Sab

A friend of mine back in Germany used to have a 911 TT cab with 850HP. The car weight 1100KG. It was a street legal car in Germany with TUV approval. I went many times with him on high speed runs, exceeding 360 KMH (225 MPH)on the Autobahn (Starnberg / Munich).
With proper tires I would not be worried to drive my GT at 200MPH at all. I think you should worry a lot more about the engine blowing to pieces under so much nitro or the tires not making out too well at that speed and weight load.
YMMV
Good luck,
Sab.

mark kibort

Thats funny, ive been stopping in a few hundred feet going 155mph? (see road america!)

MK

mark kibort

as far as aero, as someone once said, "give me enough thrust, Ill make a rock fly" with enough HP 200hp is not an issue for aero clean up you are talking about. the devek machine needed to get all the aero possible, due to only having 440rwhp or so. under body drag, rolling resistance, wing drag, etc, are not that big of a deal, if you have the HP to push the drag to 200mph. the issue of lift and downforce is really balance. if you have more downforce in the rear and none in the front you could do a wheelie and end up like that 250mph rx7 on YOUTUBE (flying at bonneville) however, as long as you have a reasonable center of pressure, and little downforce that is fairly even front to rear, you will be ok. remember, you have 3000lbs of downforce due to the weight of the car! (1500lbs front and rear)

a few years ago, the SpeedGT Vet folks went to canda for some tests on a eyeballed set up vet for world challenge racing. 100lbs of lift front end vs 150lbs of downforce rear end. I dont know the speed, but it was at a fairly high rate of speed. say it was 100mph. then, at 200mph, the front would be ?lbs and the rear would be 600lbs of downforce. The big concern would be the rear downforce being greater than the front downforce. 600lbs on the rear would be like lifting the front up with 30% of that vulcrum force. So, 200lbs lifts up on the front. that added to the actually lift in the front is what i would be concerned with

Since you dont have a rear wing, you probably wont have an issue with a flying car at near 200mph.

Mk

Imo000

Should have been a little more specific. What I ment was to do this 200+mph run and to stop safely, pluse a little extra for safety, 1.5 miles might not be enough.

mark kibort

me too. im sure i could have been stopped a couple of hundred feet later, as that turn was around 60mph. i dont think you need more than 1/2 mile to stop. certainly no more than a 1 mile.

Mk

marton

according to these guys with good tires, good brakes, and good road conditions then you will need about 1/3rd of a mile

http://tinyurl.com/yh2ozm

You just plug in the numbers and it gives you the stopping distance

Marton

Imo000

Ok, but Brett said that he would only have about 1/4 mile left after hitting 200 and this where my concern is from.

Brett928S2

Hi

Thanks all and Marton for that table....I have learnt that there is 0.4 of a mile to stop in....which is VERY close to that tables results of 590 metres....now where on the rear of a 928 can I attach a steel plate around a foot square for a chute lol ????

All the best Brett

hacker-pschorr

This one? Had some help from the car in front:
http://www.youtube.com/watch?v=4uz4qxWEEnc

How about these? A little more on topic since there was no car contact.

http://www.youtube.com/watch?v=zjTV2lBsa5w
http://www.youtube.com/watch?v=1O112Q_koGE

Keep the spoiler the way it is or add downforce. Mercedes & Porsche have more experience with aero with one engineer than the rest of us combined. This is your life here Brett. A 928 would not leave you walking away if you pulled a flip like these.

I cannot find the Mario Andretti flip at Indy diruing testing from a few years ago. It only took one small piece of debrit to send Mario flipping through the air at 170+mph. Yes I know these are "aero" cars designed to run with full downforce - disturb this, **** happens. Either way, trying to produce lift for a 200mph run in a street car is pretty silly.

marton

My boat is out of the water for the winter, I could lend you my anchor?

Is the 0.4 mile you have to stop in; is that all there is or is there a perimeter track or something that you could turn onto assuming (worst case) you will only be down to a turning speed by then?

Cheers

marton

Brett928S2

Hi Marton

Yes you are correct..it has a run off at the end of the airfield onto which I could turn but unsure of speed of it yet...

I am SERIOUSLY CONSIDERING the chute though..I have emailed Simpson in the US to see what size they consider is needed...( in case my Nitrous works MUCH better than I thnk..imagine trying to stop in that distance from 220 mph.... ...)

All the best Brett

All the best Brett

hacker-pschorr

Hold here - airfield? 200mph run with NOS? Europe?

So, is someone in this group joining the Tiff Needell 200mph challange?

RicerSchnitzzle

Brett,

what have you done to beef up the motor to handle the extra HP? I just took the plunge and ordered my nitrous kit with a progressive controller (% over time and RPM windows) and I'm honestly scared to go over 150HP. The stock 300HP is already a kick in the pants. I plan on starting at 75HP and working my way up to 150HP. What point should I stop with out needing to beef up the block? Again with a progressive controller the "hit" of nitrous is eliminated, however 450HP is still 450HP, or in your case 800Hp is still 800Hp.

Brett928S2

Hi

Nothing to motor itself....and it runs 150 of Nitrous fine...although its a little viscous without the Wizards controller....waiting for the new MAXX EXTREME controller this month...

I will increase to 300 then 400 etc etc....and let you all know here if and when I get a problem...which I DO NOT expect by the way...until around 1000 hp....although IF i get a problem ...I expect it to be with the autobox or diff...when I get over 700 hp...

Is yours a Wizards of Nos system ??? If so and you are getting the new MAXX controller it is amazing....

IF you look at the PCGB 928 site where I am moderator here>>>>

http://www.porscheclubgbforum.com/tm.asp?m=202699

You will see my thread on fitting a Nitrous kit to a 16 valve engine..

Any help you need just ask...

All the best Brett

C.F.

Hacker
What Tiff 200mph challenge ,have you a link ?