Carbs V EFI...

[anonymous-user]

I know this has been raised before but... I have got to pose the question and may be start the debate...?

I have got a serious desire to put carbs on a V8. (Mainly for the sound, secondly more reliability)

If you put a 4-barrel webber on with the right CFM, jetting and an edelbrock manifold, will it maintain the same power output?

Cheers

Doug

[JR]

Have a chat to Cirks. An excellent conversion.

[wedg1e]

Some claim MORE power on carbs. The efi was mostly an emissions-control addition, I think.

[llanelli-rob]

Hi

Just before i bought my 350 tas it had been converted (apprx 3mnths ago!) fitted with the weber?edelbrook 500cfm and performer manifold,i also just swapped the pancake filter foR an edelbrook special with washable element!

I must say that when i bought the car she was not running spot on,but this set up is so easy to adjust she now purrs!

As for the better noise! well not hearing before on injection i dont know,but now WOW!

go for it,Rpi are the guys you need to speak to and superb website also.

Good luck

[timpailthorpe]

The general principle is that EFI has greater control of the fuel mixture at all revs. This equals greater efficiency. The ECU is setup for max efficiency. Upgrades can increase power at the cost of efficiency.

Carbs are easier for an amateur to gain a lot more power but the cost is efficiency. It can also be difficult to get max power at all revs as setting up a carb is a balancing act (EFI has a mapping that can define the amount of fuel for each rev range and vacuum).

So the upshot is that you can get more power by fitting big carbs, but not as much as putting in a new EFI but at much lower cost.

And the noise of big downdraughts gulping down huge lungfulls of air is something else.

I remember seeing a mini that had side-draught webers fitted and the chokes of the carbs were inside the car to fit them in. The driver (and passenger) had to be carefull not to get their knees burnt when flames flew out of the chokes

[boosted ls1]

Compared to efi carbs are rather crude metering devices. That said they perform well enough for us petrol heads and they are simple to tweak.

I'd happily use a holley again if it wasn't for the fact it can't measure density or pressure. For a n/a application I guess cost is a big consideration. A carb is very diy orientated, efi can be to specialised for some people.

Boosted.

[adam quantrill]

I agree, carbs if you are a spanner head, EFi if you are more 'leccy and 'puter oriented.

[anonymous-user]

Yes that’s me! carbs & spanner head, but 'leccy and 'puter oriented at work. I like things boosted says DIY orientated. I want to be as far away form emission control n cats etc as possible!

Anyway, back to the topic. I did see the RPI site, which looked interesting...

I did think EFI was for better emissions and for subsequent “cat” castration device.

[adam quantrill]

Not the way I run mine!

Rising rate regulator, set up nice and rich (turned down for the MOT).

Throttle response much better than twin SU's, but there are better carb setups out there. However the best part is cold weather starting - never a problem.

[rev-erend]

I believe the EFI is much more fuel efficient... but it is cheaper to get more power from a carb set-up and DIY is easier with carbs..

[cirks]

JR said:

Have a chat to Cirks. An excellent conversion.

Well, I thank you kind sir

[wedg1e]

rev-erend said:

I believe the EFI is much more fuel efficient... but it is cheaper to get more power from a carb set-up and DIY is easier with carbs..

Hmmm. A fat pair of carbs costs ££££, for which you can buy a lot of (admittedly used) EFI parts to experiment with...

[cirks]

Well, I had an ECU that was beginning to fail (both over and under fueling at different revs). When the engine replacement was necessary, it was far cheaper to go for my carb set up than to replace the ECU, rolling road it and get it all set up. I can't remember exact price for the quad Webers on mine but it wasn't much more than £600.

[shpub]

If you want real power, EFI is the way as it gives you so much more flexibility to push the envelope.

[grahamw48]

I don't understand injection (sort of), but I don't see many carbs on F1s, dragsters, etc.

[SEvans]

Before I dropped the Cosworth engine in the 200 I did look at other options like a Warrior Head etc but decided that it was more cost effective to drop in the Cosworth engine. Initially it cost slightly more (and I mean slightly) but on the plus side the car behaves well on the road with the power when you want it. It currently pushes out about 220BHP. If I were to spend a couple of hundred pounds I could easily up that to near 300BHP. I don't think you could do that for the same money with any Carb set up, if it was possible at all.
There was also the added benefit that with EFI that you can just buy the bits and as long as all the wires go to the right place and you have no faulty components it should all just work without any setup. I've been running mine now for 18 months having adjusted absolutely nothing. Bet you wouldn't/couldn't do that with a carb setup.
Personally I would rather have the EFI setup. I don't see how anything that is infinitely adjustable can ever be spot on!!! But, when/if I get some problems maybe I'll change my mind!!