Downforce or succion? That's the question+ Remove weight

[Anders Dahlquist]

Downforce or succion? That\'s the question+ Remove weight

Hi Racers,
I want more downforce. I like my Viper like my whisky: pure. So no wings ect..(In reality I am more a milk drinker but what the heck, you get the point!)
Does anybody know if a flat underfloor and diffuser is as effective as wings and splitters. Anybody makes a complete kit??
I want it for the track not to show off.
Also how much weight can I hope to gain by removing the interior/emptying my Viper??
Thanks for your help.
Anders
S/R Viper GTS

 

[jrkermode]

Re: Downforce or succion? That\'s the question+ Remove weight

Q. Is and undertray as effective as wings and splitters?
A. If you mean can an undertray make as much downforce as a wing & splitter in perfect conditions, the answer is yes. In the real world, however, the answer is probably not. Undertrays are extremely pitch and ride height sensitive, So, perfect conditions are unlikely to occur without a great deal of set-up effort at individual tracks. You would also have to find a way to cool the tranny and diff. Wings and splitters don't have these problems, so they are much easier to get right.

Q. How much weight can be removed from a Viper?
A. The lightest possible Viper is likely an Oreca car. Those weighed just over 2500 lbs before being ballasted up to race weight.

 

[Tom F&L GoR]

Re: Downforce or succion? That\'s the question+ Remove weight

I'll second jrkermode and add that undertrays provide as much or more downforce, but without the drag of wings. Somehow those Ferraris and the GT40 (er.. Ford GT) have "effective" undertray aero. Seems Mr. Woodhouse did something like this, also.

 

[Anders Dahlquist]

Re: Downforce or succion? That\'s the question+ Remove weight

Thank you for the input.
No doubt both will be more effective but as Tom says The Modena and the Ford GT do without. I read somewhere how much it added for the Ford but have forgotten.
I will contact Bob who always has an helping hand.
And about the weight gain for a stock Viper?
Thank you
Anders

 

[Bob Woodhouse]

Re: Weight reduction and downforce response

Hello Anders: Sorry to hear about your accident.

RE: weight. Using body panels and interior as your sources for weight loss you can go from the 3380 pound stock weight to under 3000. Add back 110 pounds for the roll cage. This will take some serious pieces out of the car, side glass, light weight doors, hood, rear glass to lexan, AC, some dash components etc.

Tom and jkermode did well explaining the underbelly, it is helpful but difficult to make work properly. Keep in mind downforce is only significant at speeds of 80 mph and up. A good splitter and wing are the easiest places to find downforce. Car 13, the 96 GTS, VRL GT-1 spec car is capable of around 550 pounds at 100 mph. A good sized splitter, a low ride height (it is best to carry an air gap of 3 inches or less), and an effective wing are necessary.

If you plan to do this, then I think your next step is a good set of suspension bushings, mono-balls.

 

[Anders Dahlquist]

Re: Weight reduction and downforce response

Hello Bob!
Thank you for the final touch on the info. Now that I have the data from all three of you, I will have to add ice in my whisky(er, milk)!!
Thank you all and happy racing,
Anders