My 85 has the full Euro S engine and fuel injection with maf. Some have reported good gains with just the cams, but even with some exhaust mods we are talking about going from 180 to 190 rwhp to 230 to 245 rwhp, with the stock Euro S around 250 to 260, and a 5.0L hybrid 280 to 290 rwhp.

My "hot" cams have been sitting in the webcams boxes for about two years waiting on me to get started on that "next" motor. Goal right now is to "get er done" coinciding with my 85 Euro S next smog check in Nov of this year so I have two years to sort out how to pass smog with that cam.

Between 300 and 350 rwhp is where the magic happens, throttle breaks big rear tires loose in the second gear etc. Another 100 rwhp and drive train parts start to break, and the car gets much harder to control while applying power, becomes a straight liner.

The other factor is tuning, early cars not much possible, injectors or adjustable fuel pressure regulators, but its a wide brush to paint with.

US 85/86 brains have a fair amount of tuning potential witness Porkens S3 chips as well as John Speake's.

US 88+ brains have sophisticated knock detection, much more processing power, and a diagnostic port. Down side is that they have known issues and are costly plus use a 35 wire connection vs early 25 wire, and that means some patching of wires to make it work.

I am not a fan of aftermarket injection yet, but it has potential as long as it is ok with local smog laws or possible to swap out or hide for inspection.

its possible to shark tune them with the 85/6 brain apparently.
That would be the mod for me.
I have the brain and pigtail installed. just no skill nor stuner.

wow only 10 rwhp gain, thought it would be a bit more with Euro spec webcams installed. Tom @ 928 Intrntl says CIS cams are good for that increase in my car, only $250 ea.
or
If i buy a used '85/6 brain, i can shark tune with Porken Chip for about the same increase (10RWHP)

Will keep tuning what i can and lightening for now, but in order to do a RS interpretation I'd have to add some HP gains as Porsche would have.

I.e. 911CS of mid '80s

1987 911 Clubsport: Porsche discovered that less could be more - more $ for less weight and less equipment.

The 1987-89 Clubsport cost about five percent more than standard coupe, which was not exactly equipped.
Missing from the Clubsport (or CS) rear seats, door trim, a parcel shelf, insulation, electronic heater controls, the passenger's sun visor, a radio, a glove-box lid, power windows, and foglamps, netting a savings of 220 pounds. While the engine delivered a nominally unchanged 217 hp, lighter intake valves (sodium filled) increased rev limit from 6570 to 6840 rpm. Together, this knocked 0.4 second off the 0-to-62-mph acceleration time. More significant was the midrange punch, the better handling due to suspension tweaks, and the enhanced directional stability thanks to the whale-tail rear spoiler. Despite delete-option CS decal that straddled the entire right front fender, Porsche's Buyers failed to see the attraction of the go-faster-by-taking-out-weight concept. In the course of three model years, Porsche sold 339 Clubsport coupes and only a single CS Targa

This will be my approach, hard part is the upholstery changes (finding time to do them) and determining what may have been done.

When all changes are made, go to paint. probably 2 year deal.


Good to know about HP gain thanks

OB start at 180 to 190 rwhp, adding the cam's and exhaust make a big bump to 230 to 245 rwhp depending on all the details.

Porken makes chips to match a couple configurations, but I don't think stock us with euro cams is one of them.

Eventually maybe it will be like it was in the Mustang (Fox) world where a few guys with a LOT of experience would make chips to order.

Putting in the 85/86 brains isn't trivial on an early car, for one they expect a twin distributor and coils.

The clubs sport was a promotion with sales to racing drivers, cost to them is likely nothing like cost to normal people would have been.

"Affordably", your main option is to upgrade the exhaust system.

Get yourself a free-flow cat, and the rest of the system back. This will give you a nice little boost in HP power. Not a ton of HP, but, a decent amount, that's instantly noticeable.....Other than that, you're looking at "major bucks" to get real HP gains out of the 84'. It's an old car, and the 80's were not known for being the "Golden Years of Horsepower"

I have an 84, as well... I installed new Magnaflow system, from 928 Motorsports - From Road to Race, 928 Performance is 928 Motorsports®

84 Euro twin dizzy brains are fundamentally same, ie precursor by only a few months, of 85 USA 32V engine management system, also twin dizzy btw. John Speaks can consult with you on any advantages/disadvantages of swap. It is simple if he reworks the clocking a bit I think. Porken chips are not designed for the cams, as noted, nor will anybody likely convince him to custom program them --- he's just now dialed in on the S4, reluctantly. Shark tuning is possible. Few if any have done it. Talk to John.

Here's some unabashed advice for consideration. Do what you will. Don't waste precious time, money, or your children's burgeoning time of discovery on tweaking your 928.

Chances are it won't even beat Mrs. Smith's minivan off the line, certainly not Mr. Jones' 94 Chevy diesel pickup w/smokeroller tuning kit and 1100 hp. ( I tried that 3 weeks agp, neighbor with that truck, long bed, dual cab, beat my tweaked Euro by a long margin)

Take that from somebody whose BTDT, looking back now.

2011 Chrysler Town & Country Touring 0-60 mph 8.0 Quarter Mile 16.1
2011 Honda Odyssey EX-L 0-60 mph 7.8 Quarter Mile 15.9 (this is the fast one, others do it in 10 sec)

1983 928S with 1/2 Load Capacity and All optional equipment and accessories (automatic): 6.8 sec Quarter mile 15.2
Porsche figures were always very conservative and the cars loaded with over 300 lbs weight.

I'd take a wager on a race to 100 mph with any new stock minvan. Minivans are pushing bricks through the air.

I'd agree with you if we were in the 356 forum.

Chris out of curiosity have you done a compression test on your worked '84 with higher miles? Curious if it is moving air.

I measured it but need to redo. Think it was around 160, pretty consistently.

That's very good for a high mileage car, can't believe you sound so bored.:confused:

PO of my 85 Euro broke the timing belt while passing a minivan ...

Over 100 mph aerodynamics etc. are major factors.
Under 100 mph traction is the major factor, and dominates by 300 rwhp or so.

928's suck tractionwise, wheel hop, poor weight transfer, space for crazy wide tires etc. etc.

Am not bored. Am using/rotating the 3 cars that are currently in driveway for GT, long haul road as well as short commute.

My point is broader. I use them for what I think they are best at. The number of dollars and time needed to make them 10% to 15% more powerful I think is a chase down the rabbit hole. Fine if you like to invest a great deal of time meeting all the alice in wonderland characters, and check all the boxes of those before us.

Further broadly, its investment in family vs hobby.

For me, now looking back at the 4 adult kids we have, I'm questioning those thousands of hours of time I wasted on my merry chases of hobby. Just factor that into your overall strategy.

Am getting great enjoyment from the cars as-built for the purposes it was designed. That doesn 't include drag racing. Big brakes was a waste of time, except it forced me to address bad bjs and tie rod, for instance.

Investment would yield so much more if I'd put the time/$ into the aspirations of the cute wife/kids.

I suppose that this is a bit off topic but, I have never found the 944 very appealing; however, a 924s represents terrific bang for your buck.

Sparco Torino's (I think)

Stuff like racing seats or steering wheels and you will never talk your way out of another speeding ticket.

If you own a 928, keep it STOCK, do not try and get a bunch of HP out out it. Enjoy the car as is! It is a dream to drive, looks great, even looks better than new cars! It was way ahead of it's time engineering wise and was an expensive car. Besides, there is no rational need to go faster!

You right about that. There's enough jokers around here all fast and furioused out with their wings ground effects, that cops don't bother harassing me with my antique Porsche. I race and time trial so I have absolutely zero interest in going fast on the street anyhow. I've been pulled over once in 20 years...in my Tacoma, and got a ticket lol.

Automotive equivalent of Bob Dylan

I agree with you Landseer but also like teaching the Kids to have a hobby and to wrench, i remember how it changed how i thought (mechanics) very good for the brain and besides all kids do today is want to play video games.
Glad your not getting bored, some times when i work on a vehicle too much i can sour on it a bit and thought you might be.
WE have to remember Porsche cars were not ever straight line drag racing cars, they were for the twisty roads. I know you know that.
You'd leave that 1100hp truck in your wake on a road with a turns.

i was thinking, (yeah i know bad idea lol) about using 2 radio controled jet ducted fan engines th boost my car, if i can fit them in th air ducts, yes i know i have to seal th air box, not th cheap cheesy ducted fan engines, they do make some that move some serious air,