The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread (3 Viewers)

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So what with that is ct26 for our diesels and what is supra? I must be honest in that I dont speak CT26 very well. Even the small turbines you listed are quite large compared to what were talking about. When you start talking about T4s then they get rediculously large. For example... most 5.9 cummins sized holsets sit very close in turbine diameter to t04Es. Venturing a guess, but it looks like the stock ct26 turbos are very oversized turbine wise.


Ive read enough about VNTs to know that if your doing a compound set up just leave it out as its hard to control and inherently less effecient vs a properly sized set of regular gated compounds. That is unless you get bored building regular compounds and want to build something exotic.
 
Never build a compound setup and must admit I have not even a slightest idea of how to match up two turbos to avoid dead spots in the boost build up and then designing it to fit the engine perfect.

I would buy the gt2359v and use that a long time before I get around to actually build a compound setup. Possible after I am done studying and thats a minimum of 3 more years :/
 
Dougal we have a few landrovers coming up for sale with the 4bd1 engines in OZ. Do these engines except turbo's and pull those type of numbers in your light reading thread above.
Cheers

There is one small difference, the non turbo 4BD1's before ~1988 don't have piston squirters. So they need a leaner tune and lower EGT to not overheat pistons. Otherwise it's all the same.

I think my light reading must be a bit lighter than yours Dougal. I'm wading through but I'm not yet able to look at a map and know what it means. Do you have any idea where I could like to get a better understanding of the relationships between different A/Rs etc? (The basics) I get that a lower A/R turbine for a set motor will spool quicker and a higher one will give you more peak power. And if it's too big it will lag you too death. After that, I got nuthin....

There must be manufacturers out there selling all the bits, Graham's (Turbo god) assembling and tuning the best turbos out there now, he must have started somewhere.

I may have to start going through his rubbish and creeping around in a workshop coloured cammo suit

That's it for turbine A/R. Turbine choke flow (what actually matters) is a combination of turbine outlet size and A/R. Sometimes you get a choice of different A/R housings to tune the response.
Bigger turbine A/R gives more top end power, smaller turbine A/R gives faster spool.

Doug... is the tdo5 turbine really over sized for a 4L? I believe it is physically smaller then a stage 1 t3, have to check on that though. It is the next MHI sizing up from the TD04hl.

Depends what you want to acheive. But IMO TD04HL is as big as I want/need to go for a single.
 
Never build a compound setup and must admit I have not even a slightest idea of how to match up two turbos to avoid dead spots in the boost build up and then designing it to fit the engine perfect.

I would buy the gt2359v and use that a long time before I get around to actually build a compound setup. Possible after I am done studying and thats a minimum of 3 more years :/

VNT's aren't good for power production. The turbines are less efficient when the blades are closed, they have fixed limits on turbine flow (no wastegate) and are limited to a single stage compressor.

Compound turbo is the solution to all turbo problems. But the packaging (fitting them in) is a problem. IMO beyond 25psi you'll be better with compounds.
Compound turbo sizing is about 4 times more complex than single turbine sizing. It takes a few hours work to correctly size and check turbine and compressor for a particular engine and goals.
It takes a whole day of number crunching to do it for a compound turbo.
 
It takes a whole day of number crunching to do it for a compound turbo.
Exactly! Should have been so much easier, then we probertly seen it a lot more :)

In a compound setup you would used external wastegate anyway so with my limited to non existing turbo know how I wonder why that would be a problem. I have already bought a 38mm v-band tail wastegate sitting ready on my shelf :)

What experience do the Ih8mud community have on the stock 12H-T CT26 turbo?
Curious about what the upper boost limit of it is. Where would it go into surge or where would the boost be to much for it leading to failure?

Running with the wastegate shut/disconnected and right now it boost up to 18psi and the anti tamper wire is still on my pump so that is on stock fuel adjustment.

I know many have the believe boost kill your engine, but I have the believe heat does. In my book more boost is isn't a problem as long as you watch your combustion heat and adding more boost without adding fuel only lowers it :)
 
You don't need external wastegates for compound. The wastegate flows aren't high on the small turbo.

You can monitor compressor efficiency by measuring the temp rise and comparing it to the known pressure ratio it's working at. Bad efficiency means you're not on a good spot on the map.
You can monitor overall turbo efficiency by comparing drive pressure to boost pressure.

Boost alone can't kill a diesel. It's the combination of boost, injection timing and EGT (injection volume) that determines how safe or dangerous a tune is.
 
By drive pressure you are referring to exhaust pressure pre turbo, right?

Lets say you build a compound system and boost it up to the 3-4bar mark. Would that push so much air trough the engine that the little internal wastegate becomes a little small? Just thinking out loud here.

Are vnt turbo's still a bad idea when using an external wastegate?

It would certainly be a sweet wet dream to achieve noticeable boost pressure as low as 800-1200rpm and boost hard all the way up to 3500-4000rpm.

I bet that most certainly would be doable with the right compound setup and correct fuel adjustment.

Isn't it so that my current stock setup will start to build boost earlier in the rpm range and boost/spool up faster just by adding more fuel?
 
By drive pressure you are referring to exhaust pressure pre turbo, right?

Lets say you build a compound system and boost it up to the 3-4bar mark. Would that push so much air trough the engine that the little internal wastegate becomes a little small? Just thinking out loud here.

Yes exhaust manifold pressure. To boost 3-4 bar the turbos are working hard and wastegate very little.

Are vnt turbo's still a bad idea when using an external wastegate?

That helps, but they are then very complex and still less efficient.

It would certainly be a sweet wet dream to achieve noticeable boost pressure as low as 800-1200rpm and boost hard all the way up to 3500-4000rpm.

I bet that most certainly would be doable with the right compound setup and correct fuel adjustment.

Isn't it so that my current stock setup will start to build boost earlier in the rpm range and boost/spool up faster just by adding more fuel?

Even with my T25 I've got ~10psi by 1200rpm and 20psi from ~1800rpm to the governor.
Too much fuel creates high EGT and smoke.
 
Too much fuel creates high EGT and smoke.
Well aware of this, helps a little running no wastegate for more air to burn all the fuel. I am also unsure on how to correctly tune the boost compensator on the IP. All I know it is another design than on the rotary pumps like the 2LT has.
Have a EGT gauge I haven't had time to install yet, but hope to do it soon. certainly not going to tune any before I get it fitted :)

Even with my T25 I've got ~10psi by 1200rpm and 20psi from ~1800rpm to the governor.

I ran a t-25vnt copy with the Dodge/Chrysler T3 flange on my 2H before it said goodbye after a year abuse. Liked how quick it boosted and that was without giving it any noticeable fuel amounts. I ruined that turbo from running bad oil, at least that is my conclusion :/
 
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I ran a t-25vnt copy with the Dodge/Chrysler T3 flange on my 2H before it said goodbye after a year abuse. Liked how quick it boosted and that was without giving it any noticeable fuel amounts. I ruined that turbo from running bad oil, at least that is my conclusion :/

Those small vnts don't seem to like boost pressures above 15 psi it seems. If you didn't have a controller for it I suspect you ran it boosting all the time which is why it died so soon. They aren't designed for max overall power, but to increase lower rpm torque and to decrease emissions. Most folks think the are at the top of the food chain, but with all their benefits come some significant drawbacks and complexities.



So how big it the ct26 turbine on the 1hdt?
 
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@gerg

All ct26s have the same sized turbine. The housings differ slightly depending on what vehicle they came on.
So technically speaking you could order one of those 50 trim CT26s and just swap out the exhaust housing for a 1hd-t or ft one...

What I would be curious about is if there is a turbo map out there that is close to surge if it was adapted to fit a ct26 with one of those anti surge comp housings if we could get it safely away from surging...

The problem I am seeing but don't take my word as gospel, the kinugawa ct26s run the exact same exhaust housings on each model of their ct26
This can pose a problem. An email may be in order to them...
 
I have no idea on the 1HD-T turbine size, sorry.

I didn't run it any higher than 1.3-1.4 bar if my memory serves me right.
However I did have a 12 miles commute 5-6 days a week and that are metric miles (120km) in freezing winter. It was my first year of heavy commuting and I forgot to change the oil often enough. I was running Dynocat 5w-50 synthetic but the oil seal busted, destroying the bearing resulting in total shaft and turbine & compressor blade destruction. Also the engine started running on its own oil feeding trough the charge pipe from the turbo. Luckly the 2H has a butterfly valve restricting airflow that again restricted rpm buildup. Drove it 300-500 meters to a parking lot smoking heavy and smelling ass. Slamming it in 5th and applying all my brute force to the brake pedal chocking it with the sudden release of the clutch.
When I looked at the oil later it was thick and almost like some kind of black porridge.
At least it witnesses the durability and punishment an 2H can take :)
Drove it until the coming summer before I got around fitting a new turbo ...


My brother had an Opel Vectra with the 1.7td Isuzu engine. He made a Mercedes Benz gt1756v or gt1852v fit and he ran happily over 2bar boost for a couple of years. Not sure how much over as the gauge did only go to 2bar. He had to change the engine 4 times tough, but the turbo survived :)
 
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This is more me: http://shopping.kinugawaturbo.com/t...9tsaab9-39-5300bhp49189-0183049189-01850.aspx

Remember when looking at surge resistance that your mapping is likely done at sealevel. At 2000m up it starts getting nasty even with a tiny T25. I haven't found any turbo with a bigger than 46mm intake that will work. The 19T wheel has a big intake but radically backswept blades to give it surge resistance.
 
Yeah I see your point. I'll try remapping and see what it takes to surge it. My link was 400$ cheaper though bahhahaha!

I think that was a genu-whine MHI in that link. Generic TDo4HL-19T's can be found on ebay for about half the price. Funnily enough the cheapest way to buy one is a core and housings separately.
I'll need to upgrade my T25 when I get an intercooler in. But that's a massive job in itself (new radiator, intercooler, new AC condensor and bracketry/lines for all of them).
For my application the TD04HL-19T is close to ideal as a single, but is actually perfect as the small turbo in a compound set.
 

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