Because a bigger turbo produces less boost at low and medium speeds. Turbo sizing isn't about bigger=better. It's about choosing the right turbo for your needs. It is a lot of work to properly map out a turbo for a diesel engine. Most people don't, they simply try another one or copy someone else.
The stock turbo on a TD5 is a GT2052 wastegated. Going up to a GT2256V only works because the V is variable vane.
If you went up to a GT2256 wastegated tubo or GT2560V variable vane then you'd lose considerable low end boost and torque.
Attempting to make more low end torque without boost just makes smoke and high EGT.
Presumably you're referring to Pirate4x4 where the discussion always centres around Merc OM617 (3L idi diesel), Cummins 4BT (3.9L tdi) or the 4BD1T.
In landrovers the 4BD1T is the only sensible choice. The Merc is thirsty and has very little torque, the cummins intake and sump design doesn't fit nicely in a landrover and requires a large amount of extra height to overcome. The 4BD1T is also significantly more refined than the 4BT and is available in the US in decent numbers.
You appear to disagree mainly because you love petrol V8's. Which is more a personal choice than anything else. I don't have any love for petrol V8's, but I can appreciate why others do.
And how did you reach that conclusion when no-one here knows what I have or haven't done? Is it the stereotype that you can't know the theory and be able to use it?
I don't fit stereotypes well.
Here's a simple question for those who think they know the practical side of tuning. This is a map from one of my vehicles. Please tell me how I found it (there are no WinOls map packs available for this ECU), how I identified it, what the axis are and what significant change it made to the engine it controls.
Evidence being videos of smoke? We still haven't received any EGT measurements and likely never will. How do you tune a diesel and call it safe without knowing the sustained EGT?
It's funny how you back one tuner who produces smoking defenders (TD5inside) and bag another one (td5alive) above. What makes you treat them differently?
Smoke or not tho Dougal they get results they make the car perform how the customer want's at the end of the day mate all I can say is this - When the customer ask's the customer gets... (ie I wanted a whistling exhausts my good friend and very reputable exhausts fitter then told me that it would gain nothing for performance but I wanted and he gave even tho he didn't want to...) Customer askdo you get this?
While you say tuning all common rail diesels or mechanical pump rotary ect ect is the same
Each one would require a different hand in doing so! Kinda like tuning a Holley over a twin Holley setup same but different in there own right, I am sure between motors thing's like CAM, Head design, inlet porting, inlet flow, inlet cc, valve sizing, Valve Spring rates would all play in where the engine need to be tuned and also how it's to be tuned also might add things like plenum size plays a HUGE part in how the engine perform's and what areas of the rpm they perform. How do you factor all this in your statement?
As I understand turbos the more heat is not a bad thing at low rpm higher heat will cause the turbine to slightly expand and close the gap on the turbine housing providing a better gap and increasing the rotational speed of the turbine (in petrol engines this is critical in making big boost turbine has to be hot way hotter then 600 more like 900+) once passed this stage and as the boost gets higher one would assume it would be back to where is should be and cool as that boost increased like you state.
Correct me if I am wrong here but with the modern technology out there today are diesel turbos still weaker the petrol turbos this 650deg temps of the diesel are a far cry from the 900plus that can run in a petrol turbo, Are they really made of different material? mostly nickel from my understanding from getting turbine wheels modified.
Why is this heat so bad anyway's (Just asking) pm me answer
I am sure many tuners would like to share your blanket mentality that all diesel's are easy to tune and all the same but this not the real world....
I am also sure that ALL the tuners mentioned in this thread would do solid measurment of EGT before the customer got there car back
there is alot you have not provided as well so lets not point fingers.We still haven't received any EGT measurements and likely never will. How do you tune a diesel and call it safe without knowing the sustained EGT?
This is correct if the customer is fully informed. If they are told that a maximum power tune on the stock hardware will run smoke and unsafe EGT's that can melt pistons, then few customers would take that option.
No, I didn't say that.
I said all electronic diesels run the same tuning structure and language. We are talking remaps and reflashes. Emailing tune files across the world.
We are not talking about hardware being swapped and vehicles being individually dyno tuned. Tuners in Europe selling tuning remaps to customers in Australia never see or touch the vehicles. They have no opportunity to take measurements or even assess vehicle condition.
This is nothing like tuning carburettors.
You are correct that the turbochargers can handle high exhaust temperatures. It's the pistons that melt and EGT is used for an indicator of cylinder temperature.
The more boost you run, the hotter cylinder temp is compared to exhaust temp as intake temps are higher. Injection timing also changes the relationship. More retarded gives hotter exhaust and cooler cylinders, more advanced gives hotter cylinders and cooler exhaust.
750C is the general danger point for diesels, put your own safety factor on that. 650-700C is far more sensible for sustained load when the intake tract heat-soaks and intake temps rise.
Diesels are easy to tune badly. Anyone can wind up the fuel and make more power with smoke.
The difficulty is in the hardware and matching the tune to the hardware to give the power required with a clean exhaust, safe EGT and good drivability.
Turbocharger sizing is critical as is knowing the limits of the turbochargers you intend to tune with.
As mentioned earlier these tuners are sending files, they have no opportunity to assess or measure anything on remote customers vehicles. They can do what they want with local test vehicles.
Most tuners are computer people, not mechanics, not old school tuners and certainly not engineers. EGT measurement is unheard of on tuning forums. You would be scared with the tunes that get sold and the wrong calls made. Some are pushing diesel A/F ratios down below 13:1 in an attempt to produce more power on street driven cars.
I have answered every reasonable question put to me. I don't put my CV up online, I don't share on facebook.
If you have a specific question, go ahead and ask it.
Last edited by Homestar; 28th August 2013 at 05:30 PM. Reason: Edited out unneeded comment
Scientific theory tends to be backed up with evidence, and it seems a good way to work when you make a claim.
From where I'm sitting there isn't a huge amount of evidence of you doing anything, although I can agree you seem to know what you're talking about, or at very least are good at googling.
I'll give Jose credit as he's replied with what can be seen as a reasoned arguement, with others to back it up to some extent.
Monster Tuning gets a knock as unlike Jose he responds by getting angry at being called out on what he's doing, be it smokey diesels, or silly jacked up discoverys.
Well thats not at all true.
when I bought my Td5 it had a Stage 1 tune from a local tuner who was/is all across AULRO, I contacted him via forum & email with some issues I had about it & no response.
Enter Jose @ Td5inside on the other side of the world I emailed him with my very specific requirements & he asked for all my specs and mods plus a log from my nanocom, that can tell you so much more than a dyno test. Wrote a map for me and I installed it, and immediately fixed most of my problems, some bum in seat testing and another nano recording and Jose tweaked my map and sent it back for me to try.
Bloody Fantastic, All for about $350 , A local tuner would not bother getting out of bed for $1000 , which is about what the orig tuner charged the previous owner,
As far as I'm concerned you can shove your dyno graphs, they mean squat, its bum in seat and fuel bowser that shows results I'm talking about
This is it, the perfect reason why someone who does not give any evidence to back claims should not be able to run someone down with his "theory"
Think of the help Jose could provide if welcomed here!
Oh, I'm on the ignore list, but if anyone quotes my posts, they become visible![]()
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