[DeTomaso] Possible Hood Vents

[Art Stephens]

     I heard that during the early testing of the original GT40,  the rear 
tires would start spinning at 170 mph due to rear end lift.  The spoiler 
added to the rear of the car apparently solved the problem.

Art



----- Original Message ----- 
From: "Ken Green" <kenn_green at yahoo.com>
To: "'Dan Courtney'" <dfcex at excaliburre.com>; <detomaso at realbig.com>; "Göran 
Malmberg" <hemipanter at hemipanter.se>
Sent: Monday, June 29, 2009 9:06 AM
Subject: Re: [DeTomaso] Possible Hood Vents


>I talked to guy who builds the "Ultimate Aero" which was (not sure if it 
>still is) offically the worlds fastest production car. He said that during 
>testing, the rear end lift at high speed caused the the car to spin the 
>tires at a shift around 200 MPH.
>
> Ken
>
> --- On Mon, 6/29/09, Göran Malmberg <hemipanter at hemipanter.se> wrote:
>
>
> From: Göran Malmberg <hemipanter at hemipanter.se>
> Subject: Re: [DeTomaso] Possible Hood Vents
> To: "'Dan Courtney'" <dfcex at excaliburre.com>, detomaso at realbig.com
> Date: Monday, June 29, 2009, 5:21 AM
>
>
> Dan.
>
> At front I have used bellypan myself, but the car is very low
> and has stiff springs. The height makes for return distance
> and the stiff springs for less travel. On the downside this
> limit wheel diameter size. But I functions very well for a flat
> only bellypan. I had the whole front A-arm over the pan.
>
> The rear is worse. On the side off and aft of the gearbox we
> have the subframe that limit the possibility of a diffuser.
> The same goes for the rear A-arms that can not go much lower
> than parallel to ground or else the diffuser expansion will be
> future limited by the frame.
>
> I think you may have a point in the rear stance at high speed
> as the hood come off. Despite the fact that most people talk
> about FRONT end lift. I could imagine some slight lift force at
> speed and a reduction in rear end grip is felt as instability.
> But it might have have been amplified in conjuction with other
> issues like rear toe.
> Goran
>
> -----Ursprungligt meddelande-----
> Från: Dan Courtney [mailto:dfcex at pacbell.net]
> Skickat: den 29 juni 2009 12:59
> Till: Göran Malmberg; detomaso at realbig.com
> Ämne: Re: [DeTomaso] Possible Hood Vents
>
> Goran,
>
> Pretty incredible engineering, especially the wood model.
> Would you say a bellypan cannot be incorporated with stock A-arms?
>
> Dan
> Dan F. Courtney
>
> La Jolla, CA
>
> (858) 551-5455 Phone
> (858) 551-5456 Fax
> ----- Original Message ----- 
> From: "Göran Malmberg" <hemipanter at hemipanter.se>
> To: "'Dan Courtney'" <dfcex at excaliburre.com>; <detomaso at realbig.com>
> Sent: Sunday, June 28, 2009 12:52 PM
> Subject: SV: [DeTomaso] Possible Hood Vents
>
>
> We have some lost hoods in Sweden to. But the hood does already have
> a big hole in it for the air to escape. I don't think more openings
> does a to big job in reducing rear lift at speed. It is more of a
> direction of vented air stream, if this for some reason is desired.
>
> Check out my drawings on my site www.hemipanter.se klick A-arm geometry.
> I did made a drawing of a frame layout that will permit the use of a
> functional bellypan. The front and rear lower A-arm mounts are raised
> to give room for both front and rear diffuser. My front hood air outlet
> is handling ALL radiator air. So here a bellypan is Ok. But the front
> end is pretty low to allow for some return movement of the low A-.arms
> not to hit the bellypan. This limit front tire diameter to 600mm.
> Goran
>
> -----Ursprungligt meddelande-----
> Från: detomaso-bounces at realbig.com [mailto:detomaso-bounces at realbig.com]
> För Dan Courtney
> Skickat: den 28 juni 2009 20:38
> Till: detomaso at realbig.com
> Ämne: Re: [DeTomaso] Possible Hood Vents
>
> I think the bigger aero problem is air coming under the car and lifting
> the rear deck lid.
> Both myself and Mad Dawg have lost rear deck lids at high speed.
> The Beast has the vents in it's fiberglass front hood.
> I'll soon be adding a front air dam, but I still think a belly pan or
> louvers in a (fiberglass) rear deck lid are required.
>
> Dan
> Dan F. Courtney
>
> La Jolla, CA
>
> (858) 551-5455 Phone
> (858) 551-5456 Fax
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