1988 Porsche 944 Track Toy

Today was a fantastic day for wrenching.

I got the airbox, throttle body, intake manifold, fuel rail & fuel lines, ignition wires, oil filter, oil drain plug, coolant hoses, fan electrical, vacuum lines, and engine sensor wires all reinstalled.

I also torqued the crank bolt. CHECK.  (This was the failure mode the last time, I believe)

Still to do:

• dress the heavy electrical wires and hall sensor connectors at the rear of the engine
• source hardware to finish the dash (pull-cable end for the ignition cutoff switch, and instrument panel screws)
• clean out the oil cooler (it had some water in it just from sitting with the hose ends pointed up) and re-install
• connect the starter
• fill with oil & break-in additive
• prime oil pump
• fill cooling system with distilled water (then add water wetter after success is confirmed)
• replace bumper
• install front sway bar
• install front strut tower brace
• put tires back on
• get that car to start

I did everything above. The car runs!

I have Good News, Everyone!

A) It starts right up and sounds good. Mostly.*

B) I appear to have normal oil pressure, and the water temperature reached equilibrium and I can hear the radiator fan relay cycling on and off.

C) No smoke out the tailpipe. No leaks that I noticed. Nothing broke.

I have remaining issues.

1) The [ ! ] light at the top of the instrument panel stays on. But just to be difficult, it's not quite fully on. Below is a stock pic of the indicator. But mine's a little dimmer than this.

2) The passenger-side fan still doesn't work. But the new driver's side fan works great. Earlier I tried to trace the wiring back and I suspect it's some portion of the relay. More testing is necessary.

3) I can't tell if the oil is circulating to the oil cooler. I was hoping the lines would start getting hot but they didn't.

4) If the header seems to get really hot in a hurry... are we running rich? lean? I'm paranoid.

*So the engine sounds ok but I think maybe I need to go back in and look for stuff up front. Something sounds a little rough coming from the front of the engine. Could be anything... idlers, water pump, etc.

I'll take the front covers off and see if I can isolate the sound.

Remember: It's not paranoia if the engine really wants to kill itself.

I figured out what went wrong with the radiator fan, and now that I realize what happened, I'm not quite sure how they work at all.

I removed the low speed resistors when I did my rewiring two engines ago, because I thought they were the resistors for the heater box blower fan. They are NOT those resistors.

So without those resistors in place, only one of the fans runs, and at high speed at that. That might mean that the fans won't turn on until the radiator is good and hot (102 degrees) as opposed to 92 degrees which would normally trigger the low-speed fans.

So, I've designed a new circuit that still uses the thermistor's high and low speed switching, and which bypasses the stock fuse box which I butchered.

This utilizes a 30A fuse, two 30A relays in series (similar to the stock relay arrangement), and the same power resistors. What I need to do is calculate and/or test whether the stock power resistors (0.9A) are the appropriate size for the new SPAL-like fans that I've installed.

The fans say "12V 80W" on them. That says to me that each should draw 6.7 amps. Which is well under what the old ones drew. I figure I can combine them into the same relay which is rated for 30A at 12V.

What I don't like is that my relays say 30A but the wires coming out of the sockets are 16AWG wire. I've read that 30A should use 12AWG wire, so I'll buy a few better built ones with the beefier power wires.

I'll dive into the calculation of whether 0.9 ohms is ok or not, but if you know offhand what the resistance should be to cut the fan speed in half, let me know!

Thanks!

 All those relays are rated at 30 AMP.   So you shouldn't attempt to put more than 30 AMP thru them, doesn't mean they are always drawing 30 AMP.

    The two wires that activate the little coil can be fairly small, the point of the relay, use small current to trigger the relay and use the relay contacts transfer the actual power draw.   This way the light switch for example sees very little power, but the lights get lots of power.

   In this case the relays are used for control, but also to reduce the load on the sensor switches.

    The thicker wires in the diagram should be larger, since those carry the load.

In reply to TED_fiestaHP :

Thanks, TED. Everything you said makes sense. The relay sockets I’m going to buy are built exactly as you describe, with the high power leads having 12AWG and the switch leads having 16AWG. I will certainly use the larger gauge wires for the bold-line connections.

I would eliminate the panel switch, just pull WT from an ignition on circuit. You can add an ignition off bridge to run them engine off if you want, but remember to put a diode in to prevent back feeding the rest of the ignition circuit.   That way you can't forget to run them. This diagram leaves the driver with too many things to think about during a red flag or grid delay. Also pull your high speed BL & WT wires directly, so if the low speed relay fails the high speed fans will still run. No need to run them through two relays. 

In reply to TurnerX19 :

Those are both good ideas. Running from ignition sounds like the simplest way to go about it.

And running the power directly to each is a cleaner, less failure-prone design. Thanks!

I verified that using the 0.9 ohm stock resistors will make the voltage drop by 4V, providing 8V to each fan.

Total draw on the low relay will be 106.67W, or 8.88A. (17.78W for each resistor at 4.44A x 4V, plus 35.55W for each fan at 4.44A x 8V)

Total draw on the high relay will be 160W, or 13.33A.

Neat calculator for just this situation:

https://www.blackfiveservices.co.uk/fanspeedcalc.php?Voltage=12&Current=6.6667&Target=8

Simpler and safer. With a cool racing team logo. What's not to like?

Woof, glad to lend my experience. I cooked one once from forgetting to turn on the fan....

Labor Day weekend was probably one of the nicest I can remember, weather-wise. So I took advantage of the temps and low humidity by painting the interior of the car.

Normally, I take great satisfaction in paint prep. It's nice to get something perfect. However:

I really dislike paint prep for a large, complex, difficult-to-reach painting area. The sanding, scraping, and goo removal never ends, and perfection isn't really fun to achieve, nor is it necessary. So this sort of job really clashes with my OCD tendencies and my patience.

This stuff peeled off in messy glue globs surprisingly easily with a wire brush (but not with a wire wheel - go figure).

I removed the passenger footrest, brackets, old dashboard supports, and the hood latch pull brackets on the driver's kick panel.

The driver's footwell isn't rusted. It's had rainwater in there along with some rusty nuts and bolts.

And, the doors have always been dirty, messy, calico-colored places. I've wanted to do this for a long time.

Now, I hadn't set out to do EVERYTHING but scope creep happened, and I was still awaiting parts for my fan re-wiring project.

I ended up doing everything but the cage, which will be a different color. The doors and floors had never been completely painted after the interior and carpets were removed four years ago, so this would be the first time the tub was painted one color!

And at long last, the payoff!

I did the doors first, on Saturday.

Then after prepping all day sunday and most of monday, I primed and painted from the edge of the rear deck forward.

I'm really happy with the Rustoleum "Machine Gray" color. It's a little warmer and much glossier than primer, and it should keep things cool.

I do have plans for the upper firewall behind the dash, but I want to have the final wiring situation in place first, and there are a few unnecessary holes that should probably be filled as well.

I needed to wire in a fan circuit, and unfortunately I have now gone beyond the point of no return - the stock fuse box is coming out.

I bought some wire, a small fuse block, some relays with nice heavy 12AWG leads from the power legs, and I began mocking up a wiring panel.

In the picture above, you can see my new switch panel, which is temporarily made from aluminum. I have some pieces of carbon fiber that will eventually replace it. But for now, this is what I'm going to build up. This switch panel will hold switches for ignition, wipers, rain light, future things like a blower and/or coolsuit, and some LED's in rows. It should also have room for my stupid MyLaps transciever key which I've never gotten around to hardwiring in.

Behind that switch panel, you can see the DME (computer) which has been mounted to the firewall with some of my floor tile behind it to cushion it a little from mechanical shock. There are a couple ears that I fabricated there, and to those I'll attach the "fuse & relay" panel.

I'm pretty happy with that too. That panel will also be carbon fiber, and for now, I'm breadboarding it using some foamcore poster board.

The thing I'm hung up on right now is this switch panel, and how I'm going to mechanically tie it in with the dashboard.

It's just kind of floating up there, and there's very little nearby to tie it to. I'll keep thinking about it but I really don't have a good plan for it. I want it to provide a little support to the dash, because the dash currently bounces around a little on the fairly weak supports I've built for it.

The dashboard supports do not interface with either side of the panel, so I'll have to build something out to the sides. Maybe I'll rivet a piece of aluminum L-channel to the top and then make some pieces of aluminum sheet that jump to the dash somehow. It's gonna be ugly.

I made some major progress today, despite spending most of the time thinking, studying, looking up wires, and contemplating my next move.

I have now removed nearly all of the stock wiring. I kept the engine harness and the fan wires, but otherwise, it's all gone.

I love pictures like this. Even if it is blurry. You get the idea.

What you don't see here is a stock fuse box. It's gone, as are all its block connectors. Two wires will go to the wipers. And the other two wires there go to the alternator.

This is truly a milestone... I'm no longer afraid of my car's wiring. I will know what each wire does and where it goes. When I'm up and running, I'll draw up a complete wiring diagram and post it here.

Once I had the wires all planned out, I decided to start fabricating the new instrument cluster. I could re-use the old one despite the missing wire loom, but it would probably be more complicated at this point.

I made up several cardboard templates, each being refined a little further. It worked out pretty well.

The pieces of carbon fiber I have are only 24" wide. Any wider and I'd have to pay ten times as much for shipping. They don't reach all the way across the opening. So I'm going to keep a small section of the aluminum, give it a brushed look, give it one purpose (cutoff switch), and make it look like I meant to do that.

I have the big tachometer that was mounted to the roll cage when I bought the car. That and its shift light will go in the middle. I bought a couple gauges so far... and I may still do a little arduino project to make a fuel gauge for myself. But ultimately, I think a full set of gauges will look sharp.

The carbon fiber board still has a protective sheet of plastic on it with wrinkles in it. Hopefully the final result will be dazzling. But not too dazzling.

Also look how few wires there are! It's going to really clean up when I finish building the fuse panel. I'm pretty excited at this point!

Looking really good! Race car widing can be so good and simple.

I mounted these components to a piece of the carbon fiber board. It’s now mounted to the little ears on either side of the DME box.

I’m trying to build this with easy disassembly in mind.

I tested a 2” hole saw on a scrap piece, and then, satisfied it would work out, I went to town on the real one.

I ordered two more gauges.

So in total, I will have six gauges from left to right:

1. Holley programmable fuel gauge with integrated programmable warning light (separate fuel warning light from stock sender)
2. ProForm tachometer with shift light
3. VDO water temperature gauge (separate high temp warning light from stock sender)
4. VDO oil pressure gauge (separate low pressure warning light from stock sender)
5. VDO oil temp gauge (from new sender in oil drain plug)
6. AutoMeter voltmeter gauge

The tach and volts gauges came with the car when I bought it, but they are silver colored. Paint it black.

I had three different cans of semi flat black in various vintages. Paint came out of just two of them, but it was enough to get this little job done.

These are teeny LED lights that I’m hoping have integrated resistors so I can just apply +12v or complete ground to light up. The green ones are actually to go above switches on the switch panel. Red ones are on the way for idiot light duty here.

I bought a couple sizes of aluminum angle extrusions to build up my console support. I chose the large one.

Then I cut out a couple tabs to reach over to the angle. I fastened these with.. what else? Riv-nuts, natch!

Then I put the switch panel back in and figured out how much more bending and massaging would make them come together naturally.  Not much, it turned out. 

Just one additional gentle bend to bring the planes together and it was ready to rivet together with some glue to help out.

Now it was possible to lay out my switches and cut some holes.

To be sure I got good grounds, I used the stock grounding points with dedicated leads for almost all the gauges and sensors.

As much as I could, I made connections so that most (ideally all) components and/or entire panels could be removed without cutting a wire. I think I got there for the most part.

I'll be turning adding these pictures to wiring diagrams in my binder.

At one point, I got really smart and wired up most of the gauge cluster before even introducing it to the car. This saved me a lot of time otherwise spent on my back in uncomfortable surroundings.

And on Wednesday, I got that car started again! On Thursday, I got it fully warmed up and checked on fans. They work, and they keep it cool. But I want to check all the states of the circuits to verify they are working as I expect them to.

For example, I'm not actually sure if the fans were running at half speed or full speed. I have to do sanity checks on that with a multimeter.

Problem #1:  The oil pressure gauge's illumination light isn't working. That's annoying for a brand new gauge.

First I thought I'll have to order a bag of teeny light bulbs.

Second I thought that maybe the bulb is an LED one, just put in backwards. I may have swapped it when I had a little trouble with wiring it. One of the spade connections had pushed into the housing (also very annoying and cheap), allowing the bulb to drop and swim around inside the gauge itself. I retrieved the bulb and stuck it all back together. So I couldn't be sure if I had done that incorrectly.

Knowing I wouldn't be able to sleep unless I knew what was going on, I went out to the car. I turned on the power. The gauge lights came on (except that one). They are going to need to be on their own switched circuit, by the way. And as I wiggled the bulb a bit, it illuminated. I brought it inside for a closer look. I think that when the bulb fell out, or during its replacement, its contacts had slid aside, and weren't making positive contact in the socket. I'll put the bulb back in properly tomorrow and all will be forgiven.

Definitely not an LED lamp. VDO-branded LED upgrade bulbs are $15 apiece (!)

Problem #2: The Oil Pressure Sender Is Being Difficult

The oil pressure gauge goes to full peg on when I turn on the ignition but not running. But in that state, it should read zero psi. The idiot light, wired separately, is on, and that's normal (see pic below to see some obnoxious red LED output). But when I start the engine, the gauge drops to 80 psi (which equals 5.5 bar and is pretty normal) and as the engine warms up it goes down to around 60 or 65 psi (4.1 bar, also normal). The idiot also light goes out as soon as the engine starts, thank goodness. Normal.

I think I will have to order a new pressure sender. I believe the sender isn't really working all that well and doesn't make any contact until it gets a good jolt of 13 volts. A new one would probably work properly. What I have to figure out is exactly which thread size my car wants, and what number of bars or PSI is meant to trigger my idiot light. I could buy the OEM part for $120, or I could buy a VDO aftermarket sender for $40 or so. Same part.

^^ This is what it looks like when the mains are turned on but ignition is off.

And this is what it looks like when the ignition switch is turned on but the engine hasn't been started.

The green light is wired not to the output of the ignition switch itself, but to the ignition relay output seen at the start button. It's an instant indication of what that relay is doing.

Problem #3: The alternator isn't excited.

The blue light is the start button. This is an interesting one because it works just like the OEM warning light. It is powered by the ignition circuit (battery voltage) and the other end goes to the alternator's "exciter" connection, which is zero volts (ground) while the alternator isn't doing anything. When you press the button, it completes the starter motor solenoid, which starts the engine. As the alternator spins up, it needs to see a bit of a load at the exciter connection to begin charging. If it does, and it starts charging, the voltage on the exciter connection comes up to full alternator output voltage. Which becomes the same as battery voltage. And the start button LED goes out because the voltage becomes essentially the same at both ends (net zero volts).

Except in this case, it didn't go out right away. The start button stayed on, and the voltmeter continued saying 11.5 volts. Meaning the alternator wasn't doing anything. Fortunately as soon as I revved the engine just a bit, the light went out, and the voltmeter started reading 13.5 volts. YAY!

So I think the reason for the hesitation is that the integrated resistor on the LED is only 50 ohms, while the little 3-watt warning light bulb offers 120 ohms. I have a handful of power resistors including a couple 50 ohm ones. I just don't quite know how to add them to the circuit. Maybe a 50 ohm in series would help. Hopefully the LED would still illuminate with that voltage drop. It's pretty bright, after all.

Any thoughts?

Perfectly normal for Bosch  alternators to require 1500 rpm or so to first trigger the alternator. If kept at idle during start up both of my daily drivers do not charge. As soon as oil pressure is up a little blip and the voltage comes up. Alternator load then makes the X1/9 stall.....Volvo idle tries to come down a little, but the compensator system overcomes it. 

In reply to TurnerX19 :

Thank you sir, for helping me through this. Now that I've rebuilt the wiring system, I'm just as afraid the electrical system wants to fry itself as I am that the engine wants to destroy itself.

CrookedRacer said:

Hi, I hope my response isn't too late!

On the comment... I didn't think the face of the valves get a backcut in any case. Here's the "competition valve job" picture. This is the head that has remained on the car ever since I had that done.

If there's a shiny edge here, I think it's just because it's clean, not because it was beveled on the face side.

My understanding of a competition (aka performance) valve job was that the valves themselves are given a multi-angle grind on the seat side instead of just the usual 45 degree seating surface. I could be wrong about that.

Maybe I'm misunderstanding your comment, but: I retained the same head (pictured above) and all its valves except the #2 cylinder when I changed engines. I stole the valves from the donor engine's head and installed those in the head pictured above.

So I took two valves from this head (type of valve job unknown)...

...and put them into my original head. Your comment did get me to wondering if there was anything special about the donor engine's valves. I never really thought about it. I just lapped the seals and ran with it.

Which resulted in this:

https://s3.us-east-2.amazonaws.com/prod.mm.com/uploads/2019/05/05/1557107296_20190505_194359_mmthumb.jpg

And the only reason #2 looks shiny is that those valves have been cleaned up a bit, and I never touched the others. Again, this is a picture of my original "competition valve job" head, with two valves from the donor engine installed.

The observation:  Getting front crank bolts torqued is always a pain and in this case caused your oiling problems. Buy the crank locking pin and use it!!!!!

On the observation about getting a lock pin... Point taken! I really ought to have a tool that does the job most properly, considering the number of times I've needed one lately.

Question 1: When were you having the most fun with this car?  HPDEs or racing?  I think it may be to come though if you get the oiling issue sorted. I'm also worried about debris in your cooler now.

I think I enjoy racing far more than HPDE's for two reasons. One, I love my racing "family" at NASA-Mid Atlantic. HPDE can be lonely when you've graduated to solo. I'm sure I'll stay friends will all my racer pals if I were to return to HPDE, but there's nothing more fun than sharing all the stories about our adventures on track. Two, racing is simply more exciting and challenging than just going round and round. And those challenges aren't just on track. It's about time management, weight & fuel management, car preparation, and more. I still consider myself a novice in all of those departments at this point.

Consider Time Trials, though. I kind of skipped that step, but it seems to me that you can get the best of both worlds at much lower risk.

Question 2: What would you do different if anything?

I can't think of anything. It was a natural progression from track toy to race car, and one of the least expensive ways to get into racing (even though that wasn't my goal when I bought the car). But if I were to buy another car at this point (now that I'm a racer with a trailer and a mess of tools), I think I'd get one that was already race-prepped and ready to go.

Just a comment about buying a car race prepped .  Don't. Too many so called race prepped cars are simply worn out and need total refreshing in order to return to reliability.  Second unless the person has experience  with that car, the wrong prep may have been done. Clearances, settings, tricks and modifications vary from one sort of car to another car. 

In reply to frenchyd :

Thanks! I do appreciate that viewpoint, and it makes sense too. These concerns are all definitely real.

When I say "race prepped" I guess I only meant basic things like the chassis already being stripped down, the cage already being legal, and a good fire protection system already installed. I'd try to find a car that I know from a local ex-racer or someone I know that's moving to a different class. That way I would know what rules it had been built for. Just further along towards being "race ready" would be nice, since I don't have a garage to work in.

Your comment definitely applies to this car, which was advertised as "track ready" and "immaculately prepared". As you've read, it was basically "simply worn out" and did need "total refreshing".  At the time, I knew nothing about racing rules, 2.5L water cooled engines, limited slip differentials, or safety equipment expiration. And I guess I got screwed a little because of that ignorance.

I've enjoyed working on this car, but not so much while it's out in my driveway in the heat, the rain, or the snow. I'd just lean towards buying one that's further along in development, unless I acquired a protected workspace where I could take a nice running car with zero racing hours and transform it from scratch.

..speaking of... are you watching the Bargain Racement series on YouTube?

Just a comment about buying a car race prepped .  Don't. Too many so called race prepped cars are simply worn out and need total refreshing in order to return to reliability.  Second unless the person has experience  with that car, the wrong prep may have been done. Clearances, settings, tricks and modifications vary from one sort of car to another car. 

"How was this done?"

"I don't like how this was done"

"The way they did this is actually illegal, but it doesn't look like they knew that when they did it"

"This was done completely wrong"

"It's not done like this today. Since you don't have a logbook it has to be done a different way now."

"Since they did this it's going to use that up a lot faster"

So I was a little over-confident about being able to find a genuine VDO oil-pressure sender for way less than the cost of a genuine Porsche part. Turns out VDO doesn't produce retail senders with [edit: M18] threads (see the table I linked to).

So my choices were $25-30 for a "Uro" branded sender, or $115 for an OEM sender. I've heard bad things about the Uro part in this case, such as the posts breaking off when tightening them.

AutoHausAZ is a reliable vendor which is usually my go-to for 944 parts, but I usually have to pay shipping and wait a week. It's usually worth it for the one-stop shopping for a ton of different pieces and parts, but not in this case.

I don't have any affiliation with them other than I live just five or six miles away from them, but getporscheparts.com has recently been my source for OEM Porsche parts because I can pick them up locally and the parts are usually discounted as far as I've seen anywhere else. They've been pretty responsive to my needs too, such as when I ordered all the little hardware pieces and parts for my 968 hatch and wing. Some of the parts would have come from Germany and they reached out to ask if I really wanted to wait for them. I made some substitutions and they accommodated me. Anyway, they had the genuine Porsche part (928-606-203-04) for $82. I picked it up the same day.

My point is, your local Porsche dealer (any marque, for that matter) may have an online presence with similarly discounted parts that can be picked up locally for a lot less than it would cost if you walked up to the parts window.

The good news is that it fixed the issue! Now the gauge registers 0 psi when the ignition is turned on but the engine is not running. So Problems #1, #2, and #3 are all resolved.

On to Problem #4...