Reccomendations for various upgrades.

[FCOV6]

Now that i am finally getting back into swing of getting my FC sedan on the rd, i have a few questions on some upgrades/replacements . I'll list in order to make it easier to read -

1) CRS R&P steering conversion - i cut down a HR column but i think i can do better, torana,gemini etc ?
2) HR diff with drum brake shoes, HR front with LJ disc's/calipers - i made a HQ m/cylinder adapter but again a combined m/c and booster is preferred.
3) Fuel tank - i have a stock tank but did previously measure up an XR/XT tank that has a recessed spare wheel well and thought it may fit but filler in in the wrong place . Idea's for a replacment as my spare w/well is rusted and a new 1 will need to be made.

 Sorry for jamming it into 1 post.

regards,
Nick.

[smithy]

hi nick.
cant help with the first 2 but re the fuel tank have you had a look at the XB tanks again you have the recessed spare but honestly i cant remember where the filler neck is. i have seen it done in a FB/EK and it sat really nice.

i put a VN/VP commodore tank in mine which fills the boot up quite well ( no room for spare though) and then had to get the original FC filler neck welded to the tank i used the original neck because of the lack of a decent fuel cap for the commodores. you could always have the fuel door setup on the side of the car.

the other way you can go is to use a fuel cap from places like earls plumbing and adapt that to the tank, if you wanted to retain the original filler position a the rear of the car. also there is now a guy who is making stainless tanks for FC's
http://www.deanfabrication.com.au/gallery.php?level=picture&id=61  i have seen these in cars and they look quite good.

but i think whichever way you go there are going to be modifications it just depends on how much  and what you can do yourself.

cheers
dean

[FCOV6]

Thanks Smithy, i saw an XB tank on ebay that fits with the idea i have and since the wheel well is non existent i might as well cut it all out and find a tank that fills the space. My memroy is sketchy but maybe an XM/XP tank is what i need with the filler in the rear centre as well ? mods have always been done by myself - my motto is if i cant do it myself it doesnt get done !

regards,
Nick.

[mcl1959]

First suggestion - forget the CRS rack and go for a better set up such as Rod's Racks in QLD.
What sort of wheels do you want to run - this will determine what brakes to use. Generally better to use HQ brakes if you want to run late model mags or Torana if going with old school 13 inch wheels.
Hr diff is OK for a stock red motor and a pretty easy conversion.
I'm with Dean - use the Commo tank and adapt the filler from the FC. Much easier to do than try to make a tank from something else fit without modding it.

Ken

[FCOV6]

Some good idea's but since i already have the CRS R&P kit fitted i'm not about to replace it. When i started on the resto back in '85 i had a set idea of how i wanted it to be but now i'm starting to get new idea's 
 I might have to start back at the shell with CRS chassis and R&P kit and try to work out which direction to go, i'm leaning towards a vented front disc swap and a rear diff to match - as said HR drums and solid discs were ok for old school red 6's but if i fit the V6 i will need better stopping power. What stubs will fit to the HR wishbones/balljoints that will give me vented discs ? and then what diff with matching stud pattern will fit easily without too many mods ?

thanks,
Nick.

[smithy]

hey nick. CRS and hoppers stoppers do brake conversion kits wher you use a HD/HR drum stub axle and you can then fit commodore discs and calipers. also HQ etc.
i have commodore front and rear discs on mine, but think carefully what you want as i found out later that there arent a great deal of wheel options with correct offsets needed for commodores.
HQ discs will give you more wheels choices, same PCD as chev
but it might be wise just to ring hoppers stoppers and have a talk to them as im sure there are a few other ways you could go.

i was in a similar boat to you, the last car i built ( and said it would be my last) was an EH wagon back in 84 and then there were only a few things you could do for brakes, suspension and engine. today there is so much more with heaps of companies specialising. but you are on the right track to ask a hell of a lot of questions here first.
something i should of done, but i guess i like learning the hard way

dean

[FCOV6]

Actually Smithy, when i first got my FC i was 17 and i had only thought about shoe horning a red motor in and then a respray, body work and respray was done first which i regret now (as i did about 2 years later) and shortly after welded in an EK auto trans tunnel and the CRS chassis kit and R&P kit. So now i am dealing with the decisions i made 20 years ago and trying not to go backwards if possible, thanks for the tip on Hoppers i think i will give them a call.

thanks,
Nick.

[mcl1959]

Nick,  HQ stub axles will bolt straight up to the HR front end - this will give you vented HQ rotors - not brilliant, but will pass the brake test. HQ / Chev offset wheels are a bit of a problem for FC as they will hit the guards unless very narrow. The best stud pattern to go for if you can get over the F word is Ford, lots of wheels sizes & patterns available and different offsets as well
The H/S brake kit will fit HR or HQ disc stub axles (not drum) and can be supplied in any stud pattern you like. (The rotor is actually an AU Falcon rotor which is purchased blank and drilled to suit the customers needs - the hub is custom made to suit)
The CRS kit uses a modified drum stub axle and in my opinion is an inferior kit. Both need a minimum of 15 inch wheels but 16 works best with HR stub axles.
I designed and built all the Holden kits for H/S so I pretty much know all the answers you need.
The Ford stud pattern can be adapted to the rear axles by redrilling using a reputable diff company - A lot of people use 9 inch rear ends so it suits this conversion.
Check with your engineer about the CRS R & P as a few engineers in Vic will no longer allow them because of the turning circle and geometry problems.

What type of wheels do you want to run?

Ken

[FCOV6]

mcl1959, i have no idea on the wheels i want to run, remember when i started this my only aim was a 186S, celica 5spd, disc front. That then grew to the Buick V6 and R&P conversion, my 13x6 hotwires wont suffice any more so probably 14/15" rims. What about P76 discs ? they were a popular fitment years ago to get ford stud pattern on holdens - most likely hard to get now.
 Also have seen volvo dana diff conversion on early holdens. The HQ stub would be the least costly ( a factor for me) and be miles ahead of the current LJ disc setup.

[smithy]

hi nick, you will find that the minimum wheel size you will need will be 15inch to clear the calipers / tie rods.
with my swap i started out with 15 in commodore but have now moved up to 17 inch. heaps of clearance now.
not sure with the HQ / ford swap but the commodore rims came in too close to the upper ball joint grease nippe and tie rods for my liking.
even at this early stage as ken suggested have a think about what wheels you like and availabilty in the correct backspacing. this may save you some of the headaches i encountered later on with wheel choice.

cheers
dean

[mcl1959]

Nick, it's very important to make wheel choices early so that the brakes can be selected to best suit. There are so many choices now with brakes that they can be adapted around the wheel choice. The P76 rotors are still available new but must be purchased with a fitting kit in order to put them on a Holden. The rotors are in the the order of $150 each and the kit is $70 so they are dearer than HQ brakes. The benefit they have is to bring the track in about 20mm in each side. But this is not really necessary if you are running a new style wheel, only if running an old style Ford rim - P76 rotors were really popular on model A's with HR front ends running old Ford steel rims.
If dollars are a factor then the H/S kit is out of the question since it starts at $1100 for the kit.
Volvo diff was popular because it has early Holden stud pattern, years ago there were hardly any choices for car modifiers so they had to make do with what they could get.

ps don't call me mcl1959, my name is Ken
Ken

[FCOV6]

Thanks Dean and Ken, i might go with the HQ stubs and then depending on what diff i use i can get blank rotors and have them drilled to suit the stud pattern i require. Is there a Commodore that has a similar track to an FC ?

[NosFEratu]

Hi

Kathi's husband John here.  Hopefully I can provide a few pointers as I have done a fair bit with holden front ends, steering and brakes.

Firstly 13" (HD/HR) spindles are different from their 14"(HK to WB) cousins.  The axle and steering arm locations are moved up by about 19mm which is effectively a dropped spindle.  The big issue is that the movement in steering arm location compared with the bottom ball joint requires a different steering arm or changed position for the rack.  For you this means if the CRS rack you have was designed for HR spindles it will probably have a lot of bump steer if you put on 14" spindles due to the raised steering arm location.  Just check because this much change in steering arm height is likely to have a significant impact.

Ken is perfectly correct in observation that the very big discs 330mm will pull you up more often then the HQ/P76 (270mm).  However, you may need to consider a number of design elements vehicle use in making your choice.  Ther e are a couple of great books about braking systems containing all the formulas.  For us normal kind of people the HQ/P76 size is a good compromise as they come off vehicles that are about 500 to 600 kgs heavier than your FC even when it is fitted with a buick V6.  EG fully loaded WB Statesman is about 1600kgs while your FC is about 1100 kg.  This gives a significant safety margin for your average driver.

I just fitted a set of P76 discs to our van which we putting in a chev v6.  I bought a complete new set of discs with conversion parts and calipers for about $250 off Ebay but I was lucky at that price.  I am putting them on for a couple of reasons.  Firstly I want all our cars to have a common stud pattern (ford).  Secondly, they pull the hub faces in by 15mm compared to HK solid discs and  probably more compared with HQ or Hopper Stoppers.  This allows me to run a lot of old style Holden/Ford/Chrysler offset wheels rather than the very shallow  dish of a Commodore but this just or choice and one to be aware of before you  start buying pieces.  I must admit I rang Hopper Stoppers and asked how much there conversions pushed out the hub face and they couldnt tell me.  Knowing this is critical on early holdens as it may impact the scrub radius, guard clearance and toe rod end clearance.

Hope this helps

John   

 

   

[FCOV6]

Thanks John, which ever way i go i will need to match the diff for the stud pattern or have the hubs re drilled to suit, what stubs are you running with the P76 discs and what steering arrangement for the V6 ?
  I am most likely going to go down to pick a part so i can look at a few front ends and see what parts will suit my needs, possibly the HQ steering arms might be in the correct position on the stub as oposed to the HR arms. Anyway, lots of things to think about.

thanks,
Nick.

[mcl1959]

Nick, the standard H/S kit for HR front ends has the same offset as a Torana or HQ brake set up which is approx 20 mm out each side from stock HR rotors. There is a variation kit available with greater offset that allows better fitting for Commodore wheels and also another special kit I also developed that has the same offset as HR rotors. Unless you talk to Pete the boss, there's no one there any more who knows anything about the brake kits since I left at the start of this year.
If you use HKTG steering arms on the HQ stub axles this brings the steering geometry back to very close to right. The HKTG steering arms are the same length as HR but the tie rod end mount position is lower than a HQ steering arm so compensates for the raised mounting position.

With rack and pinion steering the good thing is that you can set it up to suit the steering arms so the choice is better if you're prepared to re-engineer your rack mounts. The best steering arms to use if you are going to re-engineer are HQ power steer arms as they are shorter than manual steer arms and allow a better turning circle. BUT the rack MUST be set up correctly to eliminate bump steer and maintain ackermann geometry.

Ken

[NosFEratu]

Hi Nick

I'm using HQ stubs, P76 discs (ford stud pattern), LC 6 cylinder steering arms and narrowed VH Commodore rack.  Not many people use the Torana arms but they are the shortest of all steering arms and provide the most direct steering. Mine is obviously a rear mounted rack which gives better turning circle and geometry.  FYI - I ran a bump steer test the other day and came up with zero through the whole range of travel.  My choice of rear mounted rack makes fitting the engine a bit more of challenge but the results overall are worth it. The engine will need to sit further back and  may need some more firewall "massaging" however this will actually make the car drive and handle better.  I build my front ends to suit my purposes and it does take time and effort to get things right.  One of the best commercial set ups I have seen is from Rod's Racks but the options Ken has provided from H/S are all feasible depending on your budget, time and resources.  Build what suits your purposes - you need to think all of this over and make your decisions for your needs.   

At the rear I'm using a Centura borg warner diff.  This also has a ford stud pattern - but - it is about 25mm wider than a standard FE/FC diff.  We are not overly concerned about the diff width for the van as we will continue to use standard 14" steelies with whitewalls and maintain a classic (read "sleeper") look to it.  You could use a 9" but there is no standard 9" that will fit without modification. A cheaper alternative is a narrowed borg warner diff out of a falcon.  Many of these bog warner diffs have interchangeable parts and a lot of the rice burners are using them.  They are a cheap and sturdy alternative to a 9" but will still cost some money especially if you want to narrow it to fit wider rims.  Remember, bango diffs are quite limited in their horsepower capability!

Hope this helps.

John

[mcl1959]

John, sounds like a really well thought out set up - The old CRS front mount rack is outdated now and the rear mounted rack is a far better solution - Have you done any tests on how difficult the wheel will be to turn with the Torana steering arms?  The shorter steering arms will give better control but the trade off is with greater effort required to turn the steering wheel.
Can you post some pics of your set up?  It would be good to see.

Ken

[NosFEratu]

Ken

We'll post a few shots of the van's front end in Kathi's member's ride thread in couple of weeks - our schedule is pretty hectic ATM.

I've used a similar set up in the Corvette on a HT front end.  As you'd be aware, Commodore racks are not fast (less movement per turn) so the short arms quicken the steering.  Yes, it mean there is some additional effort to turn and that's why I'm concerned with engine location and the scrub radius.  Minimising the scrub radius and moving the engine back further than a normal front mounted position should negate some of the heaviness.

The Torana arms provide another couple of benefits.  They provide better lock without having to narrow the rack housing any more. More importantly, they have a higher tie rod height (from memory about 40mm higher than HK/T/G arm) so the rack is higher and somewhat above the lower inner pivots.  This means the rack can be brought a bit closer to the crossmember.  It's only 20mm but this can make all the difference for the sump clearance compared with other rear mounted rack set ups.  Funnily though, they provide more ackerman than the HQ steering arms as the Torana are turned in while the HQ's are dead straight.  Of course more ackerman can be added by spacing the arms in a few mm.

I've made a couple of other mods you may be interested in which are not the norm.  I've shortened the shock towers about 25mm which lowers the upper inner pickup point.  This provides, in my view, a better roll centre location (ala Shelby Mustang mods and Holden's own RTS).  It also means I have negative camber curve in bump and has more clearance between the mudguard and tyre on lowered cars.  When I welded the towers back on I turned them slightly rearward so I can achieve more caster without using as many shims.

I've driven an old mate's car with this setup and couldn't believe I was driving a Holden.  It was so precise and went through corners like no other car I had driven.  I've also driven Kathi's old V6 FC with front mounted rack and HR front end and, for me, this was about as scary as they come!   

We'll post shots when time permits.

John
         


 

[jack_fc]

Wot???  Kathi drove an FC?   With a V6?   

[smithy]

Wot???  Kathi drove an FC?   With a V6?   

  im sure it was just a tarted up FE.
i dont think she would let herself sink to those depths