application I think you'll drop drive pressure and pickup power if you wasteget the GT2876 to higher pressure (i.e. almost total boost) and use it to unload the small turbo more.
Dougal, One thing I have noticed is I am probably going about boost control of the HP turbo the wrong way. Currently the wastgate is set up to maintain a set PR across the small turbo. Actuator boost reference is to manifold pressure, the rear of actuator is supplies interstage pressure between the HP and atmospheric turbo. What are your thoughts?
 
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