Newbie questions: tuning, aircon and towing
 

Hi

928 n00b here with a few questions. Honestly, I could probably have googled them even more than I’ve done, but then I wouldn’t have had the chance to say hi to all you knowledgeable people.

A bit of background: I live in Copenhagen, Denmark and until 1,5 month ago I was the very happy owner of a 911 G-series with a lively 3.2 short-stroke engine. Then it got stolen, and even though I got an insurance payout my budget is limited, so I thought I might give the 928 a go.

The ideal car would be a 1985 928 S model with a manual gear box, but the market here is tiny, so I’m looking at alternatives.

One of them is a 1978 model. Now, I’m a sucker for horsepower, so I know I’m going to miss the 60+ hp in a later 928 S. My question is this: What’s the easiest and least expensive way to find those extra ponies in the 1978 4.7 litre engine?

The other car has a faulty aircon, which is a showstopper according to the missus. What are the most common problems and solutions here? Is it likely that I will have to change to entire unit, are replacement units even available and at what price?

Last question: I’m going to use the 928 to tow a 500 kg race car to and from the track (which should raise an eyebrow or two). Has anyone here used their 928 to tow heavy loads, and is there anything I should be aware of?

I’d really appreciate any insights. Thanks!

Hey Slush - Welcome. There are lots of Porsche performance experts on this site - I'm not one of them. :) But usually trying to boost the horsepower of a 928 is often very labor intensive and prohibitively expensive. There are just not that many reasonable options and performance enhancing parts around - but anything is possible.

Like other older cars - an air conditioning retrofit or system rejuvenation is about the same everywhere. The problem is to track down the freon leaks in the fittings, hose and compressor seals.

As far as a tow vehicle in relation to a 928, most owners probably sees any Porsche doing better as the one on the trailer. :) I think the trick will be to locate something solid enough under the rear end to try and attach a trailer hitch to. Then once you're moving at speed, if the trailer doesn't have modern computer controlled multi-axle brakes, the 928's ability to "Out Brake" it's trailer could be a problem in an emergency. One seriously negative point would be for the 928 to stop at a traffic light only to see it's trailer pass on through the intersection.

Good Luck - Michael

Question: how do I make my Porsche faster?
Answer: how much money do you have?

Surprisingly, the 928 does have an option to increase HP. The aftermarket has developed a supercharger for the shark. I know nothing about the details - if you just slap it on or if you have to do a bunch of work on the bottom end to beef it up for the extra boost. And I don't know how expensive it is. There are several threads about superchargers on rennlist.com in the 928 section.

Speaking of RL, there's a several page sticky note for 1st time owners that goes thru a lot of issues with the 928 and provides links to vendors. Worth spending the time and reading it all the way thru.

The biggest issue when buying a shark is knowing the timing belt age, mileage doesn't matter. 5-6 yrs is generally considered the useful age of a timing belt. If it needs replacing, it will be around $2500 USD and it's a complicated job, not your typical timing belt job. The one item in your favor if you buy an older version of the 928, those engines are non-interference engines so if the belt breaks it won't cause catastrophic damage. That's not the case with the 32 valve engines - if the timing belt breaks, valves will bend and quickly escalate the cost of the job.

Hi Slush, welcome to the forum!

There actually was an OEM option for adding a trailer coupling to the 928 (pn: 92872200300), and while it's likely been NLA for quite a while, check out this thread. They're inquiring about using their 928 to tow a full camper trailer, but it should give you a good place to start.

Thanks everyone!

Hard rule with the 928, buy what you really want. Thinking of the 928 as a budget related option, puts a smile on the face of most owners.

Cheapest way to get S power, Euro S power, is with a Euro S motor, or parts of a Euro S motor. 78 is Kjet, which at best is "ok", at worst more costly for less power once its all "fixed". All of the Ljet models have moderate to good tuning ability that allows more fully taking advantage of HP improvements.

Sad bit of reality is that 928 prices strongly reflex relative desirability, except at the high and low end of the market where cost is compressed on the low end by lack of information on true repair costs, and expanded on the high end by the wealth gap.

You can safely tow a :::small::: trailer, like a teardrop or tent trailer, or lightweight boat.

The issue isn’t the horsepower. You could probably pull stumps or pull down an old barn. It’s the length and weight of the car. There are some guides to safe towing around the Internet.

Living in Europe you will have access to 4.7 liter 928’s (usually not labeled with an ‘S’ - that was an American snob requirement. Mine wears many owner installed credentials that it hasn’t earned. It has ‘s’ all over it, and spoilers, and other tinsel, but it’s a 4.5 Euro car), but there were also many sold like mine with the 4.5 liter engine.

I don’t know if you’re interested in shredding tires or just having a good time on a twisty road. If the twisty bits are what you are into, many speed thrills await you with either configuration with a manual transmission. I dream of more powerful brakes and a better front suspension setup than more HP under the hood.

My advise, leave it stock. If you want a fast car go buy a newer one all ready to go. The 928 is expensive enough to maintain as it is. It is a touring car, not a race car. Just drive it and enjoy it.