Conza

I really love the early 928s, especially the S of 1984-86, I like the clean shape, with discreet spoilers, headlights front and back, its a relatively small car for its engine and am considering having one as a weekend car, so manual optioned, am interested in fun driving more than easy torque curves, and probably reliability.

Have you owned a 1986 4.7 or 5.0 928S? Would really enjoying hearing from you especially on this question, but even an owner of any 928 would be great as well.

My main question is, for a 1986 928S would you pick SOHC 4.7l or DOHC 5.0l? Personally, If I could run the 5 litre with the same compression ratio and hence 98 octane fuel, give more power/torque, and the fuel consumption was very close to the 4.7s, and the reliability of DOHC vs SOHC was nominally the same, I would probably go with the 5.0 if available, why not?

However I'm not sure the larger engine is better in every way. For reference, the '84-'86 4.7 was updated from its outgoing '83 spec, to a 10.4:1 compression ratio giving 310bhp at 5900rpm (up .4:1 and 10bhp respectively), more importantly the torque curve was smoother, delivering more torque and from a lower rev range 400lfbt at 4100rpm (up 15lfbt, and down from 4500rpm).

On the other hand, The '86 5.0 benefited from an even lower torque curve, still 400lbft, but from only 2700rpm, it did stop revving at 5750rpm, as a result, power went down to 288bhp. There was also a compression ratio drop to 9.3:1, and I'm concerned that would also increase fuel consumption.

I've narrowed myself to the three years 86, 85 and 84, in that order, mostly for the Bosch fuel injection and the more accessible torque curve with a higher output.

I would consider older an 928S probably as old as 83, if the compression ratio doesn't make much difference, I did favour the 84s for a while because they didn't introduce the side impact protection, which saved 30kgs, but due to the synchro advances, improved alternator and integrated aerial of '85, and the superior brakes of '86, I'm in the order I am now.

If the 5.0 is much better than the 4.7, then the '86 5.0 is my number one choice, alternatively if the 4.7 is the better choice I think 85/86 is where its at for me, if the brakes really bothered me on an '85 I could always upgrade them to the 86s when they ran low next.

JEC_31

Numbers, schmumbers.
Go test-drive a well-maintained example of each and see what feels better.

DeWolf

The 86 5.0 is my pick as it comes with S4 brakes and interior upgrades. Yoiu can 'Porken' the engine and it will liven it up.

Wisconsin Joe

First off, the 4.7 and 5.0 are significantly different engines.

The 5.0 (32valve, "pipe organ" intake) was the US spec car.
The 4.7(16v, "spider) intake was the "Rest Of World" (ROW, commonly called "Euro") car.

The Euro had the upgraded suspension for the entire year, the US had it only for the later part of the year. Cars are commonly called "86.5"

For the 4.7 Euro, commonly called the S2 (only officially called that in Great Britan) the motor was available from 84-86. It has the LH 2.2 fuel management and the EZF ignition. It has the "twin distributor" setup and is visually very distinctive. It has a better intake and cams than previous 16 valve motors.

For the 5.0 US, commonly called the S3, it was available in 85 & 86 (plus 86.5). It was the original 32 valve, with a huge intake. It has less power than the 4.7. It was designed to meet US emissions specs, and that's one reason the power is down.
The 84 US still has the older 4.7 16 valve with the "L-jet" injection. Even less power.

But there is a far, far more practical problem. You don't list where you are, but if you're in the US, finding an S2 Euro, especially an 86 can be challenging. There simply weren't that many of them imported (grey marketed) into the US. Even 86.5 US cars are not that common.

If you want the earlier body style, find the best possible example you can. Don't worry too much about which engine. An 85 or 86 US is still a nice car.
The power is ample, and the torque/horsepower curves are largely academic. You are overthinking that part of it. I'm not aware of any high compression 5.0 motors, other than a "mix and match" custom build.

Euros have a bit more "zip" and the cachet of being less common (adds a fair amount of "cool factor").

Personally, I lucked out and got an 85 Euro. The power is nice. The "lesser" suspension and brakes are still fabulous. I have yet to push the car to the point that I feel the need for more of either.

dr bob

OP doesn't share his location, and sometimes we forget that there is actually some life existing east of Long Island. I'll guess that he has European cars as his immediate choices. Just a guess though.

SMTCapeCod

I wouldn't get over-invested in the displacement, your talking about three tenths of a liter.
They drive differently, and modification and maintenance will be different.
I haven't owned a 85/86 4.7. I have an 83 4.7 ROW, but it is CIS, so different still.

You should look into the HP and Torque curves, bear in mind (or check) As it appears you've done. Also take care with your research....I'd be interested in the datapoint showing any of these examples rolling out with 400 ftlbs stock....theres something swimming in my brain about lbft being a different but still valid measure compared to ftlbs that I'm accustomed to, but maybe its just another thought-mirage.
.

But bear in mind other factors for example the ROW cars sometimes had different differential gearing increasing torque multiplication and making them more responsive to drive at the expense (possibly) of absolute top speed. Which end of that tradeoff would you prefer? If a street driver, I opt in for the former.

There are folks here that have driven both, some have owned both. Often I think the individual cars manifest different characters after some 30 years, but they are better authorities to speak to that.

Wisconsin Joe

Good point. His post kind of reads as "non-US" English (not a criticism, just an observation).

I know that there were 85/86 ROW cars made with the 5.0 (Australia & Japan IIRC). Was that the same 5.0 as the US cars?

dr bob

OP updated to show his Melbourne location. Good call on the offerings in Australia and Japan, Joe.

Landseer

My preference is 4.7 over 5.0. Easier and less costly to refresh and maintain.

Wisconsin Joe

Sometimes I guess right. Sometimes.

So, the OP may have a choice between a ROW 86 (upgraded brakes & suspension) with a "Twin Dizzie" 4.7 or a 32 valve 5.0.

If you have that choice, take the 4.7. Hands down a better motor.

If you have the choice between an 85 4.7 or an 86 5.0, I'd still take the 4.7. Even with the "lesser" brakes & suspension, the better motor is a better choice. Just my opinion, but that's what you are asking for.

Conza

EDIT: Woops! thought I posted this a couple of hours ago, I just kept the draft, so yes did update my location, intending to make this post at the same time, glad someone spotted it.

Ah sorry guys, I thought I had it on my profile because I've been on Rennlist for a while - I'm from Melbourne Australia. I'm almost certain I have Euro cars here, just not sure if I have US cars as well, not even a case of LHD vs. RHD either, obviously Euro cars came as both, the RHD US would be an odd one though I'd imagine.

Would you mind being more specific please? As I'm unaware of the '86 interior upgrades. Haven't looked into the interior changes all that much, I know they redesigned the drivers seat in 1984, but otherwise most significant changes seem to be made in 1982-83, so all post 83 cars benefited from that.

This is the interesting thing with the '86 5.0 - If it's a 5.0 and its a 1986 model, does it always mean it's US spec? If so, do you believe that they made it out of the US (to say, Australia)?

If that's unlikely, then chances are the ones advertised here are actualyl 4.7s, and that last 5.0 US spec version didn't make it here.

I wouldn't say lucked out at all, especially from the sounds of things, I'm not phased with suspension or really the brakes honestly, its just if an '86 is available at the right price, might as well pick that one, I think I'd be perfectly happy with an '85 and see no serious downsides in comparison to an '86.

Sorry CapeCod... CIS? Also lfbt and lbft, same thing I think? But I misquoted, it was 400NM or 295lfbt, sorry for the confusion, I'll go back and correct the OP, but for now;

4.5 is 258 lbft 78/79 and 280 lbft 80-82 both @ 3600rpm (928).
4.7 is 284 lbft 80-83 @ 4500rpm 84-86 295 lbft at 4100rpm (928S)
5.0 (86) is 295 @ 2700rpm (928S US) EDIT: This "is" the one I drove, Aus delivered, but US spec.

Yes you're dead right, taller gearing is better for top speed, lower for acceleration, I actually prefer longer gears, I enjoy being in a gear and listening to an engine revving for longer, even if it means I'm going slower. It also helps at top gear on motorways ticking over at lower rpms - I don't think I have the popular opinion .

Appreciate all of the comments and questions so far, I might go and drive that automatic near me today and see what it's like then report back.


EDIT: I just came back from driving an automatic... I'll need to drive the manual for sure, which I've set up to do this coming Tuesday afternoon.

My first thoughts are, gee, lots of electrical equipment, hope it all stays working. It was a 27C / 81F (hot) day, and the car didn't have aircon, but did have a sunroof, and as a 6 footer I just managed to get in, I wouldn't be wearing a helmet, but can easily see the problems of the sunroof and a helmet for anyone around my height or taller.

Lots of surprises for me, I've driven a '72 911 before, and a few other older cars, but this had uniqueness to it again.

Throttle peddle, I couldn't live with it as it was. The spring was extremely tight/firm, you'd push and nothing would happen because you didn't move the peddle more than 2mm. I think slamming down would be my immediate answer, long term, do people change these springs out for something easier? This had a huge impact on the accessibility of the performance, never mind if it had it, I only used it a couple of times because of this mechanism, quite disappointing.

Brakes were amazingly good, power assisted with ABS (which I didn't need activate), made the car very reassuring.

Steering, heavy but not unpleasant, excellent connection to the wheels for me mentally, I had heard they have very responsive racks, but I didn't really find that with this car, and I didn't get it up to any serious speed for cornering - not that I think I ever would having driven it now.

I was sort of expecting it to be a small car with a big engine, but I think its a medium-large car, with a medium-large engine, the torque was obviously there, and the sound when you did finally hit the firewall, from a set of lights was truly menacing, but otherwise I don't think I climbed above 2000rpm much at all.

Then there was the drive home, and I felt so bad. You see, I have a Golf V GTI (here goes any credibility I might've had), and it was just so much easier, 2006 vs. 1986 basically, big changes. I swear, even at a drag strip, my pedestrian FWD 2 litre turbo, with its DSG is simply faster than the car I drove, hands down. I don't think it has more power, or torque, but between the lighter body, transmission and tyres, it's either just as fast and more accessible, or simply faster.

Then I turned the air-conditioning on, ect, ect, felt quite spoilt by the niceties of modern equipment, and wondered why I'm even looking at the 928 at all.

I still love the look of it, I think an even earlier car, in manual, with a much lighter body might be more what I'm after, but I'm still going to drive a manual '86 5.0 as well.

bureau13

There are a lot of cars that are better stoplight-to-stoplight dragsters than a mid-80s 928 (any 928, probably). That's really not where they shine.

Conza

Could you tell me where they do shine? I'm hoping its cornering speed, and balance, and poise, but the one I drove seemed a bit heavy, the book I'm reading says 1530kgs for a manual, so am I nudging up against 1600kgs?

DeWolf

If I look at a 928 and the air-con is not working or had just been regassed it's a deal breaker for me. You must have driven a bit of a pig sadly. I've had a 911, 930 a couple of 944T's and sold an E46 M3 to get back into a 928. I have two at the moment and have owned five in total. A good one with low kms and well maintained is a thing of beauty to look at and drive. You could run from Melbourne to Sydney, have dinner and jump in and drive straight back home again. That is what they are designed for. Quite some time ago when I had a radar detector I done Melbourne to Adelaide in 5.5 hours.
Oh, and don't forget they take off in second gear so feel sluggish.
If the wife and I travel now she wants to take the 928 and she wants to drive. This is a woman who drives 250Kmh across the Hay Plain and loves every minute of it.
Here's a good one. Flew to Melbourne with son and wife to pick up two cars, an 85 928 and a BMW E39 540. BMW turned out to be a pos and I also bought some wheels which were going in the back hatch of the 928. No room for wife. Drop her back at the airport so she can fly back home. I go get the wheels and then son and I are on our way home. Got home in time to pick up the wife from the airport

Tazzieman

You can lube a stiff throttle cable , makes a big difference when freed up. Most likely it needs a new one , but they aren't cheap.

Aircon would be needed in Melbourne , esp given your slow CBD traffic and stinking hot January's . Mine is non-operational , but I get by with the fan and windows/sunroof. The cockpit always gets hot from radiant exhaust heat through the gearshift/console.

To repeat what has been said before , you need to drive one for 3-6 months to see where its many strengths lie. Once you learn to use the gears e.g. get the auto to start in 1st , kickdown working etc) it's a quick beast , though certainly heavier in feel to Golfs and older 911s. Once you gain confidence in Weissach's engineering you can hustle through the twisties very rapidly.

And the cars have character Modern cars haven't earn't theirs.