Noahs944

For the purpose of studying the fastest cars' aerodynamic aids, please post photos.
Thank you

V2Rocket

the fastest...in a line or on a track?

924srr27l

That's got your attention............



"The Fastest!"


A very abused word which can have a multitude of answers...


On snow and Ice, on grass, the freeway etc....?


Acceleration, up to 100mph, highest top speed etc...?


A lap of your local area on the Street, Race circuit etc...?






924 World record car:


Porsche broke new ground in 1976. As a timely response to the energy crisis, the attractively priced and economical four-cylinder sports car was intended to appeal to potential new customers. Porsche wanted to go in new directions in terms of marketing, too, and planned to draw attention with a high-speed world record drive. The goal of an average speed of over 250 km/h over a distance of 10,000 miles required a Porsche 924 optimized for long-distance rec­ords. The result: instead of the standard 92 kW (125 hp), the turbocharged world-record four-cylinder put out a splendid 184 kW (250 hp). The aerodynamics also received special attention. After extensive wind-tunnel testing, the drag coefficient was an outstanding Cd 0.268, which enabled a top speed of 280 km/h. Shortly before the planned record-breaking drive in July 1977, the world-record attempt was put on ice for strategic reasons. Instead of ripping around the high-speed oval of Nardò, the fastest 924 of all time rolled into the newly founded Porsche Museum.
Years: 1976/77
Engine: Four-cylinder turbo
Displacement: 1,984 cc
Power: 184 kW (250 hp)
Weight empty: 980 kg
Top track speed: 280 km/h







Porsche 959


C29 aerodynamics study: At the Frankfurt International Motor Show in 1983, Porsche presented a high-performance vehicle that would provide an impressive demonstration of the brand’s innovative drive: the “Group B” study. The production-ready version of the concept known as the Porsche 959 underlined the technical expertise of the company in 1985. Powered by a 331 kW (450 hp) boxer engine with ­water-cooled cylinder heads and bi-turbo sequential charging, the car topped the 300 km/h (186 mph) barrier with playful ease. The electronically controlled chassis, the program-controlled all-wheel drive, and the aerodynamically optimized body broke new ground for later Porsche sports-car generations. As the predecessor of the Porsche 950, the Type 959 C29 repre­sented the beginnings of this ambitious project. It was used for exten­sive wind-tunnel testing in 1982, which resulted in a low Cd-value of 0.31 paired with an optimal lift coefficient. The special characteristics of the C29 include the rear wing integrated in the bodyshell, the smooth transition from the windshield to the A-pillar, and the aerodynamic plastic underbody cover.
Year: 1982
Engine: Six-cylinder boxer bi-turbo
Displacement: 2,849 cc
Power: 331 kW (450 hp)
Weight empty: 1,450 kg
Top track speed: 315 km/h
















Maybe a Backwards design would be better like this 928;


http://www.oskardekiefte.nl/Better%20Aerodynamics.html





R

morghen

Only track cars until now...so what about street cars?

Mine is pretty fast for a 2L 924, it does around 165mph (gearbox ratio calculation and GPS reading of actual test) with a 944S2 gearbox...and while there its not too unstable for what i can tell...it has just a 951 fiberglass nose with that chin thing. GTS mirrors, skirts and rear fenders (smaller frontal area than a 944).




EDIT: Damnit Roger those are not *****, those are her knees !! you're missleading people!

Dubai944

This one seems to have great aerodynamics.

924srr27l

Mmmmm.... without going off thread on a tangent, your above comment


"it does around 165mph" firstly says "Around" ? but then it mentions an "actual GPS test"


Has your car recorded a genuine 165mph on a GPS system? only this sounds ambitious to me?


Have you not replaced the front wings with 944 wider items? or is it the front spoiler that's giving the wings an optical illusion ?


The rear arches and wider track will be adding area & drag compared to a standard 924.




R

Noahs944

Spencer, I'd like to stick to track cars mostly, performance street cars are acceptable.

What is the story behind this one?

Morghen, your car looks so tasty it's crazy. 165mph is impressive! Do you have a rear diffuser or underbelly pans?
-------------

Come on people. Lotsa trackies here, LETS SEE EM!

V2Rocket

Noah,
Of course, that is a Rennlister's car...username thingo, down in Oz...

See:
https://rennlist.com/forums/944-turb...f-a-thing.html
http://www.worldtimeattack.com/index...p-968-porsche/
http://www.worldtimeattack.com/index...p-968-porsche/
https://www.hpacademy.com/blog/ex-wr...porsche-build/

morghen

I had someone check the actual speed on a GPS and also calculated gear ratios to double check. It goes that speed(and its not such a big deal, there are loads of faster cars).
It has smaller mirrors and smaller rear fenders than the 944 so a bit lower frontal area...but the main reason it goes that speed is the K27 hybrid turbocharger.
No diffuser, but front end covered.

V2Rocket

A 951S with 250bhp will just touch 160...so a 924 with better Cd and at least that much power should be able to crack 165 easy...

whether it feels as stable as a 951 with its enhanced underbody aero is another question...but ive taken my NA to 120-130 frequently and it feels like doing 80, but louder...

morghen

Well my red 924 has polyurethane suspension bushings, its on coilovers with good shocks and stiffer springs & sway bars and drives on top premium high speed rating tires...and alignment is spot on.
All that makes a big difference in how the car feels at speed.

That 968 looking thing is amazing, i wonder how much downforce it makes.

924srr27l

A 250bhp 924 ?


A Modified one then , stock weight or reduced?


The 951's in real road tests were around 150mph, not 160 or 165 so "165mph easy" is not the best description if at all believable


My shorter N/A gearing (3.889) I think would top at 6000rpm around 139mph, and my car is more powerful (Power to weight) than any stock 924 / 944 & 968 (Inc all turbo's) maybe with a 951 box it would be higher but I doubt it would reach 165mph, this is a seriously high speed, and I'm talking a Genuine figure, not what the Speedo reads as they are not always accurate.


R

odurandina

i'm your huckleberry.....

stock 968 ratios;

1st; 3.182 :1
2nd; 2.000 :1
3rd; 1.435 :1
4th; 1.111 :1
5th; 0.912 :1
6th. 0.778 :1
final ratio 3.778 w/ open diff.


V8 ratios;

1st; 3.182 :1
2nd; 2.000 :1
3rd; 1.230 :1
4th; 0.930: 1
5th; 0.729 :1
6th. 0.600 :1
final ratio 3.778 w/ limited slip diff.


flat out, spirited and economy driving... i run 25.8"/285-35-18 tires; ... 200mph @ 6123rpm


ratio ........ speed @ 6000 rpm ........ speed @ 4500 rpm ........ speed @ 3000 rpm ........ increase (mph) from previous gear @ 3000 rpm

.600 .................. 196.0 ........................... 147.1 ........................... 98.0 ............................ 17.4

.729 .................. 161.2 ........................... 120.9 ........................... 80.6 ............................ 17.5

.930 .................. 126.3 ............................ 94.8 ............................ 63.1 ............................ 15.4

1.230 ................. 95.5 ............................. 71.6 ............................ 47.7 ............................ 18.4

2.000 ................. 58.7 ............................. 44.0 ............................ 29.3 ............................ 10.9

3.182 ................. 37.0 ............................. 27.7 ............................ 18.4 .....................................................

.

morghen

What real road tests ? I trust my own as i drive these cars every other day. I see the RPMs, i know the gear ratios and i can also see the speedo even if its always off by a bit.
I usually take the 931 to the hardware store which is 15km away on the highway around the city.
It does 230km/h there on a longer straight reeeeeaaaaal easy, thats 142mph from a 36 years old factory spec 2L 924 - 0.7bar from a K26 with no intercooler.
The other 924 runs 1.1bar from a K27, intercooled, head ported and polished, genuine 937 ignition with better aero and shorter gears but longer diff ratio.

There you go:



Anyway...this should be a pics topic not a i doubt your car does that speed or i doubt your car has lost that much weight topic.

924srr27l

Yes I agree....

However if the thread is to Post the fastest 924 / 944 / 968 and a member claims there vehicle does x y or z....surely some of the topic / claims can be questioned or proof requested or clarified ?

Your Cable Speedo must be registering 170mph+ or more for a really accurate genuine 165mph? and your tyre's are slightly different (Revs per mile) compared to the stock 15" size.


"Morghen Mine is pretty fast for a 2L 924, it does around 165mph"

Can you take a movie or photo of the Speedo on your phone?

R