High Torque Starter Motor?

Talk and Tech about turbocharged 924/944/968 cars
AudiSport
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You say the battery is fully charged... but how old is it? Did you test with a new battery to make sure it doesn't have a bad plate or something?

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Tom
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AudiSport wrote: Fri Dec 12, 2025 7:33 am You say the battery is fully charged... but how old is it? Did you test with a new battery to make sure it doesn't have a bad plate or something?
Fair question. The battery is maybe 2 years old - I'd have to check, but it seems to be in ok shape. Holds a charge for weeks, etc. I often use a trickle charger, but I'm not great about that, so dealing with varying levels of charge in reality. Starter is still a bit slower even at full charge I think, or maybe I'm convincing myself of that to justify trying a high-torque starter (maybe to help mask my derelict trickle charging efforts...). :shifty:

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AudiSport
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I say it because I have a car that doesn’t see much use that seemed like the battery was ok when I charged it. But it really wasn’t. :)

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Tom
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AudiSport wrote: Sat Dec 13, 2025 8:33 pm I say it because I have a car that doesn’t see much use that seemed like the battery was ok when I charged it. But it really wasn’t. :)
I'll check to see how old it is... Batteries used to last years, but these days not so much. So, you're right it's worth checking. I still kind of want to try the high torque starter though. :shifty:

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Dave W.
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I installed the High Torque Starter approx 6 years ago. It made a slight improvement, but the battery I had at that time was going bad. I also replaced the wire harness between the battery and starter. Then around 3 years ago I got a nice, modern Noco Lithium NLP30 battery and that made a nice improvement.

FYI when I had a weak battery and old rebuilt bosch starter I ran the datalogger during cranking and typically saw around 175 to 190 rpm. With the new starter, cables and battery it's up around 250rpm. Starter kickback was a regular thing when it cranked slowly.

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Latitude48
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In 2021 I purchased a Bosch remanufactured high torque starter, SR0439X (Ref: Porsche 951-604-102-00, 1.7 KW, option M198,) from Summit Racing for $185.99. There was a $50 core charge. It's in my S2 with Antigravity Lithium battery and it cranks like gangbusters. Looks like Pelican may have them for about $250. Genuine Porsche can be had for the bargain price of only $870 ish.
Tom Pultz
- 1989 944 Turbo - Guards Red/Linen
- 1990 944 S2 - Guards Red/Black
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Tom
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Went back to my notes and see that I got the battery in April 2020, and that is had fewer cranking amps than the one before it. So maybe I'm ready for a new battery and starter. I didn't know there was a factory option for a higher torque starter. Does anyone know if that starter fits the turbo? I'd try that before the IMI one if it fits...

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Sansho
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Just for chuckles, I went back to my 2005 PET listings for 944 (all models) 1985-1988 USA, Germany, and ROW, and they only list one starter, 951.604.101.00.

However, looking at the current S2 parts listing, there is an option M198 for "Starter 1.7KW" (standard one, 951.604.101.00 shows 1.4KW). The part number on the 1.7KW part is 951.604.102.00. Gaudin Porsche shows still in production at $891.
1988 944 S

Gone, but not forgotten
1993 964
1981 911SC

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walfreyydo
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Tom wrote: Fri Dec 12, 2025 6:56 am Hmmm.... how low are we talking. Have any pictures?
I dont at the moment as my car is in storage. Id estimate about 1/4" to 1/2" lower than anything else on the car. It is definitely the lowest thing hanging off the bottom.

Enough to not try to straddle anything in the road if you can help it (which I normally do anyways), especially on a lowered car (roadkill, tire debris, etc)
89 S2 Variocam, Megasquirt DIYPNP
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Latitude48
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Sansho wrote: Sun Dec 14, 2025 3:09 pm Just for chuckles, I went back to my 2005 PET listings for 944 (all models) 1985-1988 USA, Germany, and ROW, and they only list one starter, 951.604.101.00.

However, looking at the current S2 parts listing, there is an option M198 for "Starter 1.7KW" (standard one, 951.604.101.00 shows 1.4KW). The part number on the 1.7KW part is 951.604.102.00. Gaudin Porsche shows still in production at $891.
Isn't this what I said above :) The 1.7KW starter is listed in the 1989-1991 944 PET. It's not 944 S2 specific, just an optional starter, along with a stronger battery. The only difference as I recall is the body of the starter is a bit longer. I asked Google if it fits the 944 turbos:

Yes, the Porsche starter with part number 951.604.102.00 (M198 option, 1.7kW) does fit the Porsche 944 Turbo, specifically for models from around 1989-1991 and often listed as a high-torque upgrade for earlier Turbos, designed for direct replacement on 944 Turbo models. This is a common upgraded starter, so you'll find it listed for the 944 Turbo, including later years like 1991 and older years with the M198 code.
Key Points:
Part Number: 951.604.102.00 / 95160410200.
Option Code: M198 (1.7 kW High Torque Starter).
Fitment: Fits 944 Turbo (and often other 944 variants).
Benefit: It's a more powerful, gear-reduction starter (1.7kW) compared to older, weaker starters, offering better cranking power.
Always double-check your vehicle's options code (M198) in your logbook or under the bonnet to confirm it's the right fit for your specific 944 Turbo, but generally, this starter is correct and a popular upgrade.
Tom Pultz
- 1989 944 Turbo - Guards Red/Linen
- 1990 944 S2 - Guards Red/Black
- 2003 Audi 1.8TQ - Denim Blue/Black
- 2003 Honda Civic Si - Vivid Blue/Black
- 2023 VW Golf R Base - Lapiz Blue/Titan Black

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