Questions: Autronic setup being configured for 210hp 2615cc

ray greenwood · Post by **ray greenwood** » Thu Feb 14, 2002 7:29 pm

Shad, be careful on your injector sizing. Too large and you will never get a handle on it. Most systems will have as much accuracy problems trying to produce a way short cycle based on exhaust input, as they will one that is beyond the injectors dependable range. Also what pound per hour based upon what PSI range. The low 30's will probably be fine with either an adjustable rising rate regulator with a tunable vacume circuit or a seperate impulse injector. You need to be thinking of not only max cycle rate pounds per hour...but also based upon max enrichment fuel pressure. A rise in fuel pressure will increase volume by a square function...negating the need for a huge injector that enriches by cycle rate alone. Keep your tank side supply lines large...and the upstream supply lines ..stockish in size . You will do best with a small spring loaded diaphram type fuel accumulator...call me and I'll tell you how to modify a CIS one to work. The problem with having too large a diameter of fuel line is that any drop in pressure requires a lot of volume from the pump QUICKLY to get that larger volume line back up to pressure. If you are using atreturn line, the system supplys much more fuel than any of your injectors can possibly use. If not, put a seprate pump on each rail with a common regulator. If you are using a dead-end line...you will always have pressure spike problems because you have injectors arrayed down the rail...and the fuel replenishes from one end only. This spike/drop may only be a half second 3 psi flicker on the guage...but think of how many injections at reduced pressure you are trying to get at 4000 rpm. Put the fuel accumulator at the end of the rail in a dead end system to modulate the pressure loss. Ray

Steve Arndt · Post by **Steve Arndt** » Thu Feb 14, 2002 11:25 pm

Shad,
If you want a short/small distributor to use only for triggering, go for the 2.1 Vanagon 205 dizzy. It has no advance mechanism. I'm going to remove three of the four vanes, then set the SMC to work with it. John and I have talked about fitting sensors directly into the face of the cam drive gear, true dizzy-less then! I have even found a sensor that works in the oil/high temp environment.

Did you buy an SMC in the group buy Shad? Jay and I did.

Jay has a set of 300zx twin turbo coils that I'm going to buy. I plan on glassing in mounting brackets into my 911 PTP shroud to support the coils. Coil on plug man! I'll power them with an MSD DIS-4 4 channel CDI.

Steve

[This message has been edited by Steve Arndt (edited 02-14-2002).]

Searoy · Post by **Searoy** » Fri Feb 15, 2002 1:54 pm

Well, with a 10000cfm TB, I can get a projected peak 216hp

Wow Shad, That's one hell of a throttle body.

------------------
*** Teach a Man to Fish ***
Searoy

"I tend to lean toward a tighter gap and a
looser skirt....a little slap never hurt." -- Joe of the West

Searoy · Post by **Searoy** » Fri Feb 15, 2002 2:00 pm

A Type 3 guy here in San Diego told me that he runs Mercedes V8 injectors. They're Bosche, but they are the next size up from stock VW. He even runs an otherwise stock T3 fuel injection.

------------------
*** Teach a Man to Fish ***
Searoy

"I tend to lean toward a tighter gap and a
looser skirt....a little slap never hurt." -- Joe of the West

dstar5000 · Post by **dstar5000** » Sun Feb 17, 2002 11:28 pm

Shad, the early Mazda rotorys had some VERY small double coils...you COULD hide THOSE in the shroud!!

NOT to step on any toes and I am a newbie to these dizzys, I have the 205S dizzy in my van(played with today...)and they HAVE to have mech advance as I can hold the bottom and twist the rotor just a bit and it springs back! That makes me think it has some mech advance. Please educate me!

Don

------------------
"An eye for an eye will make the whole world blind" M. Ghandi

Shad Laws · Post by **Shad Laws** » Mon Feb 18, 2002 9:29 am

Hello-

Shad, the early Mazda rotorys had some VERY small double coils...you COULD hide THOSE in the shroud!!

Neat idea! I'm probably not going to mess with it (my system works too well right now), but for those with more room in the shroud it'd be a clean little modification

DIS with no spark plug wires showing...

NOT to step on any toes and I am a newbie to these dizzys, I have the 205S dizzy in my van(played with today...)and they HAVE to have mech advance as I can hold the bottom and twist the rotor just a bit and it springs back! That makes me think it has some mech advance. Please educate me!

Most 205-series distributors are dual-advance. The term "vacuum-advance distributor" for them is a misnomer - they have vacuum and centrifugal advances. (BTW, mechanical advance is also a misnomer... vacuum and centrifugal are both mechanical means of advance, only electronic means are non-mechanical...). There were vacuum-advance-only distributors, which had no centrifugal advance, and these existed in the era of the 40hp engine. They were very small...

Take care,

------------------
Shad Laws
LN Engineering
http://www.lnengineering.com

Steve Arndt · Post by **Steve Arndt** » Wed Feb 20, 2002 1:26 pm

I don't know the letters that go with each 205.
The 205 for 1.9 vanagons has dual advance.
The 205 from the 2.1 has no advance. It is a triggering device only. The ECU handles the ignition settings, the dizzy is only a pickup for RPM.
Steve

<BLOCKQUOTE>quote:<HR>Originally posted by Shad Laws:
Hello-

Shad, the early Mazda rotorys had some VERY small double coils...you COULD hide THOSE in the shroud!! 

Neat idea! I'm probably not going to mess with it (my system works too well right now), but for those with more room in the shroud it'd be a clean little modification DIS with no spark plug wires showing...

NOT to step on any toes and I am a newbie to these dizzys, I have the 205S dizzy in my van(played with today...)and they HAVE to have mech advance as I can hold the bottom and twist the rotor just a bit and it springs back! That makes me think it has some mech advance. Please educate me!

Most 205-series distributors are dual-advance. The term "vacuum-advance distributor" for them is a misnomer - they have vacuum and centrifugal advances. (BTW, mechanical advance is also a misnomer... vacuum and centrifugal are both mechanical means of advance, only electronic means are non-mechanical...). There were vacuum-advance-only distributors, which had no centrifugal advance, and these existed in the era of the 40hp engine. They were very small...

Take care,

<HR></BLOCKQUOTE>

Hot Wheels · Post by **Hot Wheels** » Wed Feb 27, 2002 5:39 am

How do you calculate the injector size required? I think i need to smaller. Mine is 2199 (66X103) that should turn 8k or so. Its on the dyno now and i am having problems with the cold start and getting the 31lb injectors to idle lean enough. Im down to running them at the lower limits of adjustability at .85 volts and i still cannot make it to lean. My guess is that low voltage is hard on the injector and that if i go to 25# injectors i can operate them at a little higher voltage range and cure my low end problems.

BTW i am running the CB ultra setup with thier computer system.

Sean

Post by **Tom Notch** » Wed Feb 27, 2002 12:14 pm

I think you need to talk to CB. They will have to do some magic for youI use 36 pound injectors and have no problem, but I have a fully programable system. This is on both my 2161 and my 2.7L. If you go to 25 pound injectors, you may rum into a lean condotion at 8K. At that rpm, the total time that an engine can use an injector is around 6.5 ms, maybe a bit less, I don't have my tech stuff here at work. If the injectors can't deliever enough fuel in that short of time at WOT and full load, you will lean out and go poof! There is a link off my site that gets into injector sizing, its listed under my efi stuff and off my engine pages I think.

------------------
Tom Notch
Tom's Old VW Home

BergRace · Post by **BergRace** » Wed Feb 27, 2002 1:22 pm

Here is a free program which also does EFI and injectors:
http://www.mrm-racing.a.se/software/Div ... bocalc.zip

------------------

P.J.Berg.

JohnConnolly · Post by **JohnConnolly** » Wed Feb 27, 2002 2:03 pm

You if you are at a low duty cycle, you need to drop your idle fuel pressure, that should solve your problem. I recommend a HIGH pressur pump to overcome smaller injectors for the best of both worlds. A good pump is 4$250.

John
Aircooled.Net Inc.

Searoy · Post by **Searoy** » Wed Feb 27, 2002 2:56 pm

http://www.geocities.com/lutransys/jluc ... l-flow.htm has what appears to be a pretty good air/fuel calculator. The guy is a GT3000 freak, but the math should be the same, just with 2 less cylidners. It's in Java, so will do the moth for you.

------------------
*** Teach a Man to Fish ***
Searoy

"I tend to lean toward a tighter gap and a
looser skirt....a little slap never hurt." -- Joe of the West

airsix · Post by **airsix** » Sun Mar 03, 2002 6:34 pm

Hi guys. I just stumbled onto this thread today. I'm the guy with the hall-sensor on the fan of my 914's type-IV. Long story short - It doesn't work. Don't waste your time.

Three possible reasons
1) magnets visible to sensor for too few degrees of rotation.
2) flexing of fan causes air gar to vary.
3) some other d@md thing.
After 9 months of not driving my daily driver I said enough and yesterday I gave up on crank triggering. I dug up my distributor, gutted and locked it, and fitted a pickup and reluctor from a Mitsubishi. Everything worked great but I had to gring the corners down on the pickup. Now it fits perfectly but it's now broken <insert temper tantrum>. Anyone know what I can exect to pay for a 205 dizzy from a 2.1 l wasserboxer?

Steve Arndt · Post by **Steve Arndt** » Mon Mar 04, 2002 9:27 am

<BLOCKQUOTE>quote:<HR>Originally posted by airsix:
Hi guys.
Anyone know what I can exect to pay for a 205 dizzy from a 2.1 l wasserboxer? <HR></BLOCKQUOTE>

Yup. The Dealer, or Even Schucks for a rebuilt unit. I think the dealer price is $169. I have one waiting for my Autronic project.
Steve Arndt

airsix · Post by **airsix** » Mon Mar 04, 2002 10:04 am

<BLOCKQUOTE>quote:<HR>Originally posted by Steve Arndt:
 Yup. The Dealer, or Even Schucks for a rebuilt unit. I think the dealer price is $169. I have one waiting for my Autronic project.
Steve Arndt

<HR></BLOCKQUOTE>

Steve, thanks for the reply.

Ok, hopefully last question on this - Did anyone figure out the input voltage for the sensor on the 205? 12v? 5v? other? I'm also trying to find a pin-out diagram but no luck so far. I'd hate to fry another expensive electronic component. Thanks.

-Ben