I'm considering fuel injecting my 74 Kombi and thought I'd see how many people have done this and what their experience and results have been.
My bus currently runs a mild 2L, has a cam, exhaust and is running a pair of 44idf webers. It has good power but terrible fuel economy, somewhere between 20 & 25L/100km. Last trip to port Macquarie from Newcastle used a full tank each way.
I'm mainly looking for better fuel economy as we love taking the Kombi away on weekend trips but with fuel costing what it does we can't afford to drive it anywhere.
I'm looking at an aftermarket quad throttle body setup.
59 beetle,61 beetle,72 dual cab,58 beetle,55 splitty,
65 manx,74 camper,60 Rat beetle.....and many more to come
Off the shelf is expensive but motorbike throttle bodies and an ecu will be cheaper if you have the spanner skills.
$1500 should cover the diy option but off shelf would be double that plus. Rough top of head numbers but I know the megasquirt is the cheapest ecu option and throttle bodies can be cheap if you look around.
madness is in the eye of the beholder 👍
Fuel injection wont save you on your fuel bills Its the weight n cross section of the Kombi that uses the fuel
However FI would be better off in the long run
Go for a good computor like Autronic or Halteck
Try and get hold of the factory runners and plenum and try to find a good EFI tank
vwvic wrote:... has good power but terrible fuel economy, somewhere between 20 & 25L/100km....
It's not really fuel *economy*, is it, it's really fuel consumption at that figure. My (standard) 2L runs about 14 l/100 km. As the size of a bus dictates its poor economy at highway speeds, your cruising speed will be a big factor in determining your outcome. I run at about 88 kph on the highway (provided there are multiple lanes so I can keep out of the way of the many), because this seems to be about the sweet spot at around 3300 RPM. For the standard 2L, max. torque is around 2800 RPM, but this is too slow even for me.
You have several options open to you:
- as you suggest, you could move to fuel injection. It would, combined with dyno testing, improve both economy and drivability. Whether you would recover the cost in a reasonable time is doubtful.
- you could do a Subaru transplant. Much better fuel economy could be expected. If memory serves, one EJ22 in a bus averages better than 10 l/100k. Whether you would recover the cost in a reasonable time is doubtful.
- you could do some dyno and air/fuel testing with possibly some jet correction of the Webers; you'll certainly get better than 20 and you may even recover the cost in a reasonable time.
- you could change your driving style to match the reality of forcing a brick through the air, especially highway speeds. Air resistance (the product of the aerodynamic coefficient of the bus and the frontal area) increases with the cube of cruising speed.
I'm interested to see what you do and how it turns out for you.
hth
Peter Hill
1975 Type 2 Double Cab
modulus.com.auGet your carbs properly tuned, you'll spend WAY more going efi. You may find it's the engine performance killing the economy, ie. miss macthed heads, cam, carbs and exhaust combo.
I really believe it's purely the actual tuning where the problem is, a dyno will get the jetting but a GOOD hi-performance VW tuner will get your carbs right. You should be able to get even a stroked performance engine to deliver 10l/100 depending on variables like headwinds, ambient temp etc.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
^^^^^^^
what Matt said,
too large or poor tuned carbys, too large exhaust, inefficient combustion chamber, low compression, weight, all are major contributors towards poor fuel economy, maybe try single centremount Progressive weber carb if all else fails.
bitten by the bug..........several times
Our 1800 twin carb stock bus got 10L/100km when tuned just right with a 2L box
When we went to EJ22 Suby, we got the best ever of 9.8L/100km. The biggest advantages were the modern engine and double the hp when required.
Thanks for the input guys.
My engine was rebuilt about 70k ago so it's all good. I always thought the 44's might gave been a but large. It does have a rather large exhaust too, heater boxes are gone with custom manifolds into a performance porsche 993 muffler.
The webers have been great I've never had a problem with them apart from the fuel consumption, they've been on there about 4 years.
The injection kit would cost me abut $2.5k. So maby better spent on a new exhaust, better ignition and some smaller carby's.
I have a set of 36idf's that are ready to go, but have been told they are too small?
Maby 40idf or 40 dells?
59 beetle,61 beetle,72 dual cab,58 beetle,55 splitty,
65 manx,74 camper,60 Rat beetle.....and many more to come
The 36s are fine, just need to be set up for VW if not already
bitten by the bug..........several times
I know guys that have triple 40's on 3.3 litre Holden 6 cylinder engines and they chew the petrol. Twin 40's on a 2.2 would be similar. I would think the twin 36's on a 2.0 litre if suitable for the cam and exhaust would be fine if jetted and tuned right.
Get electronic ignition if you don't have it already.
I am sure a good opinion for exhaust will come up.
You don't need to get rid if the 44s. Just fit smaller chokes and re-jet.
40's work fine on most 2l engines if choked correctly.
36's will out the box give good low end but run out of puff above 5k on a 2L. For those 'give it some stick moments'.
madness is in the eye of the beholder 👍
psimitar wrote:You don't need to get rid if the 44s. Just fit smaller chokes and re-jet.
40's work fine on most 2l engines if choked correctly.
36's will out the box give good low end but run out of puff above 5k on a 2L. For those 'give it some stick moments'.
Yep, I agree, 36's will work ok but are more suited to a 1600-1800, a 2 litre really needs 40's, more torque than your 44's in the lower rpm where you drive mostly.
Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE
yep as per above you need the 40 or bigger for more torque
F I wont solve the problem as per above your pushing a BRICK through the air
the Vintage Speed 4 equal length headers into stock type muffler would work good as well
Oh yes, equal length headers are a must for best power and if able to get that in a 4-2-1 configuration then even better as the 4-2-1 will give better low and mid-range torque/power than a 4-1 exhaust.
The CSP Python is possibly the best out there due to it's equal length design.
madness is in the eye of the beholder 👍
Thanks for all the input guys
I've had a look around and for $700-$800 I can get a set of rebuilt 40 dells or webers.
As for injection the bolt on quad throttle kit was not real cos effective but I've done a bit more investigating and found if I get a megasquirt computer, sourse all the bits myself and get my mate to make me an intake with a single throttle body it will come in around the same as a new set of carbs. I even have a local guy to tune the megasquirt.
As for the exhaust I'm pretty sure I'll go with the vintage speed equal length pipes with the dual tip muffler.
I'll keep everyone posted on what I end up doing.
59 beetle,61 beetle,72 dual cab,58 beetle,55 splitty,
65 manx,74 camper,60 Rat beetle.....and many more to come
or you could delco it!
71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE
vwvic wrote:Thanks for all the input guys
I've had a look around and for $700-$800 I can get a set of rebuilt 40 dells or webers.
As for injection the bolt on quad throttle kit was not real cos effective but I've done a bit more investigating and found if I get a megasquirt computer, sourse all the bits myself and get my mate to make me an intake with a single throttle body it will come in around the same as a new set of carbs. I even have a local guy to tune the megasquirt.
As for the exhaust I'm pretty sure I'll go with the vintage speed equal length pipes with the dual tip muffler.
I'll keep everyone posted on what I end up doing.
Yay, another win for the Megasquirt
🙂 I mean why should getting the most from your engine be expensive
🙂madness is in the eye of the beholder 👍
