question on coilpack conversion - Electromotive HPV-1

[GregRRich]

I have the opportunity to purchase an Electromotive HPV-1 for my engine project-- a mildly modified 2.4L, which I need to purchase a dizzy for if I don't go with a coilpack option.

The research I've done on this topic seems to be only related to race engines. Is there any reason I wouldn't want to use this for a street application? I live in a state with no emissions testing and warm weather. I'll be running single plugs, dual 40mm Webers, and more than likely some sort of exhaust header system rather than heat exchangers that I really don't need. This is more of a weekend fun car with the occasional track-day, but certainly not trying to build a full-on race car.

Any advice would be much appreciated. This is my first Porsche project, and I'm trying to simplify things rather than work with the original CIS and ignition system (from the previous 2.7 that's more or less toast).

Thanks!

[MBruns]

My .02, we ran those units when that was about the only reasonable choice for 911 twin plug, and they were pretty reliable, the sensors were problematic, the HPX units that replaced the HPV1's were junk ! The problems that I have seen time and time again with all of them is severe timing drift, which you won't find unless you shoot the timing while on a dyno. What you will see is say you have it set up to have 30 deg. total as the RPM gets beyond 5k the timing starts retarding anywhere from a few to 15 + degrees. what we would do to combat this drift was add the actual loss value to the adjustment that adds/removes timing and then it would give you what you wanted. If you can find one of these units that functions and is very cheap it may be fine for what you need, They no longer support/repair these units so keep that in mind.

Mike Bruns JBRacing.com

[GregRRich]

He wants $700 for the whole kit that's set up for twin plugs, so I would get an extra bank of spare coils. It is the earlier more reliable HPV-1 (with the gold-colored bracket). If I were to purchase a new system from Clewitt, the current version would go for about $1300.

[MBruns]

If I read your post correct you have a 2.7 with 40mm webers, In my opinion the price for that setup is a bit high for something that has no support if it quits the next day. I would rather use the distributor (with points) and an MSD box and coil, the spark quality of the CDI is much better than the waste spark style of the Electromotive. and you can get spares in most any speed shop in the country.

Mike Bruns

[carr914]

Mike, It's my System that I got from Catesby, The Trigger Wheel from Art and New Sensor from Clewitt

T.C.

[MBruns]

Well that does confirm that it works because I have had that system on the dyno, If the pulley and sensor/bracket fit your engine that will give you a spare unit , I may even have a owners manual for that as well

Mike Bruns

[GregRRich]

TC, I figured you're chime in on this one sooner or later!

[Walt Fricke]

The race motor I purchesed in 1992 had the HPV1 twin plug setup. It was clearly the Electromotive, but was sold (and the manual created by) an outfit now, I think, out of business - Pacific Motorsports or the like from Seattle?

Worked like a charm. Only problem I ever had was when I had a second sensor holder made for a second engine. The pinch hole was a hair too large, and the sensor vibrated down until it hit the teeth. At least I got to see what was inside! A wrap of tape solved that issue.

I now have the more versatile EFI setup, but if I ever run one of my motors on my Weber 46s again, I'll slap these back on.

When I went to EFI I had to make short extensions so the newer coil packs would fit on the brackets which are attached to the race car. Otherwise the switch was seamless. I had a small engine fire at one time, kind of singed one of the coil packs, but it continued to work just fine, so I didn't need to install the autoparts store spare coil I carry around in the trailer.

[GregRRich]

See, everyone seems to use this setup for racing... I guess if its heavy duty enough for racing, it should be fine for street/driver use, right?

[Walt Fricke]

Well, racers seldom pay a whole lot of attention to fuel mileage. Tune motor for WOT, and forget about the rest. The HPV-1 has four ignition timing adjustments: the base setting (which tooth is TDC, typically the trailing edge of the 11th tooth from the two missing teeth. Then what you add for idle, for an intermediate engine speed (3,000 rpm), and then 8,000. You can calculate where you want it to be at your shift RPM (usually below redline - redline is a safety/longevity number, not a shift point beyond 1st gear), and set the 8,000 additional advance so you will be where you want to be. The "curve" is actually straight lines from idle to 3,000, and from 3,000 to 8,000. Ignition does not know whether you are WOT or off the gas, though you can purchase a gizmo to give you some vacuum retard.

The 4th dial is the rev limit. Has nothing to do with the timing.

The simplicity and reliability with carbs are what it has going for it. No jitter in the timing from any mechanical clearances. These things are pretty important for racing. Not bad for street, but there you seldom are at WOT at all, and then not for long. Part throttle is where you are on the street..

The 4th dial is your rev limiter setting.

[GregRRich]

Walt, I may PM you at some point in time... that's a lot to absorb, but I do understand what you're saying. I'm going for simplicity and neatness on this one. The car is a 1975, but I'm going slightly older with the engine in favor of one with Webers. I'd rather not be fighting the CIS system that even on its best day looks like an engineering afterthought of hoses and pipes.

Adding the slight modern flair of coilpacks is appealing without having to worry about locating the correct distributor (seems 1972 was a tough year) and then having to deal with actually making it work correctly!

[KTL]

You can get the instruction manual from Electromotive

Product Manuals - Electromotive Engine Controls

I like the newer XDi setup just because it puts all the controls in a remote box instead of putting the controls right there on the coil pack boards. I agree this system is simple and effective. However I certainly do not discount Mike's experience of timing float. I have yet to check my newly created twin plug arrangement, but I will definitely do so when I get it on the dyno soon.

I mounted mine on a platform in the middle of the engine between the carbs. It's mounted to the engine case breather cover via some threaded aluminum tubes So access to the board adjustments is a bit easier than the typical location of mounting it on the back of the engine bay (that's where my single plug install used to be).

I bought Clewett's mounting platform kit for the XDi small boards and made a bigger platform to mount the HPV boards. Here's a picture I literally just took last night to have an image of my plug wire layout. I have to take it all off to do the final install of the fan shroud and manifolds. So I didn't want to go thru the whole "design" process of the wire routing all over again




As you can see, the location of the boards is convenient. But the plug wire routing is a pain in the arse. The twin plug distributor with MSD 6-AL CDI wins hands down in terms of plug wire routing/cleanliness of install.

[bullethole]

I have an XDI controller and coil pack DFU that I'm probably going to be selling in about a month. Single plug only. I did blow one coil by over setting the dwell (at least thats the best i can figure), so i put 3 new GM coils on it (still have the other 2). As I am going twin plug, i'm switching to a different coil pack driven by the MSIII (which i have driving the DFU right now). If work was not such a bugger I was going to do this switch (single coil) this weekend, but thats out the window

[GregRRich]

KT-- that entire assembly is going to fit on top of the shroud, behind the alternator?

[carr914]

Greg, you only need half that space as you will be using 1 Bank of Coils

See you in the Morning

[KTL]

Originally Posted by GregRRich

KT-- that entire assembly is going to fit on top of the shroud, behind the alternator?

Finally got my engine in and running (initial startup only). Yep both boards and wires fit between the carbs behind the fan shroud.




It's not as tight of a fit as you might think. Actually better than I had expected.

Sorry for the late reply.

[GregRRich]

that looks great Kevin! I'm doing single plug, but may do a similar install as yours-- it looks more planned than mounting it to the firewall. I wonder if you could fabricate a cover? I can't imagine it needs to "breathe" much... I think that's my only gripe about this system, it's not very "pretty" with everything exposed-- might look better with a sheet metal or plastic cover over it with only the colored plug wires neatly coming out of it.

Are you using this setup for the track or as a driver? Great looking engine!

[KTL]

Mine was single plug before the recent rebuild. The board was mounted on the firewall, right behind the Y-junction for the fuel lines. I wasn't a big fan of it being back there because it made it hard to reach if you needed to fiddle with the adjuster knobs, plug wires or coils.

I don't think there's anything wrong with putting a cover/shroud over the board(s)? Here's what it says about mounting the board in the HPV-1 instruction manual

1. The mounting surface should be able to hold the HPV-1 without stressing or bending the baseplate.
2. Keep the HPV-1 away from road debris and direct water spray.
3. The unit should never be submersed in mud or water.
4. Keep the HPV-1 away from high temperatures. Do not mount too close to the exhaust or a turbocharger.
5. Keep vibration and heat to a minimum for best durability.
6. Maintain easy access for changing calibrations.
7. Use 1/4" bolts to secure the HPV-1 and use thread lock or self-locking nuts to keep secure.

I agree it's not a pretty installation. All the Electromotive installations i've seen people do, they all seem to be a bit cluttered no matter where they put the boards. It's hard to have the wires coming out of it neatly because of where you plug in the wires on the coils. The board has the wires grouped as follows from left to right, board oriented with the adjusters on the right.

Left coil = 2 & 5
Middle coil = 3 & 6
Right coil = 1 & 4

So the only flexibility you have in orienting the wires is dependent on how you orient the board or swapping locations on each coil. By swapping locations I mean the coil itself doesn't care which cylinder you plug in to, as long as its the right pair of cylinders. Left coil always has to have 2 & 5 on it (or 5 & 2), know what I mean?

I'm using the setup on a track car that is a dedicated race car. But I think you could use it on a driver. The system is pretty reliable, despite it's shortcomings that Mike Bruns noted. The coils are a durable coil. They're the same coil that's been used on GM 3800 V6 for decades. The purple boards are spotty reliability, so the gold ones are a better bet. Honestly i'd prefer the XDi to simplify the control of timing. With the XDi the boards are just a plug-in affair and the XDi controller manages the timing settings. But these used HPV systems are hard to pass up for simplicity and price. That said i'll eventually switch to something else if I progress to individual throttle body EFI.

[davec]

Shouldn't you be worried about heat with those coils directly above the block?

[KTL]

Heat isn't a concern for the coils. Many GM applications use these same coils (3800 V6, 4.0 Aurora, 4.6 Northstar) in the engine bay mounted right on top of the valve cover, which would be just above the exhaust manifold.

I'd be more concerned about the heat on the ignition boards but it doesn't seem to be a problem. Clewett came up with the idea, not me!