Brett928S2

Hi All

I posted the message below in the UK 928 forums...and will repost here as I understand that various Americans have actually got to 200 mph....nobody in the Uk has YET.....

The top speed runs will entail coming around a last bend on a fighter airfield at around 90 mph and then hitting my Nitrous (around 800 to possibly 1000 hp in total) and I then have around 1.5 miles to hit my top speed....on a perfectly flat, good surface runway.

POST...

Hi All

Who knows about aerodynamics ???

I need some help...

Later this year , when I am running between 800 and 1000 hp (on
Nitrous) I will be trying some VMAX - Top speed runs...

I want to TRY and hit 200mph...

My gearing is fine for 225 mph....

My HP should be enough....

Aerodynamics (AWFUL FOR THAT SPEED)

What I was thinking is...normally a rear and front spoiler creates
DOWNFORCE...

Could the spoilers, particularly the rear spoiler be designed to
create
UPFORCE...so I would get LESS rolling resistance ????????

Any ideas...apart from the im nuts and it wont work kind .. ?????

All the best Brett

PORSCHE 928 S2 AUTO V8 4.7 LTR 1986 IRIS METALLIC BLUE WITH X-PIPES ,RMB ,PROMAX CHIPS, KICKDOWN SWITCH, K&N, WIZARDS OF NOS - NITROUS KIT 150 HP JETTING - 505 BHP / 500 FT LBS TORQUE
PCGB UK 928 FORUM MODERATOR - Email managingdirector@pchealthcare.co.uk

hacker-pschorr

One word answer: Yes

More detailed answer: Seams like a very good way to do this:
http://www.youtube.com/watch?v=5_Dezq9K1EY

Nicole

You should get TahoeShark into this discussion. From what I hear they will attempt to approach the 220mph barrier with their 928 race car... Narrow body, not too wide tires, front splitter and modified rear spoiler. Don't know what else.

You should not expect the rear spoiler to create a lot of dowforce, but rather reducing aerodynamic drag. The round tail of the 928 is not ideal for efficient aerodynamics at extreme high speed.

You might gain more by making the underbelly smoother with additional covers (where possible). One place that looks just wrong to me is the space between tank and rear bumper - they should have closed that up better.

BTW: Bugatti had similar issues with the Veyron. The designers had finished the look before they realized the aerodynamic challenges there. And it took a lwhole lot of extra engineering to make this all work and safe for the speeds.

Brett928S2

Hi

Already watched a few videos like that, thanks to various answers on the Uk forums...which is why I asked here....

I dont want to actually fly lol...I just wondered if I could DECREASE my downforce SLIGHTLY to LESSEN my rolling resistance to aid me in getting to 200....or even if its needed...??

All the best Brett

Charley B

Your nuts, it won't work.

Nicole

...and I was trying to say 'try finding ways to reduce it without reducing downforce'.

hacker-pschorr

There is a 928 in my neighborhood that doesn't have issues hitting 200mph. 100% stock body & wheels - just a sh*t load of HP

Nicole

I owned an 86 RX-7 back in Germany. This was probably the most cross wind sensitive car I've ever owned. It looked much like a Porsche, but you could tell that the aerodynamis weren't there...

If there was crosswind, I could not go beyond 140 km/h (about 90mph) on the Autobahn, or I would need two lanes.

The 928 S4 model is the opposite. If you feel the cross wind, you're not going fast enough. From 90 onwards you won't feel any of it.

Imo000

I'm concerned that 1.5 miles might not be enough to stop after hitting 200.

Brett928S2

Hi

Which model is it ?? as mine is an S2 with the small rear spoiler...and does he do ANYTHING to improve the aerodynamics ??

All the best Brett

Brett928S2

Hi

There is around 1/4 of a mile of shut down ...if I think its needed I will put a chute on it....but I think my brakes are good enough...hopefully

All the best Brett

hacker-pschorr

87 S4 - the suspension is stock, so is the body. It looks lowered, it came that way when he purchased it.

Fabio421

Brett, you are a maniac. 800-1000 HP on the bottle. WOW! Please get this on video from as many cameras as possible. An in car camera would be great too. Good luck and God speed.

danglerb

Just for yucks have you worked out what 800 to 1000 hp works out to in torque at the rear wheels? As in what power level is going to spin the tires in 5th?

My guess is down force is your friend.

blown 87

I agree!

Fabio, if that is the same chick in you avaitar now, as it was before, I will be willing to cast the first stone.