why? you will still have the restriction of the t/b so a bigger pipe from there on won't help much, may change the overall tuned length and pick up a little more torque i think you 'd gain more from a proper mapped system,
Tried that before with a unit from an E34 530/535i on both 1.8 and 2.0 digi cars. Worked like crap as the both resistance cards (0-5v) were not calibrated for that size of hole and this in turn would upset the expect value returned to the ECU. Gave up in the end and went back STD. You be better off switching to a MAP based system.
reading that vortex thread apparently lots of tweaking of the afm spring is needed, bigger injectors and a tunable fpr help too.
by the time you have arsed on with all that you could have it running on megasquirt and use a throttle position sensor and throttle body from an ABF
its already got bigger injectors and i was thinking of an adj FPR but they seem to be thin on the ground as they are generally aimed at carb engines using lower pressure.
well an abf throttle body wont fit a mk2 inlet manifold, so you'll need a mk3 inlet, which wont fit a mk2 head so you'll need a mk3 head
Well said but it seems you have to shout harder then someone might listen! With MSnS-e you do not even have to replace the 2 stage TB to feel a gain from the AFMless intake.
i imagine there would be loads to gain with a fully mapped system, particularly with a lumpy cam and bigger capacity
prof is megasquirt similar to my omex system?????? how else can u get higher adjustable fuel pressure into a rail without using like the FSE valve that i do????
ok but surely two pb throttles mounted facing front would flow more than 1 abf throttle, I have a PB BVH so switching to mk3 inlets isnt an option, i could fabricate things up fairly easily so one offs arent really a problem. what route would be a better for the pb head I understand that switching to a map based system would be better but they can be very expensive, i dont want to spend a fortune on the car a im still spending on the audi
I'm not quite sure how you could mount 2 PB throttle bodies? You would need some kind of complex dual input air system, and remember that since the std digifant ECU is MAF based, you cant have any unmetered air getting in so would need to have both intakes connected up to the MAF which would restrict the airflow again. If you can do the work then what about modifying the inlet to accept an ABF or 2e throttle body, then hook it up to a MK3 8v GTI intake boot & bigger MAF from a beemer? This should supply more than enough air for an 8v engine I'd have thought. Could just try the beemer MAF from a scrappy first and fiddle with the spring to see if you can get it working, if it don't work just take it off & bin it
How do you know that the 2 stage TB flows less than a single 65mm TB(ABF) or even a 54mm one(1.8T/2E)? These are be questions that would need to asked before one was to undertake such a custom conversion involving manifold removal and and aluminim welding for questionable torque gains. You would still have an airflow bottle neck at your AFM and a software bottle neck at your digifant ECU. As said before larger BMW AFMs adjustments are not just as simple as teeking the spring. You also have to get the AFM flap to be on the right resistance as well to get ecu to output correct injector pluse. Get it right in one load/speed site and wrong in all the rest. When I did not know better I have tried this. Not worth it in the end The MSnS-e systems that I use/build/calibrate are not expensive when compared to an Emerald or DTA, and for what you are trying to achieve from your hardware, this can more than cope. If you are brave enough you can also build this ECU yourself and bring costs down even further. This will eleminate the AFM and free-up the air column to go straight to your throttle body and most likey lead to a more responsive motor due to increased torque once mapped well. So you can ditch the AFM system with a Split Second AFM to MAF kit ( same as the old Flimstar system years ago). Or an inexpensive MAP based ECU and have no AFM/MAF in the inlet ducting. The gains here will save you many grey hairs than tinkering with a noble idea that would ensure your car runs like a pig!
I don't, I said that answer in reply to his suggestion to fitting 2 seperate PB throttle bodies which would be a very difficult thing to achieve I remember you saying that the ABF tbody flows well however? The OTHER option is to strip out the internals of the PB MAF and fit to a larger housing, thios was also attempted in the vortex forum. Both methods were tried and if some of the posts were to believed, they worked after some fiddling! It all comes down to money at the end of the day, megasquirt still costs too much to some people dispite how much cheaper it is to the competition! Since larger MAFs are quite cheap im comparison and easily removable if you can't get em working its worth a try! I'm not saying that megasquirt is a bad choice though, or that the larger MAF is a surefire way to get round the problem. I'm just offering other options that I have heard about and others have tried with some success
something like this?I think these pics were of the vortex site were somebody did something simular but on k-jet?
interesting! Its tricky on a digifant II system becasue as said it relies on the signal from the MAF, and with this system you cant have any unmetered airflow into the engine... I wonder what the inlet system looked like that hooked up to it, or if it was even built
I responded to an untried/untested suggestion of spending a good few hours modifying a PB manifold to attach a single ABF unit to find out there is no real gain. I have said, in an 8v post on ADY/2E manifolds on a 3A/2e head installed in a MK2, that I have done this on my 3A motor and apart from a bit more air rushing into the motor from lower revs(1000-2500) with the single 65mm ABF TB there was nothing to be gained at higher revs where the 2 stage OEM TB did the same thing. I This same motor had a 2E TB as well on it and it was horribly slow, even worse that a 1.3 with its tappits loosened. I believe a 65mm ABF Throttle Body has a higher airflow limit than say a 54mm 2E unit, all things being equal. But in light of the countless motors 2.0 16v on this forum in both Kjet CIS or Digifant 3.0/3/2 that have been tweaked to around 170bhp and around 150lbft I would say that there is very little aiflow difference between the single 65mm TB and the twin staged unit. There is also a thing as too much throttle body which would make the motor feel very jerky when accelerating from idle. On an PB 8V unit I cannot see, both practical and theoretic, how an OEM 2 stage TB is a restriction at sub 150bhp levels. Same size used on the KR/9A 16v motors. MAF and AFM are two different units. PB motors and Beemers have AFMs and later cars like the AGG MK3s VRs have MAFs. Let us not confuse the terms. Can you post these links to show how the bigger Beemer AFMs were used successfully in increasing engine torque on an 8v with digifant II. There might have been someone who has got this to work after I tried this 3years ago cuss'in, kicking and screaming as I had to return the car to the STD system. So called E34 AFM modification = 20 pounds(scrappy) Time to get it working - infinite Gains = Car runs like pig ( unless, of course you can bring 3rd party evidence that this is not so). Compare to Megasquirt modfication done professionally or DIY under 350 quid built w/labeled harness or under 200quid if you order from US as kit and build it yourself. Time to get working = 4hrs-1 week to build, 45mins-3hrs to install loom, 3hrs-4days calibrating and fine tuning. Gains= STD 2.0 motor 130@5700revs and 134lbft@4100revs. Smoother operation and no digi like flat spots from idle to load. Big grin on face or pride if you built it yourself. Will OWN similar car with 'big beemer AFM' modification. I am only stating facts that I have experienced.
I was going to mention this. Read that thread though on this there was debate that it actually worked. Too much throttle body into common plenum.
oops got my terms mixed up I can't remember the link now, I deleted it becasue it seemed like 'too much work' It was several pages and I'm sure someone got it working by the end of it I'll see if I can find it again... 200 is a lot of money to me, but the bigger AFM is alot of work, so I'm not doing either
