discoverysport

New Member
hi just wandering how high in psi a td5 would boost if actuator as short as possible, I can only get 22psi so I am wondering if my turbo is a bit tired? it does have a fair bit of play in it
 
the td5 D2 is conceived to go into overboost protection at 20 psi with wastegate rod at normal lenght(iirc 13 thread)...if you have a boost box to override that you can go to 22psi but as long as you dont have a performant overheat protection too you better not mess with such boost cos you may fry the head....if you want power not the boost is the only way, get a better balanced map in it... my turbo is bran new genuine garreth and i have 1.3bar/19psi at full load without touching the rod so IMO 22psi is not bad at all
 
Could the play in the the turbo be attributed to its requirement to spin in a film of oil when running? When you move it by hand, there's no oil film "bearing" to take up the slack as it were...
 
Could the play in the the turbo be attributed to its requirement to spin in a film of oil when running? When you move it by hand, there's no oil film "bearing" to take up the slack as it were...

it could be, I know it will have some play when there is no oil but im not sure how much or how to test if it is working as well as when its new. I am thinking of getting a new "cartridge" off ebay has new bushes and fan wheels all balanced and ready to fit into old casing.
Anyone know anything about these? are they worth it?
 
Could the play in the the turbo be attributed to its requirement to spin in a film of oil when running? When you move it by hand, there's no oil film "bearing" to take up the slack as it were...

also if its the original turbo then its done 160000 miles so I am kind of presuming its worn out
 
could be worn or not, i saw good turbo with 200K miles in it... the gist is to not play with the wastegate to overboost the engine
 
fair point, I am trying to get as much power as I can though, I have a spare turbo in my shed if this one blows up lol I just want to know if its performing at its best i.e if you had a brand new turbo would it create more than 22psi of boost at full power, I have heard some one running a vgt at 28psi on a td5
 
fair point, I am trying to get as much power as I can though, I have a spare turbo in my shed if this one blows up lol I just want to know if its performing at its best i.e if you had a brand new turbo would it create more than 22psi of boost at full power, I have heard some one running a vgt at 28psi on a td5

the turbo itself might create 28 psi if you force it but as long is on the D2 the management will not let it cos it's conceived to protect the engine and the turbocharger too, that's why the ECU will activate protection for overboost and turbo overspeed ...just fitted an EGT gauge on mine and i can tell that i've got scared without boost box only with remap...i'll quote you some relecvant parts from the management which will give you an ideea what could happen if you boost the sh*t out of a Td5(and these protections are made to activate at close to 20psi (230KPa manifold absolute pressure with a medium of 100KPa ambient pressure...inputs sent by MAP and AAP sensors)
1. The ECM uses the signal from the AAP sensor for the following functions:
l To maintain manifold boost pressure.
.....
The sensor also supplies a voltage between 0v and 5v proportional to ambient temperature. The ECM uses this signal
for the following functions:
l Exhaust gas over temperature protection.
l Turbocharger overspeed protection.


2. The modulator controls turbocharger boost pressure by varying the pressure used to open
the turbocharger wastegate. This control is vital to ensure the turbocharger does not over boost the engine.

now ask yourself why would they designed the whole thing to not exceed 20psi then?

if you want more power get a proper remap, a larger intercooler, get rid of the CAT(if fitted) put a straight through exhaust and make sure everything is in working order


it would be interesting to make a statistic how many of those who experienced cracked heads/HG failures/dead turbos have had boost boxes fitted...cos the simple thing a boost box does is that it reduces/limits the MAP readings as the ECU to not trigger the overboost/turbo overspeed protection

IMO the most common cause of the above failures and turbo wear is excessive EGT
 
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if you want more power get a proper remap, a larger intercooler, get rid of the CAT(if fitted) put a straight through exhaust and make sure everything is in working order

ok so I have the biggest intercooler that will fit into a discovery, straight 3" pipe from the turbo to the back no silencers, stage 2 remap and I replace parts every week to make sure everything is working.
now how do I get more power?
 
ok so I have the biggest intercooler that will fit into a discovery, straight 3" pipe from the turbo to the back no silencers, stage 2 remap and I replace parts every week to make sure everything is working.
now how do I get more power?
if you have all these and want more power go to the gym m8 and work out a bit:D

without joking... IMO you are at the top of it then as long as you want to be on the safe side...if you dont care what happens with the engine you can fit a boost box and increase the boost to maximum or go for an LPG injection too but you should not forget it's a 2.5l diesel engine not a 4l V8;)
 
ok so I have the biggest intercooler that will fit into a discovery, straight 3" pipe from the turbo to the back no silencers, stage 2 remap and I replace parts every week to make sure everything is working.
now how do I get more power?

Its a Discovery FFS if you want to play with the Saxo Boys go and buy a Saxo
 
yeah its a discovery and its my discovery to do with as I please, I drive a 450bhp diesel the rest of the day and I don't want to go home in something small and slow


That is not that big either.

I know of people with playthings in the thousands.

How about a pair of supercharged 18 cylinder engines?
 
The limit for a TD5 and road use is a bit over 200bhp 230 240 appears to be the limit
 

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