New Member Intro -Full Sequential Porsche Engine VW Camper

[PorscheKombi]

Hi Everyone,

My names Nathan and I thought I would do the polite thing to introduce myself before I pepper the forum in the coming months with endless, mostly novice, questions.

My current ride is: a Porsche powered VW Camper. I restored the bus myself and fitted the engine myself - Its got a standard 1981 Porsche 911 3.0L SC Engine with CIS K-Jetronic injection.

I have decided to upgrade slightly to a more controllable/tuneable megasquirt system. Here is what I plan to do:

Fully Sequential - MS3 self-assemble Kit with MS3X
Utilising the 3.2L Carrera Fuel injection system I will
Replace low-z injectors with high-z injectors
Replace fuel pressure regulator with adjustable (probably with gauge)
60-2 Crank trigger wheel with Hall Sensor
Cam Sync Sensor with Hall Sensor
COP with built in drivers - (High resistance ones to avoid having to create buffers)
Replace stock TPS with variable type
2 wideband sensors - one per bank
MAP sensor
CLT - fitted to cylinder head seems to the place
MAT from intake
Stock IACV
unsure whether to bother with a knock sensor

will be keeping the cold start temp sensor - fitted to the cam chain cover
oil pressure gauge
Oil temperature gauge
oil pressure idiot light

This is my Camper:






I have build my board up:




I have built up this and managed to get the sequential spark and ignition LED's flashing away - with help from a self-assembled Jimstim and Jimstim-X.

Although I have got the minimal info in my Tunerstudio Lite build to make sure my assembly was good, I have read that you should start with a base build/map for your installation and tune from there. Therefore, if anyone could provide me with a base setup to start with this would be fantastic. Its a 3L 200BHP fully sequential N/A engine.

Any comments, suggestions or tips welcomed.

Apologises if there is a more suitable forum - feel free to move.

Nath

[Matt Cramer]

Very cool build! The recommendation means more that you should start from the default tune instead of a file full of zeroes. Generally once you get the default tune scaled for your engine / injector size and the ignition set up, it should be in the ballpark to get started.

[cmonref]

PorscheCombi,

Great project! Your setup looks almost exactly like my '80 SC, except I put a MAF where the barn-door AFM went, a single O2 on the left bank (you're right to go with two O2 sensors). I did not try to install a CHT but rather replaced the cold start injector (you will not use it for anything) on the left chain box with a different sender so it reports oil temp which I use as CLT. I use a 3.6L distributor internals for the cam sync signal -- it bolts right into the SC distributor. I tried VAG coil on plug and could not get them to work because I cut off the metal shroud, so I now use LS-2 D585 coil near plug which work wonderfully. I put knock sensors on the bars on the intake between 1-2 and 5-6 and am in the process of tuning them. When it comes time for start, I could give you an MSQ but you would have to change a few things since I'm running MAF right now.

Brian
Chester, VA

[PorscheKombi]

Thanks for the replies It's good to know that I already have an allie who has already already done very similar.

After a little reading I will be using Alpha-N.

I have to do a fair bit of reading in terms of all the functionality etc as well as all the different tables etc. Any good links would be handy.

Brian, I would be very interested to see some pictures of your build - specifically of the cam sync using the dizzy. I really want to make my install as minimalist looking as possible which is why I was going to go with the clewett cam sync. As for replacing the original timer switch in the left cam chain cover to read oil temp instead of CHT, my thinking was that it may be a more reliable/responsive temp reading than the oil. How did you find it worked?

Cheers again,

Nath

[cmonref]

PorscheKombi,

This picture shows the pieces that come out of the 911SC distributor and the ones that go back in (from the 3.6 L distributor.)

copy 100_1312.JPG

The 3.6 L parts are the two on the right. The hall sensor is the black piece in the lower right corner, and the "window" in the piece above it covers and uncovers the hall, giving the one-per-two revolutions that are needed to enable sequential. I put the original rotor on top of those simply to give a familiar picture of where the distributor is positioned -- but the rotor serves no function beyond that since the coil-near-plug setup is fired from the MS3.

I have found the oil temp in the left chain box to be a fairly good CLT representation. It is being used by several folks on the Tbitz group over on Yahoo. CHT would be better, but I have not seen one installed on a 3.0L head that worked well. Most have been put in the air stream and so have reported high temps under power and much lower temps when not under power. 3.2L heads with the CHT position would be better ...

Brian

[cmonref]

PorscheKombi,

Forgot something. This picture shows the assembled distributor with the black piece needed to bring the three wires out of the hall unit. The source eludes me at the moment, but I think it was Motec. It is the standard piece that is used in this application on the 3.6 L distributor. You will also need the special connector that hooks to the unit shown.

copy 100_1311.JPG

Also shown is the plate that covers the location where the vacuum advance mechanism was removed.

Not shown here is the rotor and the standard distributor cap I mounted to cover it all up. The cap has two spark plug wire towers cut off and no wires sticking out of the top -- again because the ignition is fired from the MS3. Reactions of other Porsche people to "look, no wires" is interesting to say the least.

On my 1980SC, I also installed the pre-1980's heater duct on the left side that passes behind the distributor. I had to modify the heater duct to provide more room for the black wire adapter shown on the distributor. (That is also the reason I had to cut off two of the spark plug towers on the cap.) If you do not make this mod, your problems may go away or might be simply different.

Brian

[PorscheKombi]

Very interesting and clean install in the dizzy. Thanks for the reference

Nath

[piledriver]

Why would you choose alpha-n? Planning to run ITBs? Installed huge cams?
Speed density is the default, unless you install a MAF that is almost certainly the way to go on a stock motor.
(from all accounts the MAF code is usable now, and MAFs are cheap used... Just saying.

[PorscheKombi]

As a learner, I thought that Alpha-n used TPS rather than MAP which is more responsive/tunable due to the lag time between throttle position and change in manifold pressure?
Would you recommend the speed density (MAP) setting then?

For reference, I'm running single throttle body as per 3.2 Carrera with TPS, MAP and MAT. Not using MAF sensor

Nath

[cmonref]

On my 1980SC with 3.2 intake, I put MAF where the AFM went between the stock air filter and the rubber 90 that turns the air down to the throttle body. (Other advice says that you need many inches of straight lead-in pipe before entering the MAF test range, but I did not do that extra fabrication.) Change out the TPS from the stock "switch" TPS to a continuously variable type (with a 3/8" spacer as shown below.) With this setup, I ran speed density for 18 months and switched to MAF about 4 months ago, and MAF came together quickly. Documentation leaned heavily onto Speed Density over Alpha-N for all but really special engines.

TPS Install.jpg

copy Center manifold detail.jpg

Brian

[piledriver]

As a learner, I thought that Alpha-n used TPS rather than MAP which is more responsive/tunable due to the lag time between throttle position and change in manifold pressure?
Would you recommend the speed density (MAP) setting then?

For reference, I'm running single throttle body as per 3.2 Carrera with TPS, MAP and MAT. Not using MAF sensor

Nath

Any production vehicle using EFI in existence uses SD or MAF. (I cannot even think of any outliers)
There is a good reason for this.

TPS is ~only used for accel corrections.
Alpha-N has a very limited use case, and even in those cases a AN/SD blend will usually give better results over the full operating range.

[PorscheKombi]

Thank you very much for the advice. I will change my method to SD

[Matt Cramer]

Any production vehicle using EFI in existence uses SD or MAF. (I cannot even think of any outliers)
There is a good reason for this.

Evidently a few motorcycles were alpha-N, in order to work with a high winding engine with ITBs. Never heard of it on a production car, though.

[seishuku]

The Nissan KA24E had a few conditions with the stock EFI that caused it to use Alpha-N, I don't recall what triggers it though. Probably applies to other Nissan engines that used similar ECUs too.

[piledriver]

It has been used by OEMS and discussed as limp mode for MS3, for MAF/MAP sensor fails etc.
Oooh, something for MS4...

[Matt Cramer]

It has been used by OEMS and discussed as limp mode for MS3, for MAF/MAP sensor fails etc.

Not just discussed, implemented.

http://www.msextra.com/doc/ms3/cel.html#fallbackmap

[PorscheKombi]

so a little update on my parts collection:


-two innovate LC-2 controllers and wideband exhaust sensors
-throttle position sensor
-knock sensor module to fit to my ecu board (will have to modify the board a little, but think its just a matter of fitting a few jumper wires
-the black circle by the blue switch is a mount for the cam sync for reading TDC on no.1 from clewtt engineering. fits like this: http://www.clewett.com/instrux/cam-ins.pdf
-air inlet temp sensor
-a load of switches and connectors for wiring all up and for my engine bay fuse box.

still have a few bits still to buy but the only main things are the elusive coil-on-plugs, the injectors and fuel pressure reg. with pressure gauge

I've still been working on the wiring design and trying to minimize it as much as possible...trying to be clever on where it will be installed.

I came across these fuse/relay boxes which are quite smart: http://www.swecheck.com.au/catalog/9004.pdf

However, when you add up the price of the box/es and relays and pins with seals it gets pretty pricey. think i'll go for it though...it wil be cheaper if i spread the cost over a longer period lol.

[PorscheKombi]

Hi Guys,

Just a quick check that I have installed my knock sensor correctly - as per instructions:

As per the instuctions I aligned the module with the DIP 40 on the MS3 Card and soldered in place.
I then soldered the two "support" pins to the DIP40 pins they aligned with.....was this correct?


I then used soldered a flying lead from PM2 to PM2, followed by two flying leads from K1 & K2 to the suggested SPR3 & SPR4 (currently unsoldered in the pic):


Just double checking this is correct.

To ensure I had good soldered joints i tested the continuity/resistance from top of knock module to underside fo MS3 board.

Cheers

Nath

[Matt Cramer]

Yes, that's how it works.

[PorscheKombi]

Yes, that's how it works.

Thanks for the clarification.