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Swapped in one of the high-torque gear-reduction starters into my 931 today, figured it'd be time for a review.

(Full disclosure - if you don't already know, I'm longtime friends with Dan, may be partly responsible for his 924 addiction... he pays me back by helping out with the racecars a bit...)

Decided to go for it after running into persistent hot start problems with my 931; cold was OK, and immediate restart after shutdown were OK, but I was f'ed at the gas pumps. The fact that the gear-reduction one was only $20 more (10%!) than stock, which we know sucks, plus that video, really sold me, no-brainer. Timing also meant I was on my way to Chicago anyway, for a beer, so catching up with Dan for this and a stack of other 931 parts was an easy decision.

I may still need to implement a heat shield to protect the starter from the exhaust downpipe, we'll see.

Quality of terminals was great, modest upgrade from stock for ease of use on the low-tension/switching side; I would suggest Dan include one or two heat-shrink splices for splicing in the harness, for completeness - since that's an area that really suffers from weather. I had one on-hand, but most shade-tree wrenchers probably won't, and a typical butt splice will let the uglies in...

I did find that the longer of the two bolts from my starter started to press into the new starter unpleasantly, before being fully seated and torqued; not sure if this was just my car or not, but adding a couple extra washers spaced the bolt out just enough to seat properly without cracking the housings. Might be something to keep a close eye on if you go this route, at least on a 931.

Results: first time I cranked, I thought the cars was busted! Spins quickly enough, but it sounds so different... it's gonna take a while to get used to! But she's plenty happy, and I'm looking forward to this helping the car become more reliable and trouble-free for DD usage...

Nice work, Dan!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

daniel · Joined: 18 Jun 2009 Posts: 686 Location: Sydney, Australia

To add to the above - I have been using one of Dans gear reduction starters in my race car for many years. No heat shields and is still going great with an 11.5:1 comp motor
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Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Got one on my 2.5 race car, increased efficiency allows me to run a ridiculously tiny battery.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

924RACR · Posted: Tue Apr 11, 2017 10:34 pm Post subject: One step forward...

Yeah, would love to have one on our racecar too - but not legal per the rules (for IT).

In related news... gave the starter a massive heat test today! It kicks ass, and my (Optima) battery also handled the load.

Unfortunately... on to the next two broken things.

Got it into a hot-start state again, and was parked at my local race shop so the perfect time, somewhat induced, to chase the issue.

So in the past I'd had trouble getting more than one or two solid cranks while hot out of the old starter (no longer a problem). However the car would not refire readily when hot. I thought it was the typical hot-start problem, exacerbated by mix/ignition settings... so I played with those.

Eventually I got to a point where the car wouldn't even crank... then I messed around and realized I could get it to spin just fine if I used my booster pack to directly power the starter up at the battery (with the 2-wire connector at the back of the head, with the wires going to the alternator and starter). So with the ignition switch, not enough juice - either to crank, or at least to fire!

OK, so ignition switch is bad. Borrowed a remote starter pushbutton... turned key on, and sure enough fired right up! Yay!

OK, so go home and order a new ignition switch. Only... on the way home... she starts misfiring again badly, like back in the fall... dammit.

When I got home (barely), tried a restart and definitely not a damn thing. Yeah, OK, so probably ALSO fried the ignition box AGAIN with the undervoltage while cranking... OK, replace that too...

Someday I'll get to drive this without so much trials and tribulations...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Ozzie · Posted: Wed Apr 12, 2017 7:24 am Post subject:

I installed a relay to the starter circuit to activate the solenoid.
This takes the current away from the ign switch and the solenoid has direct battery supply.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

924RACR · Posted: Wed Apr 12, 2017 9:57 pm Post subject:

Yeah. I was pondering this last night; while I may still have to replace the ignition switch (plan to do some voltage testing first), I'm feeling like I may add a relay anyway, up at that connector, pulling power directly from the battery as you mention. It worked REALLY well on our racecar for the same situation, so...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

MikeJinCO · Posted: Wed Apr 12, 2017 11:27 pm Post subject:

Is the gear reduction starter physically enough smaller that it would clear a set of headers better and allow a little more room for heat protection on a NA?
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Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

924RACR · Posted: Thu Apr 13, 2017 3:40 am Post subject:

Oooh, good question... maybe a bit? Would've been clearer if I'd taken a picture before installing...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

RC · Joined: 25 Mar 2007 Posts: 2637 Location: Australia

Yes, +1 to a relay in the starter solenoid circuit.

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hey Ozzie,
Thats sounds neat. Would you be able to give a bit more detail on how you did it please?
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*****1981 - 924 - Auto - London, UK******

924RACR · Posted: Mon Apr 17, 2017 10:51 pm Post subject:

I used the following in the racecar:
http://www.longacreracing.com/products.aspx?itemid=1733&prodid=7591&pagetitle=HD+starter+solenoid+only

Mounted it up on the fender, forwards of the battery, behind the strut top.

Main batt lead goes from battery (actually, kill switch in my case) to relay/solenoid. Other main lead goes to starter, with a jumper wire to the solenoid on the starter - so the starter is now hotwired, whenever that lead gets power it will crank.

The new relay, on the fender, now controls the starter. The small wire from the ignition switch goes there, instead of the starter. When it switches (when you turn the key), in fact the main power wire is switched downstream of the relay on the fender.

Make sense?
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

It sorta makes sense but due to my ability level, I'd dig a phone pic of a pencil scribbled wiring diagram to get this rigged

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*****1981 - 924 - Auto - London, UK******

WEASEL149 · Joined: 19 Aug 2005 Posts: 595 Location: UK, Sheffield

Good thread. Not really considered using a relay before but great idea. Maybe worth doing a small how-to thread for future reference (unless there is one, not looked).

Thanks for the info anyways.
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1979 UK 932