BC

I've promised myself I will not crack open this 85 Euro auto I purchased. It must stay complete and original for various reasons, two being in the garage with no motors or interiors.

Anyway, 4.7L, Huge Euro valves, and the lumpiest cam that porsche made for these cars, 2V wise, right?

So where's the beef? I have to do a few things before I dyno this car, but I have some serious interest in finding out more about what people have gotten from these "uprated" engines.

It drinks oil through the intake like a fish, which means it needs a crankcase evap system suitable for over 6krpms. It currently has those miniscule platnum spark plugs with the tiny little electrode, so I will put some coppers in there. I'll check the cap too.

I held on in a right hander today getting on the 5 and the car spewed a batmobile amount of smoke from the pipes at about 6k and wouldn't get to redline. It hasn't done that before. I assume the 5/40 I am using from Mobile is a bit thinner and is really getting whipped up more then whatever was in there before.

So do these engines have the log style manifold or the newer 32V ones? How do these cars respond to the X-overs and more open pipes rearward?

MarkRobinson

928TS system will bolt-up/work on a euro EFI '84-86 car, though the timing loop will most likely need to be connected. Boost can be kept reliably low if necessary as well, as low as 3psi. Should still make 330rwhp or more at 3psi. Hmmm......

Richard S

Should have the old style exhaust manifolds. I put down 265rwhp/269rwt with S4 cat into 3 inch single exhaust. Previously was 240rwhp with old 1980 cat and stock 1980 exhaust. (BTW, 84 Euro S motor in 1980 US 928)

Rich

mark kibort

my 4.7 US engine with the euro intake system, cams , sans the heads, and my 5 liter conversion with all euro intake, cam tb, etc, ran amazingly well.

243rwhp for the US 4.7 with euro cams, intake , plennum, TB but not the heads) and it reved and didnt use any oil

with the 5 liter bottomend, and then the euro heads too, it put down 293rwhp.
still no real oil burning or being sucked in anywhere.

However, Scots did this quite a bit, with his full euro 4.7. dont know what the issue was, but the 4.7 euro we have now for him has this baffle on the oil filler, so you just cant see down to the crank if you were to pull that assembly off. Looks like a louvered screen of some type. is this a stock piece?? I dont remember me having one of those with my 5 liter part euro, and it didnt suck any oil up.
maybe it is your oil brand and/or weight

dont know.

Mk

BC

Thats what I thought Rich. I haven't been under the car yet, but I don't see the "accordian" of the S4 style manifolds.

265 with 20% driveline is about 312. Driveline, being realistsic, is more like 15%, so even with your mods, the 310 sounds iffy.

m21sniper

My 3000lb hi-stall US 83 A/T has run a best of 13.67.

Never had it to a dyno though.

BC

Thanks Mark. I think all these cars need to evac away from the intake, but that just opinion. I haven't looked for the baffle. I will though.

BC

Thanks Sniper. This is a full weight car with a very lazy auto. The Euros do have a higher stall I think.

Was yours the car with an un-documented power-adding history? Unexplainable or was that someone else?

m21sniper

Yeah, i'm the owner of the 'mystery shark'.

I did some things to it, so those i can discuss, but it was already much faster than stock when i got it.

Richard S

The Euro's originally had a dual pipe exhaust. My motor would not rev as freely with the old 1980 cat and exhaust (small single pipe), but really likes to rev now. Also, I ran one ORR with the old exhaust, engine temp would rise (at or above the upper white line) when RPM's were over 5000 for extended runs (think 10-20 miles at over 130mph). Temps would drop when I backed off (below 5000 rpm, 110-125mph) With new exhaust, engine temps were never a problem on the same course (at or near the lower white line).

Rich

Richard S

Sounds like a Devek oil baffle, I installed one on my motor when I rebuilt it.

Rich

BC

Please share.

m21sniper

Well i've really done a couple things to increase the power to weight ratio of my shark.

The first and most dramatic as far as performance was the shaving of approx 300+lbs of weight(accomplished over some time). I swapped to lightweight 19lb racing seats, switched to a 14lb drycell(Heads up i recently become aware of, miata OEM batteries weigh 13lbs, and have a higher CCA rating than the 14lb drycells do) i removed the rear wiper arm and motor, the air pump system, the a/c system, all kinds of extraneous bolts and brackets, the timing covers, switched to a lightweight high output electric and lost the clutch fan, all kinds of stuff(when i just redid my shocks and mounts i used all reduced diameter head hex bolts that i had leftover from my auto tech days to save a few more pounds, lol). There is still more i'd like to do in that department. Probably about 100lbs worth.

And really a huge weight savings was seen by losing the stock exahaust, which is damned near about 100lbs all by itself.

Which leads to the second 'major' mod i did, which is a custom made 3" single stainless steel exhaust(no cat- 928 specialists test pipe installed), flowing through a mid-mount 3" Borla XR-1 off-road racing muffler, and fed by 1985 style 5.0 liter headers(they were on the car when i got it, but the rest of the stock exhaust was still in place, which i found to be quite odd). The total system from the 928 specialists pipe back weighs in at a mere 23lbs.

I'm not one of the dynophiles, so i can only go by how the exhaust 'felt', but it was at least a 20+ hp gain, and i think to be honest more like 30+ after some basic tuning(richening up the mixture). I also got a really nice gain in percievable HP via ignition timing advance(so much that after a ride my ex partner with an 85 US 928S asked me if i secretely installed a turbo in the last 24 hours, lol), and i've heard many other 928 16v owners say the same, so that should help you too. A suitable 3 RRFPR is a must too.

The car came with an approx 2500rpm stall converter(a very, very, very, very nice modification, tehehehehehehehehehe ) It is a 4 speed, and always starts in first regardless of throttle position.

I also installed a paralell kickdown switch and adjusted the shift firmness to the 'break your passengers neck' setting.....

I switched up from the stock 225-50-16s on the hideous slots to 245-45-16s all the way around. 16x7" phonedials up front, with 16x8"s in the rear. I just recently installed new Bilstiens(i already had bilstiens in the front, but boges in the rear- that's how i got it) and eibachs all around, and my 928 specialists HD front swaybar just came in the mail TODAY!!!

So, that's what i can attest to. The second week i got the car i ran a 14.8 in it though.........and i was totally unfamiliar with it, and was doing very poorly launching it.

I had it to the track about a month ago, but it was like a light misty drizzle, and a far too cold for launching 55 degrees(especially for my 70% whooped rear tires), and could only manage a best time of 14.242 @ 97.85mph.

My best ever time was a 13.67, and my best ever trap speed was a 103.1. I did both of those last summer.

In ideal conditions with new rubber i expect it would run a 13.5.

So you see, this is why i need to add some boost...probably in the form of a bottle.

Joe F

I wanted to get a baseline on my 5 sp '83 Euro S on a dyno a couple of years ago. This was done without any tuning, plugs. cap wires or checking for vacuum leaks. It has MSDS headers and a custom 3" exhaust made by powerbroker.net.

It did 260rwhp/263 rwt. It also was running a bit rich,
the dyno operator said I was having some black smoke at high rpm.
I think the mixture was between 10-11 to 1.
So I think there might be a little bit more there if mixture was right and plugs, wires, cap and vacuum leaks were tidied up.

or maybe not.

BC

Thanks for the info.