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20v Turbo "Big MAF" conversion
#791708
10/03/2009 20:11
10/03/2009 20:11
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Joined: Dec 2005
Posts: 5,405 Castle Combe
Flea
OP
Forum is my life
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OP
Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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This one is for the 350bhp - 600bhp brigade, especially if you want to run big boost Why?The role of the air flow meter is to measure the air mass being consumed by the engine at any given rpm/load point. This is sent to the ecu via a 0-5v signal. There is a limit to how much air flow that can be measured by the standard MAF, therefore it stands to reason that when increasing boost there will be a point where this limit is reached i.e. the MAF can only send 5v, anything above this it cannot measure. This doesn't mean we cannot fuel for the higher boost, but it does mean that there may be a "dead zone" where there is little to no resolution for mapping at lower boost points i.e. 1.3bar and 1.7bar both produce a 5v MAF signal. The fueling (and timing) can be very different between between such boost levels therefore in most instances we choose to fuel the higher boost as this is most critical and of course where more power is made. The solution?Well we need to broaden the resolution of the air flow meter. We can do this in two steps 1. Using a bigger MAF housing 2. Re-calibrating the ecu to accept the new air flow measurments. Step 1 cannot be done without Step 2 as this will create problems whereby the ecu is thinking the engine is consuming X mass air flow when in fact it is Y. Given that fueling and ignition timing are calculated according to mass air flow (amongst other sensors) we need to make sure that the our new measurments are calibrated correctly within the ecu. Results...Once the ecu has been calibrated with the new Big MAF, we can now utilise the greater air flow resolution. So if we run 2bar of boost, 1.5bar or 1bar, this can all be optimised for both fueling and timing making sure we can achieve maximum power and safety regardless of air flow. In fact, we still have headroom to run even more boost should it be required! Big boost + Big horsepower = Big MAF
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Re: 20v Turbo "Big MAF" conversion
[Re: Flea]
#791719
10/03/2009 20:25
10/03/2009 20:25
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Joined: Dec 2005
Posts: 3,158 Near Reading
JohnS
I need some sleep
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I need some sleep
Joined: Dec 2005
Posts: 3,158
Near Reading
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Nice work! It's about time someone used a larger MAF housing properly.
Former low boost hero - 616BHP@1.5 bar. 2.4 20VT RIP
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Re: 20v Turbo "Big MAF" conversion
[Re: Freddan72]
#791790
10/03/2009 21:36
10/03/2009 21:36
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TurboJ
Unregistered
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TurboJ
Unregistered
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Sounding good but how does this affect lower down the rpm e.g. idle, light cruise? If you’re moving the scope up the rev rage do you still have enough points lower down? Is there a smooth transition between the points?
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#791835
10/03/2009 22:47
10/03/2009 22:47
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MiniPit
Unregistered
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MiniPit
Unregistered
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Really interesting I'm going to follow this closely! Like you know Leighton, my 20VT is going for 400+ hp soon... so i have to keep an eye on this
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#791971
11/03/2009 05:52
11/03/2009 05:52
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Hani
Unregistered
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Hani
Unregistered
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Nice Leighton.. another development on the Coupe Was it only tested on your Coupe? I'll keep an eye on this thread as well.. You have a PM
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792232
11/03/2009 13:52
11/03/2009 13:52
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Joined: Dec 2005
Posts: 5,405 Castle Combe
Flea
OP
Forum is my life
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OP
Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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Sounding good but how does this affect lower down the rpm e.g. idle, light cruise? If you’re moving the scope up the rev rage do you still have enough points lower down? Is there a smooth transition between the points? It doesn't have any affect on idle or light throttle. It also doesn't move the scope further up the rev range, quite the opposite, it allows a broader resolution at any rpm/load point depending on the air flow requirements of a specific engine setup. Of course it has to be calibrated within the ecu in order to take full advantage. Was it only tested on your Coupe? Yes, I have been running this for a few months although finding the time to tune my own car is becoming harder! 600cc injectors (peak & hold) Big MAF Boost: 0.8bar - 2bar Idle & part throttle - stoich
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Re: 20v Turbo "Big MAF" conversion
[Re: Nigel]
#792547
11/03/2009 19:45
11/03/2009 19:45
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Daeron
Unregistered
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Daeron
Unregistered
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why MAF? why std ECU?
does it really have that much potential to be used with larger amounts of power?
I mean, when going for some serious power levels (400+) why not use stand alone ecu? by that you throw out maf and replace it with map sensor..
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792553
11/03/2009 19:51
11/03/2009 19:51
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Taz
Unregistered
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Taz
Unregistered
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Leighton, when / if you have a spare, please bung it my way ( cost will be covered ), on full chat, I now get the injector light, it's simply maxxing my AFM I'd imagine too much If it needs machining, I have a man that will do that
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Re: 20v Turbo "Big MAF" conversion
[Re: Nigel]
#792578
11/03/2009 20:25
11/03/2009 20:25
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TurboJ
Unregistered
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TurboJ
Unregistered
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I can't help but agree with Daeron. But in Flea's defence if people have the option then it is entily down to them.
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792642
11/03/2009 21:59
11/03/2009 21:59
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Joined: Dec 2005
Posts: 5,405 Castle Combe
Flea
OP
Forum is my life
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OP
Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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why MAF? why std ECU?
does it really have that much potential to be used with larger amounts of power? Yes it does. If you read my first post it should hopefully shed some light on why For me the Motronic is a stand alone ecu, I have not reached the limits at 450-500bhp which is fantastic. I drive my car almost every day, it's a road car but more than anyone on here I have abused it on the drag strip and track To be able to run 600cc injectors (I estimate 750cc being the limit), that would be over 900cc on a 4 pot! This is also with the ability to pass an MOT, and fuel big boost. As Nigel says why change? He has run up 50,000 miles or more, competed at TOTB, 12.3 on the dragstrip, track days... that says it all
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Re: 20v Turbo "Big MAF" conversion
[Re: Flea]
#792654
11/03/2009 22:14
11/03/2009 22:14
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Joined: Dec 2005
Posts: 17,370 Staffordshire
Nigel
Forum veteran
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Forum veteran
Joined: Dec 2005
Posts: 17,370
Staffordshire
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Its absolutely correct that IF I had gone for a Motec or Omex a couple of years ago, I would have spent less on mapping than I've done on getting my car right.
However, IF Leighton had been around when I first needed my car mapping, then I would have got the right map, with no learning issues and proper cold start and idling, and all for half the price of an unmapped OMEX.
I have no doubt that a standalone ECU is the BEST option, but if you include cost into the equation, there is no contest.
Forget the issues that I've had - they weren't the fault of the ECU - tell me, what would I gain by fitting a standalone ECU?
launch control? - don't need it - I don't have traction issues and I can launch my car well enough without it
Aquamist control? - don't need it - my chargetemps are fine and I have enough fuel getting in
Most owners simply don't need to squeeze the last ounce out of their setup - they just want to increase the performance without lashing out a fortune - there will always be people that spend more than they need to in order to get where they want to be - its called trailblazing and someone has to do it. I would imagine you have spent money on stuff that you later found could have been achieved more easily / cheaply. Its modders like me and people like Flea that end up allowing ordinary owners to reap the rewards from our efforts (and spending)
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Re: 20v Turbo "Big MAF" conversion
[Re: Nigel]
#792729
12/03/2009 00:15
12/03/2009 00:15
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Taz
Unregistered
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Taz
Unregistered
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I would like to compare the bods @ BOSCH to say "Motec" etc...... I doubt they would compare, else they would be making OEM ECUs from day one off the factory line. Quite simple really gents
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Re: 20v Turbo "Big MAF" conversion
[Re: Nigel]
#792734
12/03/2009 00:20
12/03/2009 00:20
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Daeron
Unregistered
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Daeron
Unregistered
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Kidding me right? launch control, traction control .. if you wish to use 400+ bhp FWD, this is must have! aquamist - why not? you raise the power for more than 100% .. when running it properly why not use water/methanol?! as for the prices.. I saw in TurboJs website he has Megasquirt.. ask him how much for the DIY kit. price is a laugh. there are lots of tutorials online how to connect it, and "starter maps".. not to mention that Flea could tune it probably every better tuner.. and the car will run brutally, without a need to spend lots of money for Motec, Autronic, Vipec or some other more expensive SA.. Dunno.. That's just my two pennys. edit: and btw, Flea respect for done. Research and development. It still stands in 20vt tuning workshop, that going beyond 440cc injector you need SA.. Well, guess what
Last edited by Daeron; 12/03/2009 00:22.
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792738
12/03/2009 00:28
12/03/2009 00:28
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Taz
Unregistered
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Taz
Unregistered
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Launch control ? At every traffic light ? C'mon ? Are YOU serious mate ? Most are rubbish spark inhibitors, they either use your ABS, or cut your spark, hardly hi-tech
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792759
12/03/2009 00:54
12/03/2009 00:54
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suba
Unregistered
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suba
Unregistered
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I have looked into all of this a LOT.
To get a proper stand alone ECU, loom, and setup would cost in excess of 3K. The only reason people went for this option was that no one at the time was willing to spend the time learning how to map the stadnard ecu, Flea has learnt how to do this by putting in a lot of effort, and is able to do it very well.
So.....£3500 for a QUALITY ecu and map, or £500 or so for a live map and a bigger MAF - no brainer.
Aquamist is a matter of debate - my opinion is that you dont need it if the car is mapped well - but that is for another thread.
Launch and traction control spoils the fun IMO. I bloody hate it when I'm having some fun in a car and I feel like it's miss-firing....there have been some nightmare stories about race logic traction control on coupes going wrong.
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792779
12/03/2009 02:03
12/03/2009 02:03
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TurboJ
Unregistered
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TurboJ
Unregistered
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£3.5K you been getting quotes from Harrods Without getting involved in the whole Bosch vs Standalone debate because quite frankly it's been discussed many times on here. I just want to clarify that I don't run Megasquirt. I made if for somebody else. Megasquirt doesn’t support a 5 pot yet but their new ECU will and will be very very cheap, worth keeping an eye on for the future...
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792806
12/03/2009 09:06
12/03/2009 09:06
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yogisdk
Unregistered
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yogisdk
Unregistered
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According to the garage tha tdid my car, he has managed to do launch control with the standard ecu, dunno how, dunno how good it is, just know what he told me...
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Re: 20v Turbo "Big MAF" conversion
[Re: JohnS]
#792816
12/03/2009 09:28
12/03/2009 09:28
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Joined: Dec 2005
Posts: 3,158 Near Reading
JohnS
I need some sleep
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I need some sleep
Joined: Dec 2005
Posts: 3,158
Near Reading
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btw I just thought I would add that I would trust Leighton to map my car for what it's worth.
Former low boost hero - 616BHP@1.5 bar. 2.4 20VT RIP
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Re: 20v Turbo "Big MAF" conversion
[Re: JohnS]
#792818
12/03/2009 09:30
12/03/2009 09:30
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Daeron
Unregistered
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Daeron
Unregistered
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sorry for OT but. http://www.vems.hu/wiki/index.php?page=MembersPage%2FJimmieJin DIY vartiant this cost ~500£. with assembled unit+loom+instaling+mapping ~1000-1300£ btw, check their home page.. VEMS powers Europe's fastest street legal car. sorry fot OT once again..
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792819
12/03/2009 09:33
12/03/2009 09:33
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suba
Unregistered
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suba
Unregistered
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I looked at an OMEX ecu - around 2-2.5K for the best one, and then around a grand for installation, custom loom, and mapping.
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Re: 20v Turbo "Big MAF" conversion
[Re: ]
#792832
12/03/2009 10:04
12/03/2009 10:04
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Joined: Dec 2005
Posts: 5,405 Castle Combe
Flea
OP
Forum is my life
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OP
Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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Kidding me right?
launch control, traction control .. if you wish to use 400+ bhp FWD, this is must have! Speaking as someone who has been running well over 400bhp for the last 2-3 years, it's not I cannot emphasise how much my car has been put through its paces. It's very much a road car but if I can manage an 11.94 @ 121mph using just my right foot, this is this same time as a Motec coupe with anti-lag, launch control and traction control! aquamist - why not? you raise the power for more than 100% .. when running it properly why not use water/methanol?! I use water/methanol injection, as Simon says it's not required but it does have some benefits. edit: and btw, Flea respect for done. Research and development. It still stands in 20vt tuning workshop, that going beyond 440cc injector you need SA.. Well, guess what Thank you I think! It's about time the tuning workshop was updated
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Re: 20v Turbo "Big MAF" conversion
[Re: JohnS]
#792844
12/03/2009 10:15
12/03/2009 10:15
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Joined: Dec 2005
Posts: 5,405 Castle Combe
Flea
OP
Forum is my life
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OP
Forum is my life
Joined: Dec 2005
Posts: 5,405
Castle Combe
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There is already basic traction control on the std ecu. It is the first thing most people had removed - the 1st and 2nd gear base boost. That can be tuned though so that it cuts in only if the rise rate means you are spinning up in 1st lets say. So if you were wise enough to still use the ECU to control boost then you can probably take advantage of this That's very true John, I have ran my car like this with an uprated ebv and it does work. That said I find the Apexi AVC-R is a little better in this regard so have reverted to that for the time being. The only thing with this is that the load point table is getting spread across a massive range of power with the same granularity as it was originally (same number of load points) which means less precision compared to an aftermarket ECU. Also on modern aftermarket ECUs you can do full wideband so the fuelling is always right under all loads. I can't argue with wideband open loop fueling! In terms of the number of load points being the same, yes that is true (for now ), however, when calibrated correctly to the car I can create more resolution where needed i.e. on boost, and reduce the resolution where it is not needed i.e. off-boost. btw I just thought I would add that I would trust Leighton to map my car for what it's worth. I thank you kindly
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