Turbo upgrade

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24 Mar 2018 05:27 - 24 Mar 2018 05:32 #461 by dandjcr
dandjcr replied the topic: Turbo upgrade

dandjcr wrote:
One thing, the boost/pressure sensor has a neoprene "bung" which pushes into a hole you drill in the inlet system. Their documentation doesn't show the actual hole size required (it's 10mm), only the OD of the bung which is useless info, too large and it will pop out.


After a bit more chasing, Auber have now updated their "Auber 303 3 Bar Boost Pressure Transmitter" document with more useful info.

They now say it needs a hole 10.6 to 10.9mm diameter, but I still think 10mm is a better fit. If it pops out, a smear of silicon should keep things together.


David and Janet Ribbans - Oka 148
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Last Edit: 24 Mar 2018 05:32 by dandjcr.

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24 Mar 2018 13:05 #462 by Holmz
Holmz replied the topic: Turbo upgrade

dandjcr wrote:

dandjcr wrote:
One thing, the boost/pressure sensor has a neoprene "bung" which pushes into a hole you drill in the inlet system. Their documentation doesn't show the actual hole size required (it's 10mm), only the OD of the bung which is useless info, too large and it will pop out.


After a bit more chasing, Auber have now updated their "Auber 303 3 Bar Boost Pressure Transmitter" document with more useful info.

They now say it needs a hole 10.6 to 10.9mm diameter, but I still think 10mm is a better fit. If it pops out, a smear of silicon should keep things together.


I was pretty dead-set on wanting a VDO gauge ;)
Looking at the dash, I can see why you used that Auber unit... it gets two gauges into the only realestate left...

Starting a new thread...

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04 Apr 2018 17:15 #463 by Holmz
Holmz replied the topic: Turbo upgrade
Two questions...

1) I think that the 4M (13') EGT wire is needed, and I just lasso up any remaining wire into a coil.
However two remaining questions here are:
1a) where does one usually mount it?
Where it is easy, or closer to the turbo exhaust inlet?
1b) What bung do people go with? I am leaning towards a weld in carbon job as that would be hard to loosen, but also need to get teh tig up there.

2) On the pressure transducer, the 3 bar unit with the 10-mm bung is common. So 15 psi boost is about 1-bar.

There is also the Auber-103 (GM-###) which is a MAP sensor.
Is there a good reason why I should not use a 3-Bar MAP sensor, as 15psi boost will be ~2-bar MAP?
It would be better if there were hills and mountains as a constant 2-bar going in at sea-level and at 4km up is the same stress on the engine, but different boost numbers.
Of course it is flat here, so that point is moot...

The MAP has a 7.5-mm barb, so a 1/4"or 6-mm hose connects it. That would be harder to blow off with less area, and would seem to be easy enough to have a barb somewhere in the inlet manifold or in the turbo outlet?

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11 Apr 2018 15:01 #464 by Tony Lee
Tony Lee replied the topic: Turbo upgrade
Isn't the Auber unit adjusted to zero out local air pressure so it will only show actual boost - but it isn't a dynamic adjustment so driving in the Andes will result in a bit of an error - not that it matters since you just have to accept what you end up with

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11 Apr 2018 18:30 #465 by Tony Lee
Tony Lee replied the topic: Turbo upgrade
Is there any place better than others for drilling the 10mm hole to take the boost pressure sensor.

Nice easy place to get at is right in the middle of the flat top face of the inlet manifold, but maybe that is just too easy

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11 Apr 2018 21:11 #466 by Holmz
Holmz replied the topic: Turbo upgrade

Tony Lee wrote: Isn't the Auber unit adjusted to zero out local air pressure so it will only show actual boost - but it isn't a dynamic adjustment so driving in the Andes will result in a bit of an error - not that it matters since you just have to accept what you end up with


The Auber boost transducer shows relative boost.
The Auber (GM) MAP transducer shows manifold absolute pressure.

The main reason I was thinking about is that it goes to 2-bar (15-psi boost), and the 3-bar boost gauge I only use 1/3 of the range.
I am not sure it matters, but that is where I was I thinking about it.

Tony Lee wrote: Is there any place better than others for drilling the 10mm hole to take the boost pressure sensor.

Nice easy place to get at is right in the middle of the flat top face of the inlet manifold, but maybe that is just too easy


And there were a few options, and the GM MAP gauge has a 7.5-mm hose barb, or it seems easier to put a 1/4" hose on, and then a small clamp or wire, in order to keep it from being blow darted out of the hole under the puff of air pressure...

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12 Apr 2018 05:05 #467 by Peter and Sandra OKA 374
Peter and Sandra OKA 374 replied the topic: Turbo upgrade
Tony I just fitted the fitting to the top of the inlet manifold, some engines have a spare threaded hole with a plug in it. Otherwise the greased drill and tap with a vacuum afterwards, a small hose attached to the vacuum inserted in the hole will get any fine stuff that falls inside, it is alloy and very unlikely to damage anything in the engine if subsequently sucked in.
The EGT on Perky's is best fitted in the cast piece about 80- 100mm past the turbo, on top so it is easy to get to, those with manual transmission will also need to check for shifter linkage clearance. I always used the Auberins threaded fitting and have never had one fall out or cause any problems in any way. Any swarf from the drilling and tapping can go down the exhaust.

OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 680w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.

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12 Apr 2018 05:23 #468 by Tony Lee
Tony Lee replied the topic: Turbo upgrade
Sounds good. After skinning every knuckle getting everything refitted after the turbo upgrade, I wasn't too keen on removing any of it just to drill a hole.

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12 Apr 2018 10:59 #469 by mort
mort replied the topic: Turbo upgrade
Hi Tony and Holmz,
For the boost I had removed the plug on the elbow connesting the air box to the turbo drilled and taped then reinstalled and the pyro was in the dump pipe which can be drilled and taped in place as photo shows its the easiest.
Martyn

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12 Apr 2018 13:31 #470 by Tony Lee
Tony Lee replied the topic: Turbo upgrade
Hard to believe that Perkins added that plug just in case someone wanted to measure boost 45 years later, but I can't think of any other good reason for having it there. Pretty elaborate bit of machining so there must have been a good reason.

Now to find somewhere on the dump pipe I can get a drill to. One of those cases where being able to see it isn't the same as being able to drill it. Guess removing the side access panel under the seat might be the go.

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12 Apr 2018 18:33 #471 by Holmz
Holmz replied the topic: Turbo upgrade
I would have thought it would be pre-turbo (go figure)

What is the dump pipe, is it the watergate bypass?
I would have assumed that is no flow through there unless one it hard on the noise peddle(?)
... and one would want it on the main pipe?

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12 Apr 2018 18:59 #472 by Peter and Sandra OKA 374
Peter and Sandra OKA 374 replied the topic: Turbo upgrade
Holmz it is on the main dump pipe post turbo.
Pic attached of the Perkins engine when I removed it, the brass plug on the top of the inlet manifold is where the boost gauge was connected and the Toyota diff breather used to block the hole in the dump pipe is where the EGT was fitted

OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 680w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.
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13 Apr 2018 11:15 #473 by mort
mort replied the topic: Turbo upgrade
Hi Tony,
Yes that good piece of British Engineering was actually the heating element for cold climate use to preheat the air.
When you remove the side panel its a lot easier.
Martyn

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13 Apr 2018 11:32 #474 by mort
mort replied the topic: Turbo upgrade
Hi Holmz,
The boost can be anywhere between the turbo and head, if you want to drill and tap that plug on the elbow leave enough tube so that if you want to install an intercooler you may need to turn it around.
The pyro goes after the head and ideally in the manifold but is a bit difficult so just after the turbo on the cast iron pipe and just be aware that you could loose up to 100 deg from your valve face to that point.
Martyn

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14 Apr 2018 05:27 - 14 Apr 2018 05:33 #475 by Tony Lee
Tony Lee replied the topic: Turbo upgrade
Peter (and Sandra) said "EGT's are in the high 500's and will go to 650 if you lug it in the gears." and Peter (and Margaret) mentioned similar values.

What is a reasonably safe range and what would be a sensible alarm point. My sensor is in the same spot as in the photos below on the bend of the tube after the turbo.

"1) I think that the 4M (13') EGT wire is needed, and I just lasso up any remaining wire into a coil."
Probably smart. The standard lead that came with the sensor just reached and that was only by taking the most direct route through a precut holehole just to the left of the gear shifter mechanism
Last Edit: 14 Apr 2018 05:33 by Tony Lee.

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14 Apr 2018 05:55 #476 by Peter and Sandra OKA 374
Peter and Sandra OKA 374 replied the topic: Turbo upgrade
As Martyn said the dump pipe temps will be at least a 100C less than in the engine, apparently alloy starts to melt above 750C so 650C in the dump pipe should be regarded as a maximum. It may flick higher as you change gears but running it constantly will cause engine damage.
As most of us live withing a few hundred metres of sea level what is a safe fuelling point at home might lead to much higher temps at altitude. I had been running the 6bt around for nearly 12 months before the Geehi get together and we travelled from Jindabyne over the range to Geehi with Min in his standard Perky powered Oka, I couldn't use any more than about half throttle up to Thredbo and Min was keeping up on the hills, Too much fuel due to the thinner air at altitude even though it doesn't blow smoke at all normally.

OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 680w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.

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14 Apr 2018 07:47 #477 by Holmz
Holmz replied the topic: Turbo upgrade
Well race cars run each EGT at each exhaust port, and the EGTs have some delay is response.
My Perkins is not exactly a light flywheeled race engine.
And i am not tuning air:fuel for throttle response.

The more insulated that big cast exhaust manifold is, then the less the temp will drop from energy going out there.
It will heat and cool more slowly that exhaust air temps.

However the tempurature drop across the turbo may be significant as it follows the PV=nRT .
If everyone is running post turbo and blow up the engine at 700C and run forever at 650C, then the theory may not matter if one alarms at 650C (or whatever the magic numbers are)

This is sort of my question about where to put the EGT, so a combo of:
- best in theory (which is always as close to the exhaust valve as possible, or directly measuring cylinder pressure)
- ease of install
- ease of comparison and knowledge transfer between other owner's vehicles

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14 Apr 2018 17:27 - 14 Apr 2018 17:36 #478 by Tony Lee
Tony Lee replied the topic: Turbo upgrade

It will heat and cool more slowly that exhaust air temps.


Although the thermocouple itself is enclosed right at the end in a small tube so has little lag heating or cooling and is right in the middle of the airflow so given how fast the airflow is, I would expect little effect from the temperature of the pipe itself or whether it is lagged or not..


Peter, could it be a case of what the eye doesn't see the heart engine doesn't grieve because most production vehicles don't have these gauges fitted. I've driven the cat diesel to over 10,000 feet up long grades and I doubt whether it being a 99 model has any protection. Same with the F350 - 2000 model V8 to nearly 15000 feet up very long grades. Or are these sort of engines well and truly detuned so they can't reach dangerous temperatures (as obviously is the standard Perkins)
Last Edit: 14 Apr 2018 17:36 by Tony Lee.
The following user(s) said Thank You: Holmz

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15 Apr 2018 06:39 #479 by Peter and Sandra OKA 374
Peter and Sandra OKA 374 replied the topic: Turbo upgrade
Tony they would be tuned so that with everything operating normally temperatures wouldn't be exceeded, also modern engines operating in high altitudes do back the fuel off. The Perky and the 6bt both have crude altitude compensation built in.

OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 680w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.

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15 Apr 2018 07:36 #480 by Holmz
Holmz replied the topic: Turbo upgrade

Tony Lee wrote:

It will heat and cool more slowly that exhaust air temps.


Although the thermocouple itself is enclosed right at the end in a small tube so has little lag heating or cooling and is right in the middle of the airflow so given how fast the airflow is, I would expect little effect from the temperature of the pipe itself or whether it is lagged or not.
...


Yeah, true, and a good correction.

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