ditto that.
jc
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i did compare maps awhile ago but i cannot remember where i found them and the other slight difficulty was theres a GT3071R and the one i got is the GTX there is 3 main differences (sorry you probably already know this dougal but just for others reading)
1.GTX is the top of the line twin ball bearing water cooled unit that has an extra compressor blade
2.it has a surge slotted compressor housing
3.i done some sorting through exhaust A/R's and found that this series has a few options main one being 0.86 but i ordered mine with 0.63A/R i did come across one that was supposedly 0.56 (something around that) but i think it may have been dodgey
i also opted for the 38mm internal wastegate with the 12lb actuator and a 5 bolt flange rather than the V-band
for more of a technical insight john did compare a few maps and calculators for me at one stage on here somewhere (thanks john)
the hino turbo will be left in my parts box as oneday i may need it after i rebuild it of course...i think the cause was from the oil seals but did seem strange that only the compressor side was spewing out oil :confused: although drainage did cross my mind as i have made a drain into the block breather plate with a little alloy tube that i tigged in so that it spits the oil down a pushrod hole my concern is that air is flowing around there and also the angle may still be to sharp from turbo to drain point so i stole a plate off a 6bb1 so its all new again without my stupid drain idea :D i am now going to drain directly down to the sump now even though from what i can gather the BB turbos require less oil...
can only throw it on and see how it performs i suppose.....ill get dyno readings once all done (few months)
Turbo seals are labyrinth type, so they all leak but in normal operation they leak inwards. Some exhaust and boost always leaks through the seals into the centre housing and out the drain into your engine crankcase.
If the drain blocks, crankcase pressurises or you lose pressure in the compressor or turbine housings then you can start leaking oil outwards. Was your hino turbo boosting when you tested it or just free running? You can spill oil from the compressor of a perfectly good turbo if it's free spinning and has no boost to keep oil pushed towards the drain.
Keep us updated. I'm hoping you've got a higher pressure wastegate than that 12psi job.
thanks dougal i didnt know all that now i do though :) unfortunately i only tryed it on a stationary car and it strated leaking not thinking about even giving it a chance to try it under proper conditions due to my impatients that day it would be worth putting a rebuild kit through it then having it as a spare....as for the actuator that was the largest one they could supply there was 6,8 and 12 from what i could gather it was the spring on the insides rating the actuator is the largest one i have seen out of all the garretts i have played with though i must say though....
ill keep my progress posted as much as i can
im contemplating a MXA-6R box i have my eye on atm too just to add to the list after seeing the price of the 6speed quaife/lt230 :eek:
Chief, what sort of hp are you chasing with this setup because it is a large turbo even for a td42.
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Compressor map here:
http://mazworx.com/pics/gtx3071rcomp.jpg
This is true but I thought I would give it a go!!!
I'm not really setting a goal as I do not want to disappoint myself but what I like to do is test different things squeezing out any potential gains I can get...I am expecting this turbo to spool up considerably slower than what I was running before but having said that the turbo was strung out past it's limits and had no more potential for what I needed so hence the larger turbo...in my opinion the td42 has the revs covered but the Isuzu has the better IP that theoretically is more capable even more than the td42 running a 14mm element ... If I find it being not suitable it will then give me a reason to put a smaller turbo in conjunction with this one :angel:
I've been plugging some numbers on the GTX3071 map.
The general shape is quite good, it has plenty of flow capacity and pressure capacity. Even running 30psi to 4000rpm you won't have any issues.
But surge is a concern as 20psi at 2000rpm puts you right on the surge line. It could work out perfectly and not surge, I don't know how much of a margin is in the maps.
So yeah, very interested to see how it goes. If garrett do the same size wheel but with a slightly smaller inducer (smaller trim) it would be looking perfect. This would shift the whole map left a bit and give it more surge resistance. It is possible to machine down wheels to smaller trim and sleeve/re-machine the housing at a later date.
There is a member on 4btswaps.com who has a gt3076R on a 4BD1t in a suburban. But he is in florida (flat, sealevel) and has an automatic gearbox (so low end torque ain't a concern).
Thread here:
how much boost is too much?
Thanks dougal...I was thinking if the map was to the left a bit more as you said it would be good..im hoping I will just manage to get it to work fingers crossed...I did look at the gt3076r but thought the 3071 would be more suitable...
I've been in touch with a fella who has all the gear to modify turbos and he recons it should be fine as is but is willing to modify it if needed...
I'll check that link out thanks dougal once again
Is there an "Intro to Turbo Diesels" thread?
I need to get my head around some concepts:
- how to relate CFM at optimal revs to a boost map
- are there any issues with exhaust manifold lengths? (Distances between head exhaust ports and the turbo impeller housing)
- what is the best practice for optimum "power band" tuning (ie: boost off idle, signing off at just below the engine rated peak RPM)
- what is the optimum after-turbo exhaust diameter? is there a formula? is there a similar connection between CFM and RPM and cam duration as experienced in naturally aspirated petrol engines?
Probably this info is somewhere, but hopefully somebody has some threads bookmarked?