I can't talk for the Di's but CRD's love boost as well.Quote:
Originally Posted by mudski
I wasn't running mine at 25 but up to 20 was common.
I can't talk for the Di's but CRD's love boost as well.Quote:
Originally Posted by mudski
I wasn't running mine at 25 but up to 20 was common.
I dragged my 1.4t camper 8 hours mate and my egt's rarely hit 400c. Most of the time it sat around 320c on the flat 'ish sections. So I'd be wary of egt's seeing 600c.Quote:
Originally Posted by MEGOMONSTER
Yep, a Diesel is a Diesel is a Diesel...
jam as much air in as you can get away with,
compress it as much as you can get away with,
shove as much fuel in as you can get away with,
wait for the bang then get whats left out as quick as you can so you can start all over.
The biggest single thing that makes a Diesel complicated is pollution control
Hey mudski how many psi do you have at 100kmh?
When you guys are talking about running 20-25psi boost, is that just a peak before it drops down or is it steady at that boost?
I'm talking max continuous boost IE constant 32 PSI on the Scangauge MAP indication.Quote:
Originally Posted by Rock Trol
Not sure about the Mudman but IRCC he has his wound up more and is also talking max continuous but I'm sure he'll post up when he sees the thread.
OK. I have set the Scangauge to show boost by subtracting 14.7 psi from MAP so that is why I was freaking out at the numbers you are talking about. Maybe I should switch to MAP so I get a more accurate reading. Just need to recalibrate my mind so I understand the figures I am reading.
So in general terms cruising at 100kph something around 27 MAP would be good and under load 30-32?
Been driving in the lower ratio on the auto, as you would expect EGTs were similar to a manual DI.
Makes sense more revs so gas gets out quicker so lower EGTs
And yes mine will hit 20 psi but it wont stay there [spikes]
I would say EGTs only slightly higher than Mudski
thats the difference between a manual and an auto I suppose.
Next trip to the Murray I might sit on 100kph in the lower ratio and see what happens
@ Mego Id be getting worried with temps that high,
maybe back the chip off two marks and see if that helps
IMHO (I posted similar to this somewhere else recently) MAP is more relevant than boost pressure.Quote:
Originally Posted by Rock Trol
Why? Because the reason the ECU monitors intake pressure is so it can limit boost to the engine cylinder pressure specification.
MAP is an absolute reading at the manifold so;
MAP X Compression ratio = Cylinder Pressure no matter what the loacal atmospheric pressure is.
Boost Pressure is the differential pressure across the Turbo IE Turbo outlet pressure - Turbo inlet pressure = Boost Pressure
Boost pressure is not an absolute, it is gauge reading so boost needs atmospheric added to it IE;
Boost Pressure + Atmospheric Pressure X Compression ratio = Cylinder Pressure
Atmospheric is a variable depending on temperature, altitude and air density
Atmospheric pressure of 14.7 is only true at sea level with an air temp of 15 degrees and standard air density.
Now the difference between the lowest and highest atmospheric pressures you will experince driving in Oz isn't a lot.
Only a couple of PSI at most but IMHO if you have MAP available it is better to use it.
Thanks ET. The reason I changed the scangauge from MAP to boost was because most people use this when posting on forums so it was easier to follow what was going on. I will change it back to MAP.
What MAP psi should I be looking at?
- Cruising at 100kph - 27?
- Foot to the floor? (35-40?)
Depends on the vehicle, Dawes or ECU, VNT tweaked or factory, load, etcQuote:
Originally Posted by Rock Trol
I would SWAG it as 30 ish MAP flat wack and 25 ish at 100
About 18 mate.Quote:
Originally Posted by paulyg
Mine is peak. When I'm giving it the berries....Quote:
Originally Posted by Rock Trol
I have 2.5" lift (closer too 3"), 33's, roofrack, drawes, winch ect..
I Have a Voltage Modifier on my MAF in my troll so I run 9 psi roughly at 100km/h, EGT'S around 320 degrees.
Max boost at 20psi and I can hit that going up a hill or headwind putting my foot down and sit on 20psi all day long till I reach the top.
EGT'S even towing nearly 2ton with a/c on I'm struggling too go over 500 degrees.
I'm averaging 11.8ltrs per 100 atm on Highway without towing, around 15.5-16 towing just under 2ton.
I'm still using factory MAF housing as well and VNT turned down 1/4 of a turn
I may get a boost spike too 22 psi but drops straight down too 20psi and sits there till I back off
Fletcha
I have Dawes and needle valve on mine (EGR block). Driving to work today if I gave it a bit it would go to 29 psi MAP but stayed around 20 most of the time so sounds about right until I get onto the highway.
Too low... give it a bit of a tweak I reckon.Quote:
Originally Posted by Rock Trol
I recall someone saying crank it till it limps and back it off a tad... or was that wheel nut torque (do one up till it snaps and back the wrench off 5 ft/lbs).
Mind you I've never set up a Dawes and Needle so what would I know
Just remember. The max boost is relative to the cruise boost. I.e 100kph boost. The best results I have found is around 8psi difference between max boost and 100kph boost. So the higher mac boost you go the higher cruise boost too. If not you will find the spool up rate of the turbo too slow and the engine sluggish. I will vary a little between cars but thats an average.
I'll try that on the weekend Mudski. Car feels pretty good though. When I had it set on boost it would sit around 12psi at 100 and max at around 18. Its a CRD so running a bit more boost is probably good for it. I read on here that 10psi at 100 is good but I could not adjust it down that low as the spool rate was too slow and car felt sluggish. When I adjusted mine I found a sweet spot and if I tried to go over (more boost) or under it the car did not run as well. Might tinker with it a bit more when I get the chance.
With the scangauge set to MAP what is a good max boost? 35psi? I think that equates to about 20psi boost. When I turned the car off today I kept an eye on the scangauge and it came down to 14.3 psi which I think is the atmospheric pressure. That would make the 29psi MAP about 15psi boost which is pretty good.
Quote:
Originally Posted by Rock Trol
That's pretty well what my crd is set on and feels good. More boost did have my egts lower when I was flogging it but went to limp mode after about a week so I took 2 psi out of it. Spikes to 20 then settles to 18 and cruise is about 12 ish but very hard to measure. Haven't hit limp again.
Been driving my auto in the lower ratio the last two days EGTs are around 200C
so revs has a lot to do with it as well
well just drove to the doctors about 15 k using the lower ratio on the auto
cruising on 60,70 and 80 egts were 200c they went up under throttle and settled back very fast
Its about 30 degrees ATM in Melb
yea mine was about the same (manual) went to Warragul about 20ks and backQuote:
Originally Posted by threedogs
at Yarragon there is a slight rise from the lights to near united temp went to 290
or a tad more then settled back to 220 on the run home
going by your results seems it works on RPM
and not KPH like most have done. that being the case
how many RPM at 100KPH for a manual 3 ltr DI,
please give tyres as either 265s or 285s
I forgot to get back on this topic. @ 100km/ph flat roat, cruising, my RPM is 2350-2400. 5th gear.