Wondered where you had gone until the influx of mails the other day.
I've sent you a mail.
On the injection front. I want to be able to control fuelling and ignition exactly rather than a dizzy. Also, being able to have 8 single or 4 double coils would be good.
Fully programmable engine management is nothing to be scared of. LR OEM GEMS/MEMS is scary. Don't want that.
Also, it means I can go 4.2 or 4.6 with no real increase in physical dimension.
Cheers
Paul
My90 wrote:
> About time you got around to doing that Paul. What abot fiixing ter Landie > first.
>
> Facny a beer sometime.
>
> Damian
>
> btw I personally would stick with the carbs. Lot less to go wrong >
Std set-up bank-fires the injectors, the ign being triggered by the pickup in the dizzy. My mate runs a DTA race system on his motor and that gives you control over fuelling and ignition, with various correction factors to play with!! If my memory serves me right I think it works on a 16x16 matrix, throttle pos'n against rpm. Can't remember if there's a MAP sensor or not. You'll be amazed at the available torque at lower rpm's when you get the ign advancing more. Badger.
Did the RR and disco keep the same system through it's life span. Did the 3.5 3.9 4.0 4.2 and 4.6 all have the same basic setup. Seems odd.
Either way, I'm sure I could incorporate this into my design.
I was thinking along the lines of a low pressure boost twin turbo system going in as well at a later date. Have to wait and see. Much more into the planning stage at the moment.
AFAIK, all 3.5/3.9 bank fire, I think the later 4.0/4.6 may be sequential, certainly the "Thor" engines.
Make sure you use low compression pistons.. I'd also strongly suggest a head stud kit as personally I'm fed up replacing 4.0/4.6 head gaskets on std compression!!! I've also heard of problems if you turbo the vitesse spec heads, the waisted stem exhaust valves can't cope, apparently.
On later systems they do - a sensor in the side of the bell housing senses the movement of the flywheel. The earlier injection systems don't (3.5 "flapper" system, 3.9 "hotwire" system). You don't want to know just how diabolically primitive Land Rover EFi systems are :-) Up until GEMS they use no injection timing at all - just pickup a pulse from the coil and open the injectors once every 8 pulses for an amount of time determined by the air flow, throttle, temperature and lambda sensors... hopefully the fuel hangs around in the trumpet long enough for the cylinder to suck it in !
Earlier systems use 2 banks of 4 injectors fired simultaneously. This is not timed to the engine other than through the counting of ignition pulses from the coil (see above).
The 4.6 GEMS system is as state of the art as Land Rover have got, sequential injection, ignition system also controlled by the ECU, knock sensors (one in each bank), crankshaft sensor, speed sensor. 4 ignition coils fired by the ECU using a waste spark system. Obviously Lambda and air flow with throttle position too.
Earlier systems are very low tech by EFi standards with the EFi only controlling fuel, no control of the ignition at all. Only inputs are air flow, throttle, temperature and ignition pulses from the single coil. Cat systems obviously use a closed loop with a Lambda sensor for each bank above certain RPM/temp/speed. Speed sensors were also introduced with the cats.
Personally I'd go for an after market controller so you can use the sensors you want to... getting rid of the air flow sensor (use a MAPS sensor and throttle sensor instead) makes installation a LOT easier in a confined space like a kit car. An distributor type 4.6 and an after market ECU would be the dogs bits IMV.
No, actually it's far better at coping with water than previous V8's as it doesn't have a distributor. Each plug has it's own coil in effect so cross firing caused by the distributor/cap is eliminated. Coil on plug units would be better but replacing the crap LR HT leads with good quality ones is almost as good.
Obviously all V8's can be made waterproof it's just easier with the GEMS system.
On or around Wed, 2 Jul 2003 18:16:32 +0000 (UTC), Dave White enlightened us thusly:
for reference, bought a set of Bosch leads from halfrauds for mine, (readily available at the time and reasonable price) but they're s**te. Leads work OK, but the plug caps come apart. I had one pull apart (lead came out of the crimped bit, through careless pulling of the cap/lead), which I put down to operator error, but now despite taking care NOT to pull on the lead, but only on the rubber cap, another has done the same thing. Won't be buying them again.
anyone know if those nice NGK caps are still extant? used to buy them, and a load of copper-core wire, and make me own - never had any problems. Bloody carbon-cored stuff is a pain.
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