Opinions please....

Opinions please....

Author
Discussion

Mr Cerbera

Original Poster:

5,031 posts

230 months

Sunday 16th February 2020
quotequote all
Wotcha Team wavey

this one will get your fingers tapping (I hope)

The phenomenally heavy plate that bolts to the chassis runners with 10 x 17mm bolts......

Is it there to aid chassis rigidity ?
OR
Prevent the exhaust from hitting the ground, in case of collapse ?

Your opinions please.
Ta !

getmecoat

TwinKam

2,984 posts

95 months

Sunday 16th February 2020
quotequote all
Both!
It would've been even more effective at adding rigidity if there were some location dowels.
If you're concerned about the weight, Pete Essling does nice alloy ones.

Imran999

351 posts

153 months

Sunday 16th February 2020
quotequote all
It is there to test the resolve of any owner who attempts to work on their Cerb themselves!

Jokes aside, I have been told (by those who should know), that it doesn’t really serve much purpose, although there are no hangers for the exhaust mid-pipes and this plate does (by means of a rubber bung/grommet) support the exhaust pipes, at the point where the welded tabs come together - the tabs often break off, and the rubber bung often melts. Depending upon the exact geometry of the pipes on any particular car, the aforementioned plate is affixed at a distance from the chassis, by means of multiple washers and a couple of bushings - all of this adds to the Meccano feel ;-)

It’s a pain in the ass, but looks (somewhat) cool.
Just avoid cross threading one of those bolts with a high power impact gun...

plasticman

899 posts

251 months

Sunday 16th February 2020
quotequote all
Really , who are those people ?

pmessling

2,284 posts

203 months

Sunday 16th February 2020
quotequote all
The alloy version that I've made cuts the weight in half but retains the strength by being thicker, new spacers (not washers) make it easier to get up

My own car never had the mid point mounts for the exhaust so fabricated my own and has certainly helped reduce the movement of the exhaust.

Imran999

351 posts

153 months

Sunday 16th February 2020
quotequote all
plasticman said:
Really , who are those people ?
It’s an opinion, not sure it matters who it came from, we can take it or leave it.

The bolt holes in the plate are larger than the bolts, and the plate itself is not particularly rigid, so I don’t believe it can add much rigidity to the chassis, the tolerances just aren’t there.

If it’s sole purpose is to support the exhaust pipes, well it only does that at the very back, so a much simpler bracket would have been both lighter and cheaper as well as being much easier to remove and reinstall.

I don’t know of any other cars that have an assembly in place to catch a failed part of the exhaust assembly, so to my somewhat inexperienced self, the notion that it didn’t serve much purpose seemed logical.

But, I’m always keen to learn, so if someone knows the real and maybe higher purpose of this part, then I’m with Mr Cerbera and I’d love to hear it too!

Thanks

Mr Cerbera

Original Poster:

5,031 posts

230 months

Monday 17th February 2020
quotequote all
1485

You have Mail

thumbup

Byker28i

59,820 posts

217 months

Monday 17th February 2020
quotequote all
The bolts on mine when I first got it used to always hit first, especially going over ramps etc, so I now have thinner washers and thinner headed bolts.

I always assumed it was to add sideways rigidity on the chassis at that point.

TwinKam

2,984 posts

95 months

Monday 17th February 2020
quotequote all
Ditto this ^ ^.
But when I fit my (thicker) ally plate, I plan to heavily counter sink the holes and use counter sunk cap head screws not only for maximum ground clearance, but more importantly for better location and hence rigidity.

Caddyshack

10,812 posts

206 months

Monday 17th February 2020
quotequote all
Sounds like titanium replacements would make a big weight saving.

TwinKam

2,984 posts

95 months

Monday 17th February 2020
quotequote all
Caddyshack said:
Sounds like titanium replacements would make a big weight saving.
roflroflroflroflrofl

pmessling

2,284 posts

203 months

Tuesday 18th February 2020
quotequote all
Before getting the aluminium ones laser cut I looked at titanium and the cost was eye watering.

plasticman

899 posts

251 months

Tuesday 18th February 2020
quotequote all
"It’s an opinion, not sure it matters who it came from, we can take it or leave it."
It matters because you say "people who should know" and if you are acting on that fact and significantly weakening your chassis .

Imran999

351 posts

153 months

Tuesday 18th February 2020
quotequote all
plasticman said:
"It’s an opinion, not sure it matters who it came from, we can take it or leave it."
It matters because you say "people who should know" and if you are acting on that fact and significantly weakening your chassis .
Yes, I see your point.
I must admit, I was working on the premise that the chassis is made of large tubular sections with significant cross-bracing on the 3 out of 4 sides. Any flexing of the chassis would be a result of very significant twist force (high speed cornering), but that such significant force would far exceed the lateral support provided by the chassis plate, not least because the bolt holes have a large tolerance.

Even though I’ve taken the dam thing off and put it back at least 10 times, perhaps I’m miss-remembering the tolerance of those holes.

I will take a look...

Imran999

351 posts

153 months

Wednesday 19th February 2020
quotequote all


Tolerances are as I remember.
Perhaps 20-30ftlb does limit lateral movement enough to actually stiffen the chassis - I really don’t know.

Mr Cerbera

Original Poster:

5,031 posts

230 months

Wednesday 19th February 2020
quotequote all
plasticman said:
"It’s an opinion, not sure it matters who it came from, we can take it or leave it."
It matters because you say "people who should know" and if you are acting on that fact and significantly weakening your chassis .
Hi David wavey

As the subject title ays, I am always interested in Cerbera owner's thoughts.
We are an interesting and creative group with strong, decisive minds.
I don't have the tendency to suicide so all comments are welcome..

thumbup

Caddyshack

10,812 posts

206 months

Wednesday 19th February 2020
quotequote all
TwinKam said:
Caddyshack said:
Sounds like titanium replacements would make a big weight saving.
roflroflroflroflrofl
Why the laughing?

I have replaced about 70% of the bolts on my car with Titanium.

People spend 4000 plus on 20-30 bhp but they don't like to spend money reducing weight which improves many more areas of performance. My battery was £600 and saved over 15kg

Edited by Caddyshack on Wednesday 19th February 18:03

Byker28i

59,820 posts

217 months

Wednesday 19th February 2020
quotequote all
TwinKam said:
Ditto this ^ ^.
But when I fit my (thicker) ally plate, I plan to heavily counter sink the holes and use counter sunk cap head screws not only for maximum ground clearance, but more importantly for better location and hence rigidity.
Thats a good idea.

Byker28i

59,820 posts

217 months

Wednesday 19th February 2020
quotequote all
Interesting. Having taken them out I'd say the front seats are one of the heaviest items, but they are really comfy. I guess there has to be a compromise somewhere

TwinKam

2,984 posts

95 months

Wednesday 19th February 2020
quotequote all
Caddyshack said:
TwinKam said:
Caddyshack said:
Sounds like titanium replacements would make a big weight saving.
roflroflroflroflrofl
Why the laughing?

I have replaced about 70% of the bolts on my car with Titanium.

People spend 4000 plus on 20-30 bhp but they don't like to spend money reducing weight which improves many more areas of performance. My battery was £600 and saved over 15kg

Edited by Caddyshack on Wednesday 19th February 18:03
Oh, a few reasons... to me it seemed pretty futile replacing half a dozen steel bolts with Ti ones when they are holding up a steel plate that weighs more than yer average fridge... or replacing the enti steel plate with a Ti one that would cost more than a new small car... or even bother trying to save weight there when it is SO low down on the car that it is probably a benefit to C of G placement... or indeed the whole concept of saving weight when the typical Cerb owner is a 'powerfully built director type' weighing in at 15 st or possibly more... biglaugh
Yep, best leave all this sillyness to folks who have more money than sense.
Pass the port!