Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

200 MPH SPOILER ??

Thread Tools
 
Search this Thread
 
Old 01-12-2007, 01:42 AM
  #16  
ZEUS+
Rennlist Member
 
ZEUS+'s Avatar
 
Join Date: Aug 2006
Location: Manchester,NH
Posts: 1,243
Received 19 Likes on 9 Posts
Default

Just out of curiosity what has been done to the engine to withstand that much pressure for that much time ? Just because the jetting is rated for a certain HP increase does not always have the same results on all applications. Only the dyno lets you know what it is really producing. Most engines doing what you want are very stout with over 500 horse off the bottle. Even then the ride is in 10 seconds or less. An average 10 second juice boost of 100 horse consumes 1 LB. Just curious what your setup is.
Old 01-12-2007, 03:22 AM
  #17  
SharkSkin
Rennlist Member
 
SharkSkin's Avatar
 
Join Date: Jan 2004
Location: Boulder Creek, CA
Posts: 12,620
Likes: 0
Received 6 Likes on 6 Posts
Default

Don't worry about the rolling resistance, it will be the least of your worries at that speed! More important is the aero. Narrower front tires maybe, and tape up the seams around the hood and over the headlights.
Old 01-12-2007, 03:38 AM
  #18  
IcemanG17
Race Director
 
IcemanG17's Avatar
 
Join Date: Sep 2004
Location: Stockton, CA
Posts: 16,271
Received 75 Likes on 58 Posts
Default

Brett
Two issues........cleaning up drag (Deveks done it with success).....and make some monster HP....nitrous will do it....but how long with the engine last?? 200mph shouldn't be a problem.....just make sure your tires are new and properly rated!
Old 01-12-2007, 04:28 AM
  #19  
littleball_s4
Racer
 
littleball_s4's Avatar
 
Join Date: Feb 2006
Location: Madrid, Spain
Posts: 320
Likes: 0
Received 0 Likes on 0 Posts
Default

Mount it upside down front and rear and get airborne. This way you'll have zero rolling resistance.

Now, serious, at that speeds even the most even surface consumes a lot of suspension travel. One episode of bump steer, cross wind, uneven grip, driver hesitate in the steering wheel (bugs in the windshield don't cause this, but birds is a different thing) at that speeds and your ride will swap ends in a breeze without the rear wing.

Front splitter + hood vent is a good idea, lowering body (with much stiffer springs and shocks) could also be useful, although tricky. Of course take mirrors away and tape cooler or make good use of the adjustable flaps of it. But, if I were you, I would keep your wing where it is.
Old 01-12-2007, 05:06 AM
  #20  
UKKid35
Drifting
 
UKKid35's Avatar
 
Join Date: Nov 2003
Location: London, UK
Posts: 2,715
Received 65 Likes on 36 Posts
Default

Originally Posted by BRETT AINLEY
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
Don't forget it was the chute that nearly cost the Hamster his life.
Old 01-12-2007, 07:28 AM
  #21  
sweanders
Race Director
 
sweanders's Avatar
 
Join Date: Jun 2002
Location: Sweden
Posts: 11,252
Likes: 0
Received 2 Likes on 2 Posts
Default

Before doing it get your car on a load dyno and make sure that it can take the nitrous shot for a minute or so.

The saying "Fast, cheap, reliable - pick any two!" comes to mind.
Old 01-12-2007, 08:05 AM
  #22  
SwayBar
Rennlist Member
 
SwayBar's Avatar
 
Join Date: Feb 2006
Location: Chicago Bears
Posts: 3,575
Received 346 Likes on 237 Posts
Default

Originally Posted by BRETT AINLEY
and then hitting my Nitrous (around 800 to possibly 1000 hp in total)
Have you dyno'd the car yet? If I remember correctly, you had problems hitting your listed hp.

Who knows about aerodynamics ???

I need some help...
You are not going to get useful help here on this topic since virually no one has any real experience. Buy a book or two on the topic and read them from cover-to-cover.

Could the spoilers, particularly the rear spoiler be designed to
create UPFORCE...so I would get LESS rolling resistance ????????
Absolutely; why not?

But after reading the first book, you'll realize that it's not a good idea. Not even remotely.
Old 01-12-2007, 08:11 AM
  #23  
Black Sea RD
Former Vendor
 
Black Sea RD's Avatar
 
Join Date: Feb 2004
Posts: 2,139
Likes: 0
Received 0 Likes on 0 Posts
Default

I agree with the others on this thread. I would not want to have any hint of lift at that speed. The car would be way too unstable and one wobble or crosswind hit and it could seriously upset the car and you will be in for the ride of your life, literally. Just watch old (and not so old) footage of speed record runs at the Utah Salt Flats.

Devek would shrink wrap the front of the car to eliminate drag on their high speed runs at the open road races, Holbert used narrower wheels with higher than normal tire pressures during his land speed 928 runs, the flag style rear mirrors should be removed and as Nicole said, clean up the underbody, but don't try to induce lift.

You might want to talk to someone who actually has done speed runs too. Wally P. comes to mind...

My $00.02 worth.

Constantine
Old 01-12-2007, 08:31 AM
  #24  
Brett928S2
Three Wheelin'
Thread Starter
 
Brett928S2's Avatar
 
Join Date: Jun 2005
Location: Bournemouth, Dorset, UK.
Posts: 1,741
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by ZEUS+
Just out of curiosity what has been done to the engine to withstand that much pressure for that much time ? Just because the jetting is rated for a certain HP increase does not always have the same results on all applications. Only the dyno lets you know what it is really producing. Most engines doing what you want are very stout with over 500 horse off the bottle. Even then the ride is in 10 seconds or less. An average 10 second juice boost of 100 horse consumes 1 LB. Just curious what your setup is.
Hi

My system will be as follows....I will replace my usual 11 lb bottle with 2 x 14 lb bottles that will probably be boosted by Nitrogen (in a third small bottle)
This will keep the pressure up to 950 psi as the Nitrogen bottle produces 3000 psi and as you correctly say , usually Nitrous is run for 10 seconds and the pressure drops towards the end of a run....but the Nitrogen will keep it constant for as long as I wish to keep the Nitrous armed and running...

At the moment my Nitrous on 150 hp jetting is producing 168 hp at the rear wheels....for these attempts at top speed runs I will increase the jetting to around 500 jetting which will give me a total of over 800 hp..to do this WITHOUT a HUGE torque hit on the transmission needs very precise electronic control....and I will be using the new MAXX EXTREME controller from the Wizards of Nos...

I will also be trying this year to take ALL the UK ..Porsche standing 1/4 mile records and also ALL the Porsche ..standing mile records...with the system above...

IF ....all goes well.....I "may" try to take the Bugatti Veryon standing quarter record as well.....which is 10 seconds dead....lol

All the best Brett
Old 01-12-2007, 09:38 AM
  #25  
ZEUS+
Rennlist Member
 
ZEUS+'s Avatar
 
Join Date: Aug 2006
Location: Manchester,NH
Posts: 1,243
Received 19 Likes on 9 Posts
Default

Good luck and be safe.
Old 01-12-2007, 12:14 PM
  #26  
H2
Addict
Rennlist Member

 
H2's Avatar
 
Join Date: Feb 2003
Location: Northwest
Posts: 5,988
Received 34 Likes on 29 Posts
Default

Originally Posted by BRETT AINLEY
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
I don't think a 1/4 mile is a safe braking distance. Risky.

Harvey
Old 01-12-2007, 12:58 PM
  #27  
Imo000
Captain Obvious
Super User
 
Imo000's Avatar
 
Join Date: Aug 2003
Location: Cambridge, Ontario, Canada
Posts: 22,846
Received 340 Likes on 245 Posts
Default

Originally Posted by Hughett
I don't think a 1/4 mile is a safe braking distance. Risky.

Harvey
Me neither! 400m leaves hardly any room for error. I remember from the 1/4 runs that even with a high 12sec, 110mph run I would need probalby at least 200m to make an emergency stop. At 200+mph ths would perhaps double but could be more. Making an emergency stop from a 200mph run can result in brake fade and that will add more distance too.

Since I don’t have any experience in running N2O I’m not going to make any suggestions but I am curious to know if the 928 engine can handle that much more extra hp for any period of time.
Old 01-12-2007, 02:54 PM
  #28  
Brett928S2
Three Wheelin'
Thread Starter
 
Brett928S2's Avatar
 
Join Date: Jun 2005
Location: Bournemouth, Dorset, UK.
Posts: 1,741
Likes: 0
Received 1 Like on 1 Post
Default

Hi

Hmmm...hadnt really thought about braking distance from 200...anyone want to work it out for me lol ??
Although mine is an S2...it has the S4 Brakes and suspension...if it helps....

All the best Brett
Old 01-12-2007, 03:14 PM
  #29  
the flyin' scotsman
Rennlist Member
 
the flyin' scotsman's Avatar
 
Join Date: Oct 2004
Location: Southern Alberta, Canada
Posts: 10,710
Received 53 Likes on 22 Posts
Default

This is deja vu from a Formula 1 race a few years ago now. The car, a Jordan I believe with Heinz Harald Frentzen at the wheel, comes around a right hander on to the main straight and as he gains more and more speed the front of the car lifts completely off the ground send it completely into the air doing a somersault. I recall it landed on its wheels and the drivers was ok but man what a ride.

Anyone got that on video?

Be very careful Brett.
Old 01-12-2007, 03:22 PM
  #30  
Jerome Craig
Rennlist Member
 
Jerome Craig's Avatar
 
Join Date: Apr 2004
Location: Fairfax, VA
Posts: 482
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Constantine
I would not want to have any hint of lift at that speed.
From what I witnessed years ago at Road Atlanta and from a tape of a "lift off" at LeMans, you will likely not get a "hint" of lift. You will be on the road one second and then in big trouble the next. That was one of the main reasons ground effects were banned in F1 racing. Loss of downforce instantly converted the driver into a passenger... generally in a turn.

Just my $0.02


Quick Reply: 200 MPH SPOILER ??



All times are GMT -3. The time now is 06:08 PM.