IRS rear clip for bagged Hilux

[dvslux]

Hey guys, I have a 88 Toyota Hilux that I have bagged etc, but Im now about to put an IRS unit in the back from a Toyota Soarer.

First question is, since I need to build a new rear clip from RHS, what size is the minimum requirement? is it still 75x50x3?

#2, whats the best/legal way of shortening the half shafts?

#3 is there any specific questions you can think of that I need to ask/discuss with my certifier (once I can finally get down to see him haha)

And now another tricky question. I want to build new tubular upper and lower control arms front and rear, What is the minimum pipe diameter and wall thickness needed to build these arms? and for the front I need new cross shafts, is mild steel ok for these or do I need to have some unobtainium machined up? and do control arms need to be tig welded (even just for bag plates etc) or is Mig welding ok?

Cheers
Ben

[Justin]

Hi Ben

It sounds like a pretty serious project!

The answers to almost all of your questions can be found in the NZ Hobby Car Technical Manual (HCTM) - this is available here - www.hotrod.org.nz/Merchandise%20Page%20Files/Hobby_Car_Technical_Manual.htm - grab yourself a copy as soon as you can, so that you're not in the position of having to change things once your certifier has had a look.

1) RHS - yes the minimum is 75x50x3.
2) Half-shafts - this should only be done by a recognised industry expert who is professionally engaged in the business of manufacturing this type of shaft.
3) That's a hard one! I can't think of anything off the top of my head, but you're undertaking some pretty extensive modifications by the sounds of it, so there will be many things you'll need to consider, and questions you'll need to ask. Just make sure that you get in touch with a 1D category Certifier as soon as you can.
5) All of the requirements for tubular a-arms are in the HCTM - these are stepped dependent of the size/weight/performance of the vehicle, so it's best that you use the table to choose the correct specs. Again this is something you should work closely with the LVV Certifier - there are many pit-falls relating to this, so make sure you've got a good plan before you get started.

I hope this helps!

Justin

[dvslux]

Thanks for that Justin, definately a help. Ive been talking with Paul Sadler about the other mods to the truck previously, Im just pressed for time at the moment, so this info helps me push forward a little more thank you.

As for the HCTM, it says trade customers can get it discounted, what qualifies for the trade discount and how much discount do you know??

Thanks
Ben

[Justin]

Hi Ben

To be eligible for a discount on the HCTM, you;

1) must purchase the manual directly from NZHRA (not an agent); and
2) be a member of one of the LVV member associations (proof of membership required); or
3) when being used for trade purposes, a trade discount is available.

For the exact prices, and further details, you'd be best to call Jo or Bobbie at the NZHRA office on [phone].

Cheers, Justin

[dvslux]

Cool thanks for that mate.

[dvslux]

I fanally got a chance to talk with Paul Sattler about the chassis, he seemed to think everything sounded good, although I forgot to ask about gussets for the bends, but he also suggested I run it past you guys as well, just in case when he submits the paper work you find something not right.

The 75x50x3 box needs to be bent to get the chassis the way I want it, as the rails need to be narrower and also go from a single rail into 2 rails (one for the lower suspension pick up points and the other for the top suspension pickup points).

Now for the bends, since I don't have access to a cad designer and mandrel bender that can bend easy and hard way, I need to do something else. But I want the rails smooth, which means internal gussets.

So, basically I plan on cutting 3 sides out of the box section, and bending the longest side to the correct radius, then cut out the top and bottom curved sections from 3mm plate, and bend 75x3mm plate for the short side of the bend, but carry the plate further past the bend (at least 100mm). Hopefully the picture can explain it, and please excuse the ms paint drawing ha ha.

Can you see a flaw in this plan (other than being pain stakingly long and tedious), and also were would I need the gussets and how big would they need to be?

Have I made you wish you were still on holiday yet? haha

Attachments:

[Justin]

Hi there

The problem with a question like this is that without seeing it, it's very difficult to give an accurate answer. There are several variables which could determine whether this will need fish-plates or gussets, for example there may be a cross-member that could take the place of one or both of these.

There are two things you should do; first is to get your hands on a copy of the Hobby Car Manual - this has loads of info on chassis modification and construction.

Second is to get in touch with Paul and arrange a time for him to have a look at the vehicle and discuss your proposed plans. He'll be able to see what you're doing, and will be in a much better position to be able to give you sound advise.

If you stick to those two pieces of advise you shouldn't have any problems at cert time.

I hope this helps

Justin