How much boost can 1HZ-T handle? (3 Viewers)

[Dougal]

A dyno is a tuning tool. I dyno my truck by loading it up very heavily, hitching up a fully loaded military trailer and then driving it up a very long (like 25 minutes long) steep highway hill in hot summer conditions (like 26 deg. C+) and observing the speed, boost, pyro, trans temp etc. I then make adjustments to suit.

I used to live about an hour and a half from a long viaduct of which I knew the slope exactly (17%). It was an excellent tuning tool, but because of the known slope, I could also use it to calculate power to the ground.
Unfortunately it's a long way away now. I still have plenty of hills for tuning, but none with such accurately known and consistent slopes.

The information presented by the posters here is interesting. The personal attacks are lamentable and tiresome.

Indeed and there has been a lot of good information lost from this site where Moderators ended up deleting whole threads.

We are mostly playing with factory boost settings and adjusting the fuel so that it just smokes a tiny bit at full throttle. The turbid 1HZs (turbo glide turbo systems) usually beat the 1HDT in power, but the 1HDT returns vastly better fuel economy.

The smoking at full throttle is a serious danger sign. No turbo diesel should ever do that.
You are likely running around 16-17:1 at full load, this is about 25% more fuel than you should be running for that much boost.[/QUOTE]

I posted the video of Shawns truck because its a hopped up td42.
Apparently an IDI can't do that according to some peoples books.

Complete rubbish.
TD42's =/= 1HZ. They are a completely different engine, only similar in basic configuration (4.2 litre, straight 6, IDI).

For a start, Nissan sold many thousand factory turbocharged TD42's.
No-one has yet found a factory turbocharged 1HZ. Nor has anyone built a 1HZ approaching the 1000Nm mark. The TD42T's however have.

My goal of re-opening this thead was to get data and results for hopping up 1hz's above the traditional boost points. There isn't much info on this availabie (at least to my research) on the internet.
Instead some decide to down talk it when I am simply trying to gather info for the benefit of others.

Don't confuse reminding someone of physical limits and "down talking".

I have given plenty of data and reverse-engineering of existing 1HZ turbo setups in this thread. All met with denial because they don't show what you want to read.

 

[TheBigBoy]

Ill help crack some of the seat of your pants myths.

1HZ - 22.7 to 1 compression
1HDT - 18.6 to 1 compression













This is just a guide to show the tuning side of things for a stock turbo. With only a fuel screw adjustment, the turbo will spool earlier as alot more fuel is used (14:1). More gas's = earlier turbo spool. But runs very low afr's until the air catches up at full boost. Running a DT with the same afr's (14:1, pre and low boost) it will go just as hard off the line. But with the abillity to tune the fuel to the correct air requirments via the compensator = No smoke, good eco. Running a subtle 19:1 pre boost will reduce fuel usage and only be slightly behind in power/spool.


If you ran the HZ (fuel screw only) @ 18:1 pre boost, it will be running leaner at full boost then the DT. Which isnt such a bad thing due the heat the IDI produces. So if you tuned by the EGT's and not the AFR's. The DT is in front for power and eco for the same temps. But this is all at very low stock boost levels.

Ive never really got into the whole tech side of IDI. Just tuned many of both. Each has their ups and downs. And the differences between the 2 is only minimal at low boost levels anyway.

Hope this helps.

 

[Dougal]

Your Y axis scale appears upside down. More boost raises A/F ratio for the same fuel, but you're showing it dropping.

 

[TheBigBoy]

Thats because its only relevant to the fuel screw (orange line) and preboost. If the fuel is running in parrallel with the air its 22:1. If its above the air line - its richer. Below = leaner.

 

[gbentink]

Bernies 1HDFT Results with 130 Deg C post intercooler temps (coolant in cooler boiled!)

Boost around 35psi, AFR's around 18-19

Great result all things considered

 

[ForealBoreal]

BigBoy.

Sweet tech graphing

Dougal.

There is a factory 1hz-t believe it or not. Came the Coaster Bus believe it or not.
I actually have a factory 1hz-t sticker from Toyota.

Graeme,

Holy crap that is crazy!

 

[Dougal]

No-one has yet found a factory turbocharged 1HZ.

Dougal.

There is a factory 1hz-t believe it or not. Came the Coaster Bus believe it or not.
I actually have a factory 1hz-t sticker from Toyota.

Yes we know you have the stickers. But no-one on this board has ever found a factory turbo 1HZ.
It's the bigfoot of the toyota 6's.

 

[VK3FHDJ]

So the Plazaman couldnt keep intake temps under-control...

What was the pre-cooler temp like?

 

[ForealBoreal]

here just found one.

Gotta find the real pictures they were wrong sorry.****

HZB51 Coaster Bus, google it. You'll find a few shots.
My thoughts on the factory hz-t are mainly that these vehicles could handle lower grade fuel without causing problems, i thought I read that somewhere where DI engines are more susceptible to fowling and creating problems with bad fuel.
That is my guess...

 

[ForealBoreal]

Now if you fitted a bigger intercooler radiator could you essentially get better hp results if your pumping cooler air into it?
I talked to someone about the Plazaman radiators and they said they are too small and are set up for air conditioning or something.

 

[gbentink]

here just found one.

View attachment 749915

View attachment 749919

HZB Coaster Bus, google it. You'll find a few shots.
My thoughts on the factory hz-t are mainly that these vehicles could handle lower grade fuel without causing problems, i thought I read that somewhere where DI engines are more susceptible to fowling and creating problems with bad fuel.
That is my guess...

Mate, I was so excited when I saw that pic!!!!

Then I noticed that the rocker breather goes to the crossover pipe :-(

Sorry but its a late EGR 1HZ no T.

 

[ForealBoreal]

Mate, I was so excited when I saw that pic!!!!

Then I noticed that the rocker breather goes to the crossover pipe :-(

Sorry but its a 1HZ no T.

I am just realizing that now.
The HZB51 has the 1hz turbo according to the internet.
Toyodiy is not proving very well though my mistake.
Give me a bit.

 

[BreckenridgeCruiser]

Dougal: to clarify, I know that DIs run fine without a turbo... If they came from the factory that way... If I had a 1HDT and the turbo went south and I had to drive for a while it would not drive nearly as well as a 1HZT would in the same predicament. Again, I choose the HZ for very specific reasons that I doubt are at all common.

Sent from my Nexus 4 using IH8MUD

 

[gbentink]

Dougal: to clarify, I know that DIs run fine without a turbo... If they came from the factory that way... If I had a 1HDT and the turbo went south and I had to drive for a while it would not drive nearly as well as a 1HZT would in the same predicament. Again, I choose the HZ for very specific reasons that I doubt are at all common.

Sent from my Nexus 4 using IH8MUD

Its worth noting a few things:

* IDI engines can run better exhaust emissions than low pressure DI due to swirl nature of the combustion design and therefore lower AFR's - closer to stochiometric ratios (air and fuel is mixed better during combustion). Typically older DI runs ~ 20:1 at full power from factory while IDI run 16:1. As a ratio, this means that the IDI can burn 25% more fuel.

* DI low pressure compared to IDI low pressure are ~ 13% more efficient (especially in range 1600-2400rpm).

So.... since the IDI can burn 25% more fuel but with 15% lower efficiency, the effective power ratio becomes 1.25 * 0.85 = ~8% more power.

But, when turbocharging an IDI, heat removal becomes an issue and to have a long life, you need to raise the lowest AFR point. This means that you loose the outright power edge.

Hope that helps with some understanding that Dougal is trying to convey.

I hope to have a very powerful IDI to show you all in 2 weeks

 

[Dougal]

Dougal: to clarify, I know that DIs run fine without a turbo... If they came from the factory that way... If I had a 1HDT and the turbo went south and I had to drive for a while it would not drive nearly as well as a 1HZT would in the same predicament. Again, I choose the HZ for very specific reasons that I doubt are at all common.

Sent from my Nexus 4 using IH8MUD

In addition to the points Graeme has run through, the 20:1 for a factory di non turbo engine is emissions dependent. If you don't care about slight smoke, you can run them as rich as you want. A 1HZ with no turbo is already so near the stoich limit (my calcs show 16:1, Graeme seems to agree) that more fuel for more power isn't possible.
A 1HD without the turbo has room for 10% more fuel before smoke becomes a problem. While burning 15-20% less fuel.

My work car was a 2.2 direct injection 4 valve diesel. It put out more power stock than the previous 2.0 turbo idi engine and burned completely clean in all conditions. Fuel economy was far better than the IDI turbo.
I was able to re-tune it to get another ~10% without noticable smoke.
Now it's turbocharged and the silliness begins.

But given I've done downright horrible things to turbos and only managed to blow up one (oil feed line came apart, turbo was wounded and still took a week to die), I'd say you are placing far too much emphasis on driving without a turbo.

As I said earlier, your SVO/WVO reasons make perfect sense. But none of the others do.

Graeme. TD42T's with a 1HZ rocker cover don't count.

 

[BreckenridgeCruiser]

Good to know! I'm just being cautious, especially since I may not be able to run on good fuel all of the time once I leave the states.

I had heard that IDIs handle crap fuel better than DIs. True?

K

Sent from my Nexus 4 using IH8MUD

 

[Dougal]

I had heard that IDIs handle **** fuel better than DIs. True?

Definitely. Their injectors are nowhere near as complicated so they can squirt out pretty much anything.

The further you go through the diesel engine development, the higher injection pressures get and the more fussy they get with fuel quality.
The later commonrails don't tolerate anything. Many people are installing extra filters in-line.

I think this is why they still sell the 1HZ in Africa.

 

[jb BJ73]

Definitely. Their injectors are nowhere near as complicated so they can squirt out pretty much anything.

The further you go through the diesel engine development, the higher injection pressures get and the more fussy they get with fuel quality.
The later commonrails don't tolerate anything. Many people are installing extra filters in-line.

I think this is why they still sell the 1HZ in Africa.

Yeah the latest common rail systems need perfect fuel going through them, and sometimes that isn't enough to stop them wearing prematurely. Got a shire truck in the w/shop with the 6hk1 engine and it looks like it needs another set-this will be the third set of 6 injectors. (Sorry about off topic)

 

[JuanJ]

Hello,

Interesting thread, attacks aside.

It is funny how easily forgotten/overlooked the fact that extra HP/kW always come at a price is. And extra horses are usually very thirsty, as someone likes to say.

For every unit of extra power generated, at least the same amount is also produced. Heat must go somewhere. Too much heat can cause a lot of damage.

That is the reason behind oil squirting loops, cooling cylinder jackets and the lengthy discussion on AFRs and the like.

On the other hand, more air pressure implies careful fuel adjustment. Too much fuel or too little fuel will simply waste the additional air made available, and generate unwanted heat in exchange for little if any extra power.

All of this must be considered when setting up a turbo. Intended applications and driving style come a distant second after this.

There are ways to do modifications. Bolt up the components and get going is one. Or run some calculations before proceeding. Especially to verify the claims on the upper end.

I read some guys are running 20 something psi on their 1HZs. I am not sure of their data, though.

As for me, in a 1HZ I would double check the numbers, go on the lower/safe side of the envelope, and I would add an oil cooler and a high temperature coolant. I have seen my share of dubious turbo installments wreaking havoc in diesel engines and causing severe (and costly) damage. But that is just my opinion.

My two cents, no offense, no flames intended.





Juan

 

[Jan-78FJ40]

So how do I determine the exact AFR in my 1hdt?
My goal is not to get as much power out of it as possible, I just want it tuned perfectly as it would come from the factory.
Everything has been rebuilt in the last 1000 miles, including the pump and injectors, and the cylinders are standard size.
What process/sequence would the experts here propose for me to get there?
thanks
Jan