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Thu Sep 25, 2008 6:37 pm

I have been reading alot on here that the 009 dizzy has always had a flat spot on acceleration, and i have also always found this to be true. So one day i take it to the local VW shop and ask him to tune the carb (i got lazy :lol: ), and he tunes it while it was idleing, and only reved it afterwards, and while he's doing it, i mention the 009 flat spot, and he says, thats just a myth, and the 009 is actually the best dizzy (or the best match) for 1600 dp engines. So he finishes and says go take it for a test runs, and OMG the flat spot is GONE. I couldn't believe it. No more stumbling, or anything on acceleration.

So have yall had similar success with the 009? Is the imfamous "flat spot" just a few people who can't tune carbs right, and blames the carb for their lack of knowledge, or does everyone have the "flat spot" problem, and those guys are just that awsome at tuning carbs?

Thu Sep 25, 2008 7:01 pm

BugMan114 wrote: i mention the 009 flat spot, and he says, thats just a myth, and the 009 is actually the best dizzy (or the best match) for 1600 dp engines.

A myth?? uhhhh :roll:
On dual port engines, I disagree. Single ports, 009s are OK. but for dual ports, sorry, but I fought the 009 on my baja bug for years before going to a vacuum distributor - before I did, no amount of adjustment would correct what is a mismatch between carburation and the ignition advance.

Your experience is not very common at all. At least not compared to what I've seen. 009's just don't match up very well with 34PICT-3s. I saw plenty of customer's cars where you could often get them to run "OK" - definately better than they were running before you tried adjusting them, but nothing like the few cars we'd get in that still had their original setups intact.

Did you ever read my article about carburetors and how the vacuum signal is generated within them? There were different version of the 34PICT-3, and each had a matching distributor, tuned for the best performance.

http://www.thesamba.com/vw/forum/viewtopic.php?t=185095

Thu Sep 25, 2008 7:41 pm

i read thru the post, and i don't quite get the carb/ ignition advance your talking about. The distributor is mechanically advanced, so what does that have to do with the carb vaccume advance? Some sort of scientific process? perhaps the rate at which gas and air enter the engine? pleasse explain. this stuff is so interesting :D

Thu Sep 25, 2008 7:58 pm

Apologies if I my tone was too down on you. I'm glad your combination worked out good!

My point is ..... each of those carbs were Intended to be run with vacuum advance distributors. A centrifugal advance does not "mate" with any of those carbs - they were not designed for each other. The stock distributor was. 009's just don't provide the advance where the 34PICT-3 needs it to be. Now, modifying the 34PICT-3 - by reducing or plugging up the hole the throttle butterfly and other tweaks, for some make a huge difference when you combine it with the 009.

The old John Muir "Idiot Book" I think is largely responsible for people thinking the 009 is awesome. I know from experience that it isn't. For single ports and for dual carbs, it's OK, but I won't use one on a 1600DP again.

Thu Sep 25, 2008 8:54 pm

The reason that a vacuum advance distributor is needed is that at part throttle conditions the lower density fuel mixture takes longer to burn, which requires the spark timing to be advanced for optimum ignition timing.

When I say ignition timing, I am referring to when the fuel mixture actually ignites, not when the spark is applied. There is a delay between when the spark is applied and when the fuel mixture actually ignites.

People have screwed around with their jetting and accelerator pumps to reduce and sometimes eliminate their flat spot. however, you lose gas mileage this way and you do NOT achieve maximum horsepower and torque under part throttle conditions. Because your spark timing is retarded from optimum your engine will also run hotter. Although running extra rich can add some cooling.

Jerking around with your fuel mixture is a piss poor method of eliminating flat spots. The 009 is also not the most stable distributor.

A high energy ignition system, using larger spark plug gaps, will also reduce flat spots caused by the retarded ignition timing caused by the 009.

But the only way to cure the flat spot, have maximum horsepower and torque at part throttle conditions, have maximum gas mileage at part throttle, and have lower cylinder head temperatures is to advance your ignition timing at part throttle conditions, whether you do this with a vacuum advance distributor, or use an electronic ignition timing setup connected to an intake manifold pressure sensor.

A centrifugal advance distributor is really only okay for driving full throttle all of the time.

Scott Novak

Thu Sep 25, 2008 9:02 pm

The 009 CAN be made to work with the 34PICT3 without flat spots, and with good fuel mixtures across the board. But jets are not the only thing you need to get there. An understanding of the carb goes a long way. The performance will NOT be as good as a matched distributor, and neither will the mileage, but it does not have to just plain suck either.

Thu Sep 25, 2008 9:04 pm

For the 34PICT-3, i've never been happy with mechanical only distributor. But with other carbs i've had great results with the mechanical only 019.

Thu Sep 25, 2008 10:08 pm

009 is all i've ever used on any vw i've owned. NEVER have i ever experienced a "flat" spot.
Guess i'm just lucky.. :roll:

Thu Sep 25, 2008 10:30 pm

Mine wasn't too bad either, but when the engine was still cold, it would hesitate a tad. Never had any issues with a fully warmed engine, but a little vac advance is better than none at all.

Thu Sep 25, 2008 10:45 pm

BugMan114 wrote: I have been reading alot on here that the 009 dizzy has always had a flat spot on acceleration, and i have also always found this to be true. So one day i take it to the local VW shop and ask him to tune the carb (i got lazy :lol: ), and he tunes it while it was idleing, and only reved it afterwards, and while he's doing it, i mention the 009 flat spot, and he says, thats just a myth, and the 009 is actually the best dizzy (or the best match) for 1600 dp engines. So he finishes and says go take it for a test runs, and OMG the flat spot is GONE. I couldn't believe it. No more stumbling, or anything on acceleration.

So have yall had similar success with the 009? Is the imfamous "flat spot" just a few people who can't tune carbs right, and blames the carb for their lack of knowledge, or does everyone have the "flat spot" problem, and those guys are just that awsome at tuning carbs?

It can be tuned to work, but as said its just not the best combo.
Is your combo running a 34 pict-3 mounted to a 30 pict manifold? That set up is easy to tune and works good, same goes for a 34 on a single port.

Fri Sep 26, 2008 1:54 am

wait and see how much fuel ur next tank goes thro

most ppl cover up the 009 flatspot on 1600 dp by dumping shitloads of extra fuel in
the only way to keep the engine happy till the mechanical advance catches up

Fri Sep 26, 2008 9:04 am

A lot of the long block engine suppliers will specify an 009 just because
they went to dual-carbs on the finished engine and lost the vacuum tap.

Its easy, convenient and gets the customer on his way but I have checked the timing on a few of our locally tuned cars and have seen
as much as 48 degrees max advance?? (009) Thats not a fix!

Now was this done to fix the flatspot at the lower end???

Who knows, but I have seen this several times now on 009's and I
wonder how the hell it would run long term with that kind of full advance?

If I back'em down to 31, the flatspot begins.

I pick a happy medium and send them on their way again...

(009 just can't cut the mustard)

Fri Sep 26, 2008 9:09 am

The bigger problem with the current OO9s is that do not advance correctly, either too much or too little. They also have poor quality bushings which causes chatter and unstable dwell.

The wholesale price on the current OO9s is around $12 including tune up parts. Some vendors are offering upgrades to BOSCH tune up parts in the hopes to reduce customer problems.

In case you didn't see this in my signature "You may not get what you pay for, but you always pay for what you get"

Fri Sep 26, 2008 9:24 am

Buggin_74 wrote: wait and see how much fuel ur next tank goes thro

most ppl cover up the 009 flatspot on 1600 dp by dumping shitloads of extra fuel in
the only way to keep the engine happy till the mechanical advance catches up
Actually, using a high energy ignition system, with wider spark plug gaps, may do as much or more to reduce the flat spots as richening the fuel mixture with the accelerator pump.

Ask yourself why would richening the fuel mixture reduce a flat spot? The answer is that to a certain point, richer fuel mixtures are ignited faster and effectively advance the ignition timing to a degree. And when I say ignition timing, I mean when the fuel mixture is actually ignited. I think that the richer fuel mixture might also have a faster burn travel, but I'm not positive about that.

High energy ignition systems, used in conjunction with wider spark plug gaps, also ignite the fuel mixture faster, effectively advancing the ignition timing.

But even richening your fuel mixture and using a high energy ignition system with wider spark plug gaps will not work as well as using some form of spark timing advance at part throttle conditions, whether it be a vacuum advance diaphragm in a distributor or an electronic spark timing advance system with a MAP sensor connected to your carb's vacuum port.

Scott Novak

Fri Sep 26, 2008 9:27 am

Scott,

Why add the expense of replacing the complete ignition system when using the "correct" distributor that came from the factory will do the same?

Fri Sep 26, 2008 9:46 am

Glenn wrote: Scott,

Why add the expense of replacing the complete ignition system when using the "correct" distributor that came from the factory will do the same?
While a distributor with the correct centrifugal and vacuum advance will improve the situation greatly, there is still a variable lag time between when the spark is applied and when fuel ignition ignition has reached the point that the ignition system no longer has any control over the burn.

There is no way to compensate for this variable lag time.

The spark timing is adjusted so detonation does not occur at the conditions of fastest burn. At all other engine conditions your optimum ignition timing is retarded, and your performance and gas mileage suffers.

While you can't actually compensate for the variable lag in ignition timing, you can hit the fuel mixture with a much wider and more powerful spark that will ignite the fuel mixture faster and ELIMINATE much of the ignition lag time. The result is improved performance and gas mileage.

I'm really getting tired about people complaining about the "Expense" of an electronic ignition system. Last week I missed the bidding on a used Jacobs Pro Street with a built in RPM limiter and a Jacobs Ultra coil that sold for only $32.00!!!!

I've purchased NEW Jacobs ignition systems, including the ignition coil for $100.00 on e-bay. Craig's list is another place that you can find great deals. With $4.00 a gallon gasoline, it doesn't take much of a gas mileage improvement to pay for the electronic ignition system.

Because distributors have been phased out of production vehicles, people are dumping their high performance electronic ignition systems at low prices, which is great for us.

Scott Novak

Fri Sep 26, 2008 1:49 pm

Eh, find a new shop. Flat spots can be slightly tuned out of 009's (but not entirely eliminated) if you're willing to sacrifice mileage, as mentioned above.

The best luck I've had was a German Bosch 009 paired up with a 34 pict 3. Never rebuilt, had a nice tight shaft, and steady timing... but I sold it. I use my Chinese 009 to fill the dizzy hole in my other engine while it gets worked on... that's ALL the Chinese ones are good for.

Fri Sep 26, 2008 1:55 pm

Never had a flat spot with a 009.

Fri Sep 26, 2008 2:57 pm

craigman wrote: 009 is all i've ever used on any vw i've owned. NEVER have i ever experienced a "flat" spot.
Guess i'm just lucky.. :roll:

maybe because all you have ever used is 009s you dont know the difference...
i know personally when i switched from a 009 on my 34-3 and my kadrons up to a 034 svda setup to match both times the difference was crazy...

and both 009s were setup right old german with steady advances no bouncing around.

if you have nothing to compare to you dont know what your missing out on.

Fri Sep 26, 2008 5:06 pm

Brian,
yes i have used stock dizzy's before.
When i took out the stock dizzy, and put in a 009, i could actually feel a difference, so i've stuck with them ever since.
Like i said, it's just what i have experienced.