Slow spool on w202 250 TD
Slow spool on w202 250 TD
Hi guys,
i got a problem with my daily drifter. I installed the stock turbo again, but the spool is still very slow. Starts at 2k rpm wich is great, but too long... Nearly impossible to drift, because when i kick the accelerator, it takes nearly two seconds until i´m getting boost.
I checked the vacuum lines, they are all okay i had already an issue with them
I´m not sure if it is just normal that it takes some time to build boost, or if there is anything wrong... What could i do to degrease spool time? Even with evry mod it´s not good. Will killing the middle muffler and decat help a lot?
It is not caused by turbo properties but ECU itself, compared to other brands like old BMW pre-chamber M51 or any TDI engine with VE EDC pump its like 3-4 times slower.. Just like you said, it take 1-2s to even notice you pressed the pedal. I assume it was tuned like this from factory for smooth ride.
Yes remap, you get two birds with one stone.. one have to alter drivers wish map, I doubt it will ever be as fast as mech. pump or TDI since the slowiness sure comes from some PID loops inside of ECU which no tuner will tinker with. When at it raise torque limiter to unlock those few ponnies locked within. Be sure you have it tuned by someone who knows what he is doing, pouring in downloaded soft will do nothing to gas pedal response only raise maximum power.
OM 605/5 engines, despite what most may say are like any other compression / ignition engine fitted with indirect injection, any one may name any brand that feels more alive than the other for the same displacement and same injected quantity.
Direct injected engines are twice as powerfull and feel 4 times alive compared with a IDI for the same displacement and injected quantities.
The only way one can trick this in a OM605/6 is by reducing the injection time , and injection quantities, of course since fuel need to be increased amount of air need to be too, likewise a higher pumping capacity turbo is needed. to have more air for the same displacement means increase in pressure, pressure increase heats up air a lot , so a means of cooling is needed, intercooler.
the rest is just dependent on anyone wishes , me i like 4 valves and big , i like VNT turbines too, hand build daddaa.
Basically if u want to have a fun to drive car, a 7.5mm pump (M with RSF or EDC governor is the same) is needed, max fuel output need to be above 80cc, a VNT turbine of a GT23 size , cooler the size of a W211 320CDI , direct 70mm exaust and a race filter, like this the investment is in the 1500€ área depending where u send the goods to tune and if u can do a lot by yourself.
sorry to put it like this , but unfortunatly it can´t be solved by a software replacement like in a AUDI A3 PD engine.
regards
As far as my knowlege goes , no.
If u want 25% more power u can use the resistor mod , or install a chip to have your ECU using 4.5 volt to the governor that may give u enough rack for 80cc.
i can find out if any of the members here report the voltage at the rack actuator(with the mod), like this i can test in the bench and i can tell u how much x voltage gives.
even then u need the turbo, and the cooler .... that M EDC pump wont help either
i´m not talking about power atm, i just want to make the response of the car better. Sure i want to get to about 200hp, but only if it´s possible to get it with very slow spool. Drifting like that is nearly impossible, i kick the pedal, nothing happens, and when i´m thrue the corner the car starts pushing
(01-24-2016, 04:31 PM)barrote haha , tricks and tricks one takes about half life dealing with all kind of pumps , and people still belive the ECU has the answear.... not even in common rail ... the response comes with stupids amounts of fuel
(01-24-2016, 04:31 PM)barrote haha , tricks and tricks one takes about half life dealing with all kind of pumps , and people still belive the ECU has the answear.... not even in common rail ... the response comes with stupids amounts of fuel
Well, yes yes I almost forgot about standalone EDC controllers in which PID loop is as fast as it can get without big overshoot etc. Slowiness of pedal response have nothing to do with fuel engine burns and how it burn Barrotte. Its just like Baldur said, it comes from shit calibration. Well maybe it was not shit when they made it, they want it to be slow shit so it won´t jerk when you slap pedal. I had BMW M51 which is virtualy same engine as OM603 but equiped with VE EDC pump and it reacted instanteously-different calibration of PID loops, nothing else. Same for 2.5TDI with VP37 pump, I would say it reacts as fast as mech. pump.
mr starynovy,
the way it is injected makes all the diff... the way it burns is the same as u say...
why dont u try such a VE in the OM 606 , and a M in the M51 and then u can understand what i´m talking about ....
its pointless to discuss reaction time, its a question of fueling .....
And for the VE´s despite they have diff cam plate for IDI and DI the IDI is a lot faster than any regular M pump.
i´m not familiar with the M51 engine , but drove some in stock conditions and they seemed to be as slow as 605TD, the 606 is slower than the 605, the idea was to compare displacement rather tha volumetric eficiency.
regards
ok, what i just did was, i closed my wg mechanically, then i drove without evry mod on. The response was much faster than normally with the vakuum actuator. I didn´t rev high because boost rised quickly above 1 bar. Then i turned on the evry, and the response was even faster. I think i´m happy with the response of a closed wastegate. So i´ll go and get myself a pressure actuator, what i wanted to do anyway...So barrote, you where right in that kind that you said, more fuel = faster response. But not with the vacuum actuator.
Well if you say so mr. ECU programmer.
Regardless, it will never be fast because of calibrations made by factory inside of fueling part of ECU which translates fuel map into Voltage to drive fuel pump actuator ie. rack.
Yes, and then I recommend pressure operated GT2260V or 2359V. Almost instanteous boost when you slap pedal.
Yes they are, but you can make them work with standart pressure waste gate actuator.
Yes you can, you will detach original vacuum actuator and fit normal pressure actuator taken from WG turbo.. then you have to work out good spring pretension for desired pressure, it almost everytime involves shortening actuator rod so some welding or thread cutting is needed. I ve done this with many turbos, it works.. namely I fitted many of them on 525tds removing old WG turbo and fitting 2256V from 530d, or VNT20 on AEL 2.5TDI which had some WG KKK16 turbo... Funny thing is that this was made originaly on some fiat CR diesels too, like first 2.4JTD and on some HDI engines.. you just have to be carefull, there is no protection to turbo. If your pressure hose to actuator breaks there is nothing to push vanes open and it will overboost. Or actually you still have EDC system so engine goes in limp since pressure goes higher than 1.4Bar.
or does not REV at all , hammer valves and that kind of things ... as we say in my country cork style...
Mr repetitio, i belive some time ago i told u to slap closed the WG and watch... now u understood what i was talking about...
Since u are in germany , u can take mr starynovy advice and search for a GT23V , but since u have to spend some Money go after a C30CDI or the one in the OM648, despite is electricall actuated , u can buy one with the actuator defective since u dont need it.
The pressure controled actuator works ok , and for a 605 this baby is the best, but its not like mr starynovy said ... u still need stupids amounts of fuel to kick it ...
Well I count on that remap he mentioned.. not a stupid amount but it will work very well. When we are at it, you know what else is cheap? 3rd gen VNT from new BMW X6, its GTB2260VK, real beast. They go as low as 200€ for like-new unit from crashed car.. dunno why but who am I to ask.. I have one on my bench right now.
The slow reaction comes from the very careful fueling of the original ecu. I remaped mine, it reacts as fast as a mechanical one. If I press and release the throttle as fast as I can, the engine hicks once an blows a tiny, tight, black cloud from the exhaust one second later.
The engine also revs a lot faster without the exhaust.
There are two more cheap modifications for quicker spooling you can do if you didn't remap it yet:
Intake Air Temperature sensor: The ecu prevents smoke by reducing fuel at higher intake air temperatures.
Simulate lower temperature to surf a different part on the map by putting a resistor in series to the sensor.
I got a 22kOhm potentiometer, now full turned up, gives a little more fuel across the whole rpm range, you can feel the difference at low rpm.
MAP sensor (boost): To simulate higher boost at low rpm you can compress the signal of the map sensor.
Unmodified signal at idle is about 1.45V.
Put a diode in forward direction between map sensor ground pin and the "real" ground from the wiring loom.
Put a potentiometer (I'm using 10kOhm about 3/4 turned up) in line with the boost signal to get higher maximum boost.
With that mod you get an idle boost signal of about 1.63V, better low rpm response / quicker spool and max boost of about 1.4 to 1.5 bar from the stock gt25c turbo.
I can make a drawing if somebody wants to try this.
(03-24-2016, 02:45 PM)ecFSE Whats the purpose of the diode?
A drawing would be appreciated.
(03-24-2016, 02:45 PM)ecFSE Whats the purpose of the diode?
A drawing would be appreciated.