I think bigboy has contributed largely to this thread and would hate to see him banned.
How much boost can 1HZ-T handle? (2 Viewers)
- Thread starter nick4jc
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Tapage
Club 4X4 Panamá
fun to see how Dougal ends always in the same position .. 
Dougal, walk away, you have the experience and knowledge and can summarise politely. TBB will drag you down and down and down, and eventually he will be banned, as he has been on most of the Aussie Landcruiser forums... but hey I've got a ban on one of those sites too
To be fair, TBB has put in a fair effort, but usual antics... come on dude, put the crack pipe down!
My LC, tuned by THE MAN, pumps 610C POST turbo in 5th gear, starting at 110kph, slowing to 100kph at 6+tonne with camper attached up a 4km hill that is a 30% gradient... AFR is mid 19s, no noticeable smoke out the back (although mirrors were a bit dirty)... Would I do that again, probably not, but it was confirmed to be safe by THE MAN.
I love dyno read outs, there was a discussion on one just today, about needing a bigger exhaust, and the graph compared a stock car, to one with an upgraded exhaust... Apparently just adding a bigger exhaust gives you an extra 150Nm at 900rpm lower, yet only gives you an extra 4kw. That was some funny marketing!
Ah, interesting background.
I've seen people argue black and blue that advancing injection timing gave their 1HD-T 1000Nm of torque, with "dyno sheets to prove it."
But didn't change power by much either.
Its funny how pictures are painted in people's favours. To correct the info, 1 forum. The same 1 your are banned from south... I highly regard Dougals experience and knowledge, he knows this. And we speak in emails. I don't doubt for a second his tech is spot on. But it's not the numbers I'm getting. When I crunch the numbers - they don't add up. And extensive algorithms are required to correct them. Dougal has what? 15 years of experience, and half a thermal dynamics book in there.
The only difference is, I'm working back from results. The timing has not been touched. Graeme has already said it is safe as houses.
This thread is about "how much boost can a 1HZ handle". Well this is exactly it. 23psi and 19.8:1. This is what the stock piston crowns can handle from cylinder temps vs combustion pressures safely.
The only difference is, I'm working back from results. The timing has not been touched. Graeme has already said it is safe as houses.
This thread is about "how much boost can a 1HZ handle". Well this is exactly it. 23psi and 19.8:1. This is what the stock piston crowns can handle from cylinder temps vs combustion pressures safely.
Last edited:
Now why this psi and afr out of curiosity? Failures or how are we basing this?
Why wouldn't someone running 25 or say 28lbs of boost be ok at say 22:1 or 20:1
Not doubting you guys by any means
Combustion pressures - break pistons. As mentioned, increasing fuel can result in an increase of 10 bar, playing with timing can increase it by 100 bar. This is shown in the hp/torque/egt's.
What some don't realise. Is this dyno sheet is run in shoot out mode (shoot 6). You can take it too any dynamics dyno anywhere and it will read the same. The operator has no input and is unable to alter anything - it's locked. With all the data on the print out. So the only thing that can be altered is the way the vehicle is strapped. And the intake air temp probe. So whether people agree with the results or not is a wasted argument. This is how all the trucks will be run.
What some don't realise. Is this dyno sheet is run in shoot out mode (shoot 6). You can take it too any dynamics dyno anywhere and it will read the same. The operator has no input and is unable to alter anything - it's locked. With all the data on the print out. So the only thing that can be altered is the way the vehicle is strapped. And the intake air temp probe. So whether people agree with the results or not is a wasted argument. This is how all the trucks will be run.
Now why this psi and afr out of curiosity? Failures or how are we basing this?
Why wouldn't someone running 25 or say 28lbs of boost be ok at say 22:1 or 20:1
Not doubting you guys by any means
Tuners sell power. The lower they run the A:F ratio the more power they can sell to their customers.
But the lower the A:F ratio the higher the combustion temperatures, the lower the piston strength and the higher risk of failure.
Conflicting goals. Marketing vs reliability.
Dougal. If a HZ engine has many k's, or has previously had a turbo system running very low afr's. I usually tune it very conservatively. I will advise a Gturbo running around 16-18psi depending what condition their pump and injectors are in. 24:1 mid range 22-2400rpm, this drops to 22:1 and as their 10mm pump Max's out higher in the rpm the afr's climb to 26:1. Very noticeable power gains going from 8psi 16:1 and far far safer.
Informative, comical, heated, fair, mediated, and entertaining,
Any update on the 1hz test you were going to do?
No, I broke my leg and that set me back two weeks, so customer urgently needed it and didn't have time to run it half an hour up road for a run. Dissapointed.... But oh well, I do plenty of them so I'll do the next one or I'll dyno the one mentioned when I see it again in March - maybe on my own dyno.
mmmm - maybe 20psi and 20:1
arnott1t
SILVER Star
ok I'm dragging this thread up. I need some help in tuning my 1HZ.
Truck is a 1981 HJ47 RHD
1HZ from a 92 HZJ77 with 200k on the clock. Rebuilt injection pump.... at some point recently
G turbo Grunter 1 I believe originally destined for a 13bt before I bought it
EGT and boost gauge. EGT is pre turbo in the center of collector on the way to the turbine.
H55f
North West Fab Black Box
Split Case
4.11 diffs
33" rubber that will be 38....
Pump is not boost compensated.
3" mandrel exhaust..... right now its less than 1m long but will be routed to the back with a likely side dump
3" cone air filter.... needs to be upgraded to a water proof box. Looking to fit a donaldson unless someone has better advice... or XXI will sell me a sexy filter?
As it stands now I'm running about 12psi max boost. EGT can be lugged to 1000f pre turbo but are more like 700f most of the time. This was with the fuel screw turned up a turn or so...
I want:
a smile everytime I depress the go pedal....I get this already as it seems to pull pretty hard.
a reliable engine. I know power comes at some longevity cost and am prepared to sacrifice but not create a time bomb
I'm willing to add:
top mount intercooler. don't think even a WTA rad will squeeze in front of my rad as it is tight up there already though I'd like to try.
Boost compensator, if it will help performance... or reliability....won't add for mileage.
additional fuel filter
electric lift pump
AFR gauge even just for tuning if you can recommend one.
really excited for this rig.
Truck is a 1981 HJ47 RHD
1HZ from a 92 HZJ77 with 200k on the clock. Rebuilt injection pump.... at some point recently
G turbo Grunter 1 I believe originally destined for a 13bt before I bought it
EGT and boost gauge. EGT is pre turbo in the center of collector on the way to the turbine.
H55f
North West Fab Black Box
Split Case
4.11 diffs
33" rubber that will be 38....
Pump is not boost compensated.
3" mandrel exhaust..... right now its less than 1m long but will be routed to the back with a likely side dump
3" cone air filter.... needs to be upgraded to a water proof box. Looking to fit a donaldson unless someone has better advice... or XXI will sell me a sexy filter?
As it stands now I'm running about 12psi max boost. EGT can be lugged to 1000f pre turbo but are more like 700f most of the time. This was with the fuel screw turned up a turn or so...
I want:
a smile everytime I depress the go pedal....I get this already as it seems to pull pretty hard.
a reliable engine. I know power comes at some longevity cost and am prepared to sacrifice but not create a time bomb
I'm willing to add:
top mount intercooler. don't think even a WTA rad will squeeze in front of my rad as it is tight up there already though I'd like to try.
Boost compensator, if it will help performance... or reliability....won't add for mileage.
additional fuel filter
electric lift pump
AFR gauge even just for tuning if you can recommend one.
really excited for this rig.
If your planning on running water look at Moonlight Fab's duramax filter set up. Seems a bit more suitable for preventing water ingestion having the exit up top....
That turbo is good for 20lbs of boost. Your pump with a good air to air intercooler will max out at 22:1 AFR at 18lbs of boost i believe.
Roughly 150rwhp on 33s.
I vote front mount, enlarged plenum, airbox and boost comp.
I had fun for about 1000kms with my XXi pump but now I am having issues isolated to the pump.
That turbo is good for 20lbs of boost. Your pump with a good air to air intercooler will max out at 22:1 AFR at 18lbs of boost i believe.
Roughly 150rwhp on 33s.
I vote front mount, enlarged plenum, airbox and boost comp.
I had fun for about 1000kms with my XXi pump but now I am having issues isolated to the pump.
