G-Body

Hi There, 944 Fans!

I have a 1983 5-speed naturally-aspirated base 944. The power is really low by modern standards, so I was wondering what choices we have and what the limitations are for low-boost adaptation of the early 2.5-Litre 8v engines like mine...? (Without rebuilding with forged internals, or swapping in a later turbo engine, or anything drastic like that.)

Cost being somewhat key here.

The later turbo transmissions can handle more power - of that, I am aware (and I actually have a line on one), so I am more interested to know what budget boost options we have on the earlier cars for the engine-side of things? Can the early 2.5 litre 8-valve at least handle SOME boost (like perhaps 6-7-8 psi from a small, efficient supercharger maybe?)

The reason that I'm asking is because I'd like to avoid a costly turbo plumbing setup and perhaps look at a solution that does not involve the cross-over underneath the engine (and it would be nice to have something that's easier to install.) It would also be great if I could just leave the exhaust header side and the rest of the exhaust system in place to save cost. (There's just so little room to work on the header side.)

However, I'm uncertain about boost limitations, without rebuilding the engine.

Also curious what power increases one might expect from such a low-boost setup? With a 150-horsepower crank rating for the US cars, what do we see at the wheels on a dyno? A 120-horses or so? What could be expected from such a low boost setup on one of these - perhaps 180-200 horses or so? That would really wake this little car up, but will the engine last (IF it is in reasonably healthy condition now?)

Cost-wise, would $7-8K be sufficient to get there? (Crazy, I know - that's more than the value of some cars I guess.) Then again, Our cars can't remain this cheap forever, so I have to imagine that at some point, this type of investment may not be completely lost. Air-cooled 911 prices have run away, 928 prices have started to move (as have values for clean 951 and 968 examples) and the new cars are very expensive.

Smart money says that at some point, buyers who want an entry-level Porsche experience will even start chasing base 944 examples. Stated / asked differently; would you rather low-boost a base NA 944 (for around $7-8K and have a total of around $10-12-15K invested and lots of fun), or chase a 951 for $20-25K+ and still not have crazy power by today's standards anyway?

Northern_aqs

There have been a few on here who have gone the route of supercharging a base 944, but the packaging limitations start getting in the way. You can do it with enough money of course, but you’ll see limited benefits without building the engine for boost, adding a standalone and even then, you likely won’t have comparable power to a 951 for almost 951 money. For that budget, you’d be better off going the 07K route or LS swapping, but this is not for someone without real experience. It is not plug and play.

There are no shortcuts to performance here.

walfreyydo

Assuming your engine (and HG) is in good shape, yes it can handle some boost, but I wouldnt go more than 6psi. Youll need to source all the plumbing and parts from a 951 but it should otherwise be plug and play... You will need to figure out a solution for engine management though - whether through a budget rising rate FMU, or something like standalone. You will also definitely want to install a wideband O2 so you can monitor your AFR.

This is no different than what we did back in the day turboing NA honda engines in the late 90s early 2000s. The folks that didnt know what they were doing usually blew up their engines, but there were actually quite a few reliable setups.

I disagree that the cost is similar to an LS swap or 07K swap. If you use and source used 951 parts, it can be done for probably close to 2k or possibly less. Just keep in mind there are a lot of failure points and potential pitfalls just due to the age of the engine and parts, but I definitely think it could be done. I think the consensus here on the forums is the NA trans can hold around 200hp before it destroys itself, so if you have a 951 or S2 trans, that will increase your reliability factor (but also increase the cost another 1k-2.5k)

Again, you need to know what you are doing and understand the fundamentals of turbo tuning.

Parts youll need from a 951:
turbo
exhaust manifold and all plumbing (crossover pipe, wg etc)
intake manifold and all intake plumbing (you could diy some of this)
drivers side engine mount (contains the oil feed)
intercooler
other misc vacuum lines, oil return lines, turbo coolant lines, etc
do your research (and keep a spare engine)

Tony5

@G-Body have you heard of the924.com ? A guy from Romania puts together a complete low boost supercharger kit minus the supercharger for $1400 shipped. A guy on FB is basically doing the same thing for 944's and was starting to take orders last I knew. It's more expensive because it requires a standalone, injectors, and comes with an intercooler. It was around $3k if I remember correctly. I believe he was shooting for 7-8psi and maybe 200whp, built around an Eaton off a Mini Cooper S.

G-Body

Thanks TonyS - all good information to have...

bendavis2

I looked into this before for my 1983 NA 944.

I arrived that the fact that it would be cheaper to sell the NA and buy a turbo than try to modify the NA to have more power.

I still have and enjoy the pokey 1983 NA 944.

Tony5

How recently was this? Does that logic still hold water now that everyone thinks a 951 is worth $15k minimum?

walfreyydo

Piecing together 951 parts and putting them on an NA will not cost the same as buying a 951 at today's prices. This does not mean you can match the performance of a 951, but rather, somewhere in between a stock NA and a 951 (max 200 crank hp I would think). It will also likely require constant monitoring of AFRs to make sure the fueling is functioning correctly.

I also forgot to mention in my post above the need for 951 injectors, FPR (or aftermarket) and potentially upgraded fuel pump to go along with the rising rate FMU or standalone.