Remote Turbo Install on 2L-ii engine in Cabover truck (2 Viewers)

[fenderfour]

I've been watching this thread on installing a turbo in an old Hiace truck. Unfortunately, it ended in failure with what sounds like some piston ring blowby. I own one of these trucks and it sure would be nice to have just a little more power, but as you can see in the OP's posts, the big issue is packaging in the engine bay. As a cabover truck, there isn't much room in there, and when you add the shift linkages running through the exhaust area, there is even less room. A lot of compromises have to be made, part modified, etc... At it's root, engineering is balancing compromises, right?

I've been considering a remote turbo installation. The turbo isn't on the exhaust manifold, it's plumbed into the exhaust down the line a bit. These are pretty common in racing and other areas of motorsport and motor-enthusiast. I'm thinking there is space just aft of the engine or just behind the passenger cabin. I don't need to mount it all the way back like the sports car guys.

Pros:

• Eliminates engine bay packaging problems
• Reduces heat in engine bay
• reduces EGTs
• Use stock manifold (need to add EGT bung)
• Reduces heat in passenger cabin (driver sits above exhaust manifold)

Cons:

• Increased oil routing
• Requires scavenger pump to return oil
• Requires oil sump to ensure proper pump operation
• slower spool-up
• colder exhaust = less power
• More exposed oil path
• Possible pump failure

Looks like there are some well proven scavenger pumps designed for the purpose, so parts are off-the-shelf: Turbowerx Pump and a range of ready-made oil tanks. Main issue is going to be exhaust which had to be replaced with a traditional turbo as well.

It seems the spooling issue is real, but with my slow-af truck, I don't care at all, especially since the turbo gets to pressure and stays there. I'm also not worried about losing a little performance in reduced exhaust temps at the turbo. My modest 7-11 psi system will be just fine.

Has anyone here added a remote turbo? What was your experience? It's looking like a really good option.

 

[Eurasiaoverland]

I don't think the lack of space in the engine bay had much, or probably anything to do with the engine's very premature demise. The fact is that these engines are just not suited to forced induction. This puts them at their limit in terms of heat flow with very little margin for error. Each to their own, but I'd rather have an underpowered reliable vehicle than a slightly less underpowered vehicle that is running on the edge of failure.

 

[Dougal]

Remote turbos are the worst idea on diesels. They don't have the high exhaust energy/temp that petrols have so response would really really suck.

The problem with the 2L engines (and other japanese IDI) is they run at stoich under full load. This is why they're hot/dirty and crack heads. They last an acceptable time between head swaps with no turbo, but if you add a turbo and maintain fuelling it's all over.

The only way to make them last is to add a turbo and use that to lean them out. But that leaves you with only a very modest power increase.

 

[fenderfour]

Remote turbos are the worst idea on diesels. They don't have the high exhaust energy/temp that petrols have so response would really really suck.

The problem with the 2L engines (and other japanese IDI) is they run at stoich under full load. This is why they're hot/dirty and crack heads. They last an acceptable time between head swaps with no turbo, but if you add a turbo and maintain fuelling it's all over.

The only way to make them last is to add a turbo and use that to lean them out. But that leaves you with only a very modest power increase.

Thanks for the feedback Dougal, I saw you significant contributions on the other Hiace Truck thread.

Yeah, my plan is a turbo to lean it out. I've got a setup from HD Automotive in Australia. They have plenty of experience with adding a turbo to the L family of engines. I'm not planning a big boost, sticking with the 7psi as kitted up to turn some of the soot coming out the tailpipe into power. I think they recommend a modest change to fueling, but no new injectors or pump compensation.

Thanks for the feedback on remote turbos. I'm sure response will not be great. I'm starting with a 90hp engine, so I'm not really looking for a speed demon. More like a few more HP to get over the pass at 50 instead of 40.

I'm still trying to figure this thing out. A few years with a modest turbo, then maybe a less modest engine/drivetrain swap in the future. Who knows?

 

[fenderfour]

I don't think the lack of space in the engine bay had much, or probably anything to do with the engine's very premature demise. The fact is that these engines are just not suited to forced induction. This puts them at their limit in terms of heat flow with very little margin for error. Each to their own, but I'd rather have an underpowered reliable vehicle than a slightly less underpowered vehicle that is running on the edge of failure.

I also don't think his engine failed due to a tough packaging problem, the issue was running 14+ psi and not having an EGT properly located on the manifold.

My plan is to install a modest system that has been developed by the Australian tuners at HD Automotive. I know they are trying to sell parts, and their copy will support this, but they say that their turbo helps lean out the system a bit, as Dougal mentions below. Having unburned fuel coming through increases EGT's and can lead to premature failure. The goal is to add a little air, burn that fuel and maybe get a little power back. When we are talking 90ish HP, even a 10% increase is great.

 

[Dougal]

Thanks for the feedback Dougal, I saw you significant contributions on the other Hiace Truck thread.

Yeah, my plan is a turbo to lean it out. I've got a setup from HD Automotive in Australia. They have plenty of experience with adding a turbo to the L family of engines. I'm not planning a big boost, sticking with the 7psi as kitted up to turn some of the soot coming out the tailpipe into power. I think they recommend a modest change to fueling, but no new injectors or pump compensation.

Thanks for the feedback on remote turbos. I'm sure response will not be great. I'm starting with a 90hp engine, so I'm not really looking for a speed demon. More like a few more HP to get over the pass at 50 instead of 40.

I'm still trying to figure this thing out. A few years with a modest turbo, then maybe a less modest engine/drivetrain swap in the future. Who knows?

Boost isn't the problem. A/F ratio is. It's the combination of boost, fuel and timing that kills engines.
7psi isn't enough. I'd go 10psi.

At 7psi you can only safely increase fuel by 10% (18:1 under load) which will give you a whopping 63kw at 4000rpm.
At 10psi you can get a safe 15% increase without risking engine life. Should give you 70kw (about 90hp) at the crank while running clean and cooler than stock.

 

[Eurasiaoverland]

I also don't think his engine failed due to a tough packaging problem, the issue was running 14+ psi and not having an EGT properly located on the manifold.

My plan is to install a modest system that has been developed by the Australian tuners at HD Automotive. I know they are trying to sell parts, and their copy will support this, but they say that their turbo helps lean out the system a bit, as Dougal mentions below. Having unburned fuel coming through increases EGT's and can lead to premature failure. The goal is to add a little air, burn that fuel and maybe get a little power back. When we are talking 90ish HP, even a 10% increase is great.

One thing to bear in mind is that without stringent emissions regulations, I believe that Australia got the L Series engines for longer than JDM and European markets. Also, they mostly have 3L and 5L engines. The 3L and 5L had improved heads with additional cooling passages, which I am not sure the 2L ever got. Certainly if your 2L is from the mid nineties or earlier, it will not have had them on the stock head. In Europe there was a later 2LII-T engine from about 1998 which seemed to be more robust than the earlier JDM 2LII-Ts. No idea what the difference was, I would suspect improved head casting, but possibly also fuelling.

Anyway, seems you are keen to go ahead, so it will be interesting to see how it goes. I personally would put a 5L engine in, easy swap with no mods and no turbo to worry about. If you want a project, put a 5L-E in. I've driven a 5L-E Prado and while they are still underpowered compared to modern diesels, they are a significant improvement on the 2L.