Supercharge a 924S?

[rbuswell]

I've seen a few YouTube videos about supercharging the Audi engine in an earlier 924 using an Eaton unit that were very successful. Curious if anyone tried the same thing with the Porsche 4 banger in a 924S? It seems viable.

[Monkey Wrench]

how about the electric turbos? Just basically an kit with an electric fan. They seem cheap but whether they work well or not, I dont know. I'm keeping mine stock.

[djnolan]

Some years ago there was a forum member, flash_968 I believe his name was, who manufactured and sold a supercharger kit for 968's. It was California emissions compliant. The 968 is a 16V engine versus an 8V engine. Also there are these guys: https://speedforceracing.net/product/stage-1-944-supercharger-system/

[Jfrahm]

I had a supercharged 968, the 928 motorsports kit and also had a supercharged 928S4.
None of the 968 systems were set up to work on a non-968 engine.

IMO an aftermarket supercharger is nice if you like to tinker and are pretty aware of what's up with your engine, a big concern is if you get a tank of bad gas or the like the engine can get damaged pretty easily. Maybe less of an issue with an 8v engine with longer piston skirts and lower compression. The big issue IMO is that the DME is not boost-aware and won't prevent boost if pinging is detected.

If I did it again I would deffo want an aftermarket standalone ECU that is capable of managing boost and knock.

One of my other modded cars, a Saab 9000, was risky to drive without a factory boost control system. I could drive around most of the year just fine but a hot humid July day I could tell it was overboosted for conditions even with the best pump gas I could get. I either had to use a boost and knock aware ECU or be hyper-vigilant and ready to adjust things, and that was not how I wanted to live.

From a boost and knock management standpoint superchargers are harder to manage than turbos as the boost comes on like a ton of bricks and can cause problems even before a knock sensor can try pulling out the timing.

A 20 year old Passat 1.8T has a MAF, A MAP, two knock sensors and boost set by the ECU. You can just drive it around and if it's very hot out and/or you get lower octane gas it compensates. You might notice less boost than expected but no big deal. If that's the sort of experience you hope for then an aftermarket supercharger is probably not for you.

[walfreyydo]

Originally Posted by rbuswell

I've seen a few YouTube videos about supercharging the Audi engine in an earlier 924 using an Eaton unit that were very successful. Curious if anyone tried the same thing with the Porsche 4 banger in a 924S? It seems viable.

Those "kits" (if there ever were any) are likely long gone. You would likely need to fabricate something yourself, which can/has been done probably but would require a ton of work.

Of course you would also need to upgrade the fueling and the engine control to accommodate the added air (likely a standalone plus injectors, pump or at a minimum a rising rate FMU like they used to do in the late 90s turbo honda days), similar process to "turboing a 944 NA" but more involved fabrication wise.

If the above is not making sense, then its likely not an option for you.

Originally Posted by Monkey Wrench

how about the electric turbos? Just basically an kit with an electric fan. They seem cheap but whether they work well or not, I dont know. I'm keeping mine stock.

Oh god... no

[rbuswell]

The videos I've seen for the blown older, Audi engine, 924 cars implied but didn't come right out and say that the boost was pretty mild from the Eaton units; that come off the supercharged BMW-built Minis. They were driving impression videos but not technical at all about how it was done.

The vendor for the 944 kit linked above implies that it's complete but doesn't really address the ECU changes that may need to be done or using a new ECU (e.g. MegaSquirt) altogether. Plus if I planned to spent that kind of money, I might try to source a 951 engine and components instead. It may just be my ignorance but it seems like that engine could fit in there too. I've always thought the 924S and 944/951 engine bay is the same size or can be adapted. I may be way off on that.

[Monkey Wrench]

I sometimes see hot rods with superchargers on the street, they sound cool and really go. who wouldn't enjoy a car that goes plapa plapa plapa with that unmistakeable whine, always ready for a street race...? people encouraging you to do a burnout at every corner..

I think the thing is it is also possible to make your car so hot that it becomes a bit hard to actually drive in city traffic. a car can be super cool but also a bit too "hot" to be practical for daily use.

I sometimes see a guy in a tiny old school austin mini blasting around with stacks out the hood. it looks really fun! If it's something like an american muscle car then its more normal to see.. I see them come out in the sunny days and get put away during rainy season.. garage queens..

with some older little cars the power can be comparable to what the lady beside you in a modern honda has, my 66 volvo is a bit like that. .I can sometimes race people in their new and quite powerful plastic jelly bean cars without them hardly even knowing it ;-)

even with that it's the occasional out for a blast then put away.. It's reliable, but I decided I have ot work on it as much as I drive it so I use it less often.. when I drive it I cant; resist the urge to hear the carbs sucking and flat out redlining every shift past second with a **** eating grin on my face..

it sounds like fun but you may also be turning it into a fun sunday driver rather than a practical car you might use as a daily driver.. I can see how that would be fun and a mechanical challenge too.

If you go for it It will be an interesting read.. ;-)

[Jfrahm]

I think there have been 951 engines swapped into the 924S, kind of a weird idea unless a parts car drops into your lap IMO. And even then, much better to start with a 951 chassis.
People said it would be fun to have a "sleeper" but
1 - who cares? Would it impress someone I wanted to impress?
2 - Making a modest performing Porsche perform like a medium-performing Porsche is a "sleeper?"

If you are paying for a swap you might get it done for less than the cost of a Cayman S but not for less than the cost of a decent 928S or S4 5-speed.

After the swap, expect something of a "kit car experience" as 100 small and medium issues arise and need to be dealt with.