Fixing the wide front of the Fujimi 917?

[aurfalien]

Hi,

Has any one used the Renaissance 917 wide rear body piece to correct the unusually wide front of the Fujimi 917?

It doesn't really fix it, but makes the rear wider so that optically it looks a little better, here is the part for reference;

https://www.renaissance-models.com/ter/index.php/autos-toutes-echelles/echelle-1-24/transkits/produits/1670-porsche-917k-set-de-correction-capot-arriere

 

Edited September 23, 2019 by aurfalien

[Bainford]

I wasn't aware that the Fujimi kit is too wide. Good to know, as I've been seriously thinking of picking one up. Is the model visibly too wide and out of scale, or just one variant of the 917 compared to others? ...or is just a matter of two halves of a body that do not line up well?

If the Fujimi kit is inaccurate, it makes me wonder, though... wouldn't it have been better for Renaissance to create a correct width front body? Presumably this would be much harder to do, but 'correcting' a kit by creating an inaccurate transkit to supplement an already inaccurate kit in an effort to make it look better seems like a step backward. Especially with an iconic car such as the 917, and I would imagine the combined cost of the Fujimi kit and the Renaissance transkit is not insignificant.

Either way, I'm interested to learn more about this.

[aurfalien]

Hi Trevor,

Here is a link detailing several 917 kits and for brevity, I've quoted the relevant info;

https://robdebie.home.xs4all.nl/models/917kits.htm

The kit has a shape problem is the front side, which is too wide (reportedly 4 mm), it's almost as wide as the rear side. The windscreen is accordingly too wide, which is very visible, and the makes the problem very difficult to solve. Heller got the dimensions almost spot-on for a '17" rear tire tail' 917K, as far as I can tell. Here are two forum pages that compare both bodies:

http://www.modelbrouwers.nl/phpBB3/viewtopic.php?f=31&t=28164

http://www.forum-auto.com/automobile-pratique/modelisme-modeles-reduits/sujet8495-1260.htm

 

PS The problem with getting an older Union/Heller kit is the possible body warpage.

PSS Another great article from Modeling Madness;

https://modelingmadness.com/review/cars/sports/brown917.htm

Edited September 23, 2019 by aurfalien

[Ace-Garageguy]

I would tend to take any "expert" posting about the width of the 917 with a grain of salt. I'm not implying what you've seen is wrong, but there's always the chance. Accurate dimensions of the real cars take some serious effort to unearth, and in-person access to real ones to measure is, in a word, limited. We've gone through something similar with the 904, where much of the published (online) data is just flat wrong, or has been misinterpreted. Some drawings of the 904 online billing themselves as "blueprints" are poorly-scaled, warped, misshapen renditions, and any "scaling" taken from them will be equally flawed.

There were multiple versions of the 917, quite distinctive from each other visually, and there were running changes in the most familiar LeMans-style cars, as in all race cars, repairs, and obvious differences from car to car in photos. Un-crashed early cars appear to be widest...in front...at the top of the wheel openings, whereas other cars appear to be widest in front lower down, just behind the lower portion of the headlight openings.

Add that to the apparent difficulty MANY kit designers seem to have measuring accurately and dividing by the scale denominator...you have plenty of points for inaccuracies to creep in.

Edited September 23, 2019 by Ace-Garageguy

[Bainford]

2 hours ago, aurfalien said:

Hi Trevor,

Here is a link detailing several 917 kits and for brevity, I've quoted the relevant info;

https://robdebie.home.xs4all.nl/models/917kits.htm

The kit has a shape problem is the front side, which is too wide (reportedly 4 mm), it's almost as wide as the rear side. The windscreen is accordingly too wide, which is very visible, and the makes the problem very difficult to solve. Heller got the dimensions almost spot-on for a '17" rear tire tail' 917K, as far as I can tell. Here are two forum pages that compare both bodies:

 

Thanks much for the links and info. Very interesting.

[89AKurt]

I acquired the Fijimi kit last year, along with photo-etch and the engine detail set.  I've known about this issue with the body, and have wondered if it's that important.  There is a Facebook - Porsche race cars group, some guys have built numerous models of the 917, so might be worth the time to check it out.

[aurfalien]

12 minutes ago, 89AKurt said:

I acquired the Fijimi kit last year, along with photo-etch and the engine detail set.  I've known about this issue with the body, and have wondered if it's that important.  There is a Facebook - Porsche race cars group, some guys have built numerous models of the 917, so might be worth the time to check it out.

I think what both you and Bill are eluding to is what Ben Brown also mentions in his Modeling Madness piece; Just enjoy the build etc...

When funds permit, I may opt for the Renaissance corrective part out of curiosity. 

[Ace-Garageguy]

6 hours ago, aurfalien said:

...The windscreen is accordingly too wide, which is very visible, and the makes the problem very difficult to solve. Heller got the dimensions almost spot-on for a '17" rear tire tail' 917K, as far as I can tell. Here are two forum pages that compare both bodies...

This is another statement that makes the whole premise suspect. If one has a feel for spacial relationships and carefully analyzes the front screen on these cars, it's obvious it's not a compound curve, but rather a curve in a single direction. This was most certainly intentional on the part of the 917 designers, as forming compound curves in perspex almost invariably induces distortion...not a desirable characteristic in a race-car screen. It also needlessly complicates the fabrication and fitting processes, which are typically made as straightforward as possible by competent designers.

Therefore, narrowing the body by taking a section out of the middle does NOT cause a "very difficult to solve" issue with the windscreen, as a replacement can be relatively easily formed from flat stock.

EDIT: One of the reasons compound-curved sport aircraft canopies, like those made for German sailplanes, are so expensive is that it often takes several tries to get one that has acceptable optics, without significant distortion. This is another one of those areas where I have considerable experience (and about which I am often called, by a certain cadre here, a liar who does nothing but falsely build himself up; once again, I sure thank you...and you know who you are...for having added so much enjoyment to my experience on the board). 

BELOW: obviously non-compound curve of the windscreen, as evidenced by the straight line from top to bottom.

 

Edited September 23, 2019 by Ace-Garageguy

[Deathgoblin]

Good to know that going with the Heller kit was worthwhile.    

[afx]

Some specs and information on the 917K

https://www.supercars.net/blog/1970→1971-porsche-917-kurzheck/

length	4140 mm / 163.0 in
width	1975 mm / 77.8 in
height	920 mm / 36.22 in

[afx]

Don't know the origins or the validity of these drawings.

Edited September 24, 2019 by afx

[afx]

This website list these dimensions:

https://www.topspeed.com/cars/porsche/1969-1971-porsche-917k-ar171301.html

Length	4,120 MM (162.2 Inches)
Width	1,980 MM (78 Inches)
Height	940 MM (37 Inches)
Wheelbase	2,300 MM (90.6 Inches)
Track (fr/r)	1,564 MM (61.6 Inches) / 1,584 MM (62.4 Inches)

[afx]

[afx]

Race cars evolve throughout the life of the design.  I would suggest stating definitive dimensions for the 917 would be very difficult.

[Muncie]

JC - Great research! you did good. thanks

[Ace-Garageguy]

1 hour ago, Muncie said:

JC - Great research! you did good. thanks

Agreed. Helpful.

 

1 hour ago, afx said:

Race cars evolve throughout the life of the design.  I would suggest stating definitive dimensions for the 917 would be very difficult.

And as your posted drawings attest (with very obvious differences in lines and shapes), the published sources often disagree, or show different versions of the cars with no supporting data to permit making really meaningful assessments of the accuracy of the drawings.

Scaling from a known dimension, like a 15" wheel or the wheelbase, both easily verified on all the drawings above, and deriving the width of the base of the windshields in each drawing would be a start to have something meaningful to compare the same dimensions on the kits to.

[89AKurt]

1 hour ago, afx said:

Race cars evolve throughout the life of the design.  I would suggest stating definitive dimensions for the 917 would be very difficult.

No kidding!  I found that out with my Paris-Dakar 959.  The top drawing, the two vertical stabilizers are not on the following car drawings, and notice the flare to the rear wheel arches.  The angled steering wheel is good to know.  I'm looking at lower two, the vent size on the front fender difference, curve of trailing edge above the engine, curve of the bottom of the windshield, makes me wonder.....  Personally, I'm not going to stress about it, I just wanted the dang engine!

[Ace-Garageguy]

20 minutes ago, 89AKurt said:

 ...The top drawing, the two vertical stabilizers are not on the following car drawings, and notice the flare to the rear wheel arches.  The angled steering wheel is good to know.  I'm looking at lower two, the vent size on the front fender difference, curve of trailing edge above the engine, curve of the bottom of the windshield, makes me wonder...

But here's the thing...you can not assume that ANY of those drawings are accurate. "the-blueprints.com" regularly posts drawings that are kinda like the car they're supposed to represent, but not really accurate. It's common. Of the drawings posted, I'd tend to trust the top one that looks like it might be an actual sheet from Porsche. The others I'd take with much bigger grains of salt.

If the windshield width (as referenced in an early post in this thread) is taken as a definitive place to measure (as it's doubtful it changed during the closed-cars evolution), I'd suggest the method I described above to get a ballpark figure.

[89AKurt]

30 minutes ago, Ace-Garageguy said:

But here's the thing...you can not assume that ANY of those drawings are accurate. "the-blueprints.com" regularly posts drawings that are kinda like the car they're supposed to represent, but not really accurate. It's common. Of the drawings posted, I'd tend to trust the top one that looks like it might be an actual sheet from Porsche. The others I'd take with much bigger grains of salt.

...

AGREED!  I still draw house plans by the dinosaur method of graphite on velum.  I've seen plenty of GIGO computer generated plans, the draftsman having no clue how things are built, with glaring mistakes.  If I ever get around to building this, I'm more interested in making it look realistic, than obsessing over dimensions, unless the mistake is glaring.

[Matt Bacon]

First draft drawing, 917-001:

Short tail, 1969:

Long tail, 1969:

Long tail, 1970:

Skin draft, Le mans test Coupe, 1971:

Short tail, 1971:

All drawings from "Porsche 917: Archive and Works Catalogue 1968-1975" by Walter Namer, Published by Editions Porsche Museum

https://www.amazon.co.uk/Porsche-917-Archives-Works-Catalogue/dp/3768838374

(...looks like I bought it just at the right time, when it was in the discount clearance bin, not the rare and hard to find collector's shelf!)

best,

M.

[Ace-Garageguy]

2 hours ago, Matt Bacon said:

...All drawings from "Porsche 917: Archive and Works Catalogue 1968-1975" by Walter Namer, Published by Editions Porsche Museum

Wow. Thanks, Mr. Bacon. Guess that about nails it, as far as anybody could reasonably want.

[afx]

I 

On 9/23/2019 at 10:04 AM, aurfalien said:

The kit has a shape problem is the front side, which is too wide (reportedly 4 mm), it's almost as wide as the rear side. The windscreen is accordingly too wide, which is very visible, and the makes the problem very difficult to solve. Heller got the dimensions almost spot-on for a '17" rear tire tail' 917K, as far as I can tell. Here are two forum pages that compare both bodies:

http://www.modelbrouwers.nl/phpBB3/viewtopic.php?f=31&t=28164

http://www.forum-auto.com/automobile-pratique/modelisme-modeles-reduits/sujet8495-1260.htm

 

Brian,  I couldn't find the photos that compare the Fujimi and Heller bodies, can you post the photos or direct me where they are in the thread?

[aurfalien]

1 hour ago, afx said:

Brian,  I couldn't find the photos that compare the Fujimi and Heller bodies, can you post the photos or direct me where they are in the thread?

Well, I'd love to oblige but neither can i

I wouldn't be surprised if a member here had both to compare for us.

I did find these 2 build articles;

Fujimi http://www.modelersite.com/en/1690/porsche-917k-fujimi--1-24-scale

Union http://www.modelersite.com/en/231/martini-porsche-917k-22-union-1-24-scale

[Ace-Garageguy]

54 minutes ago, aurfalien said:

..I wouldn't be surprised if a member here had both to compare for us...

I do, and was intending to do the comparo. However, I was also intending to scale some dimensions off of the drawings Matt posted so the comparison would have some factual relevance (let the rivet-counter slurs begin).

It's a couple hours work. I don't have a couple hours right at the moment.

Anybody else wants to jump on it, feel free.

[Bainford]

53 minutes ago, Ace-Garageguy said:

I do, and was intending to do the comparo. However, I was also intending to scale some dimensions off of the drawings Matt posted so the comparison would have some factual relevance.

 

I'd be interested in seeing this if/when it happens.