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Ive got another thing that bugging me. So thought you guys may have the answer??

Im using the Mallory Unilte distributor (I know some of you don't like these but mine been good) at present. When the car went on the dyno, the guys were limited with what they could achieve with the distributor apart from dialing in the timing. 

I searched for the Mallory Spring kits etc prior to the dyno but everyone was/is out of stock. Both here in the U.K. and your neck of the woods, USA.

When l bought it from Jake he told me he set the springs to suit the type4 and l never checked to see what colour springs he fitted. Looking into the Mallory l have, I've got one red spring and one Grey. Is this right??? I was told the normal type 4 motor settings have x2 greys springs which equates to  mechanical advance 20 degree and static 10 degrees. 

Anybody know what curve l have with one red spring and one grey spring?? Or is this what it would have left Jakes shop with??

Rich


Are we ever finished ;-)

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On a somewhat related note:

My fun pedal was getting a little soggy just off idle, so I checked the timing and, sure enough, it needed to be advanced some. Just a few degrees more and it perked right up.

These cars are very sensitive to spark advance in the 1000-2500 range. Probably more than peak power or torque, throttle response down low is how we judge subjectively if an engine is strong or weak.

Most of us could probably benefit from more advance in the lower range, but our dizzies are usually not adjustable, so the max advance at high revs is what limits how much advance we end up with down low.

The more I get to know this engine and how it responds to tuning, the more critical I think spark advance curves are. Carbs seem to get all the attention because they're easier to fiddle with, but I'm starting to think more than half of 'Weber flat spots' are really Bosch flat spots.

 

So with the Mallory spring sets not available until further notice. l bit the bullet and during my road trip l went to collect and go through the setting up of the 123 Tune + distributor.

This type of distributor has an App that you can download. And gives you the advantage of changing the curve whilst on the rolling road to set throughout the rpm. It works via Bluetooth. So the changes you make on your phone app are instant.

 

IMG_2957

 

IMG_2956

I'll see how good it is once I'm back on the rolling road and have a play. 

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I almost eliminated the one I had just by advancing the timing a little, but still keeping max advance under 30.

It's amazing how sensitive my engine is to a few degrees of advance down low. It makes more of a difference than fiddling with mixture.

It would be nice to try out a different dizzy without having to invest in it. It's not like if you try one 019 that the one you order is going to be exactly the same.

Maybe I'll have a chat with Wilhoit. I may have to sell off some real estate first, though.

 

 

I wonder if the graph Al posted shows results plotted from actual examples, rather than the theoretical Bosch design targets.

I've been using this as a reference:

BoschAdvanceCurves01

And here's one that compares the BR18, spec'd for 356 engines to the 009. The blue range is what Porsche spec'd their 1600 engines required.

BoschBR18AdvanceCurve

I guess it helps to remember that the 009 was used mainly with sort of stock VW's and most of our engines are anything but. I'd guess a hi-po engine around two liters would need something closer to the BR18 than the 009 (as Will seems to have discovered).

Look how much more advance the BR18 supplies than the 009 in the critical 1000-2000 rpm range - right where most 'Weber flat spots' show up.

This looks like a good article on the subject, but I've yet to plough through it.

 

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Last edited by Sacto Mitch

I must apologize...

I never looked at the distributor Jim installed until now...and it's not a BR8...obviously!

I guess it's a JFR4 or 022...but it does work brilliantly with no flat spot anywhere in the rpm range, but most importantly, between idle and 4,000 rpm...

...whatever it is, I love it!

and I am jealous, Bug and Karmann Ghia owners such better engine access.

I took this photo with my illuminated/extension mirror and iPhone stuffed into the nether-zone that is a Speedster engine compartment...

IMG_5081

and as penance for misleading the SOC faithful, here's a photo distraction; Kath in Whitecloud today at Cayucos surf-checking. There were hollow overhead sets pouring through groomed by 90 degree offshore winds, it was hotter at the beach than inland. Mid 90's at the coast, mid 80's inland...just a crazy California fall...

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Last edited by Will Hesch

I always thought that the Bosch 009 was meant for a constant-speed commercial engine usage.   Like running a generator or pump, not necessarily for road use, and then at 2,500-3,000 rpm or something like that.  That's why the advance comes on so abruptly under 2,500 rpm.  Easy to start with little advance, then full advance beginning at the bottom of the power band.

Richard, have lots of fun playing around with your curve. I can say this because I have Megajolt ignition and I went through 21, yes 21, different curves before I arrived at the final one. I have found that high power type1 engines want all advance in around 3500-4000, right around the torque peak. But also, if you can swing it, retard the advance at hi rpm up until redline. Jake Raby told me this, and I have found it to be true. 4 degrees retard for every 1000 rpm above 3800 works nicely.

The Megajolt unit extrapolates the values in between the load and rpm bins.

The left side of the picture is throttle load, from 10 to 100 percent. This allows me to give a "vacuum advance" effect at light throttle loads. I have a throttle position sensor on my left Weber.

I hope this helps you.

 

Ignition map pic

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"...retard the advance at hi rpm up until redline. Jake Raby told me this, and I have found it to be true. 4 degrees retard for every 1000 rpm above 3800 works nicely...."

@DannyP- I've heard of drag racers doing this, and with the ultra high compression ratios they'd be running they'd get better power in the 5-10,000 rpm range and no detonation.

The redline is an independent parameter, as is cranking advance. The hi-rpm retard is sweet, no pinging at all WOT up there, but pulls like CRAZY.

Ed, no need for 5800 bin, as the Megajolt extrapolates between bins in linear fashion.

Also, it does idle at 500 when it's ice cold, but once warmed the 2 degree bump at 800 makes it settle at 900-950 nicely. There is also a warmup factor, cold advance is a few degrees more until a CHT sensor hits 200 degrees. 

Ignition also has 4 outputs switchable for load and rpm, plus a hard rev limiter(advance goes to 0 degrees 100  rpm before hard cut). I use the rpm outputs for a 3 segment shift light, and the fourth for my crankcase evac solenoid.

All in all, a really advanced system with all the options installed. And user friendly, help is just a forum away, like here. Especially for the money invested!

i am actually playing around with my megajolt maps too.  i don't know if i have made 21, but i've made lots.

Danny - would you be ok with sharing your .mj file with me?  i'll use my own config stuff on the map, but it would save me retyping the BIN / LOAD numbers.

I'll let you know how it works on my T4

 

Richard - what cam are you running?  i've got a webcam494 that provides TONS of torque and power seems to cap out at ~4K RPM

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