Porsche 924 conversion

JimDanielson · Jun 2, 2009

We were considering a metro, crx, or small pickup covnersion. Found this porsche on our local craigslist for 750. We got it to $500. The engine isn't working to well on it, so thhats no big deal. But it is in good enough condition that it may sell for 1 or 2 hundred. Pluss all the extra parts we dont need will hopefully sell for more then the car is worth (gas tank, exhuast, radiator, starter, alternator, ac pump etc)

Few problems with the car:
-driver side mirror hangs cuse the moounting bolt is stripped
-will neee a manual steering rack
-rear windshield wiper cover broken
-hood and roof are slightly faded
-cant hold to many batteries
-cracke windshield wiper fluid container
-cracks in dash
-one window button is finiky

The Plan:
-144v system
-12 140Ah deep cycle batteries (already bought from local car part supply store for $1158 total, $80+$8 core charge each)
-Logisystems controller, 750amp or 1000amp undecided currently (please tell us if the extra 250amps is worthwhile)
-build our own vacuum pump
-144v quickcharge
-either a conmputer psu for dc to dc or something cheap
-some ebay guages

I attatched a pic of our car

JimDanielson · Jun 2, 2009

Here is the rear seat area... not really space for a person, but it will fit some batteries.

PatricioIN · Jun 4, 2009

interesting project. Any idea how much the car weighed stock? What kind of range are you hoping to get? I would suspect there is space for lots of batteries.. weight capacity maybe a different matter.

martymcfly · Jun 4, 2009

I haven't looked under one of those for a long time. Don't those have a torque tube that goes to the rear end? If I remember right, the rear end looks like a front trans axle out of a VW Fox. You may be able to mount the motor in the back and use the whole under hood area for batteries.

JimDanielson · Jun 4, 2009

I edited the first post with more pictures. Tomorrow once we pull the engine completely, we will ad more pictures.

JimDanielson · Jun 5, 2009

6/4 UPDATE:
Today the engine was fully removed and started planning on the placement of the motor/mounting of the new motor.

One problem we see is that we originally planned to rest the motor on the main cross support, the shaft of the motor will not be low enough if we do this.

Thaniel · Jun 5, 2009

probuild521 said:
interesting idea, i'll have to look into it once we fully take out the motor tomorrow just not sure how the clutch would work as it appears to be right off the engine in the front of the car

If there is enough space I'd try to do it. Would drop some extra weight.

Looks like you got a deal on the car.

JimDanielson · Jun 5, 2009

we have considered this one because it is cheap and would run off our pack voltage, but not sure if it will be fast enough

http://www.surpluscenter.com/item.asp?UID=2009060514504683&item=4-1801&catname=powerTrans

Jimdear2 · Jun 18, 2009

jimbo12d said:
we have considered this one because it is cheap and would run off our pack voltage, but not sure if it will be fast enough

http://www.surpluscenter.com/item.asp?UID=2009060514504683&item=4-1801&catname=powerTrans

At that price buy 2 or 3 and parallel them for volume, then you have not only inexpensive but redundancy for safety. Heck buy 10 (about the price you would pay for some of the EV rated noisy pumps) and have spares or a profit center if you find out you only need one.

rillip3 · Jun 21, 2009

Amazing progress! In re: the vacuum pump, I've read most breaking systems ned 14" of vacuum, this says it can provide 25 max, so that should be no problem. My only concern is the VDC; typically I've read about 12v pumps being used. With a 12 volt system, the car is going to be D-E-D dead before you have a problem with the breaks. With 135 volt, you only need a 10% drop in voltage before it's underpowered. If you decide to go with this I'd definitely try it out at low speeds first (obviously) and strongly consider a resivoir in case of a voltage drop.

rillip3 · Jun 27, 2009

Your coupler looks spot on! And what you're describing sounds like a taper lock, which I've read is the ideal setup. You're comming into the home stretch, what do you think the final cost/time will be?

JimDanielson · Jun 27, 2009

4 weeks (we worked several hours a day on it for the past 4 weeks, and still will have some work getting the guages and all to work once the drivetrain is working)

$5,500 -$4,000 gov rebate (that might take 4months to file though)

Zukiru · Jun 29, 2009

state government rebate?

man that is a cool EV.

rillip3 · Jun 29, 2009

probuild521 said:
yeah in Illinois the government reimburses 80% of the conversion cost up to 4k its pretty nice.
http://www.illinoisgreenfleets.org/

MAN that is great. I wish we had that! I found out that there was up to 500k available through North Carolina's energy department for alternate fuel vehicles, but they do not cover personal vehicles.

JimDanielson · Jul 7, 2009

We test drove it today. About 10miles on the conversion today.

Things we need to fix
-no vacuum brakes(still stops fine if you push hard)
-accessory battery dead (the dc-dc is not hooked up yet)
-no clutch
-lots of vibration at high rpm
-either cant get into 1st and second or cant get into reverse.
(we did a fix on the shifter and the bolt needs to be shortened)

We drove it at night and were about 3miles from home when the accessory battery was basically completely dead. If the headlights were on, the contactor did not have enough power to turn. And even when the headlights were on, they were barely visible. So we will need to make the dc-dc work soon

The vibration is ridiculous. Any high rpms make the car motor go crazy, and it coasts forever (making shifting without a clutch hard). Ill post another thread about vibration so more people read it.

Have some pictures and a video.

Youtube seems to not be accepting uploads now, so ill add that later.

Here is one picture, the rest are here: http://picasaweb.google.com/jim.danielson/PorsheController#

Jimdear2 · Jul 7, 2009

jimbo12d said:
We test drove it today. About 10miles on the conversion today.

Congratulations That first move is the scarry part, the releif when it does what it is supposed to is fantastic.

jimbo12d said:
Things we need to fix

-lots of vibration at high rpm

The vibration is ridiculous. Any high rpms make the car motor go crazy, and it coasts forever (making shifting without a clutch hard). Ill post another thread about vibration so more people read it.

I would suggest that you revisit your coupler and adapter, what you are describing sounds like a misalignment or balance problem. Take another look at how the ICE, clutch housing and torque tube lined up. One thing I noticed is, it appears, (the pictures are inconclusive) you did not have a pilot bearing in your motor to clutch adapter for the driveshaft to center in. This keeps the clutch disk centered in that flywheel.

Be sure the concintricity of the original ICE installation has been retained.

Another thought, A lot of engines use the flywheel to act as a bob weight to balance the crankshaft. The Chevy 400 ci small block is a famous example. This would cause a major imbalance. The fix would be remove the flyewheel and have it rebalanced. You may need to contact Porsche to be sure this is the problem. It might also be found by a simple visual exam. If the flywheel appears lopsided it probaby is.

jimbo12d said:
-either cant get into 1st and second or can't get into reverse.
(we did a fix on the shifter and the bolt needs to be shortened).

The shifting problem you mention. Is this with the vehicle stopped or while driving?

While Stopped:
If it is while stopped you might find a quick tap on the throttle will bring ths syncros into alignment so you can complete the shift. Remember, with an ICE that shaft is always spinning a little even if it is only slight drag with the clutch disengaged.

For my own use I was going to put a momentary switch on the clutch pedal that would parallel a low ohm resistor into the throttle circuit to give the motor a slight kick. But in the end a slight bump on the throttle works and it's simple (K.I.S.S.).

While Driving:
If the problem occurs while driving it is a matter of timing your shift. It will be almost like clutchless shifting. there is no real drag on the motor like an ICE so you just have to wait until things align. with the extra length and rotating mass of the clutch to trans drive shaft it's going to be worse.

A possible help would be a mechanical or electric brake to apply a slight drag on the motor shaft to emulate the engine drag. This would be applied when the clutch was depressed.

Hope this helps you

rillip3 · Jul 7, 2009

Well it sounds like you have a good handle on everything, except that vibration. Vibration means something is moving that shouldn't be. Most likely the motor or transmission. Might want to make sure the motor doesn't have any wiggle room, the transmission, it seems to me, would tend to produce vibration at lower RPMs.

JimDanielson · Jul 8, 2009

http://www.youtube.com/watch?v=JH0F_WnWl7g

samabhi111 · Jul 14, 2009

Yeah! This project is quite interesting. Keep up posting about your progress man.

Jimdear2 · Jul 15, 2009

probuild521 said:
still not happy with how the motor and clutch assembly is running (offbalence and squeaky), going to be pulling the motor again and mess with the flywheel alignment some more.

going to return the part that attaches the flywheel to the other half of the coupler. the motor side half of the coupler has already been returned and with in the .001" so thats pretty much as good as my non-CNC abilities go. so dont think its that part mostly just the flywheel mounted half.

if it doesnt get sorted out by this weekend may consider giving up on clutch plan and run a clutch less setup (been driving the car around the street and shifting w/o it isnt horrid, takes quite a bit longer and reverse you have to wait for it to come to a stop but other than that...) thats pretty much the last ditch effort to get it to work hopefully it doesnt come down to that.

probuild,

I have gone through all of the thread again and I've still missed how you ensure the concentricity of the motor shaft to the transmission drive shaft.

In the pictures I've seen showing the motor to trans adapeter plates with built two sets of stands offs and no sign of dowel and/or hollow pin alignments (that I can see) keeping the longetudinal centerline of the motor perfectly in line with the centerline of that long driveshaft. Even a degree or two of misalignment or a few thou off center and you will have BIG problems.

I think you should take anothe look at how you did the adapter plates. maybe a few photos or drawings, maybe we can spot something to help out.

The motor to bell housing adapter has to perfectly duplicate the back end of the engine.

The Flywheel mounting face of your motor shaft adapter has to be in exactly the same place as the end of the crankshaft. If it's in or out or off center or off angle. you will have vibration and or bent parts. Look up the thread that M38mike and his electro Willys Jeep. I think you might have some of the same problems.

Tom Thomson · Jul 15, 2009

Probuild
Glad to see that someone else is doing a 924 conversion. Mine has been on the road for a while now and it was a learning experience. I went no-clutch and have had no problems whatever shifting. I let the charger cord dangle out of the gas filler cap and it never fails to get a laugh.
tommyt
'82 Porsche 924

JimDanielson · Jul 16, 2009

We pulled the motor again today. Found out we were missing the rod that holds the fork in place for the clutch, it must have fallen out. This was our main scraping problem, but we still need to fix some vibration before it goes back in and get a new piece for the fork

Tom Thomson · Jul 16, 2009

Probuild
Sorry-no pics. Even if I had any I don't know how to send them. And even if I could, I doubt you would want to do things the way I did. Finding room to put things was my biggest problem. I went with an 84V system using 6V Interstates (14 of them) and put 2 in the spare tire well, 2 in the rear fender cavities, 2 in the rear seat area and the remaining 8 on an angle iron rack which mounts on the original motor mounts and the tie down tabs. The car now weighs 3167#. I used a D&D 15A-6 motor, mounted on a frame which attaches to the A-arm mounts and the cross-member attach points. I cut about a foot off the torque tube and the drive shaft, and welded up a basket to connect the motor face to the tube. This all works well but the motor is in the drive shaft tunnel and barely fits (some hammer body work was required). The shaft coupling which I used had a taper lock sleeve which held the torque but it had some backlash which was very noisey on trailing throttle. I threw it out and made a new one. I have had the car up to 60mph but the small motor and poor airflow cause a heating problem (the motor has a thermocouple in the brushes) at heavy load. Range is my problem now even with Nokia LRR tires (the car will coast for over a quarter mile starting at 30mph) and I am going to have to change my driving habits.
Good luck on selling the IC stuff; I threw all mine in the dumpster after I saw a guy on the 924 website offering to give away 3 good motors. I posted the radiator, AC coil and some other stuff and got not a single bite. By the way, whose project is this, probuild or jimbo. Whoever it is, it sounds as though you're making super fast progress. Good luck.
tommyt

kek_63 · Jul 18, 2009

Ah ha. The cardinal rule of Bridgeport setup. If you don't KNOW that the head is true - indicate it.

Before I had my own shop I screwed up a few parts assuming that the previous operator (based on what he was machining) had trued up the head on the mill.

ASS/U/ME
Keith

Jimdear2 · Jul 18, 2009

probuild521 said:
so the dowel pins werent in straight and causing issues.

should find out if everything works tomorrow

Wonderful, I think you have the problem in hand.

From the descriptions of your problems I was sure that there was some form of concentricity problem. Thats why I kept asking about alignment pins and such.

Milling head alignment is such a basic thing you never even think to ask about it. You just assume (ASS/U/ME).

Can't wait to see it roll down the road (Noiselessly).

PatricioIN · Jul 20, 2009

I think most of us went clutchless, so no help from those of us anyway. My coupler was made by a local machinist for $225 - solid one-piece unit.

joseph3354 · Jul 21, 2009

dumb question,do you have a pilot bushing on your adapter? also,i purchased the same type motor from ebay as well and noticed that it has a bit of vibration of its own with nothing attatched to it.does yours vibrate also?

i see the pilot bearing in your adapter,scratch dumb question #1 !

joseph3354 · Jul 21, 2009

probuild521 said:
haha yeah its in the adapter.

i'm going to go check the w/o any adapter on it and i'll let you know what the result is.
just checked the motor it runs perfectly smooth, only vibrations I have are caused by a slight mis-balance in the adapter assembly which is hopefully getting fixed today

hmmm,guess i have to pull my armature and get it checked for balance.it has only slight vibration but i fear that it will amplify with the addition of coupler and flywheel.

Porsche 924 conversion

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