danglerb

Lust for power has me looking at various motor options, and what makes the Euro S better has me curious. I know there is a bit more to it, but it looks like it mostly just flows better, similar torque, with more top end hp.

Can a US model be ported and modified to Euro S or better performance?

Can L fuel injectors work in a K Euro S intake, or would a US intake need to be ported or a new intake fabricated?

John Veninger

Heads, cams, intake. Everything was bigger than the US model.
No you can't get the US intake spiders too EuroS spec, but close. The TB is also bigger on the EuroS. The valves are bigger and CR is higher.
Just buy a used EuroS motor.

mark kibort

cheap way:

extrude hone the US runners, (stock US runners are 1.5" ID vs 1.6"for the euro), hog out the plennum entrance, and aluminum weld a flange for larger throttle body, and find a 3.5" throttle body, while hogging out the "U" that fits the AFM. put in a set 79 cams or find some euro 82 cams. this will bring you up about 30-40HP.

better way:

find complete euro 84 intake, hog out "U" from AFM to port match it, then put in some 82 cams (or 79s) good for 43hp

Best way:

get a '85 bottomend and pull it apart, re-ring, bearing, and cut the pisons for 2 valve cuts, add above. get near 300rwhp

start with headers first and a rising rate adjustable fuel regulator (only need one as you can close off the other stock one by several ways.)

mk

hacker-pschorr

Mark - you forgot the even better way - bolt on a blower.

danglerb

RE best way, thats a "hybrid" motor, 5.0L shortblock with a Euro S top end, and very close to the top of my option list, but I wasn't expecting that much rwhp out of it, maybe 250 ish on 91 pump gas.

I'd like to keep it as simple as possible, using the L brain and injectors.

If I can find a source for cam cores, even 944 cores maybe, then I might have a custom ground cam a bit more fun than just a Euro.

What I can get away with here in Calif on the exhaust side remains to be seen, but certainly 85 manifolds would sneak through, not sure about headers, maybe if I got lucky and kept it fairly quiet.

This all has to fit into some sort of a reasonable budget compared to non Porsche engine options (that I don't know enough about to discuss yet).

danglerb

Blowers offer percentage gains, best to clean up airflow issues first, and in "many" cases I think once airflow is good the need for a blower is less.

For my 91 Mustang I was planning on a Kenne Bell, not a huge HP bump, but a solid 100 ftlbs of torque increase from just over 2000 rpm all the way to redline. Perfect for a street car, totally wrong IMHO for a 928, too much of a change of character.

mark kibort

pretty standard results for a 5 liter ljet, with no real mods. get the 85 tubular manifolds and make them work, and you can address the smog stuff. look for near 275 to 290 at the rear wheels as far as hp on 91octane pump gas.

just find some used euro 82 cams (or 84 cams if you are doing the 5 liter )
either way, they will both work and pass emmissions.

mk

AO

You haven't ridden in one yet, have you? I don't think the character is wrong at all. In fact it feels the way it was meant to be. The HP is about 150-175+ as is te TQ. It's a super feeling. Giddey up and go!

But the price differential is pretty big between that and going wth a hybrid.

hacker-pschorr

Let me know when your increased air flow is anywhere near 400hp

"Change of character"???
Considering every version of 928 has a totally different character when it comes down to the motor (78-79 vs US 16V vs Euro 16V vs EuroS 16V vs S4 vs GT vs GTS.........) I'd say you haven't driven enough 928's yet. In fact, the centrifical supercharger is nice because it retains the car's original character, just moves everything up a few notches.

danglerb

I'll LT-1 you know when it happens.

Keep in mind I am not racing, I am having fun, so its not some specific hp I want, its balanced feel, and I think a hybrid motor might do that for me.

Starting with a purely stock US 16v and its 180 ish rwhp would take a ridiculous amount of boost to make 400 rwhp. I know people who manage 22 psi of boost on the street, but most of them clear up the flow in the motor first and make 750 rwhp instead.

hacker-pschorr

With that kind of money a stock boosted 928 (32V) can make over 600hp
I have nothing against hybrid motors, I'm building one for my track car - it will also be supercharged. Dollar for dollar, the blower is the better buy.
Really? Based on what? My 81 with 85-86 manifolds and custom exhaust broke the 300rwhp mark with 6psi of intercooled boost (chart was posted a long time ago). My air / fuel was way off, so was the timing so there is still more power to squeeze out with better tuning. Parts of my system were not working correclty, so we left it as-is. This spring I'll hit the dyno again with all of the parts fixed and a different fuel pressure regulator setup.
I have a 12psi pulley what will get me close to 400rwhp on the stock engine with no other changes. Once I have this tested the 14-15psi pulley will go on. Baby steps.
I know guys running 50psi of boost on street cars. He averages 20mpg on the highway. With a proper engine management system a high hp / high boost car will act like a stock vehicle when you want it to.

Jean-Louis races with a stock 4.7liter EuroS motor - 270ish rwhp IIRC. With 6psi of non-intercooled boost he made close to 380rwhp. So yes, starting with a higher HP, better flowing motor will make more power. However, he is limited to how much boost he can / should run with 10.4:1 compression. My car with a factory claimed 9:1 I can easily push it to the limit - we've already tested the L-Jet fuel system, plenty of headroom for this kind of boost.

Imo000

Andrew, wrong comparrison! Compare a boosted S to a Hybrid S and the difference will be very minimal.

danglerb

You might as well try and talk me into a red car, its personal preference, and yeah I have ridden in a supercharged car, like 900 hp and didn't care for it a bit.

Doing the hybrid just seems more "Porsche" to me.

hacker-pschorr

Ridden & driving are two different things - so is any other car.

Yes it is personal preference - do what you want, just trying to help since many of us have gone down this road with 928's. N/A upgrades on these cars are very expensive for very little gain vs. boosting. There are also two different types of blower - with various models within these. To say one blown car will be like another is not apples to apples. That is like saying I don't like Corvette's so any other V8 car will not be my cup-o-tea.

Dropping in a 100% Euro motor is doing it the "Porsche" way, not mixing up parts from various years / models.

I'm happy to see anyone do anything to make a 928 faster. What I don't like is how many threads or posts from people after doing a hybrid route wondering why they spent so much money for such a little gain.

AO

Well sure, 900hp is crazy power. 400-450 is a real nice power level which is what I have using a Kenne Bell-type setup.

But as Hacker said, anything to boost the power up is fine. Just offering alternatives to get there.