Carbs for the 4AG

[SutteR]

Hi!

Recently I started to read after this topic, namely running the 4AG with some carbs instead of 20 years old injectors and ooold electronics. I've found some technical stuff on club4ag.com ( ), and asked some of my friends about this thing.

Now I'm not sure what I really want...

The carbs (actually Webers, Dellortos or Solex's) have some advantages and some disadvantages. Let me summarize my +/- facts I've learnt until now.

+ (why the carbs are way better than the stock EFI):
- better throttle response
- less parts -> less chance to get wrong
- no old stock electronics
- aaawesome sound!
- I know someone who masters these beauties...

- (why don't go with carbs)
- this project won't be cheap
- need for a custom made intake manifold
- need for some aftermarket ignition system (programmable (maybe EPROM) ignition were suggested by my "master")
- need for adjusting for time to time (Solex's sucks after some opinions, others are better but they are still carbs that need adjusting)

Sooo, what do U think guys? I'm curious whether U will advise or refuse this carb thing!

Please post some pics also if U have about 4AGs equipped with nice carbs!

Bye,
SutteR

[banpei]

From what I read about switching to carbs are only minus points:
- even more narrow powerband
- more difficult to pass emission regulations

[SutteR]

Powerbrand can be located to the lower or upper rpm's using different venturi tubes (?) and/or nozzles (?).
Emission regulations...my hachi can't even pass them with EFI...

I agree that there can be a lot of negatives the question is only whether it worths because of the positive things (especially the noise of it).

Any other opinions?

[SutteR]

Who voted, plz post here why he voted that way! I'm really interested!

[jamiemirror]

Depends of the costs. Here carburators are cheap and it worth.
This setup is ITB style: increased power and response.
But you must fabricate intake adapter (I started such fabrication - in progress) and work on ignition management (or drive with static ignition).
You must change the fuel pump also.

[SutteR]

jamiemirror Wrote:Depends of the costs. Here carburators are cheap and it worth.
This setup is ITB style: increased power and response.
But you must fabricate intake adapter (I started such fabrication - in progress) and work on ignition management (or drive with static ignition).
You must change the fuel pump also.

The hardest thing is the intake, yes. For the ignition, I have an alternative. A programmable microcontroller-based ignition system which is used by a lot of tuned cars here in Hungary.
Why a need to change the fuel pump?

[jamiemirror]

Quote:A programmable microcontroller-based ignition system which is used by a lot of tuned cars here in Hungary.
Why a need to change the fuel pump?

Tell me more about this ignition module ?
You must change the pump because carburators need 0.2-0.3 bar of fuel pressure versus 2.3-3.0 bar regulated/4+ bar unregulated fuel pressure(stock EFI system).

[SutteR]

Than isn't it only about the fuel pressure regulator?

The documentation of this ignition system is available only in Hungarian language so you will have some problems with it. I'd be glad help you out with some basic translation but I don't have any time for it yet... (have to learn for my exams)

If you find some online translator or something you may can use some information: http://www.roxel.webzona.hu

With MAP sensor we can use the vgc120, totally changing the stock ignition we can use igc60. This costs about $80-90.

OK, I don't want to learn...I translate some of the description of the IGC60...

1. The system can be used for 4 cylinder / distributor engines and works with regular Hall generator or compatible.
2. 24000 sparks/min max, which is 12000rpm at a 4 cylinder engine.
3. The rpm range is divided into 60 parts: 650/min...9500/min, in 150rpm steps.
4. The wanted ignition degrees (???) are freely programmable in this range.
5. The pre-ignition (???) can be adjusted between 0,5-63,5 degrees in ,5 degree steps.
6. The closing time (???) is programmable between 0,8-10 ms.
7. The opening time (???) is programmable between 0,2-2 ms.
8. The parameters can be edited in an excel sheet or with a Windows based program. The data can be transmitted via the COM port.

Optional features:

... (not for us...)
e) The rpm range and the intervals can be set (by factory) custom: in the range of 600-12000rpm.
f) Optional output for a shift signal. (The wanted rpm is programmable)
...
h) With IGN-tuner you can tune your ignition on the brake pad or on the street.

[meshin]

... my vote goes for carb.. why?

The engine response and sound... I drove on carbs and no electric fuel injection car can match in that matter...

[SutteR]

meshin Wrote:... my vote goes for carb.. why?

The engine response and sound... I drove on carbs and no electric fuel injection car can match in that matter...

I looove your opinion!