The V8 Owners Forum -

Ian Anderson wrote:I'll make some calls about the EFi replacement

If it does not cure the Kangaroo full refund?

See what they say on that

Ian

Since you're running hotwire there's no AFM to pulse. I dunno the hotwire well - but don't some of the later factory EFI systems have problems with a wild cam? Something do do with being able to process data fast enough?

I've not read any such reports with MS. However, there's no such things as a plug and play one for a non standard engine. It will require some tuning.

here we are again,
the issue all along has been the refresh rate on the Rover ECU, combined with insufficiently small incriments in holding open the injectors means the ecu cannot keep up with what the engine is doing on light throttle and transition as the throttle is opened. The standard Rover ECU works ok-ish on a RR with a mild cam and a big heavy flywheel but not on a GT40 with a lumpy cam.
Best regards
Mike

Mike,

Agreed the carb will not just be a bolt on job especially as it's second hand, it will need stripping and re-building with the appropriated rods, jets and step up springs to get it near optimal and then trial and error after that.

Ian needs to factor in the cost of a new fuel pump to suit the carb and probably a fuel pressure regulator and air filter, by the time you add the cost of the manifold you are getting close to the cost of the plug and play for the injection only I would have thought, as the ignition side adds on quite a bit extra cost.



Kevin.

DaveEFI wrote:

Ian Anderson wrote:I'll make some calls about the EFi replacement

If it does not cure the Kangaroo full refund?

See what they say on that

Ian

Since you're running hotwire there's no AFM to pulse. I dunno the hotwire well - but don't some of the later factory EFI systems have problems with a wild cam? Something do do with being able to process data fast enough?

I've not read any such reports with MS. However, there's no such things as a plug and play one for a non standard engine. It will require some tuning.

Hotwire is the AF meter, the problem being that it reads the pulses coming back as well as the air that beig sucked in and provides fuel for that volume,
making it far too rich untill the engine gets on the cam.

Kevin.

I spoke at length with V8d this afternoon

Plug and play will work to improve the 1000 - 2000 rev range a bit but to get it good will need the ignition put on it too

So it's crank wheel, loom etc to go semi sequential etc.

Cost was said to be in the £1200 range.

The system also does not "self learn" so it's driving and then replugging the computer, adjusting and trying again.

Hell that's a lot of money and it's still a 3.9l Rover that will do south of 300hp.

Now
Put the £1200, add another grand or 2 and put it into heads, stroker crank Holley and I'll have 400 plus hp, monster torque, reliability and no emission problems as the engine is a 1971 block!

What to do - I think the Ford needs a serious look!

Ian

I think as I said above,
drive what you have as it is and build the ford!
No brainer to me.
Best regards
Mike

With a careful £1200 you could probably see 400bhp from a SBF, and would be much more reliable and probably more torquey than the Rover!

Take advantage of Mikes "mild" advice for once

Hi all,
I looked into going another route, rather than the RV8, a few months ago. But its not straight forward:
Exhausts
GBox
Mounts
Radiator
Clutch
Intake
thats without the cost of an engine
Decided to keep with the RV8 and get V8D to make me a 5.4L

As for the carb, my opinion is a little biased, but that would be a step back 20 years. If cost is an issue but your willing to do the work, then go for a normal MS ECU and wire it in yourself. No ECU will tune itself, you will need to do some work to get it right, but its not hard and theres loads of info out there, especially for the RV8.
As Shaun at V8D explained, ignition control (wasted spark) with fuel control is the best way forward,
Phil

Phil

Sorry I missed your post on this thread.

I agree a lot of money will need to change hands to put a Ford in the boot of the GT40 - Decent motor that will handle some revs, aluminium heads, cam etc - £4500 - £5000. Cross over headers £1300, Ceramic coat the headers £300, Clutch, adaptor Starter etc £1000, The gearbos is then marginal so £8000 for a stronger box, mounts and fitting £1000 I'd need to budget £16000 to get it all done - and at that stage I have £43000 in a car that will be worth £30 - 32000!

Suddenly the £1200 sounds a bit more reasonable!
But if I'm going to do that how about 8 trumpets feeding the Efi system?
I'd think £2500 will have full spark efi and "bling" in the rear window!

I used to be indecisive but now I'm not sure!

And how can an Efi system not learn? Low throttle low revs and it should be sniffing the exhaust to confirm what it needs at 14:1. Is that a full loop system or something else?

Cheers
Ian

Ian Anderson wrote:
[snip]

And how can an Efi system not learn? Low throttle low revs and it should be sniffing the exhaust to confirm what it needs at 14:1. Is that a full loop system or something else?

Cheers
Ian

You'd only stick to 14.7:1 where a cat. is involved. Without one you'll likely vary from approx 12.5 to 16.5.

It's pretty easy tuning a Megasquirt etc for maximum power. And to make the engine just run decently. Tuning for best economy as well takes the time.

Dave

I thought that EFI and the lambda meant that any time at constant speed on flat road would generate 14.7 (or damn close)

Climb a hill or accelerate and it will need more fuel and go down hill or brake and fuel is cut off

It should not make any difference if a cat is present or not - most lambda sensors are before the cat and the cat only burns off any unburnt hydrocarbons.

Am I totally mistake on this "simplistic thinking"?

Ian

Hi Ian
If you use narrow band lambda sensors then it will try and maintain AFR of 14.7 at a constant throttle. If you use wide band lambdas and later code you can map the required AFR you want acording to manifold absolute pressure, throttle position and revs, so you can have pretty much what you tell it to deliver against a target AFR. It really is very flexable it is a simple matter of importing a map off a similar spec engine to get it running then refining it to what you want after logging it while driving. The reason it takes time is that generally you will get better results the more work you put in, it has very few compromises you have to live with so you always get a reward for "just a little more work".
Best regards
Mike

Phil - what are V8 Dev wanting for a 5.4 block, pistons, rods and crank - they only seem to list up to 5.3 on their site.

Thinking of bolting my Buick 300 heads to something bigger than the 4.6. Flow bench indicates they'll support over 400hp potentially which could be interesting with the right cam and induction.

Ian Anderson wrote:Dave

I thought that EFI and the lambda meant that any time at constant speed on flat road would generate 14.7 (or damn close)

Yes on a factory setup with cat. But the 14.7 is for the cat - not the ideal for performance/economy. If no cat, you'd go much leaner when cruising. So with aftermarket EFI systems and no cat you use a wideband O2 sensor system which can measure a wide range of AF ratios. A narrow band one only stoichiometric.

Climb a hill or accelerate and it will need more fuel and go down hill or brake and fuel is cut off

It should not make any difference if a cat is present or not - most lambda sensors are before the cat and the cat only burns off any unburnt hydrocarbons.

Am I totally mistake on this "simplistic thinking"?

Ian

A cat is only efficient at stoichiometric, and can indeed be damaged outside that, IIRC.

Ian Anderson wrote:
I used to be indecisive but now I'm not sure!

And how can an Efi system not learn? Low throttle low revs and it should be sniffing the exhaust to confirm what it needs at 14:1. Is that a full loop system or something else?

Cheers
Ian

For an ECU to learn, it would have to run a complex program which would map errors, monitor weighting of cross over points, log differentuals and use them to calculate desired values, etc. This is beyond the scope of a uP that runs an engine. This is why we use a laptop connected to the ECU to run these programs. This leaves the ECU to do what it does best and the laptop can work in the background auto tuning, or better still you tweak it and tune it yorself whilst its running,
Phil