Stick with EFi or Go to Carb?

Ian Anderson · Post by **Ian Anderson** » Mon Mar 03, 2008 1:06 pm

Ok usual stuff
GT40 replica Total on full tanks at SVA 1100kg.
Rover3.9 worked by JE Motors, 102 cam, biggest valves possible, full cross over exhaust running on hotwire efi, with a choice of 2 ECU packs. Standard gives more reasonable driving at low speeds and the "worked" one gives more power higher up.

Problem has always been that at town speeds the car kangaroos as the 30 - 40 mph stuff puts the engine in the 14 - 1700 rev range and it is not happy at that rev range - it seems to me that the unit decided to fuel - then the ecu says too much , turns the fuel off and so starts the kangaroo.

So I can get by for a short while by leaving in 1st or 2nd and running at over 2000 rpm but tend to heat up.

So question is, if I take the EFi stuff off and go for a Webber 500 will the "old technology" not prove as effective in trying to "sort itself out" and result in a smoother ride?

Also carb fed would also make the car look more period correct.

Comments etc. most welcome

Ian

sidecar · Post by **sidecar** » Mon Mar 03, 2008 1:13 pm

If your car was SVA'ed with the EFI fitted then you might have problems getting a carb to run to the same emssions level. This could be an issue at MOT time.

kiwicar · Post by **kiwicar** » Mon Mar 03, 2008 1:27 pm

At the risk of sounding like a stuck record, I would stick with EFI but get a properly mapped ECU, "modifying" the standard rover unit by adding a couple of resistors or upping the fuel pressure then bleading a bit off here and there will always be a bodge. And a carb will always have trouble on transition from one cct to the next and at part throttle.
Are you sure you do not have an issue with a sticky/ stretchy throttle cable (or it getting caught on somthing)? just it is a mighty long way from your foot to the throttle on the GT40.
Mike

Post by **katanaman** » Mon Mar 03, 2008 2:28 pm

A proper mapable ecu will cost you less than a carb and manifold so no contest. If a computer cant get your engine to run properly how do you think a dumb carb is going to manage it?

HairbearTE · Post by **HairbearTE** » Mon Mar 03, 2008 6:47 pm

100% agree with above two posts. An edelbrock + intake will cost 500 quid when you take into account all the other bits that go with it. An Emerald ecu comes in at a little more with the opportunity of getting it dialled on the rolling road for another 250. If you can stretch to the extra few quid then go with the new ecu. Gives you more scope for future mods too.

Ian Anderson · Post by **Ian Anderson** » Mon Mar 03, 2008 10:13 pm

All good info - many thanks

V5 says CO3.5 and HC0.12
I believe this is reasonably achieved on a carb.

Accelerator cable only does one sweep from the rear bulkhead up to the EFi. Fitted with 4 springs (3 normal Landrover ones at the engine and one on the pedal) so it does not stick and is smooth in operation.

The reason I asked the question is that in the for sale section there is a webber and manifold at £250.

I've looked at other ECU's and always thought they would be over £1000 to be got running properly. Perhaps prices are dropping

Ian

Post by **katanaman** » Tue Mar 04, 2008 12:11 am

http://www.vems.co.uk/vems.html
http://www.extraefi.co.uk/ms2_products.htm
no where near that cost unless of course you want to spend it

Eliot · Post by **Eliot** » Tue Mar 04, 2008 6:41 am

Indeed, especially as its already injected. Just swap the ecu.

[/quote] · Post by **[/quote]** » Tue Apr 08, 2008 10:39 am

if one ecu is better down low and the other is better up top, you should be able to program a standalone to have the best of both worlds