v84x4 Posted November 23, 2006 Share Posted November 23, 2006 hi i am thinking of swaping from carbs to efi on my v8 rover powered QT and wondered if it is a large job, im am happy to do the work but i am unsure of what i need to do the job and what is best .the engine was a 3.5 vitesse it had a total rebuild now 3595cc and it really sings it was built by a guy in cornwall at great expence to it last owner i was told i need a 3.9 efi. thanks Quote Link to comment Share on other sites More sharing options...
mwncidur Posted November 23, 2006 Share Posted November 23, 2006 3.9efi is more responsive and reliable imo, i've run this system on my 4.6 racer for about 3 years, with out the slightest glitch. go for it you won't be disappointed. Quote Link to comment Share on other sites More sharing options...
Mark Posted November 23, 2006 Share Posted November 23, 2006 Moved to the Int forum, as this doesn't seem too t&f related. Incidetally, I asked a very similar question about the 3.5 carb to efi swap earier this evening too! Mark Quote Link to comment Share on other sites More sharing options...
jules Posted November 24, 2006 Share Posted November 24, 2006 Very easy swap inlets over and efi harness wire to battrey wires to ignition wire to tank mouted fuel pump earth the ecu original v8 engine harness leave well alown as its still needed for clocks cranking etc. job done welcome to power Quote Link to comment Share on other sites More sharing options...
V8RRC Posted November 26, 2006 Share Posted November 26, 2006 Not wanting to hijack the thread but my old flapper efi system was pants (several faulty bits) so at presant I am running carb's on the engine! I have also been told the 3.9 hotwire system is better so is there any problem with putting a hotwire system from a 3.9 on a 3.5 or will it over fuel it since it is off a larger engine? Any comments welcome as I am in the dark with this one! Thank's Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 26, 2006 Share Posted November 26, 2006 No it will be fine - both systems are MAF (Mass Air Flow) so they measure the amount of air going through and add the correct amount of fuel accordingly. The advantage of these systems is that they tolerate wear, tuning, variations in engine size etc. well as the air/fuel ratio will stay fairly constant. Flappers are old, hotwire is better but there is a lot more wiring in it and some systems (perhaps only later ones) seem fussy about road speed transducers and such like whereas the flapper is about as simple as you can get. I vote for the third option Quote Link to comment Share on other sites More sharing options...
V8RRC Posted November 26, 2006 Share Posted November 26, 2006 No it will be fine - both systems are MAF (Mass Air Flow) so they measure the amount of air going through and add the correct amount of fuel accordingly. The advantage of these systems is that they tolerate wear, tuning, variations in engine size etc. well as the air/fuel ratio will stay fairly constant.Flappers are old, hotwire is better but there is a lot more wiring in it and some systems (perhaps only later ones) seem fussy about road speed transducers and such like whereas the flapper is about as simple as you can get. I vote for the third option Excellent thanks Fridge the 3rd option will be the ultimate goal which I would like to work towards B) Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 26, 2006 Share Posted November 26, 2006 Why prat about fitting a 3.9 setup then? It's worth fitting the 3.9 inlet manifold and injectors but if the loom is in good condition it's preferable IMHO to have the flapper loom to convert to MS as it takes ~2 hours to do. Quote Link to comment Share on other sites More sharing options...
V8RRC Posted November 26, 2006 Share Posted November 26, 2006 Nothing is set in stone & I don't plan on doing it until the spring so I will have to look into it then & have a read about the MS & if things are that simple I will go for the MS from the word go B) So you are saying it is easier to use the flapper loom over the hotwire one then due to it being more basic? If thats the case I must look for a serviceable loom as the old flapper one got ditched due to the wires being in a general poor state! Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 26, 2006 Share Posted November 26, 2006 Chnage the Fuel Pump to a RR High Pressure one. Best to buy a knacker but complete unit with all the ancillaries, then take off what you wnat. I like the simplicity of flapper, plus the parts are dirt cheap S/H and I would say more robust in off road use, I killled a number of AFM from Hotwires, and they are NOT cheap, flapper stuff is Very tunable, and more relaible than many make out nige Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 28, 2006 Share Posted November 28, 2006 If your ultimate goal is MS then you only need a flapper loom, a Hotwire one will have about 50-75% more wires in it than you need. Finding a good one may be tricky, Nige has just bought a new one (Gen parts!) which was pricey but about the same as buying the wire & connectors & relays etc. from VWP and doing it yourself plus it comes ready-made. I've made custom EFi looms before and believe me it's well worth considering buying a new one Flapper is tunable although for the price of a chip for a 20-year-old ECU you can buy a MS so IMHO kinda pointless. It's be like sticking a Pentium into a Commodore 64 - sure it's possible, but not really worth it Quote Link to comment Share on other sites More sharing options...
V8RRC Posted November 30, 2006 Share Posted November 30, 2006 Just had a look on Craddocks site & the only loom I can find is "HARNESS FUEL INJECTION TO ENGINE R/R PRC5347" If that is the loom in question they want £249.80 I don't think I will be going for a new one if thats the case Also while I am on Fridge what do you reckon to the pre built MS ECU's from http://www.extraefi.co.uk/ ? Just wondering if you had heard anything bad about them? Yes I know I could build the ecu myself but when I do go for it I am tempted to buy a pre built & tested ecu to speed the job up! Cheers, Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 30, 2006 Share Posted November 30, 2006 Phil is a good lad, those are going to be fine. I can build identical but for identical money, I won't undercut Phil as he's done so much development on MS over the years. Only thing I would say I can do that he doesn't is I can supply a MS-to-Lucas wiring tail with the correct wiring colours and a diagram / instructions of how to connect it. I was also quite chuffed with my MS-in-Lucas box where I stuck a megasquirt inside a dead 14CU box so it pretty much drops into a flapper EFi system with the minimum of wiring, and you can plug a flapper ECU back in if you really want to. A V3 ECU from me (or Via Bill Shurvinton) is £225 built, doesn't include the serial cable or the wiring loom as Phil does. Software is free to download anyway. I can flash the "extra" code into the ECU and upload a basic Rover V8 fuel map that will get you starting & running. Wiring tail from me: Is £30 ish depending on how long you want it and if you want extra bits / HD connectors etc. With a bit of planning you can MS a flapper vehicle in an evening using the wiring tail. I can do all the mods that Phil does (extra ignition drivers etc.) for similar prices, and supply serial cables, software CD's and fuel maps. At the moment I'd say go to Phil first as I'm a bit busy and every MS build I get seems to require mods that take almost as long to sort out as building the thing in the first place. I will be doing a batch of MS-to-Lucas wiring tails soon (next week hopefully). Quote Link to comment Share on other sites More sharing options...
V8RRC Posted November 30, 2006 Share Posted November 30, 2006 Cheers FF for the above info it is much appreciated As said before I will collect all the parts together & do some reading before I fit it so we will be looking spring (ish). I will leave the MS ecu purchase until last, so before I do get one I will see how busy you are I like the job you did fitting the MS in the old lucas box very tidy Quote Link to comment Share on other sites More sharing options...
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