GoRideSno

This is a friend's 87S4 automatic with 217k miles. The engine seems to never have been rebuilt.

My friend bought this car with intentions to install one of my TWIN-SCREW systems. It was done

What awsome cars. It hardly even drips a drop of oil.

He said he recently found a very old list of goals he had written. Among them were make $1,000,00.00/yr and buy a 928S4. I am glad I could help with one.

With each run the times got quicker, but then it was time to go .

The best fun of the day was when I was up against a huge 1970's stationwagon that almost got me. Later I found out he had 700hp/tq. Very cool guy.

I also met another 928 owner but he was there with his MR2.

A crazy supercharged Viper ran a 10.8

I don't suggest SCing a car with over 200kmi although this is the 2nd 928 with over 200k being driven with one of my SCs. The other is daily driven by a 19year old and it dosen't even have an intercoler.

This car is going to someone who, judging by his highschool driving habits from 15yrs ago, will never even drive it fast. I think he just wants it (with the TWIN-SCREW) so that he can think to himself "I can beat that car". Without the timeslip he just couldn't think it authentically. Ths timeslip is really what he has purchased.


Andy K

Jim_H

Very Cool Stuff Andy

Shane

slate blue

Thought you might find this article interesting Andy, I copied this article from a website that reviews cars. I was doing some research on my supercharger setup, I thought it was interesting, the other tidbit I can share is that the Koenigsegg despite its superior power to the Zonda and the McMerc was beaten around the Topgear test track. The McMerc is very fast and I believe the main reason is its incredible power right thoughout its rev range. Below is the article.


"On paper, this engine delivers 655 horsepower at a high 6800rpm and it redlines at a mighty 7500rpm. The peak torque of 553 lbft arrives at 5000rpm. So, it should have the best combination of power and torque on the market. Unfortunately, that is only on paper. In reality, the high-boost 4.7 V8, with its unusually high specific power, lacks torque at low to medium rev to fight against its rivals. Its torque curve is more like an old-fashion turbocharged engine’s than a supercharged engine’s, putting emphasis on the top end of its spectrum. At 3000rpm, only half the maximum torque is available. In contrast, Mercedes SLR’s supercharged V8 emits its peak 575 lbft at that rev. No wonder Autocar magazine criticized it lack flexibility. It found the CC8S took a laughable 10.2 seconds to accelerate from 50-70mph at top gear while Pagani Zonda C12S needed only 4.4 sec.

Much of the blame must go to the Vortec supercharger. It is a centrifugal-type supercharger, unlike the screw-type supercharger used by other supercars such as Mercedes SLR, SL55AMG and Ford GT. Centrifugal-type superchargers are very much like turbochargers except that their turbines are driven by crank instead of exhaust gas. Their advantage is high power gain, which the Koenigsegg needs to get most from its 4.7-litre capacity. The disadvantage is weak boost when the turbine is not spinning quick enough, just like turbochargers. They also cause some throttle delay, similar to turbo lag, as Evo experienced in the Koenigsegg.

However, peaky power delivery is not all the problem. Autocar also suspected the engine is not as powerful as claimed. Theoretically, it should match or at least come close to McLaren F1 in acceleration, but the data recorded said otherwise: 0-60mph took 4.4 sec, 0-100mph in 8.4 sec, 0-150mph in 17.6 sec and 0-200mph in 35.4 sec. For comparison, McLaren did that in 3.2 sec, 6.3 sec, 12.8 sec and 28.0 sec respectively. This miss the mark by a large margin and falls behind other less powerful rivals. "

Cheers Greg

PorKen

Greg Gray,

I wonder how old that article is, or which car they reviewed. Koenigsegg currently has two engine choices, one with a centrifugal w/655 and a twin-screw w/806:

"The CC 8S air intake system incorporates a large centrifugal supercharger, which is coupled to a custom-built intercooler that lowers the charged intake air temperature from 150 C to 50 degrees C. This system enables a 1.0 bar maximum boost pressure and a compression ratio of 8.6:1. The CCR features a Lysholm Twin Screw compressor that feeds the engine with air at a 1.2 bar maximum boost pressure. This compressor both significantly increases high-end power and low-end torque, and also enables quicker on-off throttling responses. Another vital part of the CCR engine is the novel carbon fibre monocoque intake plenum with hyperbolic trumpets."

mspiegle

Hey Andy, I turned 20 last month. And i'm missing a little more than just an intercooler =)

atb

Andy,

Need to work on that R/T bro'.

Tony

next time you run Andy, let me know when your staging and i will call you on your cell and remind you that the green light is about to appear ..that or you can set an alarm



As simple as it seems to go when the light turns green i remember the 1st time i staged up, i couldnt believe the adrenaline rush i was having. A stop light and a 1/4 tree are two different animals! I cant imagine staging with a few 1000hp on tap, a chamionship run and a 1st place purse money at stake.


I cant wait to run my car later this summer at the Strip here.

slate blue

Check this link sounds similar to the Koenigegg, that artilce I posted Porken isn't out of date but just not the latest. I read about that 806 hp car but didn't know how they were doing it. Cheers for providing that link.

Aussie throttle body

tuk_928

Andy,
How neat is that!? Good for your friend and his 217k 928!!! I have often thought of taking my S4 to the nearby home of the Gator Nationals when they have a "run what you brung" night. Would be a blast...thanks for reminding me to check it out. It would be fun just to go watch and listen on open night.
Best,
Tim

GoRideSno

Thanks everyone.

Greg, Ken,
Looks like a good percentage of the world's fastest supercars use a twin-screw supercharger, no surprise to me.

Adam, Tony,
Yeah very slow reaction time. Cool thing is that nothing beat me to the finish regardless.


In regards to Mike's car. He has no intercooler, no by-pass valve and brings hot air in from under the hood. His sig is no longer accurate as he has been dialy driving this car for several months now.



Andy

slate blue

Please jump in here if I'm wrong but I think a decent reaction time is .4 of a second. Now if that is the case that means that these cars are high 11s for the quarter. Is this correct or not?

GoRideSno

Thanks Tuk.

Greg,
The reaction time does not matter in the ET. The ET time just starts when you break a light beam at the begining of the track and stops when you break a light beam at the end of the track. You could sit at the start for 10 minutes after the green and still get the same ET. However when you have to go when someone else says go you are less likely to have a good start good shifts etc. than if you could do it on your own time. So if you had the time and the space, such as automotive journalists do, you could probably get a few tenths of a second better times.

HTH,
Andy

PorKen

Greg Gray,

That twin roller throttle body is cool (it better be for US$2000!).


I wonder what the Koenigsegg 'Cylindrical Throttle' looks like:
"The amount of intake air is controlled by the precise rotation of a cylinder, through which an oval channel leads air into the plenum. This unique barrel-design greatly increases the sensitivity and response at low-end throttling, while at the high-end the perfectly unobstructed flow of air generates a higher horsepower output."

It sounds a bit like the roller barrel throttles on Lotus engines:

slate blue

I was chatting with the fellow from the roller throttle body company today, They are made up when ordered, he said he could drop the price if they did an investment casting and sold more of them. It also has a few special features, he said it bolts upto the opcon superchargers etc. He told you don'y really need one but it has smooth throttle progression and compact size. I was interested in their dry sump pumps, they are quite affordable and well made.

Cheers