1HZ fuel adjust for new turbo.... EGT discussion

[BEU77Y]

Hi all,

I've finished installing our new turbo to our 105. I've basically replaced the turbo of a Safari set up with a bigger turbo. I'm a bit disappointed that it's only brought the boost up to 8 PSI from 6. But that's a different issue....:cry:

Just want to double check which is the fuel adjustment screw? In the picture you can just see the idle screw and the max rev screw... I'm pretty sure the other one is the max fuel screw.

http://i8.photobucket.com/albums/a22/lisa76/BEU77Y/TUNEUP.jpg

At the moment I'm only getting EGT's of about 550 pre turbo, so I might up the fuel a bit.

Any pointers appreciated...

[Davo1]

Not a 100% sure mate but it does have the hole where the lead seal and copper wire go to stop people adjusting it. I'm sure Pete@Aewen will know and give his informed opinion on it though!

[Z()LTAN]

yep that is the fuel gov screw.

Screw in to increase

550 is as high as you want to go.

It sounds like its running too lean, if its too lean it can run hotter than when its over fueled

[BEU77Y]

yep that is the fuel gov screw.

Screw in to increase

550 is as high as you want to go.

It sounds like its running too lean, if its too lean it can run hotter than when its over fueled

Thanks

Is that 550 pre or post turbo.... I did a search a while ago and gathered that 550 post turbo was max but 700-750 PRE turbo was max. Not many kits come with the pre turbo probe fitting as it's easier to put one in the exhaust pipe.

I'm tuning it with the pre turbo temps.

[Z()LTAN]

oh right yeah 550 post is max

[dakar61]

It sounds like its running too lean, if its too lean it can run hotter than when its over fueled

Incorrect, Z()LTAN.

When you reduce injector pump output on a diesel engine, combustion and exhaust temps go down, not up.

Put simply, when tuning you should strive for the highest torque output with the lowest exhaust temps possible.

[BEU77Y]

OK boys and girls... done some testing...
I've wound the fuel up 1/4 of a turn.
I'm working on the limits of 700 deg pre turbo and 550 deg post turbo.

I was able to hold a speed/rev up a steep hill.
45-50k/hr
2800 RPM
Full throttle
8.5 PSI


I got 650 deg per turbo
and 600 deg post turbo.

Most people have said 550 post turbo but I've found the pre turbo temps to be more accurate and quicker at changing.

Any comments???

[Z()LTAN]

you are correct dakar but..
Just like overfueling if it were to be greatly underfueled the psychlometric ratio is too low causing the mix to ignite too early and create an intense heat front that will end up burning holes in your piston crowns.

[dakar61]

you are correct dakar but..
Just like overfueling if it were to be greatly underfueled the psychlometric ratio is too low causing the mix to ignite too early and create an intense heat front that will end up burning holes in your piston crowns.

So....you`re saying I`m correct by disagreeing with your previous statement but you still stand by it in your latter statement??

All I know is with diesel engines you remove the fuel then you remove the combustion heat and power as well. All the engine/vehicle tests I`ve ever done have never shown EGTs increase with fuel decrease.

If what you say is true, are all the new common rail diesel engines in danger of meltdown? They use around 50% less fuel when comparing similar sizes/outputs, yet develop an average of 30 to 50% more torque.

When you say psychlometric, do you mean psychometric in the numerical measurement sense or do you actually mean stoichiometric in the ideal air/fuel ratio combustion sense?

BEU77Y, you should use 550c as your max post turbo temps on a 1HZ. This will give some head room if you ever have to maintain high torque outputs for longer periods of time and at higher ambient temps also. Is the post turbo probe close to the turbine outlet?

[Z()LTAN]

stoichiometric yeah thats the one cheers for that.

I may have to do some more reading your argument is sounding very convincing.

If this were true some of my recent teachings are misleading.

Cheers Dakar, im always up for being corrected.

[BEU77Y]

Sorry to interupt your psychosomatic discussion boys....LOL

Yeah, I've read that 550 post is the max but the pre temps are more accurate. I found just today with the pre temp at 650 (well under the 750 max) the post temp hit 600..??? Ideas?

I noticed the pre temps are much quicker to react to throttle inputs.

The post probe is right behind the turbine... you can see the fitting in the pic.

http://i8.photobucket.com/albums/a22/lisa76/BEU77Y/ResizeofPICT0008-4.jpg

[udm]

zoltan, diesel engines work the opposite way to petrol engines, no fuel in diesel means less combustion, no power, low egt's, while more diesel will give higher combustion, more power, more heat.
btw, i have never understood the reason behind petrol engines running hot when lean :o, do you mind explaining? i have always been a diesel man

and for beu77y, the max egt you can go around 650c at the exhaust manifold.

[udm]

looks like a nice turbo, do you know what boost it has been setup for?

btw , i must have a stuffed injector pump, i have never been able to get egt's over 500c pre.

[Z()LTAN]

looking at your pic of the fuel adjustment screw, its alot further out than my mates 1hz turbo screw.

[udm]

looking at your pic of the fuel adjustment screw, its alot further out than my mates 1hz turbo screw.theres a missing lock ring, thats why it looks longer

[Z()LTAN]

yeah i did see that, even though. I have screwed his one out alot more.

[udm]

if you unscrew it , you end up getting less fuel, less power... any reason why you had to downgrade?

[BEU77Y]

looks like a nice turbo, do you know what boost it has been setup for?

btw , i must have a stuffed injector pump, i have never been able to get egt's over 500c pre.

The turbo is set up for 15 PSI... but I'm only getting 8 at the inlet manifold.
The intercooler set up is not so nice and I'm going to connect the boost guage before it to check the boost.

It punches out a cloud of black smoke when you first take off, but it always has... should see our front gate:(

The extra factor in tuning our 105 is that it's an auto. It makes working out the boost/rev numbers really hard... but at least when the torque converter is locked at 2200 RPM it's on full boost and stays there.

Actually produces a bit of whiplash when I 2 footed it off the lights.:D

Thanks for all the comments guys.... will keep you posted.

[Z()LTAN]

lol by screw out i meen screw in.... :drink:

[HDJ105]

The turbo is set up for 15 PSI... but I'm only getting 8 at the inlet manifold.
The intercooler set up is not so nice and I'm going to connect the boost guage before it to check the boost.

It punches out a cloud of black smoke when you first take off, but it always has... should see our front gate:(


Dave,

You're always going to get that initial puff if you don't have a boost compensator.

Who spec'd / sized the turbo for you? If you are sure the wastegate is set for 15psi, then based on the info (temps) you've mentioned then I'd say the turbine side may be too large.

Have you tried a quick spin with the wastegate hose blocked or linkage removed, just as a quick test and confirmation that it's not the wastegate that's limiting it to 8psi?

[HDJ105]

Yeah, I've read that 550 post is the max but the pre temps are more accurate. I found just today with the pre temp at 650 (well under the 750 max) the post temp hit 600..??? Ideas?

I noticed the pre temps are much quicker to react to throttle inputs.


On the 1HZ, I wouldn't be pushing any more than 650C pre-turbo. How long after the pre-probe hits 650 does it take the post probe to show 600c?

The pre-probe is much quicker to react, which is why I reckon it's the best place to measure as it gives a quicker look at what's going on in the engine.

[BEU77Y]

Dave,

You're always going to get that initial puff if you don't have a boost compensator.

Who spec'd / sized the turbo for you? If you are sure the wastegate is set for 15psi, then based on the info (temps) you've mentioned then I'd say the turbine side may be too large.

Have you tried a quick spin with the wastegate hose blocked or linkage removed, just as a quick test and confirmation that it's not the wastegate that's limiting it to 8psi?

A mate used the same turbo on his GQ and I can only assume they are the same. Bought at the same place about the same time.
His GQ runs 15 PSI at 1900 RPM but has a top mount intercooler so a bit of a different set up.

I'm going to plug the boost guage in before the intercooler to see what it's putting out. Then I will start tinkering with the wastegate signal.

On the 1HZ, I wouldn't be pushing any more than 650C pre-turbo. How long after the pre-probe hits 650 does it take the post probe to show 600c?

The pre-probe is much quicker to react, which is why I reckon it's the best place to measure as it gives a quicker look at what's going on in the engine.

The 650 pre and 600 post were at the same time. Yes the pre temps are much quicker to react and sometimes the post goes up when the pre goes down...

I'm not sure if the $13 Jaycar probe will stand up to the test of time before the turbo... I was planning to remove it in case it desintergrates. After I've tuned it. Might pull it out at intervals and see how it fairs.

I need to test it on some longer hills.

Does ambient temps make a big difference to EGT's? As it's now winter, I'm hoping I don't have to detune it to cope with summer.

[BEU77Y]

Finally got the boost gauge hooked up before the intercooler and guess what.
8.5PSI... bummer.
Boost controller it is I think.
Wind it up to 12 or so and see how it goes.

[HDJ105]

Finally got the boost gauge hooked up before the intercooler and guess what.
8.5PSI... bummer.
Boost controller it is I think.
Wind it up to 12 or so and see how it goes.

Dave, as I suggested just block the wastegate hose (pointy nose Vicegrips are ideal ;) ) and go for a very brief drive with boost gauge connected, that will confirm it for you.

[BEU77Y]

I'll give that a go.... shame I haven't got any vicegrips... will work something out.

How far should I go with the boost?... I liked the idea of 15PSI but it kinda scares me a bit... I think I might go 10 then maybe 12 and see how it goes.

Last thing I want to do is replace a 1HZ....

[udm]

i've seen 1hz's boost up to 14psi (intercooled) mine being one of them , just keep an eye on those egt's.

[lshobie]

I am running mine at 15psi with front mount intercooler, EGT's can go up quick but I can adjust with throttle input. Nice to have 15 when I need it though - ok, I never really need it but it is still fun.

YouTube - HZJ79 turbo aeroturbine landcruiser (http://youtube.com/watch?v=Edy7k11tLGs)

[BEU77Y]

Installed a air regulator this moring onto the wastegate tubing. It's a bit coarse for small adjustments but it's working ok.
Took it for a test run and found that without the wastegate could easily go above 15PSI. Wound it back to 11PSI. It's feels like a whole new truck.
I've added another 1/6th of a turn on the fuel and on 1 test hill only just got to 600 deg pre turbo.
With the auto on ours it's always been a bit of a slug.... test drove another N/A 1HZ auto that was just painful to drive.
With the extra mid range power it is now much more drivable... accelerates better out of corners without kicking down and revving too hard.

I'm very happy for now. I'd like to load it up for a proper test but I can't afford the fuel!

[HDJ105]

How far should I go with the boost?... I liked the idea of 15PSI but it kinda scares me a bit... I think I might go 10 then maybe 12 and see how it goes.


With the APS kit (i.e. turbo + intercooler) for the HZJ105 they state 12-13psi & 650C peak (pre), but as you don't have their kit then you really have no bench mark. But as has been mentioned, the EGT is more important than overall boost, especially if intercooled.


Last thing I want to do is replace a 1HZ....


I'll get shot down for saying so, but with a HZJ105 history dictates it's potentially when, not if :mad: Had another email from a guy today who has diagnosed a cracked piston in his @ 190k km.

[JD`s]

It looks a pretty small turbo to me I have just put a AXT Garrett 3'' ball bearing turbo on my troopy it was an amazing transformation. But don`t forget also to pay attention to your exhaust system.
I am running 3'' with mandrel bends all the way through and what a difference that made.5psi with the standard exhaust and 8psi with the 3'' with no wastegate adjustments and at least another 20% power OH YEAH!! Just remember my motto "Too much power is JUST enough!"

[BEU77Y]

It looks a pretty small turbo to me I have just put a AXT Garrett 3'' ball bearing turbo on my troopy it was an amazing transformation. But don`t forget also to pay attention to your exhaust system.
I am running 3'' with mandrel bends all the way through and what a difference that made.5psi with the standard exhaust and 8psi with the 3'' with no wastegate adjustments and at least another 20% power OH YEAH!! Just remember my motto "Too much power is JUST enough!"

Sounds like you've been schooled in heavy industry...
"Tighten it until it breaks, then back it off 1/4 turn!":D

I changed most of the exhaust with the original turbo system. That made a big difference on it's own. Finished the rest with 3" when the new turbo went on.
Got that nice whistle to it.