Thread: Fuel consumption V8

Is it possible to retro-fit a newer system to an old GEMS engine?

Er If you have a Disco1 it will have a 3.9 with Lucas14CUX which is a copy of a Bosch LE Jetronic.
It is not possible to update to GEMS or THOR as they both need a block with provision for knock sensors and and a crankshaft position sensor .

If you have a P38 with a GEMS engine, these are regarded AFAIK as a very good system , the Thor only better because of the new inlet manifold.
Graeme Cooper claims good reults for a Haltech chip with GEMS as well as 14CUX, but the improvement on 14CUX is much greater.
Regards Philip A

philip - i recall your earlier posts (the dyno graph you posted showing the improvements for each of your mods) where you are very happy with your unichip. as you run closed loop, i assume that (all?) most of the benefits you are seeing (from unichip only) are from timing control as opposed to fuel control which is just about always under closed loop?

philip - i recall your earlier posts (the dyno graph you posted showing the improvements for each of your mods) where you are very happy with your unichip. as you run closed loop, i assume that (all?) most of the benefits you are seeing (from unichip only) are from timing control as opposed to fuel control which is just about always under closed loop?

Yes.
My panto dyno I think maybe perhaps indicated that I lost a little bit of power (at small throttle openings) when I installed the o2 sensors. But I hoped that this would mean I gained a bit of economy. My plugs and the inlet ports /valves are certainly cleaner on the heads I just took off after 90KK than the ones I cleaned up and put on after only 15KK before I fitted the o2 sensors and after I fitted the Unichip. However some of this was the new injectors.
Regards Philip A

if you are getting perforance upgrades done with before and after dyno runs, be on the lookout for tricks to show lower initial power output, like having the A/C on, lights on etc, it is a lot more common than you think.

if you are looking to save money on running costs, try getting the original system set up correctly first, on the open road with not too much extra to pull they should get 14l/100km.