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Urgent help, L-shaped kidney reinforcement fit early cars?
Posted: Wed Mar 30, 2022 6:10 pm
by deano
Would anyone be able to tell me for certain whether the L-shaped kidney panel (91150707740,840), as fitted to 1985 to 1989 ish cars, will fit directly to longhood inner and outer sills? Is jack socket in same place etc.? I searched, but didnt find the answer on here....
My car just went onto the jig today and has dropped slightly in the middle, so we are thinking of going down this kidney panel route to help combat future droopiness... its amazing, once it was lifted up, all the panel gaps popped immediately into place. LOL, I wish I could have gotten it onto a jig two decades ago - it might have saved me a decade of work!!
Hope someone can answer, cheers, Dean

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 6:48 pm
by g3ngs2
Short answer I think so...... there was one, albeit of a homemade construction, but the same shape on my 73. As I recall it the lower leg part of the L was left short as it it looked like it would snag on the ripples of the inner sill part.
If this is the part you had in it might need some fettling where it meets the sill
https://www.design911shop.com/Kidney-Pa ... =doofinder
It got chopped out yesterday and the inner sill installed and the kidney area prepped to receive the new part so there's a very good chance it's still on the workshop floor. I can head up there tomorrow morning and see if it's about and take some measurements if that helps
Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 7:06 pm
by deano
Thanks for the reply and very nice of you to offer but I just learned that the inner sills seem to be the same for longhood models and later models and changed for the 993, so I would expect the later L-shaped kidney to fit the inner sill no problem (unless its a Dansk part - ha ha).
The outer sills do look the same for longhoods and G-models up to 89', but are listed separately on Design911 etc. - I think the only difference might be the shape and positions of the drain holes, but I'm not certain.
I think the only question is, does the L-shaped kidney panel fit the longhood outer sill, and is the jack in exactly the same position? Probably yes, but its a £500 risk...

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 7:20 pm
by g3ngs2
Ah cool - my mistake it wasn't the inner sill that was in the way more the part of the jack receiver bracket that I think would get in the way
https://www.design911shop.com/Porsche-9 ... =doofinder
The rough dimensions of the part that was home made was just shy of the replacement kidney part and I'm pretty sure it would fit. About to do battle with Tapatalk and some images and will send you how mine looked
Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 8:45 pm
by deano
Great, thanks!
The jack support bracket is integrated into the L-shaped kidney panel - I'm not convinced that is a good thing, but what do I know - I have a feeling that the jack support bit might not be as robust (the original jack support bracket is held on the inner sill face and the sill/floor edge, whereas the L-shaped kidney is box section, with less load spreading, and probably flexes when jacked up).
Overthinking aside, I hope I don't ever have to use the jack tubes anyway - I might scratch them

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 10:23 pm
by DustyM
Yes it will fit but you will have to reshape the rear most part of it slightly to get it to sit nicely against the rear inner wing.
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Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 11:08 pm
by coomo
deano wrote:Great, thanks!
The jack support bracket is integrated into the L-shaped kidney panel - I'm not convinced that is a good thing, but what do I know - I have a feeling that the jack support bit might not be as robust (the original jack support bracket is held on the inner sill face and the sill/floor edge, whereas the L-shaped kidney is box section, with less load spreading, and probably flexes when jacked up).
Overthinking aside, I hope I don't ever have to use the jack tubes anyway - I might scratch them

Yup......Me too

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Wed Mar 30, 2022 11:11 pm
by coomo
If your concerned about droopy sills...............

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Thu Mar 31, 2022 10:00 am
by Gary71
Seem to remember the larger kidney fouls the oil
tank on a ‘72. But this probably isn’t relevant!

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Thu Mar 31, 2022 10:16 am
by deano
Thanks guys, so it seems like they might need a bit of fettling to make the vertical kidney part sit against the inner wing.
I'm still undecided, but swaying a little towards the L-shape version to stiffen it up...
> go-for-it or keep it as-original comments most welcome at this point !

Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Thu Mar 31, 2022 11:03 pm
by early911parts
Very common in use for race cars as it stiffen it up , I allways use it for ( not for the pursit builds) or hotrod builds
Re: Urgent help, L-shaped kidney reinforcement fit early car
Posted: Fri Apr 01, 2022 3:41 am
by RobFrost
No expert here but I think my 1970 has a vertical member with the bottom open and a horizontal member welded to the front of that. I liked the fact any water which may get in there can drain out and there's a good flow of air inside it.
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