Increased boost, lower EGTs?

[CanuckMariner]

This is a fresh start from ancillary discussions on one or more other threads.

I have a '91 PZJ-T77 with a generic turbo which Wayne (Crushers) installed for the previous owner. Not sure of brand of turbo he installed but probably a Toyota or Garrett. Manual trani.

With my gear all loaded and full tank of fuel, she weighs in at 5650 lbs. Consequently, when I climb steep hills or long grades, the EGTs tend to climb upwards to +1000F where I gear down and generally have to complete the hill climb in third or sometimes in second.

I have backed off the air/fuel mix so there is minimal to no black smoke and I believe this also reduces EGTs. I do not think this vehicle came with an altitude adjust device, nor was there one installed with the turbo.

Before I go the inter-cooler route (water to air), I thought I would try to get more boost, thereby reducing EGTs (is this a correct assumption?) and perhaps get a bit more power. Prior to fiddling with the actuator rod adjustment (shorter for more boost?) as it can be a bit cumbersome, I thought I would try a boost controller/compensator. A friend has a TurboXS which I tried as per their website instructions and although it "seemed" to make it "easier/faster" to get to my max boost (set by Wayne at about 8-10 lbs), it did NOT increase the boost past the 10 lbs. I was hoping to get 14-16 psi or more and then reinstall the device "In-Cabin" so I can adjust on-the-fly. I went up hill in third at +/- 4000 rpm and could only get to 10 psi. I tried in second at same result. I increased turns as per their website instructions and still nothing. Thought I might have reversed the tubes, so I did that and still nothing. Put all back the way it was and I am back to square one.

Anyone have any ideas as to what I may have done wrong? Do these boost controllers even work on diesels?

If I did things right, I have eliminated this device as a possible solution. Is my premise correct that if one leaves all else alone and can increase boost, EGTs should come done?

Next, I will try to shorten the actuator rod to increase boost. Hopefully, I can adjust it with out disengaging the end from the swing arm as I have heard the small C clamp is difficult to remove and reinstall, as well as reconnecting the actuator rod to the swing arm. Wish you were still in Cowtown, Wayne!

 

[ForealBoreal]

This is a fresh start from ancillary discussions on one or more other threads.

I have a '91 PZJ-T77 with a generic turbo which Wayne (Crushers) installed for the previous owner. Not sure of brand of turbo he installed but probably a Toyota or Garrett. Manual trani.

With my gear all loaded and full tank of fuel, she weighs in at 5650 lbs. Consequently, when I climb steep hills or long grades, the EGTs tend to climb upwards to +1000F where I gear down and generally have to complete the hill climb in third or sometimes in second.

I have backed off the air/fuel mix so there is minimal to no black smoke and I believe this also reduces EGTs. I do not think this vehicle came with an altitude adjust device, nor was there one installed with the turbo.

Before I go the inter-cooler route (water to air), I thought I would try to get more boost, thereby reducing EGTs (is this a correct assumption?) and perhaps get a bit more power. Prior to fiddling with the actuator rod adjustment (shorter for more boost?) as it can be a bit cumbersome, I thought I would try a boost controller/compensator. A friend has a TurboXS which I tried as per their website instructions and although it "seemed" to make it "easier/faster" to get to my max boost (set by Wayne at about 8-10 lbs), it did NOT increase the boost past the 10 lbs. I was hoping to get 14-16 psi or more and then reinstall the device "In-Cabin" so I can adjust on-the-fly. I went up hill in third at +/- 4000 rpm and could only get to 10 psi. I tried in second at same result. I increased turns as per their website instructions and still nothing. Thought I might have reversed the tubes, so I did that and still nothing. Put all back the way it was and I am back to square one.

Anyone have any ideas as to what I may have done wrong? Do these boost controllers even work on diesels?

If I did things right, I have eliminated this device as a possible solution. Is my premise correct that if one leaves all else alone and can increase boost, EGTs should come done?

Next, I will try to shorten the actuator rod to increase boost. Hopefully, I can adjust it with out disengaging the end from the swing arm as I have heard the small C clamp is difficult to remove and reinstall, as well as reconnecting the actuator rod to the swing arm. Wish you were still in Cowtown, Wayne!

lowering fuel and increasing boost would get your egts down. Your essentially adding more air. But as you know when you increase your boost your compressed air temp increases.

10psi I think is safe without an intercooler.
14.5 psi with an water to air setup would be as high as I would go.
I think having an altitude boost compensator would help but I know there expensive and hard to install....

I am also a bit in the air if I should turbo the future 1hz.

 

[Radd Cruisers]

1000 F is fine for an EGT. My 12HT sees that all the time on hills, and if I push it I will see 1200 (I don't push it that hard as a rule).

Is your Pyro before or after the turbo?

The more fuel you add to the fire, the hotter it will get. If you add more boost, to a point, you will burn the fuel more efficiently and can get a lot more power from the engine. If you have effectively consumed all the fuel, then any extra air traveling through the engine can act to cool it down - but remember that compressing air makes it hot, so if you run too much boost you're going to be adding some extra heat in.

I would think that a max boost of about 10 PSI would be a good place to be. Think about an inter-cooler if you're going to go past 12PSI.

You have to adjust the waste gate to get more boost. Boost is related to exhaust pressure - and therefor revs, load and fuel (added by your right foot, and set at the inj pump).

Revving your PZ to 4,000 RPM sounds like you're beating the daylights out of the thing. It won't make any more power past about 3,200, so drive it on the torque and not the revs.

It really sounds to me like you're driving your engine way too hard on the revs side of things....


~John

 

[CanuckMariner]

1000 F is fine for an EGT. My 12HT sees that all the time on hills, and if I push it I will see 1200 (I don't push it that hard as a rule).

Is your Pyro before or after the turbo?

The more fuel you add to the fire, the hotter it will get. If you add more boost, to a point, you will burn the fuel more efficiently and can get a lot more power from the engine. If you have effectively consumed all the fuel, then any extra air traveling through the engine can act to cool it down - but remember that compressing air makes it hot, so if you run too much boost you're going to be adding some extra heat in.

I would think that a max boost of about 10 PSI would be a good place to be. Think about an inter-cooler if you're going to go past 12PSI.

You have to adjust the waste gate to get more boost. Boost is related to exhaust pressure - and therefor revs, load and fuel (added by your right foot, and set at the inj pump).

Revving your PZ to 4,000 RPM sounds like you're beating the daylights out of the thing. It won't make any more power past about 3,200, so drive it on the torque and not the revs.

It really sounds to me like you're driving your engine way too hard on the revs side of things....


~John

Pyro is pre Turbo. I only had RPMs up to 4000 to see what max boost I would get. Normally the RPMs rarely get past 2500. Thanks, John

 

[CanuckMariner]

lowering fuel and increasing boost would get your egts down. Your essentially adding more air. But as you know when you increase your boost your compressed air temp increases.

10psi I think is safe without an intercooler.
14.5 psi with an water to air setup would be as high as I would go.
I think having an altitude boost compensator would help but I know there expensive and hard to install....

I am also a bit in the air if I should turbo the future 1hz.

I have a 1HZ in my 73 series with a turbo set for about 6-8 psi and it runs fine. Keep EGTs at or lower than 1000F and all is well.

 

[CanuckMariner]

I am thinking that to get an additional 4 psi and the cost and work to install a water inter-cooler, just doesn't seem to justify it.

 

[lshobie]

Not if you drive at 85 kms/hr.

 

[CanuckMariner]

Not if you drive at 85 kms/hr.

I realize that Louis, just trying to get the EGTs down by increasing boost rather than going through all the effort/expense of a water to air cooling system

 

[lshobie]

Hard to find a balance without a boost compensator, not the HAC - it is just for high altitude ops. The boost comp will basically give you fuel when required, unlike without when you just get it when you don't need it.

 

[CanuckMariner]

Hard to find a balance without a boost compensator, not the HAC - it is just for high altitude ops. The boost comp will basically give you fuel when required, unlike without when you just get it when you don't need it.

I tried a Turboxs boost controller and couldn't get it to give any more boost, reversed the tubes, opened/closed it etc. tried it all, no worky!

 

[crushers]

Jan,
'quit screwing with things...
set it back the way it was, 1000F is WELL within the caution zone.

secondly, rpms have NOTHING to do with boost. LOAD has to do with boost. you can sit all day at a light and rev the s*** out of a diesel with little boost showing. you can pull from the light in second and watch the boost hit 10 lbs easily.

put it back the way it was set.
you DO NOT need an intecooler for under 14 psi and that is a SUSTAINED 14 psi, not a "minute" long spurt.

you backed off the fuel, reducing heat which in turns reduces the boost which in turn reduces the power.

crank the fuel back up to where it was, maybe even a touch past. put all the boost lines back the way they were and you will be fine. i had it tuned for perfection for a combination of power, safe EGTs adn fuel economy...

kids, sheesh.

 

[lshobie]

Boost comp on the pump - not boost controller. I'm with Wayne, you don't need to lower your egt's the way you drive - you don't need an intercooler at 85 kms/hr and I don't expect you push your truck enough to warrant it.

 

[cicak]

Greate advice from the greate toyota professor crushers.

 

[CanuckMariner]

Alright already!...

 

[crushers]

you asked me to contribute and you know i will speak what i feel is right.
don't take it personal.

 

[CanuckMariner]

Nothing personal Wayne. Just that I thought I could do better than 30 kph up hills and still not be at 1000F!!!

 

[lshobie]

Something isn't right.

 

[crushers]

that truck shoudl be able to climb hills (unless we are talking the Coqu or Rogers pass) with no problems at 100.
set it back to the original settings. go for a drive. if you are breaking over the 1200F then let me know. that setup has the EGT probe PRE-turbo so 1200F is safe, 1400F will be pushing it for an extended climb.
so, increase the fuel, increase the boost to 14 lbs max, check the EGTs. remember very seldom will you ever be at 14 lbs.
on the highway you should be turning between 6 and 9 lbs, hit a hill and the boost will climb (or a 'flatlands headwind'). you will also notice long gentle grades have the same effect but a bit more gradual than the short steep hills (like Antler hill on the way to Edmonton or Scotts hill heading to Banff). on the gentle grades you will see 10-12 lbs and on the short steep hills you might see 12-14 lbs.
you might creep up to 1200F on the short steep hills but don't start to panic unless the EGTs are staying in the (lets call it this) the danger zone 1200F-1400F then lift your foot a 1/4" or a touch more and the EGTs will drop quickly.

this is my suggestion, accept it or reject it. i really don't care either way.

cheers

 

[CanuckMariner]

I haven't touched the boost at all, so it still as you set it. I will turn the fuel/air mix back to your setting and see what happens. I have never had it boost more than 10 psi.

BTW: do you recall if it has an altitude compensator or not on it? Would that make a difference?

 

[lshobie]

I doubt it has an alt comp if it does it is mainly for smoke reduction at high alts. I have no idea how you drive, but hopefully you gear down on the hills bring up the revs and thin the mixture. If you are 1000 degrees and 35kph then you better be in second gear. Actually you couldn't get it to 1000 in second.

Would have to sit beside you to see what is going on , try taking a video.