engine hood lift support question
01-10-2017 | 11:42 PM
#17
I haddah Google dat
Rennlist Member
Rennlist Member
Joined: Nov 2008
Posts: 11,501
Likes: 4
From: Fresno, CA
Mise en Place, Sugarwood.
Get everything ready in advance, then assemble. The hinge could have been either a Turbo, or off of a 911 Carrera with the "Carrera Tail". I do not know. Bought it from a wrecker yard. The reason that I did so was I did not want to guess at the geometry, and used the factory original hinge to judge where to put the mount on the firewall. I chose to install it centered on the firewall lug, which also ended up putting the strut horizontal. It came out perfectly.
Get everything ready in advance, then assemble. The hinge could have been either a Turbo, or off of a 911 Carrera with the "Carrera Tail". I do not know. Bought it from a wrecker yard. The reason that I did so was I did not want to guess at the geometry, and used the factory original hinge to judge where to put the mount on the firewall. I chose to install it centered on the firewall lug, which also ended up putting the strut horizontal. It came out perfectly.
01-11-2017 | 10:09 PM
#19
Pro
Joined: Jan 2006
Posts: 602
Likes: 59
From: Texas
according to Paul Frère, without the front air dam the total lift is about 55kg in the front, and with it it is reduced to 17kg at 250km/h (~150mph).
the differece is a good 38kg at that speed. but he speed has a square factor on aerodinamic lift, not linear.
the difference is therefore reduced to a mere 6kg at 60mph and 13.7kg at 90mph.
Unless my calculations are wrong, the imbalance is something to worry people consistently driving a speeds higher than the average speed of a LA freeway and could be easily offset by keeping the fuel tank full or some weight in the luggage area.
Furthermore, the exit ramp from my garage has an aggressive uphill and I always scrape the front reinforcement bar (the one ahead of the condenser) no matter how careful I go over it. I think the benefit of the improved handling would be offset by the requirement of replacing the air dam every couple of weeks... but I got your point, If I ever need to drive fast, remove the rear spoiler or add the air dam!
the differece is a good 38kg at that speed. but he speed has a square factor on aerodinamic lift, not linear.
the difference is therefore reduced to a mere 6kg at 60mph and 13.7kg at 90mph.
Unless my calculations are wrong, the imbalance is something to worry people consistently driving a speeds higher than the average speed of a LA freeway and could be easily offset by keeping the fuel tank full or some weight in the luggage area.
Furthermore, the exit ramp from my garage has an aggressive uphill and I always scrape the front reinforcement bar (the one ahead of the condenser) no matter how careful I go over it. I think the benefit of the improved handling would be offset by the requirement of replacing the air dam every couple of weeks... but I got your point, If I ever need to drive fast, remove the rear spoiler or add the air dam!
01-15-2017 | 11:17 PM
#21
Thread Starter
Advanced
Joined: Jan 2017
Posts: 71
Likes: 3
From: Lou, KY
You can make the factory mount out of sheet steel, which will allow you to install a right side factory strut.
Once you do this, the engine lid with tail will perfectly swing squarely, even better than the engine lid without tail and a single strut. I pop riveted this to the engine firewall. Works perfectly.
Once you do this, the engine lid with tail will perfectly swing squarely, even better than the engine lid without tail and a single strut. I pop riveted this to the engine firewall. Works perfectly.
other option i found is this kit
http://www.pelicanparts.com/More_Inf...540&SVSVSI=821
but probably yours is a more refined option
01-16-2017 | 01:59 PM
#23
I haddah Google dat
Rennlist Member
Rennlist Member
Joined: Nov 2008
Posts: 11,501
Likes: 4
From: Fresno, CA
There is a section in Paul Frere's excellent book "Porsche 911 Story", in which he details all of the aerodymanic lift data that Porsche used to design the front and rear spoilers.
The "Carrera Spoiler" may have been the best spoiler combination of all of them in terms of reduction of lift, drag, and front/rear balance. The "Carrera" rear spoiler had the happy result of reducing the rear lift the same percentage that the front spoiler did, thus not upsetting weight distribution, or causing the car to pitch. When I read that it also aids in cooling the engine, I was hooked. I had to have one.
The "Carrera Spoiler" may have been the best spoiler combination of all of them in terms of reduction of lift, drag, and front/rear balance. The "Carrera" rear spoiler had the happy result of reducing the rear lift the same percentage that the front spoiler did, thus not upsetting weight distribution, or causing the car to pitch. When I read that it also aids in cooling the engine, I was hooked. I had to have one.
01-16-2017 | 02:01 PM
#24
I haddah Google dat
Rennlist Member
Rennlist Member
Joined: Nov 2008
Posts: 11,501
Likes: 4
From: Fresno, CA
i might do this, as you said it will stay squarely.
other option i found is this kit
http://www.pelicanparts.com/More_Inf...540&SVSVSI=821
but probably yours is a more refined option
other option i found is this kit
http://www.pelicanparts.com/More_Inf...540&SVSVSI=821
but probably yours is a more refined option
01-17-2017 | 07:04 PM
#26
Pro
Joined: Nov 2014
Posts: 729
Likes: 31
I think the story goes that the double strut thing was a hack done at the local dealer for the tail.
As you can see, all those nuts and washers are not exactly factory stock.
Yours does not even look like the dealer hack.
As you can see, all those nuts and washers are not exactly factory stock.
Yours does not even look like the dealer hack.
01-29-2017 | 02:26 AM
#28
Thread Starter
Advanced
Joined: Jan 2017
Posts: 71
Likes: 3
From: Lou, KY
what about when closed? aren't those struts strong enough to push it out of alignment when closed as well?
01-29-2017 | 05:21 AM
#29
Addict
Joined: Jan 2007
Posts: 37,770
Likes: 12
From: Alta Loma Alone
If it's out of alignment when it's closed then your adjustment screws/bumpers are out of adjustment. ...one too high or one too low. They are located on the underside of the decklid and screw into and out of the sheet metal.