Si, There are plans to line up one of the correlation vehicles to analyse the manifold on a OE Digifant vehicle, with and without remapping. I just have to get the time to ask the owner to borrow the vehicle and set up a back to back test.
The original idea was to show all three setups, all mapped. This considers the advantage gained from the ECU as the baseline, so we are comparing: MS ECU with ABF with stock runners & stock plenum MS ECU with ABF with short runners & stock plenum MS ECU with ABF with short runners & large plenum Basically the only variable was the intake parts. My Mk2 went from an 8V engine straight to ABF 16V with a MS ECU. This is why there hasn't been a mention of Digifant in the testing. As Toyo has mentioned, we did talk about using a Digifant car, but this requires all the parties involved to have their free time align
For the average ABF owner though, it would be excellent to see what effect the modded manifold has on an otherwise only mildly tuned engine - Eddie has talked about the possibilities of mapping digi, which would make a massive difference to people who like to tune on a budget (not everyone can afford a standalone aftermarket system). I'd be really interested in seeing a comparision of: Mildly modded ABF with standard manifold and untouched digi Mildly modded ABF with modded manifold and untouched digi Mildly modded ABF with modded manifold and remapped digi (if possible) Mildly modded = mods that we all agree are the standard amongst GTI owners - exhaust, airbox mods and maybe a cheap chip In my mind this would show the full extent of the effect of the manifold and what could be gained from mapping after it is fitted and be immediately applicable to many GTI owners. If you need a car to test this on, I'd happily offer my own ABF for the greater good of clubgti for test and R&R - I can be available pretty much whenever
I imagine it would be of interest to those out there running mildly modified Digifant setups (in original Mk3 Golf / SEAT vehicles, or converted vehicles using original ECU). Our Mk3 16V was being dismantled for spares around about the time the study was going on, so unfortunately it did not become involved. I would suggest the tests are: Standard ABF Digi ECU with stock intake manifold Standard ABF Digi ECU with modified intake manifold Chipped ABF Digi ECU with stock intake manifold Chipped ABF Digi ECU with modified intake manifold The same vehicle has to be used & it doesn’t matter if it has modified induction parts and/or aftermarket exhaust if these remain the same for all tests. A bespoke remapped Digifant chip is a whole different subject (& probably better off in a new thread), but if the developer has complete control of the fuel & ignition settings, then the result should be the same as the standalone ECU results.
Still haven't tried it on a Digifant 3x equipped vehicle Ed, but it has now been dyno tested back to back with the standard item. Update coming soon featuring two engines, two manifolds, two different exhaust downpipes, all optimised.
Whats happened to all the photo's on this thread? As a dedicated ABF/megasquirt user I find the results on this thread very interesting, especially as I have a short runner/stock plenum ABF manifold on the shelf that I've experimented with over the years..
The photos are still up, try page 1 & 2. Just checked now on both PC and an android phone and the images are working OK
Just read this start to finish, that was an excellent read! Im a strong believer in the importance of gas flow in an engine, and knew the inlet manifold played a huge part in torque curves and the power the engine produces. But i must say that these tests you have run and findings posted have described it better then any book could and show clear findings that i find really interesting. Well done lads! I take my hats off to you all! I Have one small question... say you could have the perfect inlet fabricated from scratch for the ABF....what would be different from the modified one Ben S had made? would you do away with the lower section and just make the whole thing one piece? would you have the runners a bigger diameter tube? would you have the beginning of each runner funneled like previously suggested to help air flow? Not aiming this at any one in particular, just looking for your idea's as i have the fabrication equipment to make one and could make one for someone to test on the RR?
It all depends on the spec of the engine, for example, std ABF head has inlet ports equal to 42/43mm bore, why use a bigger tube than that? However, tapering it may have an effect, my ITBs runners are tapered from 52mm down to 42mm. You can rev std ABFs to 7800+ but will your cams be effective here? Inlet manifold runners lengths can be turned to rev ranges with first second and third waves being captured and used if you get the runner length right, really long runners might be useful, however you must consider packaging in the bay. Any bend or lip or bore change will effect flow, personally I would keep the runners straight as possible and add bel mouths to their ends inside the plenum. Pay attension to the radious on the bel mouth themselves as well. You could move the injectors so that they have less protrusion in the runners, maybe point them down the end of the runners in the plenum. Lots to consider and do you want out and out peak power or a drivable vehicle at all throttle openings?
Still here, and watching, and working on it, it will come soon. Been looking at an awful amount of heads lately, everything from oem, to race, to F1, the kr/abf has the biggest volume/cross-section intake port of them all.... Ive said it before, and Ill say it again, someone needs to fill them in a bit with chemical metal, and try some tests. Loads more on that later, working very hard on it, and will post in all one hit. @ Ben, excellent work, nothing like concrete info. Brian
Hi Brian, I have done just that in the past. Chemical metal and reprofiled the inlet ports to a more sensible cross sectional area. Unfortunately I had some other changes that threw the cam timing out and I damaged the head before getting it running properly. Maybe time to revisit it? Gurds
I defiantly think so. Even modelling clay and a flow bench may do as a rough guide without going all out for the time being? I know flow benches are xyz but it would give a rough Idea. Could be an idea with a live engine to bore 3mm holes 2mm deep into port walls to give filler a grip should it come loose. A small right angle dentists drill(ebay) can do this. Having said that, chemical metal(yellow tube) is hardcore in terms of sticking, and easy sand too. Brian,
I`d always have that nagging feeling that it might break loose and damage the head. I know it`s doubtful, but after my error caused some debris to be sucked into the engine and destroy a head, I`m always extremely cautious about what I put in the inlet side of my engine.
I hear ya Nige, and cant blame you for being that way. My thoughts were more-so to get an improvement on the flow bench using clay, then use this clay model to make a full flange either in cast or billet with protrusions extending down into port that could be all bonded in as one 16'' wide unit. Im shipping an F1 port to a Ferrari guy in the Us to get flow readings on later in the week. Ill ask him if he will take a vw head section and play around with it too. Brian,
Well lets take my own MK3 ABF just for example. Previous owner said to me that it had been cam'd, chipped and remapped (remapped bit i doubt, as is it not tricky to remap the standard ECU?) It does feel quicker right enough compared to standard ones i've had in the past so he could be right. Other minor mods include custom de-cat exhaust system, pipercross induction kit with cold air feed coming from lower grill in bumper and iridium plugs. so how much differance would a modified inlet make for me? Now i havent had any headwork done yet so as you say, anything with a greater inside diameter of 42/42mm would be pointless, i was just wondering if having a greater volume of air in the runners would make a difference? Maybe tapering down to 42mm at the head flange would have a different affect again?* I was thinking along the lines of one steady, slow bend for each cylinder from flange over the top of the rocker cover, keeping the plenum in roughly the same position as standard.* When you say bel mouth inside the plenum, what affect would that have? would it not be a similar affect to having a wide taper from the runners straight onto the plenum where they join? (excuse my many questions here, but my thirst for knowledge seems to be taking over me right now! haha!) You ideally want the injectors as close to the head as possible so your not compromising response, so would probably be best to keep them in roughly the original position but work on the protrusion as you say. Maybe make a slightly longer injector port to keep the nozzles from disrupting the air flow. But depending on the angle of the spray, would need to make sure that the fuel mist was not hitting the port and condensing before it got to mix with the air. Well im just looking to have a practical yet quick daily runner to be honest with you. As you know, you can never have enough ponies under the bonnet!
The aim/range of this exercise was to work exclusively with the 52mm ABF intake manifold. Cylinder head & other intake manifolds whether from the VAG parts bin or full custom jobs were out of the scope. The ABF intake manifold does taper internally. Remember that the taper/ bellmouth is part of the runner length. The 52mm manifold could not accomodate fully round/ large diameter trumpets as there would be interference with the bonnet/ rocker cover.
Sorry ben. I got a bit sucked into this topic and my head started wondering off to "what would the perfect inlet for the ABF be/look like" lol Is there another Thread open on custom / perfect inlet manifold topic? Yes i completely agree with you there, space always seems to be the issue when working or trying to develop something like this. but i guess where thers a will theres a way. haha. So how do you think the standard manifold would perform with longer runners as opposed to your shortened one? Kev
No problem Kev, I was just reminding folks what the original idea was. By all means feel free to discuss intake manifolds in this thread. Re: perfect inlet, the problem is always going to be packaging, unless you don't mind cutting big holes out of your bonnet / slam panel, using custom radiator or relocating the original etc. Long runners (of course depending on how long we are talking) would potentially make more peak torque but at a lower RPM value. The effective 'powerband' would be narrowed, due to the torque being lower at high RPM. This is the sort of thing you would do if using the ABF in a 4x4 or a van. Of course in a Mk2/3 Golf, packaging is again an issue and too long would hit the bulkhead, and even a little increase in length would mean the intake pipe to the throttle body would start to interfere with the suspension turret.
I don't think you would want to increase the inlet track of an ABF, if you do the calculations for the bore and peak revs etc you would want to decrease them. But as Ben has said else where in this thread you cannot do that with an over the head manifold because it would interfere with the ingnition leads. Also bending the inlet track to 180deg is not ideal for flow, you want to keep it as straight as possible. So best to go forward of head towards slam panel. My ITB setup has the inlet track length ideal for around 5500-6000rpm peak torque and that just fits in a mk2 engine bay even with a slim plenum fitted. If you do want a bigger plenum with the same inlet track length then you will have to cut the slam panel - not a big issue, mines cut and is fine. Some rough inlet track lengths. What was the inlet track length of your modified plenum Ben? If you want this thread to split Ben, just say.
