Front end question

[MickFB265]

Hi all,

Just a silly question: for my straight line 1/8th mile FB sedan that doesn’t need circuit car-like handling or brakes and won’t ever be registered do I need a HR front end if I’m looking at doing an engine swap or can I get away with the original front end? (albeit beefed up/reinforced with a CRS chassis kit or similar)?

Plans are relatively open at this stage but It’s going to be a big straight six and manual combo. I’m seeing huge prices for HR front ends and just wondered if people only fit them for the balljoint and disc brake advantage or is it required for fitting higher HP donks?

Cheers for any help

[Blacky]

G'day Mick, sounds like an interesting project mate , I assume a 265 ??? If you arent licencing it I cant see why not - dont know how a kingpin front end would be at the top end of a 1/4 mile but 1/8 would be worth trying before changing ?

[Errol62]

Mick if you want it legal on the street you will need the ball joints and brake upgrade. In NSW you’ll need to employ a road transport engineer, who will dictate requirements. If you’re racing it’ll be up to the regulating authority involved. If there is no authority involved it’s your neck. In theory you could stick some mounts on the stock crossmember, cut the tunnel, reinforce the floor and hang a rear crossmember off it. Cheap and easy fun all being well. The stock rear ended may not last long of course....


FB ute fixer upper, EK van on rotisserie

[MickFB265]

G’day fellas, thanks. I’ll post some photos up in the relevant projects section so you can check out what I’m up against but yes keeping it cheap, fun and in the budget while also being safe enough for the 1/8th mile is the goal. A 265 would be ideal but I will be looking at a stronger rear end to suit.

[Harv]

No need for a ball-joint front end, provided the king-pin front is not flogged out. Kingpin front ends have seen considerable speed without deteriorating/wobble. Probably cheaper to reco an original front end than to buy a HR front end and reco that.

The brakes are likely to be marginal, though the runout distance behind the traps is considerable. To get disks without the ball-joint front, this may be an option (it's what I am planning for my meth monster project):
http://www.fbekholden.com/forum/viewtop ... 27&t=22297

Cheers,
Harv

[MickFB265]

Thanks Harv- that sounds like the solution I'm after too.

I'm sure in combination with a decent late model diff with disc brakes I should be able to slow it up in time (or a good long runway!)

So really there's no structural difference in the stiffness of the original and HR subframes or the thickness of the steel itself...? Sounds like I will be sticking with the original then! I'll keep trawling through old posts to see what others have done in regard to bracing or improving their vehicles' chassis for racing.

Cheers- Mick

[Harv]

You can go silly and put in a fancy rear end (four link etc) to get it to hook up, though for a cheaper option:

a) put a set of 3/4 chassis rails in from the front floor brace back to the rear spring hangers (the two pieces of steel on the left and right hand side of the image below). Castlemaine Rod Shop sell them:
https://www.rodshop.com.au/holden/fb-ek ... s-kit.html
though they are easy enough to make... little more than glorified lengths of RHS though are weld-in to the rear spring hangers. The braces make it easy to fit a DIY tailshaft loop, which will keep ANDRA happy.

CRS kit.jpg (67.82 KiB) Viewed 453 times

b) put a set of braces in from the front floor brace forward to the subframe K-members. Castlemaine sell these too (the two bits in the photo above with triangular plates), though again easy to make and are bolt-in.

c) consider a steering box brace (suspect these are made by Sonic Injection):
https://www.ebay.com.au/i/323777053378? ... gKAj_D_BwE

d) Consider mounting a chain from the firewall to the engine block rear to prevent tilt under heavy braking (old humpy trick).

e) You are likely to get axle tramp, which can be cured with a set of slapper bars (a.k.a. traction bars, tramp rods). American Autos in Sydney sell what appear to be the Lakewood generic set:

traction bars.jpg (10.37 KiB) Viewed 453 times

These will need some buthering to fit FB/EK, but are a good starting point.

Cheers,
Harv

[MickFB265]

Thanks Harv, awesome info

I love the chain suggestion!

Got some good reading to do now!

[Blacky]

Mick , if you want I can send you a PDF of a home made chassis kit very similar to the CRS kit that you can fab up yourself

Was drawn up by NoMad on the forum here who is a drafty.

If you are building a dedicated racer there is plenty of info on the web for a home made ladder bar setup which could be easily mounted to your new chassis kit - that's what I planned if I was to go ahead with the EK gasser I was considering. Works well and looks cool

[MickFB265]

Mick , if you want I can send you a PDF of a home made chassis kit very similar to the CRS kit that you can fab up yourself

Was drawn up by NoMad on the forum here who is a drafty.

If you are building a dedicated racer there is plenty of info on the web for a home made ladder bar setup which could be easily mounted to your new chassis kit - that's what I planned if I was to go ahead with the EK gasser I was considering. Works well and looks cool

That would be fantastic Blacky, I’ll give anything a go to save a few more dollars for methanol!


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[Blacky]

PM me your email address mate