Ausmini
It is currently Thu Mar 28, 2024 10:04 pm

All times are UTC + 10 hours




Post new topic Reply to topic  [ 9 posts ] 
Author Message
 Post subject: Toe board strengthening
PostPosted: Mon Apr 26, 2021 11:04 am 
Offline
998cc
998cc
User avatar

Joined: Tue Nov 13, 2007 4:17 pm
Posts: 946
Location: NOR, Perth, W.A.
I've heard of high-powered minis causing cracks in the toe board where the subframe bolts pass through the floor. The solution (or prevention in a new build) seems to be to add a steel spreader plate around those mount points, but is there a good plate area/dimensions and thickness to use? As opposed to complete overkill and welding in a 3mm steel plate across the entire width of the toe board :shock: Any photos would be appreciated too.

_________________
-Alan
I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
I also blame my Dad for me being 6' 1" - not really the optimum height for driving a Mini.


Last edited by Mearcat on Mon Apr 26, 2021 3:34 pm, edited 1 time in total.

Top
 Profile  
 
PostPosted: Mon Apr 26, 2021 3:24 pm 
Offline
848cc
848cc
User avatar

Joined: Sat Jan 03, 2009 3:08 pm
Posts: 339
Location: on the side of the road fixing my shit
wow how much are you hating on your mini??

ive sagged them in the middle long before ive had issues with the sub-frame pulling out



to answer your question, an engineer will say dont make it any more that double the metal its attached to, so a 2-2.5 mm would probably be better

_________________
Image


Top
 Profile  
 
PostPosted: Mon Apr 26, 2021 3:34 pm 
Offline
998cc
998cc
User avatar

Joined: Tue Nov 13, 2007 4:17 pm
Posts: 946
Location: NOR, Perth, W.A.
greyghost wrote:
wow how much are you hating on your mini??

No hate yet, but about 160hp once it's on the road :P This is about forward-planning

_________________
-Alan
I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
I also blame my Dad for me being 6' 1" - not really the optimum height for driving a Mini.


Top
 Profile  
 
PostPosted: Mon Apr 26, 2021 8:22 pm 
Offline
998cc
998cc

Joined: Fri Aug 30, 2013 8:59 pm
Posts: 1029
Location: Western Sydney
I think David Vizards “how to modify your mini” had some recommendations on this.

_________________
Find a job you love and you will never have to go to work !


Top
 Profile  
 
PostPosted: Tue Apr 27, 2021 8:53 am 
Offline
998cc
998cc
User avatar

Joined: Tue Nov 13, 2007 4:17 pm
Posts: 946
Location: NOR, Perth, W.A.
Phil 850 wrote:
I think David Vizards “how to modify your mini” had some recommendations on this.

The only stiffening reference in the body work section of the book mentions behind the carb, pushing the bulkhead into the parcel shelf.

_________________
-Alan
I blame my dad for my love of minis. I think I was conceived in the back seat of one :D
I also blame my Dad for me being 6' 1" - not really the optimum height for driving a Mini.


Top
 Profile  
 
PostPosted: Tue Apr 27, 2021 10:05 am 
Offline
1275cc
1275cc
User avatar

Joined: Sun Apr 29, 2012 1:19 pm
Posts: 4336
Location: Wollongong, NSW
Mearcat wrote:
Phil 850 wrote:
I think David Vizards “how to modify your mini” had some recommendations on this.

The only stiffening reference in the body work section of the book mentions behind the carb, pushing the bulkhead into the parcel shelf.

Are you looking at the new yellow one or the old white one? The old white one that was specific to minis had a few references for the body & subframe modifications

_________________
Image


Top
 Profile  
 
PostPosted: Thu Apr 29, 2021 10:59 am 
Offline
848cc
848cc

Joined: Fri Oct 06, 2017 6:39 pm
Posts: 191
Location: Perth, WA
Dutchy boxed up the section in his. But I believe it was for suspension and steering mounting purposes. But if you extend that concept further, there could be a solution somewhere:
viewtopic.php?f=23&t=100203&start=75

My thinking is that the torque from the motor would want to push the bottom of the subframe into the cabin? Therefore, pending any clearance issues (the default clutch pedal his the bolts...) you may get away with a stiffening plate parallel with the two mounting holes?

I'm thinking something like this cardboard mock up for illustration purposes...


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
 
PostPosted: Thu Apr 29, 2021 5:15 pm 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39621
Location: near Baulkham Hills, NSW
Torque from the engine is opposite direction to wheel rotation, so it would try to pull the floor down, not up.
I've not seen 200 HP Toyota conversions damage the floor, but their problems were all around the lack of any rigidity at the RF corner of the subframe, after people cut the RH side out to fit the engine in.
I had a bit to do with 3 of these. :roll:

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
PostPosted: Fri May 28, 2021 12:11 pm 
Offline
1360cc
1360cc
User avatar

Joined: Mon Aug 23, 2004 10:07 pm
Posts: 10650
Location: SE Melbourne
My car has a removable front and a similar 160hp to what's being discussed.
What I did with my subframe is make the lower mounts bigger to help spread any loads as much as possible.

The two top holes match up with the original rover mounts.
The 3 bottom holes go through the area of the floor where the floor panel meets the toe-board - which is fairly rigid. There is a flat bar with 3 holes in it on the inside of the shell - so the arrangement sort of 'clamps' down on the floor too in that area.
The plates having the 5 bolts and a large surface area also means that in the event of a front impact the subframe would be less likely to 'punch' through the floor to where your feet are. That was the plans anyway - I hope to never find out.

The cars been driving around in anger for a few years now and there is absolutely no flex down there - by comparison I can feel the floor moving around under my feet when i drive my old deluxe!


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 15 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

© 2016 Ausmini. All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.