VW EFI Control

[David McCollam]

Does anyone know the Bosch P/N for the Volkswagon control unit that will work with the Opel L-Jetronic. I believe that it's from the 75-77 VW Bus. Any clues? Offers a bit more performance/fuel delivery from what I've heard.

Thanks,

Dave

[Gary]

Dave - I have one in my '75 wagon. I sent the numbers to someone last year (Scott D?) I'll try to look this weekend.

Gary

[rallye73]

Gary,
What do you think about starting a document that outlines direct conversion/crossover items and the opels they will work with? I realize there is/was a forum to handle this, but I was thinking about a stand alone file that was password protected (to prohibit unauthorized changes) and downloadable. On that note... what do you think about a similar document that could be an addendum to the FSM?
Darrin

[Gary]

Great idea Darrin. Keep an eye on the announcements.

[David McCollam]

Hi Gary,

Thanks. I talked to Scott, but he never sent the word on the part number.

Does it inprove you performance any?

Dave

[Sportwagon75]

Sorry Dave - Been swamped lately. Here's the note Gary sent me for the mass flow meter:

Hope this helps:
'77 Van

Bosch
0 280 000 149
022 906 021 S


I'll get you the computer part number tonight when I get home. -Scott

[Gary]

Originally Posted by David McCollam Does it improve you performance any? Dave

Tough to say as it was in the wagon when I got it so there is no 'before' reference.

I will say this though, there is a power band from ~4,000 to ~5,200 RPM that is impressive. Goes through it in a blink of the eye. That ECU is feeding a hi comp engine with a stock cam in a ported, big valve roller rocker head.

[David McCollam]

Gary,

That is what I have in mind for the engine that I'm building. Have the roller rockers on 2.0L valve head and flat-top 2.0L pistons.

Dave

[David McCollam]

Scott,

Thanks. How's every thing at the house?

Dave

[tekenaar]

Originally Posted by Gary Tough to say as it was in the wagon when I got it so there is no 'before' reference. I will say this though, there is a power band from ~4,000 to ~5,200 RPM that is impressive. Goes through it in a blink of the eye. That ECU is feeding a hi comp engine with a stock cam in a ported, big valve roller rocker head.

Believe you would see the same thing with the stock ECU with your mods, Gary . . . I mean, the performance is due mostly to your engine mods, not the ECU. As I see it, not exactly an "apples-to-apples" comparison with just a stock engine and only the different ECUs .

[RallyBob]

I believe with the stock ECU the power would start to 'lay down' at 4500 or so, since that is the point at which the stock air flow meter stops telling the ECU to add fueling....fuel delivery is linear at that point.

Gary's engine has 9.8:1 compression and decent airflow (102 cfm) from the (1.9H) head, plus a larger exhaust system than stock.

[David McCollam]

This engine will have the 2.0L valve on a 19H head with the Norris valve springs from Otto's Norris posting of last year with titanium retainers. The pistons are a .050 mm over-sized flat-top 2.0L in an E-block. The cam is a Norris solid lift unit with .451" lift and 282 degrees duration on a 108 degrees lobe separation. The lifters are the Purple Samdog Specials. Will L-Jetronic feed that? I have access to an 2.0L LE-Jetronic unit. Better choice?

Dave

[RallyBob]

Originally Posted by David McCollam This engine will have the 2.0L valve on a 19H head with the Norris valve springs from Otto's Norris posting of last year with titanium retainers. The pistons are a .050 mm over-sized flat-top 2.0L in an E-block. The cam is a Norris solid lift unit with .451" lift and 282 degrees duration on a 108 degrees lobe separation. The lifters are the Purple Samdog Specials. Will L-Jetronic feed that? I have access to an 2.0L LE-Jetronic unit. Better choice? Dave

What's the cam duration @ .050"? That might be too much cam for L-Jetronic to function correctly. It likes smooooth cams with wide lobe separation. Choppy idle quality will make the air flow meter fluctuate and the idle will literally go 'rich, lean, rich, lean, rich, lean..etc.' Plus the added overlap will affect the air flow meter at higher rpms, maxing the resistance value out even sooner than stock.

Tried this (2.0 L-Jetronic) on a 2.4 with a healthy cam, it was choppy at idle (actually sounded tractor-like, as if it had really bad piston slap). It was actually the air flow meter bottoming out.....open/close/open/close. It had nice torque, but by 3800 it started losing power, and by 4500 it started to detonate fiercely...no amount of tuning would compensate, if you made it richer to extend the power to 5000...it would load up the plugs and bog off-idle. You had a trade off at one end of the spectrum or the other. Motronic would work to a certain degree certainly. I really have no experience with the LE-Jetronic, but it's not really all that much more sophisticated than the L-Jetronic.

Basically if you start adding big cams you need to consider a programmable ECU. You will be much happier, the engine will make more power, will get better mileage, and it will live long enough to talk about it!

[David McCollam]

Bob,

I can get the specs at .050 and let you know. I also have a new hydraulic lift Opel 2.0E camshaft. Can't remember the specs on it, but Otto put them up somewhere, slightly stronger than the 1.9E I believe. Any thought on that?

Dave

[RallyBob]

Originally Posted by David McCollam Bob, I can get the specs at .050 and let you know. I also have a new hydraulic lift Opel 2.0E camshaft. Can't remember the specs on it, but Otto put them up somewhere, slightly stronger than the 1.9E I believe. Any thought on that? Dave

Cool, if you get those specs that will help.

Almost all the stock 1.9/2.0/2.2/2.4 Opel cams are sooo close as far as specs go, there's very little discernable difference.

The only OEM cams that are really worth the trouble are the stock solid lifter Opel cam (all pre '71 US Opels and most Euro 1.9's), the slightly hotter Rekord 'Sprint' solid cam (good luck finding one!), and the Kadett GTE cam....which is probably the best stock cam for EFI, hands down. Good idle quality and a few more HP, plus it was designed by Opel for factory EFI.

I've done a few custom cams for EFI I'm happy with, the hottest I'd recommend was a .441" lift, 214 @ .050" duration with 112 LSA.

The 2.4 that I mentioned before was fitted with a bigger cam still (222 degree intake duration, 218 degree exhaust duration), and even with the larger 2.4 litre displacement it was not happy until I put a carburetor back on it! Basically the bigger the engine the more cam you can give it without ill effects...to a point.

[David McCollam]

Bob,

These are the specs from the cams that I have:

Norris-Intake Valve Lift .451,
Duration 282
Intake Opens 31 deg BTDC
Closes 71 deg ABDC
Exhaust Valve Lift .451
Duration 282
Exhaust Opens 71 deg BBDC
Closes 31 deg ATDC
Lobe Center Sep. 110 deg.
Solid Lifters.

Opel-Intake Valve Lift .412,
Duration 302
Intake Opens 34 deg BTDC
Closes 88 deg ABDC
Exhaust Valve lift .412
Duration 302
Exhaust Opens 74 deg BBDC
Closes 48 deg ATDC
Lobe Center Sep 110 deg.
Hydraulic Lifters.

Any help?

Dave

[Sportwagon75]

Dave - Thanks for asking...all is well here. Still recovering from our trip to the RP. The Bosch part number for the VW computer (brain) box is 0 280 000 166.
Just in case it might be useful...the VW P/N is 022 906 021 AG. Hope these are helpful. Good luck. -Scott

[David McCollam]

Scott,

Thanks for the input. Glad that all is well on your return. I am totally confused now. Gary gave me a number that is different from the one that you've offered up. Guess that there are at least two. Gary says that his works well on a modified engine. You have also indicated that the box you have enriches the mixture at idle on a stock engine. This must mean that both boxes up the mixture across the range from idle to full throttle.

Much food for thought! Thanks again. Will soon have pictures of the Sport Wagon with fresh paint at Gene's.

Best wishes.

Dave

[jtb]

I have seen this used on rotary engines with much success:
http://www.bgsoflex.com/megasquirt.html

If you really want complete control of your fuel injection, and aren't afraid to really get into it (you have to solder the circuit board together!!!!)

jtb

[Sportwagon75]

Dave - I'm pretty sure the computer I have is from a 76 Bus where Gary's is a 77. Not sure what the difference might be. But here's sumthin else to consider. When I ran the VW computer in my 75 Manta...I didn't change anything but the computer. So the MAF, throttle body, injectors and everything else were original 75 stock Opel components. As I said, you could smell the unburned fuel and hear the rougher idle. I think Gary's setup is using all the bigger VW parts...including the MAF. What happens when you begin to mix and match parts is open to speculation. I have the MAF but never got around to putting it in with the computer. So I'm sorry I haven't had time to do much in the way of tuning and experimentation. Perhaps someday I'll find time. You might want to talk with Charles...he has a reference book for all of Bosch's early L-Jet fuel injection components and their specifications. I know he has it and I was planning to borrow it from him when I got around to finishing my engine and experimenting with different F/I component setups. Good luck.
BTW: Is this for the Rallye? Have you changed your mind? Or is this for the wagon?? Inquiring minds and all that rot...y'know?

[David McCollam]

Hi Scott,

You are probably right. That mix and match is not the best way to go. The increased performance aspect of Gary's engine probably also has some impact. I've got several of the Bosch reference manuals and service guides. I'll take a look at them and see. I have a cross reference for the injection parts and will take a closer look at those.

Thanks for your help.

Dave

[RallyBob]

Originally Posted by David McCollam These are the specs from the cams that I have: Norris-Intake Valve Lift .451, Duration 282 Intake Opens 31 deg BTDC Closes 71 deg ABDC Exhaust Valve Lift .451 Duration 282 Exhaust Opens 71 deg BBDC Closes 31 deg ATDC Lobe Center Sep. 110 deg. Solid Lifters.

Still no '@.050"' specs however, so it's hard to say. This number is more important than the advertised duration. Even though the stock Opel cam is listed as 302 duration, the '@ .050"' numbers are pretty small on the stock cam, so it is no doubt much smaller than the Norris cam.

[David McCollam]

Bob,

I'll check the card at lunch and see if there is anymore information. The valve clearence check was listed as .020" does this help?

Dave