Why Does No One Like The Bosch 009 Distributor?

[veedublover12]

I have heard a lot of people complain about the Bosch 009. Why is this? I have used it for years on both my Bus and my brothers have used it in their Bugs and Ghia's with no problems. I am willing to change my ways I just want to know why I should.

[OB Bus]

Bog. Flat spot. Stumble.

Great dizzy if you are running flat out but drivability is not great. Been there done that. Rumor has it that gas mileage will be significantly better with a SVDA.

I love that vac advance. I did not love the 009.

[Adventurewagen]

Welcome to the board.

I'm going to keep it real simple and let one of the ultra guru's explain exactly why.

The 009 is a centrifugal advance distributor. It advances along with RPM's but, your engine also produces a vacuum signal and if you could take advantage of that you could have a distributor that is also based on load. So that's why VW put distributors that were both centrifugal and vacuum advance with the bus when you originally got it. It helps during acceleration and gives your engine more total advance overall. The advance curve it generates is also better suited for your engine while a 009's isn't advanced enough and overall doesn't have enough total advance.

So while the 009 works, it isn't taking advantage of everything it could from the engine. So if you want to possibly run cooler, have smoother acceleration, get better gas mileage and probably out perform your brothers, you should upgrade from the 009 and get either a stock distributor with the vacuum advance or go with the ACN SVDA which is the same thing just new.

[veedublover12]

Interesting explanation, I never knew. I found a few SVDA dizzys on CIP1, would that be a good option or would anyone recommend another brand or distributor?

[vdubyah73]

CIP1 will sell you an SVDA. John Connelly at aircooled.net will ask what it will be used in and sell you an SVDA specifically for that vehicle. Advance curve for a 1500 pound dune buggy is different than the advance curve our heavy buses want.


The vacuum part of the advance comes into play at part throttle actually. Such as cruising at a steady 60-65 on the highway. This is where the fuel economy comes in. You need less throttle to maintain speed. The vacuum signal goes away when you open the throttle wide, when under load such as climbing a hill or accelerating. This reduces ping or detonation.

SVDA is a good thing. The 009 that I used to run in my buggy, with a Compufire, is now my loaded spare distributor that I carry on road trips.

Bill

[Adventurewagen]

Also take a look at this thread:
Mallory vs SVDA

Like Vdubyah mentioned Air Cooled Net (http://www.aircooled.net/) sells a vacuum advance distributor that is considered among many to be the best stock type distributor you can get for your bus. Although another option is to go with the electronic Mallory unit.

I should note though that both the ACN SVDA and the Mallory come with vacuum advance. So no matter which one you get, both come with vacuum advance which should give you a bit more insight into what is "best" for the bus.

[RSorak 71Westy]

Vacuum advance is simply a good thing and all engines will run more efficiently with it. Most car engines have had this since about 1960, why VW chose not to use it is a complete mystery to me.

[Amskeptic]

Vacuum advance is simply a good thing and all engines will run more efficiently with it. Most car engines have had this since about 1960, why VW chose not to use it is a complete mystery to me.

VW used vacuum-only from early 60's to 1970! Unmystify yourself young RSorak. . . .
Colin

[Randy in Maine]

Interesting explanation, I never knew. I found a few SVDA dizzys on CIP1, would that be a good option or would anyone recommend another brand or distributor?

Stay away from the "Bruck" as they seem to have some QA/QC issues.

[RSorak 71Westy]

I've been running a bruck for the past 6000 or so miles with no problems at all. The quality seems to be fine.

[karl]

Vacuum advance is simply a good thing and all engines will run more efficiently with it. Most car engines have had this since about 1960, why VW chose not to use it is a complete mystery to me.

VW used vacuum-only from early 60's to 1970!

And that was why the 009 came out. On the early distributors, they were vacuum only. When the diaphragm ruptured, you had zilch zip nada advance. Your VW was a turd going nowhere slow. Bad for the engine, all you did was lug it. So some enterprising person put together the 009 from industrial applications and the blue coil and marketed it as The Screamer Kit. Sure it made your engine scream: you went from no advance to 30 degrees advance. You did not miss the vacuum advance because it died slowly. If it died all at once, then you would have noticed the day and night lack of power.



Sure, it gave you full advance and woke up your engine via RPM's only, but it lacks the needed vacuum advance that is load controlled.

[Amskeptic]

Listen to the man. . . . ^

[spiffy]

If ya don't have the cabbage to spring for a new SVDA your choice of carb can greatly affect the "size" of the flat spot. If you are running an earlier carb (28 & 30 pict 1) then the flat spot isn't as noticable but the later carb's, especially the 34, you will have a flat spot from hell.

FWIW....