Defender 90 TD5 - Remapped. Power issues beyond 65mph

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I will leave the link right here http://www.wcengineering.com/articles/dieselturbo.html
although I rebuild turbo s and part of the job is understanding how they work just saying
it explains how heat works and expands with a pressure drop the turbo needs an incentive (just like a supercharger uses up to 50 % of its own power to run)

as for rpm flow to spin a turbo yes that would be correct if the turbo does not match the engine

but the td5 can make power down low and make full boost @ 2000 rpm for example doing 100KPH I would be in TC lock up when I negotiate a slight incline my accelerator peddle needs to pushed slightly to hold the 100KPH ...... RPM will not rise but the boost pressure will
reason engine is seeing more load more fuel means more heat more heat that will expand

exhaust gasses are always hot ..correct for the human skin but not for a turbo and materials used this is why EGT come to play the exhaust gas temp does not stay the same during boost or under load

the reason sierrafery has noticed response time is because he is containing the heat ..this heat is ready to expand making his turbo run more efficient than a colder turbo
I can only suggest to those who don't have boost gauge install one ..you will learn allot more about a turbo and its characteristics

merry xmas to all
hope you all have a good time and be safe
 
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I think some of you need to go away and read about thermodynamics, and the 1st law of thermodynamics because sierra and Deano are correct

Heat is very important in a turbocharger.

High temp gas comes out of the cylinders, the turbo creates backpressure (as it is an obstruction to that gas wanting to just escape - it slows it down) on the engine causing exhaust pressure to be higher than atmospheric pressure.

A pressure and temperature drop (expansion) occurs across the turbo which is what drives the turbo. (Temp drops when you expand a gas). The hotter the gas the greater the energy potential for work.

We all know what happens on the cold side of the turbo - air is compressed which heats it up hence why we need intercoolers.

Contrary to popular belief the Pistons don't 'push' the exhaust has put the valves, the gas leaves the cylinders because it is expanding

So heat isn't solely what actually makes a turbo spin but it is a hugely important factor.
 
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Jesus.... and I thought I was opening a thread on how some TD5s strangely don't like to rev beyond 3k :D

As flat says, even though blankets and exhaust wrapping will only have a marginal effect on a TD5 or most road going engines, it has an effect nonetheless in a good way.

rapid cooling such as when air leaves a hot combustion chamber through the cooled head and an exhaust manifold (still hot obviously but cooler than a combustion chamber all the same) air velocity and pressure drop due to the exhaust gas losing energy from heat to the atmosphere through the manifold, turbo etc. If the manifiold and turbo are insulated, the heat is contained more so the potential energy the exhaust gas has to spin the turbo is greater and also even on an engine without a turbo, the exhaust gases are quicker to leave the exhaust system to the cooler open air and especially on NA engines, the increased exhaust gas velocity helps the scavenging effect of a well designed manifold which cause pulses back along the primaries to extract the gases from the next firing cylinder quicker. When this is done on an engine with valve overlap, it causes the escaping exhaust gases to pull intake gases in before the valves fully close abit like a vacuum or drafting effect.

On a turbo diesel, it's just mostly down to keeping the exhaust gas temps high to retain all the energy just for movement before they exit the exhaust however.

Maybe small differences in doing things like this but as I always say on engine tuning, every little bit helps. Just depends if the time and money it takes do produce it is affordable :)




Now... back to the TD5 seeming to run out of steam beyond 65 or 3k in 5th at heavy load. Mine kinda does the same after a remap. Now, the remap is insanely good at responsiveness and power through the midrange but I'm getting limp mode under heave load in 2nd or 3rd gear say around 3000rpm under hard acceleration and then in 5th gear at about 60mph under load and full acceleration again.

I have a nanocom and boost is around 1.3-1.5 or so (ECU boost limits are reset to 1.6bar so no need for a boost box anymore to fool the ecu and nanocom into thinking it's just at 1.2)

I don't think it's spiking over 1.6bar which would just cause it to overboost and limp but I'm going to adjust the actuator a tiny bit to bring down it's peak boost potential a small bit to see if it allows the engine to rev more freely.


Granted, this TD5 is far from just a plug and play remap too :D
Fully rebuilt engine with oversize pistons, reconditioned head, Turbo Technics S205 VNT, large intercooler, EGR and de-cat, straight center pipe with just rear box, silicone boost and coolant hoses etc. Injectors were tested and came back ok but I'm fitting new ones in a few weeks regardless and keep it's own spare for it and my Dad's Disco 2
I'm wondering is the MAP sensor sensing an overboost too. my MAF etc seems to be working fine.
Waiting on EGT temp guages and proper boost gauge etc in the new year.


It's not really annoying really as the engine has so much torque, it rarely needs to be reved beyond 3k anyway and over 65mph is rarely justified too on a lifted 110 on 35s :D
Just be nice to get to the bottom of it and have it perfect really :)
 
DaveM-sport said:
....my MAF etc seems to be working fine....
Click to expand...
Did you try with it unplugged though? cos at that increased boost the suction can be higher than the MAF can bear and then the ECU goes into turbo overspeed protection(if the MAF reading exceeds 680kg/hr)... make a test with MAF unplugged too just to rule out this thing, also how is the IAT and AAP reading?
 
Yep, done it both with MAF connected and unplugged and no real difference. I had a very similar issue before with my last 110 where it wouldn't pull beyond 3000rpm for love nor money but was prefect when disconnected and then with a new MAF fitted. I can't remember if I still had the standard turbo and no boost box fitted at the time though and just some random ECU map that was on it.

That ECU was fitted to my new Defender then though along with the VNT with the boost box when rebuilt the engine though and MAFs, MAPs etc changed I didn't have any issues or at least didn't notice any. I'm not really sure if it was able to go over 3000rpm or not as still had under 500 miles on it so was only running it in really but definitely wasn't over-boosting and shutting down.
New map is night and day all the same though in response and pick up. I wondered too was the boost box fooling the ECU on the old map into thinking everything was still ok at 1.2bar even though it was secretly over-boosting but not showing up but you'd imagine it would have pulled alot harder then

Over the last couple hundred miles with new ECU map, it seems to be getting better though and not going into limp as much. Was terrible the first drive. Now, it only goes into limp if you really push it. I can't remember off hand what AAP and IAT I was getting but will keep an eye on those on the next spin. Mostly just keeping it on the first screen on the nanocom to keep a good eye on coolant temp etc when the engine is still hasn't a 1000miles under it's belt :)

It could possibly just the actuator has been stiff on the VNT as even though still pretty low mileage done, it's been sit for nearly 2 years since on my last 110 before fitting on my new one as the engine **** itself last spring and then due to waiting on new pistons and having a bike with a hospital stint over the summer before ready to put it together :)
 
sierrafery said:
On that principle, what if i fit something like this http://www.ebay.com/itm/12V-Electri...o-Scavenge-Conversion-Gear-Pump-/281765875529 on te turbo oil feed pipe and connect it through a timed relay as to keep working for let's say 2 minutes after the ignition was off ?
Click to expand...
this may work but your going to need a pump that can deal with high oil temps with out the motor burning out
I cant say if this would work or not I have never come across this install nor do I know who has

an accumulator tank works the same as a turbo savour but with out the extra oil filter
basically its a mechanical version of an electronic turbo timer


if you have a boost gauge installed you can also change driving style 2 to 3 minutes before you arrive at your destination
 
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ozzyboydeano said:
I still cant believe you have noticed issues like old intercooler leaking if you have the money to do a remap surely the boost leak should of been fixed first

as for adjusting waste gate lengths do you have a boost gauge installed ?

boost gauge install before messing around with the turbo adjustments

higher speeds means more engine load due to wind resistance meaning more boost ..and more boost means more heat ..not to sure if you know but a turbo works on heat... the more the heat means more expanded gasses to push the turbine resulting in more efficient turbo

as for the remap are your sure they have not just compensated for worn injectors
do you still have the EGR active ?
and stock exhaust ?
stock intercooler ? with leaks
Click to expand...

This had been edited since I responded, maybe it was badly worded, but it definitely lead me to believe that the poster was saying that heat was the MAIN factor, I wouldn't of bothered to respond otherwise.

sierrafery said:
I say again, nobody said that heat is driving the turbo, at least not me, read again what i said, that's what i said when i butted in:

after there were few replies posted by Johnlad, bankz and Gottschalk that heat has nothing to do with the turbine e.g.:
and i wanted to sustain ozzyboydeano who has tried to explain that it does and the experiments are showing clearely that.... so that was the subject nobody sustained that the turbine is not driven by exhaust gas flow just that heat can't be neglected in this ecuation and as long as nobody proves that i'm lying i reiterate that it's noticeable on the Td5 too(on mine it is) so IMO no need to argue untill somebody who sustains the contrary just for the sake of argument doesnt do an individual objectiv test on his own vehicle

MERRY CHRISTMAS TO ALL !
Click to expand...
 
Gottschalk said:
This had been edited since I responded, maybe it was badly worded, but it definitely lead me to believe that the poster was saying that heat was the MAIN factor, I wouldn't of bothered to respond otherwise.
Click to expand...

You clearly said that heat had nothing to do with turbo function, see your reply below.

The flow of the exhaust is caused by the heat of it and it rapidly expanding, it isn't 'pumped' out the engine.

I think it's time we all bow out of this thread rather than go around in circles.


Gottschalk said:
Basically johnlad and bankz are totally correct. The turbo spins up from the flow of exhaust gases passing through it. The fact that this is hot air is nothing to do with anything turbo wise, exhaust gases are always hot!
If you put a straight through pipe on a mapped td5 you will notice the turbo spools up much faster, and lower down the revs, that's because the gases are unrestricted and are spinning the turbo up faster.

The turbos JOB is to force the cold dense air into the cylinder, and this occurs from the FLOW of exhaust, not the temperature of it
Click to expand...
 
sierrafery said:
You should check the fuel pressure with a gauge screwed instead of the FPR
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Yup, that was one of my next things to check and then do a permanent job for it :)

Going to make up an inline sensor and then have a gauge for fuel pressure either in a seperate VDO gauge on the dash as have a few spaces now on the mud pods etc or use one of the outputs on the EMS for it.
 
here is a vid I have just done cold engine yes cold if you notice my coolant gauge
in the next up coming days I will do a hot test

but how did I make more boost being under load ..and not RPM related ?... fuel pressure ..my gauge above the boost pressure is showing

more engine load means more fuel to burn ..heat to expand this gives the turbo its energy to turn more power

if there is no heat there is no power ..if there is no heat means there is no fuel



 
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flat said:
You clearly said that heat had nothing to do with turbo function, see your reply below.

The flow of the exhaust is caused by the heat of it and it rapidly expanding, it isn't 'pumped' out the engine.

I think it's time we all bow out of this thread rather than go around in circles.
Click to expand...

Yes, and at that point I didn't think on a defender that heat would be a major factor, obviously, others felt otherwise, and if the difference can actually felt by wrapping the turbo, I'm happy to stand corrected.

As previously stated, for the umpteenth time, the only reason I responded at all was because I WAS stated that the main source of energy was heat, not kinetic. It turns out that badly worded posts, and responses can cause confusion.

I HOPE the OP can forgive us for muddling his thread.
 
Jessy said:
Right so I have attached two images that i quickly took showing you why I refer to the radiator and inter cooler as ****ty. They undoubtably need replacing soon but I want your opinions of whether this could be causing me the issues. I drove to work and noticed that actually in every gear once hitting a certain rpm I have the same effect. I usually change gears pretty swiftly and tend to sit in 5th so hadn't noticed beforehand. It's nice and smooth with a 'hiss' until that rpm limit then it's louder less hiss and slight vibrations. If you could, would you be able to configure a list of all the little things it could be with a rough price of each and then i could tick them off (starting with cheapest) and report back on this thread?. I'm only 20 with not a great amount of money expesially around Christmas so it might take a while!!.


Thanks everyone
Click to expand...

Hi mate, the offer still stands, your very welcome to my original intercooler if you want?
 
Gottschalk said:
Yes, and at that point I didn't think on a defender that heat would be a major factor, obviously, others felt otherwise, and if the difference can actually felt by wrapping the turbo, I'm happy to stand corrected.

As previously stated, for the umpteenth time, the only reason I responded at all was because I WAS stated that the main source of energy was heat, not kinetic. It turns out that badly worded posts, and responses can cause confusion.

I HOPE the OP can forgive us for muddling his thread.
Click to expand...

Yeah, sometimes written word doesn't always convey the correct meaning etc.

Anyway, merry Christmas, let's all get along :)
 
Out fkr
sierrafery said:
Did you try with it unplugged though? cos at that increased boost the suction can be higher than the MAF can bear and then the ECU goes into turbo overspeed protection(if the MAF reading exceeds 680kg/hr)... make a test with MAF unplugged too just to rule out this thing, also how is the IAT and AAP reading?
Click to expand...

Out for a spin there again. IATs around 14-22 degrees and AAP at about a 1000 pascals.

Fuel temp just for sake of only one left out is about 45-50 degrees
 
About the 100KPa yes, sorry the other value is 100.000Pa off course:oops: ...i corrected the other reply too, thanks for noticing it
 
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