Jump to content

For Questions Regarding WOFs/CERTs/NUMBER PLATEs


Recommended Posts

  • Replies 7.7k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Hi Clint,

 

I'm about to start the process of mounting a 20B into my FD.

Have yet to get a certifier on board, but thought the internet would have all the answers anyway ('cause we all know that if it's on the internet, it's gospel).

Anywho, what are the rules around modifying the factory subframe, specifically where the steering rack mounts to the subframe?

The mounting points for the rack are at the front of the subframe protruding forward.

Xcessive Manufacturing in the States does this kit: https://xcessivemanufacturing.com/mazda/20b/mazda-20b-m-20b-fd-xmm-k.html

Kit is for LHD cars so can't be used here.

 

Essentially I want to do the same, but rather than cut out the subframe and weld in new parts, the plan is to:

Cut the stock subframe either side of the mounting brackets

Bend the front of the subframe down which will rotate the rack downwards.

Reweld the subframe

Notch the subframe slightly to clear the steering shaft.

This effectively drops the height of the steering rack.

 

The below pic shows what I want to achieve - see the nearest edge of each subframe with the rack mounts:

3138d1051020130-20b-pettit_subframe_and_

Top subframe is an aftermarket option, bottom is the stock subframe.

 

The second aspect to this, is the bump steer issue caused by dropping the rack.

Most kits out of the states use 'bump steer adapters' which is just an adjustable rod that spaces down the tie rod end - is this legal in nz?

 

Both of the above things have been done in circuit cars, but unsure of legality for nz roads.

The other option is to build a custom subframe, however, I'm trying to limit costs.

 

All of this is to get the motor as low as possible in the chassis, and maintain the factory bonnet.

Already cutting 40mm out of the intake manifold, however need atleast another 30mm to make it fit.

 

Thanks

Link to post
Share on other sites

I don't think this is too big a deal, but just double checking on behalf of a mate (he can't get in touch with the local certifier in Whangarei to ask)

S12 Silvia with H190 solid rear axle.  He's changing the shocks on it to something else and the lower bush is wider than the factory one.  Is it ok to cut the existing u shaped bracket off the diff, and then make a new one (out of 3mm folded plate steel?) and weld it on?  The spring is run separately so is not load bearing as far as that goes.

Bracket in question:

89749037_312811873027803_249842478151106560_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=VfNOKa4jWdYAX9GDTka&_nc_ht=scontent.fakl8-1.fna&oh=efef0ebf5fb5c7918f2610661c8bdae4&oe=5E987AEA

Link to post
Share on other sites
On 20/03/2020 at 13:32, spiderwebfx said:

I don't think this is too big a deal, but just double checking on behalf of a mate (he can't get in touch with the local certifier in Whangarei to ask)

S12 Silvia with H190 solid rear axle.  He's changing the shocks on it to something else and the lower bush is wider than the factory one.  Is it ok to cut the existing u shaped bracket off the diff, and then make a new one (out of 3mm folded plate steel?) and weld it on?  The spring is run separately so is not load bearing as far as that goes.

Bracket in question:

89749037_312811873027803_249842478151106560_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=VfNOKa4jWdYAX9GDTka&_nc_ht=scontent.fakl8-1.fna&oh=efef0ebf5fb5c7918f2610661c8bdae4&oe=5E987AEA

Dumb question, why not trim the lower shock mount to fit the car? 

Link to post
Share on other sites
On 20/03/2020 at 13:32, spiderwebfx said:

I don't think this is too big a deal, but just double checking on behalf of a mate (he can't get in touch with the local certifier in Whangarei to ask)

S12 Silvia with H190 solid rear axle.  He's changing the shocks on it to something else and the lower bush is wider than the factory one.  Is it ok to cut the existing u shaped bracket off the diff, and then make a new one (out of 3mm folded plate steel?) and weld it on?  The spring is run separately so is not load bearing as far as that goes.

Bracket in question:

89749037_312811873027803_249842478151106560_n.jpg?_nc_cat=104&_nc_sid=b96e70&_nc_ohc=VfNOKa4jWdYAX9GDTka&_nc_ht=scontent.fakl8-1.fna&oh=efef0ebf5fb5c7918f2610661c8bdae4&oe=5E987AEA

Yep no problem to do that 

Link to post
Share on other sites
On 19/03/2020 at 16:00, SHGWAG said:

Hi Clint,

 

I'm about to start the process of mounting a 20B into my FD.

Have yet to get a certifier on board, but thought the internet would have all the answers anyway ('cause we all know that if it's on the internet, it's gospel).

Anywho, what are the rules around modifying the factory subframe, specifically where the steering rack mounts to the subframe?

The mounting points for the rack are at the front of the subframe protruding forward.

Xcessive Manufacturing in the States does this kit: https://xcessivemanufacturing.com/mazda/20b/mazda-20b-m-20b-fd-xmm-k.html

Kit is for LHD cars so can't be used here.

 

Essentially I want to do the same, but rather than cut out the subframe and weld in new parts, the plan is to:

Cut the stock subframe either side of the mounting brackets

Bend the front of the subframe down which will rotate the rack downwards.

Reweld the subframe

Notch the subframe slightly to clear the steering shaft.

This effectively drops the height of the steering rack.

 

The below pic shows what I want to achieve - see the nearest edge of each subframe with the rack mounts:

3138d1051020130-20b-pettit_subframe_and_

Top subframe is an aftermarket option, bottom is the stock subframe.

 

The second aspect to this, is the bump steer issue caused by dropping the rack.

Most kits out of the states use 'bump steer adapters' which is just an adjustable rod that spaces down the tie rod end - is this legal in nz?

 

Both of the above things have been done in circuit cars, but unsure of legality for nz roads.

The other option is to build a custom subframe, however, I'm trying to limit costs.

 

All of this is to get the motor as low as possible in the chassis, and maintain the factory bonnet.

Already cutting 40mm out of the intake manifold, however need atleast another 30mm to make it fit.

 

Thanks

Yes moving the rack down is do able.  You definitely want to get a certifier involved from the start so they are happy with how you are moving it down and what you do to sort bump steer issues  

Some types of tie rod droppers are not legal, some are. 

  • Like 1
Link to post
Share on other sites
12 minutes ago, kws said:

I was under the impression vtnz and the likes were a essential service? 

Banner on the VTNZ site says they shut yesterday. NZTA just say "Don't contact us". I assume any mechanics open would be for maintaining essential services fleet. Of which my Commer Van is essentially a pain in my arse and is due on the 11th of April. 

  • Sad 1
Link to post
Share on other sites

VTNZ, VINZ, and AA will be open for essential services vehicles only. No private vehicles. If your vehicle is used in the support of life, then join the queue at their lane, don't get out. They will come to you, they will judge your need, if they deem you are not essential service they will turn you away. Don't try to take the piss. If in doubt you're probably not essential

  • Like 1
Link to post
Share on other sites
33 minutes ago, Snorkpipe said:

VTNZ, VINZ, and AA will be open for essential services vehicles only. No private vehicles. If your vehicle is used in the support of life, then join the queue at their lane, don't get out. They will come to you, they will judge your need, if they deem you are not essential service they will turn you away. Don't try to take the piss. If in doubt you're probably not essential

would this for example apply to a nurse's private car needed to get to work?

 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...