Compound turbo 1kz-te project

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How much boost are you running on the large turbo?

My thoughts are you want to keep it around 10-12psi (unless you go for a lot more boost and fit an intermediate intercooler) as this won't overheat or overload the compressor wheel on the small turbo.
 
With the wastegate line plugged, it just sees about 11psi. It probably doesn't get there until about 2500rpm. It comes on very gradually. I don't mind running a second intercooler if I have to. I don't think it'll run more boost without any more fuel.
 
Okay, a bit of an update. Been running it for about a month now. Seems good, have done about 3000kms. Boost is 30psi at the moment. I have ordered a TD05H-16G to try, and should be here early next week. Its a bit laggy in lower gears, but at highway speeds it hauls ass. My fuel economy is a consistent 12.3L/100km, Which is the best this engine has ever got. Heat soak doesn't seem to be a problem, and runs around the same temperature as it used to run.

I'll see how it goes, may consider replacing the TD04 with something smaller if i'm still not happy. Next thing will be getting a dyno run and seeing what power its making, oh and I wouldn't mind a wideband o2 sensor.
 
Just an 8cm T3 rear... Internal gated. Yeah Its a bit tight down that side of the engine bay. I stuffed it up though, Should have run the intermediate dump pipe straight down to give it better clearance on the clutch master. I reckon it just knocks it when the engine moves around.

When I did the conversion, I made the engine mounts too high and needed to lift the body for gearbox clearance. Could always lower the engine mounts to give it more room.
 
Got the Td05 on today, haven't had much time to try tuning it properly. The boost curve is much better, pretty much makes 20psi at about 2100. I still see a really slow rate of boost increase bellow that, But i've been almost thinking that the intercooler and pipework might be contributing to that too.

The torque curve is quite wide now, Pulls very linearly from 2000-3500 now, and is consistent up hills too. Peak power feels similar to the td06. If I get time tomorrow to play with the pump, I might try getting it on a dyno next week or the week after and see what it is doing.

Also want to work out a 2nd intercooler, and I have considered bypassing the front mount to see how it affects the lag, and considered top mounting it if that proves effective. That'll help the radiator keep cool too.
 
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@Dougal says that turbos should make an additional 1psi per 100rpm. Do you know when your wastegate is opening?

In any case, sounds like good progress :D
 
Its hard to say. I am waiting for a better boost gauge to arrive. Had the big turbo wastegate open to see what the small one would do, and no matter what I do with adjustment, and taking the wastegate line off , its only running 20psi of boost. So I need to make sure the gate isn't creeping open with manifold backpressure. By then I'll have my gauge here and I can see what pressure the big turbo is running. At the moment it gets to the top of my 15psi gauge. Overall boost at the moment is 35psi. Need to get it running as well as possible by thursday for the dyno run, then I can knuckle down and make sure things are going to be reliable and efficient.
 
Okay, got the dyno run today. It was a great starting point, and shows that I certainly have room to improve it! Especially the AFR!! Waaaaaaaaaaaay too rich the whole run, half the workshop was black by the time the run was over! My mate's car made 118kw, which was pretty nice. I suspect my pump isn't giving me anywhere near enough timing as it revs, peak power was at only 2800rpm. Boost was about 24psi at the time I did the run.

By the look of the graph, he could have started the run a bit earlier in the rev range, would have been nice to see a bit more before peak torque.

Power and torque


Power and AFR :-p
 
That AFR would be not too far wrong on a petrol! You need to shift it upwards by about 4 points!
 
Yeah I most certainly do. I have found if I adjust it too stiff, it won't richen up until I get a good 7psi or more boost, and if I use the more aggresive profiles it smoke's like a freight train.

Thinking I'm gonna have to work on the timing side of things now. You can really feel the loss of power on the road after peak power, and its always been really sluggish about 3k with this pump on it too.
 
You might need a different spring. But with the turbos working as they should your boost and fuel should roll in together.

I've got a diesel with the VE pump and AFC but I haven't yet played with that (it's got bigger issues). The boost compensator on my Isuzu I had to make another internal stop which I tuned without boost (wastegate open) for maximum fuel without smoke. Once I had that sorted the drivability and turbo spool improved immensely and I was able to tune in the pre-load for the best response while building boost.

I've still got a small dip in A/F to around 15:1 (from 19-20:1) as the boost compensator opens too fast during acceleration. I need a stiffer spring to sort that.
 
I have wound the fuel screw out a little bit to make it better for now. More worried about the dynamic timing, as this pump is set for a direct injected 14b, and not indirect like mine. As long as I've had this pump, it has never liked to rev past 3k and always blows a hell of a lot of smoke up there too. I had the pump mechanically as far advanced as possible and was a lot better, but still very noticeable. I do have some other timer springs I can try and fit, see what difference it makes.
 
bumpstopbrawler26 said:
I have wound the fuel screw out a little bit to make it better for now. More worried about the dynamic timing, as this pump is set for a direct injected 14b, and not indirect like mine. As long as I've had this pump, it has never liked to rev past 3k and always blows a hell of a lot of smoke up there too. I had the pump mechanically as far advanced as possible and was a lot better, but still very noticeable. I do have some other timer springs I can try and fit, see what difference it makes.
Click to expand...

Sounds like you might be over-advanced on timing!

IDI's do better at higher rpm than direct injection does (unless you step into modern injection pressures) and may need less advance. Your 14BT pump might be already starting on the advanced side and then trying to advance even further.
 
Is there any way I can actually measure that? Because advancing the timing seemed to make the top end less flat. When I had it retarded a long way, I had to wind the fuel screw in quite a way to make similar power, and once parked up and building engine bay heat it would have a lot less power when I would drive it again. With the timing up you don't really lose that power. When I first put the pump on I did time it with a dial indicator, but haven't had access to one or a timing light to accurately work out where it is set.
 
With inline pumps you can spill-time them to find the start of injection and the resulting crank angle. I don't know how well that method works for in-line pumps.

Can you find any injection timing specs for the 1KZ? I know for the Isuzu 4BD1T (direct injection) vs 4BD2T (indirect) the 2T runs a lot less advance.

also keep in mind that highly advanced timing with a lot of boost and fuel on a high compression IDI engine makes life hell for the structural parts. Crank, head, block, pistons etc.
Keeping the timing near stock may feel like a bit less power, but the peak combustion pressures are a lot lower and the stress on the engine is much reduced.

Basically it's kinder on the engine to run more boost and matched fuel to get the same power with less aggressive timing.
 
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Normally you wind a plug out the back of the pump head and measure the plunger lift at TDC. Problem is that most 1kz engines were efi and don't have a timing spec, so I set it up originally to have a little more advance than an L series engine. Even then, the dynamic timing is also set by internal pump pressure, so if that's not right it'll also affect what it runs.

At the moment I've taken a lot of timing out of it. Has a lot more bottom end torque, still has the big flat spot at revs though.
 
1KZ-T used a mechanical pump, should be able to find the timing specs for that application. Used in KZJ71W and KZJ78W LC Prado's, likely some others as well.
 
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