Scott M.

DING!

Everyone to their corners.

Dam*, is this getting counterproductive or what?

It's like discussing religion, there never was, nor never will be a winner, until all are abolished.

Tomato, tomat-o who cares, lets just keep it clean and try to remember, the only winner is the one who dies w/ the most toys!

Scott
93 GTS Renntech Stroker that WON'T be at OCIC '04, I'll be there 'topless' instead.

Z

You did leave out that the Kelly-Moss engine did 711 hp, and 680 ft/lbs of torque. That was back when the car was pretty much first built and I talked to the Kelly-Moss mechanics. I din't know how much if any they've increased those numbers by now though.

As far as shops who will build a stroker, Don Hanson's having his rebuilt by a shop up in the Pacific Northwest this time. Not sure what the name of the shop is, but I'm sure some of the PacNW 928 guys could let anyone interested know.

Normy

A lot of things come to mind with this thread for me.

First of all, no matter what you build...there's always someone with something faster. Just ask my boss, Connie Kalitta.

-500 hp? 600 hp? Great. Go for it. Now...what kind of drivers training have you had? Mine was with my history teacher from high school in a Dodge Aspen. Great. I feel completely ready to take a 600 hp 928 onto the streets of Orlando...

The past week I've spent here in town. Its cool out, and my car has been running right for a change. DAMN- my tires hate me. Blue smoke is only a tiny amount of pedal away, and full-on sideways antics are easy too. Yesterday while driving up from Miami, I cruised for a while at 100 mph/160 km/h just to see how the car operated at those speeds [I-95 is the "Florida Autobahn"] I noticed that my 310 factory [how much does a Borla twin exaust and an Ott X-pipe add?] horsepower can cruise at that speed with the pedal about 25% of the way down.

So you're going to double this? What nobody on here has discussed is what happens downstream of your engine. Specifically.....how do all those ponies [more specifically all the ft/lb of torque] wear your transmission? I've been told that Porsche [Primarily A Manufacturer Of Cars For The Street] designed and built the 928's transmission to handle about 600 ft/lb of torque.

And a 600 hp Porsche street car in the works [Carerra GT], and it has incredible brakes. What are you planning for your brakes, if you do this conversion? Surely you're not going to build a 210 mph car with 155 mph brakes....right?

My own car is enough for me at this point, though I've watched Lagavulin's sucesses with great interest. Tim Murphy's kit would likely bolt right up to my Austrian S2, and produce within 3-5% of the power with the same boost pressure. Since my S2 weighs about 200 lbs less than his car.....

-Reliability is an issue to me big time. I just won't burn a piston! I will NOT take a car with 10.4-1 compression past 7 psi...which means that I can make about 430 hp max with a blower. But can I control myself with this power?

Maybe. I don't trust my skills with that much power without attending a good drivers school, which adds about $1500 to the outlay.

As to what is better, boost versus cubic inches: Marc is right- there is no replacement for displacement. You simply CANNOT go to an open road race and firewall your throttle with a supercharger. But Devek's $20k kit can-

DEVEK: Magic. But it shouldn't take 2 years, and it shouldn't cost anywhere near that much- its just not worth it. And Marc your radiator SUCKS! I still buy things from these people because they are masters at their trade and NOBODY knows these cars better.

["Piehole"? I knew that term from Stephen King's novel "Christine". I think I drive "Christine" some times. Jim Bailey's comments were cogent and correct. I just think he needs to shave off that damn beard~]

AT the same time....

At the same time I still love drag racing. I don't know why- this is a silly contest...but the thrill of wasting someone is immense! It must be something in my blood...perhaps a remnant of the fact that I was born in Michigan. But I love acceleration, and don't care for speeds much past 100 mph. Really, what is needed with 928's, after spending many a Saturday at "Test-N-Tune" in Bithlo, Florida is a SET OF GEARS!

4.11/1 gears in these cars would change everything. ViribusUnits has a pretty typical US '83 car, which makes 240 hp or so and I guess that thing weighs about 3300 lbs. This should be good for low 14's on street tires with the right gearing. Stock, I suspect that low 15's are the best that this car can achieve. Lets remove 1 second from the quarter mile times [a huge difference!] and not even open the hood!

And this of course brings up nitrous. Frankly, I don't have a problem with this [visions of trailers: there is a strong redneck factor here!], as long as it is a true NOS system, done by the company, with individual NOS and fuel nozzles at EACH cylinder, and a progressive controller. As long as the engine is not asked to make more than about 430 hp [on an S2] it occurs to me that this system would work very well...and cost only about 13% what Tim Murphy's system would cost.

What am I thinking of late? I'd love to try to adapt Tim's system to my car. I suspect it would be pretty easy, and I'd keep the boost at 7 psi. I suspect that this $8k system is pretty well thought out and known, and that at this level of boost that reliability shouldn't be an issue. I won't do this to my car yet however- I'm not convinced that my engine runs properly [see my "Rough Running" threads], and I need to work this out first.

B safe!

Normy!
'85 S2 5 Speed

Jim bailey - 928 International

Marc the sales and marketing reference came from the initial announcement when You and Susan switched from customers of Devek (Red and Lucky) to direct involvement and Yes it touted Red's background at that time as well . Phil Tong's website had the text as I recall but that is no longer accessible . I do have to give you a lot of credit for the image you have created and the general perception of many people of the size , scope , depth , accomplishments , and nature of the business of Devek and your repair business Dynotech . I have always thought it odd , with a name like dynotech why do you NOT have a dyno ? driving 23 miles each way to Mustang Ranch has to take a lot of time especially with the traffic . It just seems a bit like having a kentucky fried chicken store ......someone asks for chicken .... and you have to drive 23 miles to get some ! And it is O K with me you can win ....you can be on top of the Horse P pile Even with an engine which I believe you never saw or touched . Competition certainly can be a good thing , stroker cranks now seem to be worth about $2,400 a copy . And yes Marc I too find this fun ! Now what about those six stroker engines you were all set to build nine months or so ago ? and did it really take two years for Louis Ott to get back his short block as someone else mentioned ? With Don Hanson now using another engine builder who will you be building a race engine for ? So many questions so few answers .....

Jim bailey - 928 International

Normy ..."I just think he needs to shave off that damn beard~]
" ............. But what would I hide behind ? actualy just think of all the time I save by not shaving everyday ..... my wife says she likes it I figure she just did not want other women to see how really good looking I am ... I keep thinking I will bump into a pretty young thing with a Santa fetish . After this job at least I should be able to find work Thankgiving to Dec 25 th .......

bcdavis

It's so funny that there is so much debate over the power and performance of our cars.
They are all 928s, and they are all going to have similar characteristics.

MarkA's racecar could most likely do 200MPH in the Silver State, with proper aero mods.
MarcT's white car could do well in racing, if he raced it more.
The Wisconsin cars could also do both quite well.

What is the HUGE difference between a stroker 928 and a supercharged 928?
50 horsepower at the moment? 25?
And what is the huge difference between MarkA's car, and MarcT's car?
They are both 928s, with the same body shape, same suspension geometry,
same engine block, etc... If someone is going to claim to be king of the hill,
or debate who is faster, it should be a debate between different models of cars,
or different kinds of cars altogether. Or cars vs. bikes... But 928 vs. 928, you
are arguing over tiny differences in design and concepts. Race cars are
not the same as street cars. Who cares which intake design is better?
I'm sure the 928 Developments manifold, and Marc's throttle body manifold
both gave an extra 50-75 horsepower. Big difference overall? No!
When you guys can top the 800hp Supras, then you can beat your chests.
I met a guy with a street driven 98 Camaro with 1100 rear wheel horsepower.
It's not really "streetable", but still...
Until then, other than the 928 people, everyone else is going to be laughing
at these kinds of debates. The Rennlist is where we should be sharing
our hot-rodding secrets, so we can work together to achieve success
in whatever arena we choose to compete. Regardless if that is on the
street, track, or top speed...

You know the posts I love?

The ones where people are sharing what rods work with what pistons,
so that more people can use that info, in the quest to build motors that
can really be respected. MarkA, wouldn't you like it if MarcT had some
info to share with you, that would let you win some of those races you
run? If people tried to help each other, and share ideas, we would
all be better off, and have more products and power available.

3 cheers to those who are out there experimenting and sharing...

Normy

Jim you're a card!

N!

Gretch

Well, for some of us, the debate is important because it is business, and for some of us because, it is an expensive hobby. When you look at the arguements people make here, they parse well into these two camps.

FWIW, my choice to go with SC was based on a balance of cost and elegance of engineering. (Did I mention performance?) Both were important issues for me. I have had a turbo powered car. I liked it a lot, but didn't believe I had the same committment that John has shown to get the job done right. The stroker got eliminated based on cost and complexity issue for me. Complex in the context that I would much rather do my own wrenching and just did not want to tear the engine down. NOS was never really an option as it is, IMHO not elegant enough. So the SC route was chosen. (Did I mention performance?)

Then I had to decide where to go to get the kit. And "Kit" was very important to me. I am not an automotive engineer, just an affectionado who is reasonably competant with a wrench. I wanted a "system" that had reached the highest level of testing that I could find. (Did I mention performance?) I looked at at the products that were available for almost 2 years. I nearly bought the FAST kit, but ended up with Tim's. $6 grand versus $8 grand. What did I get for my extra $2 grand? Well, I have convinved myself (after getting a bill of materials from both vendors) that Tim's kit was more complete and that the engineering for the pulleys and the bracket and tensioner was the better design. For example, Tim's pulley accomodates a belt with more ribs than the FAST kit does. And as I have mentioned before, I was immediately impressed with the engineering elegance and functionality of Tim's bracket and tensioner. (Did I mention performance?)

The install is progressing at my leisurly pace, (which I am enjoying immensly). Tim has been available for counsel and has been an enthusiastic receipient of my suggested edits for the install manual. Best of all, he is a Packers fan and oh by the way....did I mention performance?

To each his own, at least we are all voting with our own money, large pie hole or not. BTW, Did I mention performance?

Jim bailey - 928 International

Normy ....... the world to me is a very amusing place .

Jersey Joe

This might be a good place for this:

FOR SALE:

1990 GT, BLACK ON BLACK, REAR A/C DEALER SERVICED SOUTHERN CAR
140K GARAGE KEPT LOTS OF NEW PARTS, CLEAN CARFAX NO COLLISION DAMAGE MUST SELL:

$15,000 OR B/O

LOCATED IN NORTH JERSEY
201 991-2937

Lagavulin

GREAT idea; let’s do it! Let’s get the ‘whole picture (i.e. entire power curve)’ regarding 928’s, twin-turbos, and centrifugal superchargers, since

‘....it isn't about some number you pull off on an inertia dyno for 5 seconds at the redline.’

For contenders, we’ll use the centrifugal dyno-sheet with the lowest hp output, and for the twin-turbo, we’ll use a dyno sheet which ran 1 psi more of boost than the centrifugal. Using those sheets, we’ll compare the numbers at various RPM points. So far, as predicted by John, it’s not looking too good for the centrifugal as it’s already down 1 psi of boost.

So let’s take a look at what the dyno charts say.

In the left corner, a twin-turbo 928 dyno chart weighing it at 12 psi boost, (..scroll):
https://rennlist.com/forums/showthre...5&pagenumber=2

In the right corner, a centrifugal supercharged 928 dyno chart weighing in at 11 psi:
https://rennlist.com/forums/showthre...hreadid=97863/

Picking through the twin-turbo’s graph and looking for intersection points, here’s what the graphs reveal about torque production for both blowers. While looking at the results, please keep in mind the statements made by John:

‘..remember the mid range power would far surpass the centrifugals out there’, and,

‘....it isn't about some number you pull off on an inertia dyno for 5 seconds at the redline.’

Ding! Ding!

Round 1 - 2200 RPM:
300 ft/lbs centrifugal
190 ft/lbs twin-turbo

Round 2 - 2900 RPM:
360 ft/lbs centrifugal
250 ft/lbs twin-turbo

Round 3 - 3200 RPM:
390 ft/lbs centrifugal
300 ft/lbs twin-turbo

Round 4 - 3600 RPM:
395 ft/lbs centrifugal
350 ft/lbs twin-turbo

Round 5 - 4300 RPM:
440 ft/lbs centrifugal
375 ft/lbs twin-turbo

Round 6 - 4700 RPM:
460 ft/lbs centrifugal
382 ft/lbs twin-turbo

Round 7 - 5400 RPM:
469 ft/lbs centrifugal
335 ft/lbs twin-turbo

That doesn’t look so good, does it? All the judges score the centrifugal winning in every round, despite the other corner’s claim that the much-maligned centrifugal is lacking low-speed and mid-range punch, and therefore wouldn’t make it past Round 3. As it turns out, it looks like it was all over for the twin-turbo once both stepped into the ring and both were idling waiting for the bout to begin.

John, do you remember YELLING this?

I don’t think if I ‘ROUND UP’ will change the results of the judge’s score card at all. I do agree that you do have ‘MID RANGE TORQUE’, but then again, all engines do such as the Yugo.

Do you remember SHOUTING this one?

When you were looking at the dyno charts and typing, are you sure you weren’t dismayed with the results while:

‘HOLDING IN MY HOT " ANGRY SPITEFUL LITTLE MAN" HANDS’

...and giving ‘TWO PULLS’ on your LITTLE ‘RICHARD’ instead?

Alright, let’s continue investigating the claim by John regarding turbos and 928’s.

Here’s the horsepower numbers:

Round 1 - 2000 RPM:
110 hp centrifugal
80 hp twin-turbo

Round 2 - 3000 RPM:
215 hp centrifugal
150 hp twin-turbo

Round 3 - 3300 RPM:
250 hp centrifugal
200 hp twin-turbo

Round 4 - 3700 RPM:
290 hp centrifugal
250 hp twin-turbo

Round 5 - 4100 RPM:
340 hp centrifugal
300 hp twin-turbo

Round 6 - 4600 RPM:
395 hp centrifugal
350 hp twin-turbo

Round 7 - 5200 RPM:
495 hp centrifugal
350 hp twin-turbo

Round 8 - 5800 RPM:
500 hp centrifugal
320 hp twin-turbo

Again, it’s not even close as the numbers show the centrifugal dominating the twin-turbo with relentless low and mid-range body blows. The centrifugal mercifully ends the bout by registering a KO in Round 8 with a crushing right hand, sending the already staggering and stupefied twin-turbo hard to the canvas as it's thinking..

‘....it isn't about some number you pull off on an inertia dyno for 5 seconds at the redline.’

Yeah, but is sure does deliver the knock-out blow.

Again, the numbers themselves say that the ‘fight’ was not even close; the centrifugal dominated down low, dominated the mid-range, and ripped the twin-turbo a new one on top. Once again, so much for LITTLE ‘RICHARD’ ‘s claims...

‘..remember the mid range power would far surpass the centrifugals out there’

What can we learn from this? A well thought out, carefully matched and engineered centrifugal setup can easily beat out a twin-turbo setup (..in this case), despite the twin-turbo having the advantage of running more boost.

It's all there in the numbers for all to see.

BC

Any dedicated beard-man will tell you the beard is for saving lunch in it after breakfast.

Is the kelly moss engine sleeved? I know its stroked, but....

Jim bailey - 928 International

Too bad Andy goridesnow is busy this week in a national sales meeting or the Eaton / whipple low buck could be part of this tag team .......... Lag , John was talking about a hypothetical engine why muck it up with FACTS . After all the horsepower winner is the HYPOTHETICAL twin turbo 1,500 hp evil twin for the Devek white car, parts of which were sold to Tom Cloutier when that project aborted . Watch the low blows you get points deducted for that !! John build it and see if they will come ...........

BC

....If you wanted some aftermarket rods for the 928, then here they are:
http://www.pauter.com/porsche.htm

These will be about 1800, and they will include the ARP bolts. They are also stronger because the bolts screws into the main body.

I really wanted to get sheaper Chevy rods, but the changes need to run them on the stock crank (I have not gone the stroker route) would probably get close to the cost noted by pauter.

JE says that they can make a piston that will run in an alusil bore. They have 4340 steel and another steel thats starts with a 2. Like 2056 or something. The 4340 doesn't expand as much.

There actually three options. Stroker, SC, or a bored-out SC. See, the rod ratios of the Stroker are not conducive to boosting. There is just too much rod angle, IMHO. This is just me. And torque is not something that these cars need. They need blinding accelleration from 3k up. Thats going to ber HP.

If you sleeve an block (however you choose) to 5.6 liters (106mm bore) you will have a great bottom end to play with. YOu can use any piston you want, and could lower the compression ring a tad for more mass to contain the heat. With a 9:1 or so compression ratio (8.5 if you really want more saftey), you can then run all the way up to 20psi if you wanted to. If you wanted to keep to the 1075 number (which Mercedes has surpased by a few hundred on thier SC cars - I think the number GoRide gave was 1300), then you would do less boost.

You then stick on GT or 85/86 cams (which have to be changed a bit) and have a 350-380 NA engine, which you then add 16psi to. Using Lags calcs, 700hp at the crank would actually be a SAFE temp level for CCT.
An d you would be able to stick a 7k rev limit on the engine.

Cams: 1000-3000 (I foudn them for 1000)
High Tension springs: 400
Sleeving: 3000 (this varies as to process)
Pistons: 1000-1500 (I was told 1000)
Rods (1800-3000) (Pauter is 1800)
Crank Drilling: 400
Optional: 2-4k for big valve heads (many choices for vendor)

Murph's SC kit, or Go Ride's - 3-8k


HTH.

John..

LAG, You truely do talk like a man with a paper *ss-hole. Lets see, comparing the blown status of a stock 1981 16 valve 4.5 liter with the blown status of a stock 5.0 liter with 32 valve heads.....WTF? Does the S4 not make nearly 100 more HP out of the box? As I recall you started this whole debate long ago on another board after George 911V8 asked for a comparison.

Did you consider for once that my statement would be based on an even playing field (i.e. turbo S4 vs. Centirfugal S4)? When you make a comparison like that, or any other Enginnering (okay so you aren't an engineer) comparison for that matter you always use a common playing field. It is sort of like doing ANY experiment and holding all other variables constant. In this case, HP of a given engine is a function of Boost.

Why don't you take a good hard look at the power curves before and after turbocharging, as that is the real story. Yea, Lag, that's right.....I DOUBLED the power with less than one bar of boost. Exactly what is your percentage gain again LAG? Do tell...

Let me put it to you this way LAG....the Bastard, complete with its "Briggs and Stratton" manifolds can product 10 lbs of boost at 4,000 RPM, then boost builds up after that to my wastegate setting, which mind you I can dial in on the fly if I wish. I can have 5 lbs by as low as 2500 RPM in higher gears. You must remember telling me how "impossible" it all would be.

Feel free to tell us all how much boost that centrifugal makes at 4000 RPM. While you are at it, tell us about how long the car holds onto 11 lbs of boost....is it more than 1/4 of a second, because I figure you have to shift....right?

My point was a twin turbo setup on an S4 WILL have substantially more mid range torque than with the centrifugal blower equipped car does and I'd lay money on at least 30 more crankshaft HP at an earlier engine speed. Lag, does the term "on the gates" mean anything to you? Maybe you should look at Andy's results and get your calculator out. There is always Turbo Math to finalize your math skills.

I've already proven your math is BOGUS and your latest statements and comparison make absolutely no sense whatsoever. It's apples and oranges my friend.

BTW, do give us some performance specs on that car you drive...or are you just out to post a dyno number? Perhaps a day on track with Kibort will calm you down?