carb or injection
Turbo Mini Forums

ive currently got a 1.3 cooper injection and somebody said i should change to carbs if so how hard is it to change and also is it any better on performance and fuel.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

I'd much prefer and injection setup

If something is worth doing, it's worth doing half of.

My second version of my engine will most definitly be injected. For now it's carbd and 5 port for cost reasons. It's a long way off v2 and not quite complete at v1 yet lol

My second version of my engine will most definitly be injected. For now it's carbd and 5 port for cost reasons. It's a long way off v2 and not quite complete at v1 yet lol

I have seen people in my local club convert to carb as the SPI injection had a failure and the parts were either hard or too expensive to source. They only use the car as a fun car and not a daily drive.

If its running fine why not leave it as is.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Carb over standard injection. However if your talking about throttle bodies, ect then injection everytime (budget allowing) i would be injection if i could afford it

Injection for me

Alright Danny!

Minichipper and I had been struggling with elusive electrical gremlins on his new mini. It's sorted now but we got so frustrated with previous owners mystery wires, crimps, splices and relays I was demanding a pair of SU's and ready to bin the ECU


We're talking about standard SPI.
Carbs give similar if anything slightly worse economy and similar power (dependent of what carbs and intake manifold you fit)

I have little experience of the mini SPI system specifically but the rover MEMS setup actually seems pretty flexible and copes well with engine modification. Even so it does still have the usual limitations of any standard ECU because we cant alter the map.
The ECU will compensate to a point but more the engine is altered the further away from optimum the air/fuel ratio and ignition timing will go.
There will be a point when you need to ether A) fit carbs B) fit a programmable ECU (and potentially throttle bodies)

Sprocket
I don't think 110HP is possible with just a cam and rebore, well I'd be very surprised.
People seem to be managing around 80HP with a worked head, hi-lift rockers, exhaust, filter ect
100 seems to be the limit. IIRC you managed 100hp on your SPI? What spec was that?

Your going to make me look silly and tell me you have got 110 nanas now aren't you...

Didn't say there was anything wrong with it just, more power would be achievable with a carb seen 1293s on carbs with more power then 110 .

On 21st Mar, 2011 Sprocket said:

On 21st Mar, 2011 Gaball said:
Carb over standard injection. However if your talking about throttle bodies, ect then injection everytime (budget allowing) i would be injection if i could afford it

Nothing wrong with standard injection. I recon I can easily get 110hp out of a factory injection system on a 1400 with a 'mild' cam. Thats far better than a lot of 1380's with a 286 cam and a carb!!

The way I see it is that if you understand injection you wonder why people who don't, like carbs.

Most people now understand that mapped ignition is better, but how long did it take to convince most.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Carbs are quicker to set up i would imagine its the main reason. Not to mention price.

However i agree injection is much better for power as well as fuel economy but this would be with a minimum of a remap. If you think by the time you have a full system of injection you have spent atleast £500 upwards even running a webber will cost you £350 brand new

I'd like to see a properly set up webber set up quicker than injection. For that matter any carb. Accepting the difficulties with the 5 port, there is no reason to use a cab these days, unless you are racing and the class forces you to.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Dam you to think of more reasons, but apart from originality all the others make no odds.

Simplicity: Now you can buy off the shelf injection kit for most cars, including minis, it is no simpler to have a carb.

Knowledge: I think for most people it is easier to understand injection than how a carb works, particularly performance carbs like webbers. They just think they know carbs because they are familiar with them.

Ability to make/install/tune etc etc: Can't see and difference really apart from tuning, where injection is much simpler, IMO.

Having been a complete novice, at injection, and then helped take a car from not running to running full bore on the rolling road and then continued to develop the map, I can honestly say that it is not a black art. The beauty is that when you make a change you know what you have done and you can see the effect at the stroke of a key. To change the tuning on a carb means stopping the engine and stripping the carb down to some degree, doesn't sound simple to me. I stop bleating on now.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

You need the ££££ tho.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

I just want to add that filing needles is definitely not a simple or quick way of tuning fuel delivery. Hitting the up or down arrow on a computer keyboard seems trivial in comparison.

Jean

http://www.jbperf.com/

http://www.jbperf.com/

Carbs are not cheap but they are cheaper then injection by far.
Both have their advantages and disadvantages. Injection as a hole is better however like everything it costs.
Carb will make more power then the factory spi for A LOT less money then even getting it remapped if that was possible

I am aware injection not to be a black art however carb are still simpler and quicker to set up.

This debate will continue for years because in reality like I said they both have pros and cons

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Its no myth a whole day can be spent fitting an injection system and then creating a map from new.
Carbs can be set up by someone with the knowledge in say a couple of hours. The downfall is that the carbs do not keep their tune so long term more time will be spent. But unless we are talking over a 10 year period this is not a worry.

To be honest though the main arguement for carbs over injection is always going to be money,
Id rather run carbs and still have the money to run different cam, maybe overbore ect ect then spunk it all at an injection system straight away.

Once you've used injection, even complicated 5 port stuff, then you will never go back to carbs.

All of our 4 Mini projects are going to have injection.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

IMO carbs (and a dizzy) are great to bung on and get somthing running, but as for ease of tuning, injetion wins hands down.

Edited by Joe C on 23rd Mar, 2011.