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MAF removal - performance gain? - Printable Version

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MAF removal - performance gain? - m1tch - 08-17-2015

Hi all,

Just wondering about this, how much does the MAF affect the running of the E300? I know that it would obviously make the car run more efficiently with regards to fuel usage as it can then gauge how much air is getting into the engine. Just wondering what would happen if I ran without it and simply fitted an air filter directly to the turbo. The MAF is actually pretty massive for an OEM sensor as it has a 3" bore - example is that the a larger 3" MAF from a Nissan 300zx is fitted to the Nissan Skyline for better flow to be able to max out the engine, whereas the stock E300 MAF is already that size.

Just wondering what will happen when I fit a larger turbo, I am guessing that with the MAF plugged in it would sense the additional air flow and then fuel accordingly to a different cell on the ECU map?


RE: MAF removal - performance gain? - barrote - 08-17-2015

well u can surely try!!! removing the MAF sensor iplies a trick to the ECU otherwise it will limp home.
people use to do a thing called "resistor mod" like this u can trick the maf info for more fuel.... not sure about it, my business is mech pumps. in the future it is my intention to dedicate some time to the EDC pump, but that implies a ECU remap wich is more less dificult to put in practice.
regards


RE: MAF removal - performance gain? - m1tch - 08-17-2015

I am guessing it would drop back to a fixed map that takes the engine rpm and MAP sensor for boost, might try it out and see what happens.


RE: MAF removal - performance gain? - barrote - 08-18-2015

u should guess right , with out the MAF plugued in it limps. when this MAF start to appear people use to drill a hole in it, wich lead to a fake info , but that was to correct a default MAF , and not all responded the same way.
what is your intention with the MAF? more fuel? if is that u try the resistor mod, people say it works fine.
otherwise a remap is needed.


RE: MAF removal - performance gain? - m1tch - 08-18-2015

I was just wondering 2 things:

1. What affect the MAF has when its unplugged, I know I had a bad MAF before so replaced it with this one, the car didn't go into limp home but I am guessing it would have gone to an unoptimised richer fixed map.

2. How does the fueling change when running a larger turbo, I figure that the additional airflow would be sensed by the stock MAF and then match the fueling on the stock map.

I have tried a resistor mod using a variable resistor - doesn't really work on my car, will just try with a straight resistor and see, there aren't any remappers in the UK I can use so stuck with a stock map at the moment. Will be upgrading the stock pump with large elements but will be fine running on the stock map (although wouldn't max out in terms of power) but will still be well above stock.


RE: MAF removal - performance gain? - Booster - 08-18-2015

(08-18-2015, 06:13 AM)m1tch I was just wondering 2 things:

1. What affect the MAF has when its unplugged, I know I had a bad MAF before so replaced it with this one, the car didn't go into limp home but I am guessing it would have gone to an unoptimised richer fixed map.

2. How does the fueling change when running a larger turbo, I figure that the additional airflow would be sensed by the stock MAF and then match the fueling on the stock map.

I have tried a resistor mod using a variable resistor - doesn't really work on my car, will just try with a straight resistor and see, there aren't any remappers in the UK I can use so stuck with a stock map at the moment. Will be upgrading the stock pump with large elements but will be fine running on the stock map (although wouldn't max out in terms of power) but will still be well above stock.

Mine runs Maf-Less, Don't know how. It was done prior to my ownership. Ill have a look and see what they did (ECU is not modified) 

Resistor mod has been applied and works fine, Just need bigger elements and ECU Mods.

There are people in The uk That will Mod your ECU, Wont be cheap though.


RE: MAF removal - performance gain? - m1tch - 08-18-2015

(08-18-2015, 09:26 AM)Booster
(08-18-2015, 06:13 AM)m1tch I was just wondering 2 things:

1. What affect the MAF has when its unplugged, I know I had a bad MAF before so replaced it with this one, the car didn't go into limp home but I am guessing it would have gone to an unoptimised richer fixed map.

2. How does the fueling change when running a larger turbo, I figure that the additional airflow would be sensed by the stock MAF and then match the fueling on the stock map.

I have tried a resistor mod using a variable resistor - doesn't really work on my car, will just try with a straight resistor and see, there aren't any remappers in the UK I can use so stuck with a stock map at the moment. Will be upgrading the stock pump with large elements but will be fine running on the stock map (although wouldn't max out in terms of power) but will still be well above stock.

Mine runs Maf-Less, Don't know how. It was done prior to my ownership. Ill have a look and see what they did (ECU is not modified) 

Resistor mod has been applied and works fine, Just need bigger elements and ECU Mods.

There are people in The uk That will Mod your ECU, Wont be cheap though.

Thanks for that, the car will work fine without it, it will just be running on a fixed map (not limp home) instead - the engine knows the RPMs and the boost pressure from the MAP sensor so it will run fine, it just can't do the fine adjustments the MAF could do.

What size resistor did you go for? Guessing 11kOhms on the right hand wire from the MAP sensor?


RE: MAF removal - performance gain? - Booster - 08-18-2015

(08-18-2015, 12:32 PM)m1tch
(08-18-2015, 09:26 AM)Booster
(08-18-2015, 06:13 AM)m1tch I was just wondering 2 things:

1. What affect the MAF has when its unplugged, I know I had a bad MAF before so replaced it with this one, the car didn't go into limp home but I am guessing it would have gone to an unoptimised richer fixed map.

2. How does the fueling change when running a larger turbo, I figure that the additional airflow would be sensed by the stock MAF and then match the fueling on the stock map.

I have tried a resistor mod using a variable resistor - doesn't really work on my car, will just try with a straight resistor and see, there aren't any remappers in the UK I can use so stuck with a stock map at the moment. Will be upgrading the stock pump with large elements but will be fine running on the stock map (although wouldn't max out in terms of power) but will still be well above stock.

Mine runs Maf-Less, Don't know how. It was done prior to my ownership. Ill have a look and see what they did (ECU is not modified) 

Resistor mod has been applied and works fine, Just need bigger elements and ECU Mods.

There are people in The uk That will Mod your ECU, Wont be cheap though.

Thanks for that, the car will work fine without it, it will just be running on a fixed map (not limp home) instead - the engine knows the RPMs and the boost pressure from the MAP sensor so it will run fine, it just can't do the fine adjustments the MAF could do.

What size resistor did you go for? Guessing 11kOhms on the right hand wire from the MAP sensor?


To be honest I couldn't Tell you, Was a variable resistor. So couldn't tell you exactly what its set at. I could check if you want.
Good Improvement in power, but its dull still. Spools a big Holset Fairly well though. 


RE: MAF removal - performance gain? - m1tch - 08-18-2015

(08-18-2015, 12:37 PM)Booster
(08-18-2015, 12:32 PM)m1tch
(08-18-2015, 09:26 AM)Booster Mine runs Maf-Less, Don't know how. It was done prior to my ownership. Ill have a look and see what they did (ECU is not modified) 

Resistor mod has been applied and works fine, Just need bigger elements and ECU Mods.

There are people in The uk That will Mod your ECU, Wont be cheap though.

Thanks for that, the car will work fine without it, it will just be running on a fixed map (not limp home) instead - the engine knows the RPMs and the boost pressure from the MAP sensor so it will run fine, it just can't do the fine adjustments the MAF could do.

What size resistor did you go for? Guessing 11kOhms on the right hand wire from the MAP sensor?


To be honest I couldn't Tell you, Was a variable resistor. So couldn't tell you exactly what its set at. I could check if you want.
Good Improvement in power, but its dull still. Spools a big Holset Fairly well though. 

I fitted a variable resistor in, I found that it delayed the boost slightly, I am still running the stock turbo and boost solenoid so it might just be messing with the stock setup. I found that the resistor did give a lump of extra power but not much low down - eg it moved the power band up. Are you running a Holset with a stock pump etc?

I have bought some fixed resistors to just make sure its not the variable resistor I am using that is causing the issue.


RE: MAF removal - performance gain? - Booster - 08-18-2015

Yeh massive holset and standard pump.

If I didn't know better id say more had been done. Drives nice, full boost by 3000rpm.

20 something psi at the moment, no wastegate. Will do double that with good pump.

When I have some cash to spend it will be on some elements. The I'll have ago at some ecu mods

I couldn't tell you how much the power had been shifted rpm wise. I would say it was normal with the amount of fuel vs turbo size....


RE: MAF removal - performance gain? - barrote - 08-18-2015

The thing with the EDC pump is that there´s no way it will deliver more than 3.75Volt to the rack electroactuator, unless u remap the ECU!!! and usually 3.75 volt is good for 63cc thats why is sso dificult to tune EDC´s and people change to a mech pump.
For instance if u change the elements , for the same 3.75volt u´ll have 80cc for a 7mm element and maybe 90 for a 7.5mm. that is nothing , for real power u got to have 120cc and above , of course 90cc in 7.5 element right turbo (not a holset crap) good intercooler ported head timing da da da, i can reach 250hp.
well as i said for a 120cc and above a remap must be done , by who i dont know, basically if u feed the pump electroactuator 5volt it will give u almost full rack something in the order of 18mm, and at that rack foward 7.5 mm can go 140cc.
now lets see some hardware limits, i can feed the electroactuator with 6.5 volt or 20volt in my bench , but how much will the ECU be able to deliver? i dont know, maybe no one knows for sure. 6.5 volt at the electroactuator is full rack , with the 6mm element means 140cc. 7.5 160cc but as i said no way the EDC can deliver 6.5volt.
now another hardware limit wich is RPM , most people i spoke to can´t REV a 605 EDC more than 5500RPM, even with remap made by good tunners, why?? is one of the RPM sensor wich has max RPM at 5500rpm, despite the EDC can be solved the sensor can be tricked to REV more. with the right mech governor 6k at full fuel deliver is pitta.
of course u can build the ECU just to drive the pump rack irespective of the other parameters , but that is still to be discovered how.

as i said previously if the engine runs without MAF something is wrong it shouldn´t cause MAF is directly related to emissions and a engine not compliying with emissions must run in emergency mode. maybe in UK is diff.

people usually do the resistor mod to trick the ECU, sure it is not on the MAF sensor is in the rack position sensor. or they just chip tune it wich does the same, some chip tunes play with turbo WG , giving more TQ by boost increase, but they loose max speed (RPM)
anyhow with out fuel there´s no way it will pull Wink


RE: MAF removal - performance gain? - ecFSE - 08-18-2015

Read this tread
http://www.superturbodiesel.com/std/showthread.php?tid=731&highlight=evry


RE: MAF removal - performance gain? - Booster - 08-19-2015

Barrote

What is it about holsets you dis-like so much. Every comment you make slags one off one way or another.

I know nothing, so this is just a question and not an argument. However if you could show me a comparable turbo to the holset h1c that I currently have. At a budget of no more than £250 which in the UK is a reasonable amount to pick one up.

Sorry to go off topic but I'd like to see what my next amazing turbo is going to be. Or at least know where my seemingly reliable and cheap turbo is going so wrong?


RE: MAF removal - performance gain? - m1tch - 08-19-2015

(08-18-2015, 04:09 PM)ecFSE Read this tread
http://www.superturbodiesel.com/std/showthread.php?tid=731&highlight=evry

Thanks for that, I know that there was an EVRY mod on other cars, didn't know it was something we could do on ours, will look into it to see what gains I can get.

(08-19-2015, 01:55 AM)Booster Barrote

What is it about holsets you dis-like so much. Every comment you make slags one off one way or another.

I know nothing, so this is just a question and not an argument. However if you could show me a comparable turbo to the holset h1c that I currently have. At a budget of no more than £250 which in the UK is a reasonable amount to pick one up.

Sorry to go off topic but I'd like to see what my next amazing turbo is going to be. Or at least know where my seemingly reliable and cheap turbo is going so wrong?

Thanks for your findings about your Holset and stock pump, I know that the Holset turbos are pretty good considering they are usually found on commercial vehicles which drive long distances and need to be reliable. I would be running a Holset HX35 on my car, but due to being in the UK they aren't that available so have had to go with another option but similar size.

I am keeping the stock EDC pump for mine, the standard 6mm elements should still be able to produce a bit more power, will be upgrading them to 8mm and then ask for the rack position sensor to be reset and the forks to be adjusted to increase the fueling - as per Dieselmeken's video on this meaning that the EDC pump is producing 120cc or more of fuel. I will try and find somewhere to get the ECU remapped at some point, but considering just upgrading the elements and running a stock ECU map would produce 36% more fueling over stock I am sure it will be fine for a bit until I get it remapped for a slightly more aggressive map.

The other alternative is that I simply run larger elements than usual in the pump to make up for the lack of rack travel - example being some 10mm elements out of the Ford Transit pump. This would mean that I would be getting the same amount of fuel with less rack travel compared to the OM603 mechanical pump.

Also - not planning to rev it past the stock 5,500rpm limiter so thats not really an issue.


RE: MAF removal - performance gain? - barrote - 08-19-2015

(08-19-2015, 01:55 AM)Booster Barrote

What is it about holsets you dis-like so much. Every comment you make slags one off one way or another.

I know nothing, so this is just a question and not an argument. However if you could show me a comparable turbo to the holset h1c that I currently have. At a budget of no more than £250 which in the UK is a reasonable amount to pick one up.

Sorry to go off topic but I'd like to see what my next amazing turbo is going to be. Or at least know where my seemingly reliable and cheap turbo is going so wrong?

Easy to answear, Waste Gated turbos are from the past , and the needs from a truck engine are far diff from our engines, but if u still want to go that way (Holset crap, i mean all WG turbines from all brands), why dont u use a MB truck engine turbo, garret or kkk , they have many kind of engines , from 6 inline to V10´s so should be easy to find a better solution for a 2500 to 3000 cc engine.

The holset´s that are good , are the VGT technology but they have a sliding ring to modify exaust chamber diameter a direction of flow, they seem to be tricky to control, and the mechanism prone to failure. And they were fitted in the cummins or powersroke´s wich are 5 liter and 6 liter engines , so too big for us.

Garret VNT on the other hand , has the most simple of all mechanism, they can be easily controlled or left in a certain position, and a WG used, the diff from a WG is that turbine and compressor are far more efective.

in the Garret region u have GT17V, small for us, GT20V , not so small, and the best GT22V series u find it in many flavours and shapes,
and my "precious" GT23V wich is like the best turbo i used in a 2500 cc engine.
at the moment mine is running a stock turbine whell, some modification on flow path, and a MFS 64mm compressor. 2.5 bar is like at 2500RPM, at 4500 start to climb to 3 bar and keep til max 5500/6000 but i dont like to REV my engine past 5500.

this days almost all Scania and Volvo truck use a garret or KKK VNT turbine , despite the needs are quite diff u can find a good one there too.

if u have a 605 use GT23V, if u have a 606 use a Pair of GT20V , thats my advice. gt 20V are most likely to be found in the audi 1.9 and BMW 320 318 that kind of turbo.

and for the holset users, well  sorry i didn´t mean to offend , but is like 2valve and 4 valve Wink  strenght X performance


RE: MAF removal - performance gain? - m1tch - 08-19-2015

Of course the VNT/VGT mechanism never cokes up and fails at all, the VNT/VGT turbos are indeed good for every day drivability however I haven't really seen any high power drag cars running VNT turbos. Wastegated turbos are indeed older technology, but they are simpler with less parts to go wrong and a simple way to control the boost levels without the need for additional VNT/VGT controllers.


RE: MAF removal - performance gain? - Booster - 08-19-2015

(08-19-2015, 04:31 AM)barrote
(08-19-2015, 01:55 AM)Booster Barrote

What is it about holsets you dis-like so much. Every comment you make slags one off one way or another.

I know nothing, so this is just a question and not an argument. However if you could show me a comparable turbo to the holset h1c that I currently have. At a budget of no more than £250 which in the UK is a reasonable amount to pick one up.

Sorry to go off topic but I'd like to see what my next amazing turbo is going to be. Or at least know where my seemingly reliable and cheap turbo is going so wrong?

Easy to answear, Waste Gated turbos are from the past , and the needs from a truck engine are far diff from our engines, but if u still want to go that way (Holset crap, i mean all WG turbines from all brands), why dont u use a MB truck engine turbo, garret or kkk , they have many kind of engines , from 6 inline to V10´s so should be easy to find a better solution for a 2500 to 3000 cc engine.

The holset´s that are good , are the VGT technology but they have a sliding ring to modify exaust chamber diameter a direction of flow, they seem to be tricky to control, and the mechanism prone to failure. And they were fitted in the cummins or powersroke´s wich are 5 liter and 6 liter engines , so too big for us.

Garret VNT on the other hand , has the most simple of all mechanism, they can be easily controlled or left in a certain position, and a WG used, the diff from a WG is that turbine and compressor are far more efective.

in the Garret region u have GT17V, small for us, GT20V , not so small, and the best GT22V series u find it in many flavours and shapes,
and my "precious" GT23V wich is like the best turbo i used in a 2500 cc engine.
at the moment mine is running a stock turbine whell, some modification on flow path, and a MFS 64mm compressor. 2.5 bar is like at 2500RPM, at 4500 start to climb to 3 bar and keep til max 5500/6000 but i dont like to REV my engine past 5500.

this days almost all Scania and Volvo truck use a garret or KKK VNT turbine , despite the needs are quite diff u can find a good one there too.

if u have a 605 use GT23V, if u have a 606 use a Pair of GT20V , thats my advice. gt 20V are most likely to be found in the audi 1.9 and BMW 320 318 that kind of turbo.

and for the holset users, well  sorry i didn´t mean to offend , but is like 2valve and 4 valve Wink  strenght X performance

Thanks

But unfortunately we are missing the point with this. 

All you have explained is what is best. You have avoided the point of budget. 

I don't believe I could get a VNT or compound or anything else for £250.

There is no offence here, the simple fact is if I wanted the "best" engine i wouldn't start with a 200,000mile old diesel. 


RE: MAF removal - performance gain? - Hario' - 08-19-2015

The trick is to get a Holset from a medium-duty truck as they have smaller capacity engines with much smaller turbine housings as a result.

Regarding OP's question - Assuming you're talking about a E300Td and not the petrol equivalent: The MAF is for EGR control only, the fuel (rack position) is calculated via the 'speed-density' method, where manifold pressure (MAP) and temperature (air temperature) are used to calculate inlet air density.

So it can be deleted with the resistor mod. My car, the W202 C250TD (OM605), does not have a MAF sensor from the factory..


RE: MAF removal - performance gain? - m1tch - 08-19-2015

(08-19-2015, 09:05 AM)Hario The trick is to get a Holset from a medium-duty truck as they have smaller capacity engines with much smaller turbine housings as a result.

Regarding OP's question - Assuming you're talking about a E300Td and not the petrol equivalent: The MAF is for EGR control only, the fuel (rack position) is calculated via the 'speed-density' method, where manifold pressure (MAP) and temperature (air temperature) are used to calculate inlet air density.

So it can be deleted with the resistor mod. My car, the W202 C250TD (OM605), does not have a MAF sensor from the factory..

Thanks for that, I did have a feeling that it could be EGR related as I know that the EGR system checks the MAF sensor readings when the EGR is opened to make sure its functioning correctly.


RE: MAF removal - performance gain? - dude99 - 08-19-2015

If you simply remove the MAF it will throw a code. There is a large thread over at benzworld w210 on how to bypass it, which resister to use etc. As mentioned above, it is for EGR only.


RE: MAF removal - performance gain? - barrote - 08-19-2015

All depends on what u want engine to do , for a drag beast a GT 40 like , holset hx35 or bigger will work great , since the engine will not be used in mid range RPM....
for a circuit like car unless u find a 8 th toothed gearbox it becomes impossible to compete... since only 1000RPM are available with power!!!
for a street racer/day driver , the engine must be able to provide power as soon as possible in the RPM range , and keep it to the max .
of course my engine does not give 100HP cylinder, but it can go at 75hp cylinder and smash an amazing 700Nm tq from 2500 til 4500 so ...

if i wanted a drag racer u would install post combustion injection, and that would spool up a gt60 like able to kick 10BAR for 1 minute just before the head blows...hehhe.

for those who want to use the garret VNT in a day driver PM i´ll explain how to control it, since i can´t understand the drag kind.....


RE: MAF removal - performance gain? - m1tch - 08-20-2015

(08-19-2015, 02:36 PM)dude99 If you simply remove the MAF it will throw a code. There is a large thread over at benzworld w210 on how to bypass it, which resister to use etc. As mentioned above, it is for EGR only.

Yeah I will be installing the EGR resistors at some point, the car is still running on the stock KKK K14 turbo at the moment so can in no way max out a 3" MAF lol, just planning for upgrades and simplification in the future - still need to fit a catch can of some sort to remove the rocker cover breather pipe being fed into the inlet first though!

(08-19-2015, 04:50 PM)barrote All depends on what u want engine to do , for a drag beast a GT 40 like , holset hx35 or bigger will work great , since the engine will not be used in mid range RPM....
for a circuit like car unless u find a 8 th toothed  gearbox it becomes impossible to compete... since only 1000RPM are available with power!!!
for a street racer/day driver , the engine must be able to provide power as soon as possible in the RPM range , and keep it to the max .
of course my engine does not give 100HP cylinder, but it can go at 75hp cylinder and smash an amazing 700Nm tq from 2500 til 4500 so ...

if i wanted a drag racer u would install post combustion injection, and that would spool up a gt60 like able to kick 10BAR for 1 minute just before the head blows...hehhe.

for those who want to use the garret VNT in a day driver PM i´ll explain how to control it, since i can´t understand the drag kind.....

This would be why I am also looking at adding a supercharger in as well although I have gone for a GT35 so should spool up fine, was going for a GT45 but was in need of the additional boost due to the lower volumetric efficiency of the engine so went with a slightly smaller turbo (without a massive turbine housing for quicker spool). Also I don't really want loads of torque too far down the rev range as I still need to get traction from the type. On my RX7 I had the boost dialled in to reduce the boost in 1st gear to get traction and only provide full boost when in 2nd as then I know I would have traction.

Also another benefit of the 'old fashioned' turbo - I can drive the car off boost most of the time when I don't need to have loads of power - eg driving to and from the track or picking up things (its an estate after all) - this would reduce the drivetrain and tyre wear.

Also, check out the Queen street racing 26B rotary  (4 rotor eg 2x13b engine) running a GT60 on youtube, makes just over 1,600bhp from a 2.6 litre engine, I do find it funny how small most of the stock piston engine turbos are vs stock rotary turbos.