38 Chev Coupe Suspension options?

[mick_in_oz]

Thanks again Col and Frank,

Does anyone know what the typical amount of Caster on one of these would be, guessing perhaps no more than about +2.5Deg? I really was hoping for a good bit more and use power steer. Anyone know if a different upper arm with an offset balljoint, like the UC Torana has, fits a HKTG front end? I think the HD has an offset upper arm and similar looking crossmember? Thoughts?

Power steer, has anyone gone with an EPS (electronic power steer)? I grafted a frankenstined 2002 Barina (Vauxhall Corsa B) into my Torana column as a way to leave all of the geometry and stuff under the bonnet alone, have the column looking original inside, but have power steer, and also the less assist with increasing road speed which is nice, makes it a breeze in the driveway and still weighty on the highway. This would free up the steering rack selection a bit, when you say early Commodore, I'm guess everyone is referring to VB-VL?

Do any of the aftermarket assemblies have worthy/proper geometry? Just thinking of something a friend said yesterday and the possibility of using bags or something like a shockwave. I really think the money could be better spent elsewhere, but it should at least be investigated properly, or is that lets overthink it a bit too much...

[jeffa]

Hi Mick.

The Holden front ends have been discussed many many times on this forum in the past. Have a search - it's all there.
They are a very simple fit. The donor cars are similar weight and size to your 38, so the Engineer will be happy he can sign it off without too much investigation.
The stock 6 cylinder springs will probably be ok (I have a set of lowered HR springs in my 36 roadster and they are way too soft).
The beauty of using standard springs is that they will most likely come with the front end and so are free. So you get the car on the road fairly quickly.
Then, if you desire, you can go with bags.
Racks: I went the modified Commodore manual rack route but found that it has about 5 turns lock to lock. It takes forever to steer the thing! Many old-time rodders used Morris or Austin/MG racks. I changed the rack in my 36 to a MG type. 2.5 turns lock to lock. Manual - no power assist and I can easily turn from lock to lock with the car stationary. They are so light you dont need power steering. There's only two issues: They need modifying (so does the manual Commodore rack) and they are getting scarce.
Keep us posted whichever way you go. Its your car, build it your way. The guys on here are very supportive no matter which way you build it.

[Chrisso]

What jeffa said Mick, my Pilot which isn't a big heavy car but still substantial is fitted with a HG front end and HQ discs, the steering is a manual VL commodore rack (adapter from V6 conversions in Moree) and I figure that a manual rack is better than power as it isn't a truck and with the 302 Clevo under the bonnet there will be limited space and frankly it isn't needed as I said before. I used 6 cylinder lowered heavy duty springs and it sits about right and will handle the Clevo with ease. That's just some info from my build that may help. Mine are not expensive parts readily available and not expensive so it suits me fine and best of all it functional and most important it is super safe.
I hope this helps

[mick_in_oz]

Thanks jeffa and chrisso,

I have access to a HT front end for free, and I have a mix of spindles etc from all the years of playing with the hatchback, so would have most of the configurations covered with the Holden front end. I'm just very conscious of the limitations of the Torana front end, and can't see the earlier HKTG being much different and thought it best to ask a bunch of questions.

I am kind of sure the HKTG front would work for me, and would ride nice, I just still have a question mark over outright handling. But as I have read numerous times, many of the aftermarket offerings seem to do more about looks rather than handling, to the point of some of them being far worse than an original.

Appreciate every ones feedback, time to get the tape out and start looking at a few things I imagine.

[Chrisso]

Thanks jeffa and chrisso,

I have access to a HT front end for free, and I have a mix of spindles etc from all the years of playing with the hatchback, so would have most of the configurations covered with the Holden front end. I'm just very conscious of the limitations of the Torana front end, and can't see the earlier HKTG being much different and thought it best to ask a bunch of questions.

I am kind of sure the HKTG front would work for me, and would ride nice, I just still have a question mark over outright handling. But as I have read numerous times, many of the aftermarket offerings seem to do more about looks rather than handling, to the point of some of them being far worse than an original.

Appreciate every ones feedback, time to get the tape out and start looking at a few things I imagine.

Mick I've been in a few rods with Holden and Jag front ends and IMHO for the money saved and the ride/handling Holden wins out every time, mind you as I stated this is only IMHO.

[rx4ord]

Happy birthday Mick.
Now how is progress on the coupe going?

Tassie Dave

[monte]

Just had a read of this old post and Mick I have fitted a HT front end in my 34 RPU and is on the road now ,love it ,the car rides great and at 100kph I can let the wheel go and it steers as straight as an arrow ,would never go back to the old 4 bar beam axle set up on my old rod like it was fine in the end but it took a lot of setting up and changes to get it right ,lot of good info from Col and lots of others on here helped too ,I have a shortened Commodore rack and yep it has about 4.5 turns from lock to lock which is a bit of a pain and Ann has trouble with it as she is used to power steering in our BF ute ,I am looking at the electric power column you are talking about to solve the problem .You can forget the Air bags if you are going through the QLD TAC as they banned them ,last car with them was Blown36 and he just made it

[steve the ford guy]

Anyone know if HK rebush kits will fit HT/HG front ends?. HK frontends are supposed to have more longevity without the rubber bushes, haven't seen anyone ask this yet.

[pilot48]

The hk bushes screw on a very course thread on the inner pivot shaft and into the A arm the ht-g rubber bushes have a sleeve that slips over a smooth shaft and press in to the A arm and are held in with a bolt and large washer
Charlie

[monte]

Anyone know if HK rebush kits will fit HT/HG front ends?. HK frontends are supposed to have more longevity without the rubber bushes, haven't seen anyone ask this yet.

No they will not fit

[Oldcol]

Anyone know if HK rebush kits will fit HT/HG front ends?. HK frontends are supposed to have more longevity without the rubber bushes, haven't seen anyone ask this yet.

...as stated,no won't work at all . The HK is a stand alone design,the last of the steel bushed front end style that came out in mid HD. For HT and G they did a revamp using rubber bushes , trying I think for a bit of isolation from road noises...or maybe just a bit of cost cutting?....hard to say and the boffins from GM never did say why, just gave us the new spec sheets and a bit of the usual rah rah talk bullshit ...anyway,they were a fucking disaster, the rubber was too soft and would chop out before the 10,000 mile warranty was up. Worst affected were the V8 cars due to the extra weight. Somewhere along the way they revised the compound and things were better,but they never ever were as good as the HK units which would last indefinitely if you kept them greased. They are also supposed to be set up with negative caster,theory being that the forward motion of the car would pull on the bushes and the control arms would go into positive caster as a result. That's why you don't mix upper and lower control arms as many folks do....the other very negative consequence of the rubber and the movement is, HT/G don't like wide-side out wheels or even very wide tyres....makes them very twitchy and they don't track well. So...if you use an HT/G, try and get hold of genuine GM rubber bushes ( near impossible now) as the plastic junk bushes tear themselves to bits real quick and they are not nice things to replace, very messy and destructive to nicely painted arms. Maybe the Rare Spares rubber bushes are OK, but most of their rubber parts are disappointing, so I wouldn't bet on it........and don't put big fatties on the front or it will be a turd to drive......

[steve the ford guy]

Good to understand the differences between them, thanks Col

[mick_in_oz]

Hi ALL, not sure why, seems I'm missing out on getting notifications on the thread!

Thanks for the Bday wishes!

Not lots happening to date, well its seems like not a lot has happened... Too much chicken and egg stuff, can't do this till ya have that, cant have that till ya this or the next thing, I'm sure everyone went through this the first time they thought, "Oh, I'll build a Street Rod" I think too much, often far too much, prefer to do it properly the first time and hate redoing things, but I've realized that I simply needed to start, rather than keep on looking at it!

Car mostly gutted, only the tar paper sound deadener left to remove, but the inside in empty, doors empty, floor bare, and firewall and some of the floor relieved with a motor and box sitting on crude temporary adjustable mounts assessing how much to cut out and where things will fit nice. Sorting measurements for the chassis work, how deep the chassis bracing will be, how much extra rear kick up is needed to have it sit where I want.

So, early next year will see a final decision on the type of front suspension and finally some action on construction rather than just pulling stuff apart and doing research!

Couple of things...

Airbags, yup, QLD TAC hate em, even seem to hate even hearing the word, got am abrupt email reply about using them!

BUT, only due to a job at work and needing an ADR approval as part of a job we were going, I got talking with the guy doing the ADR inspection and documentation and Hot Rods and the ASRF came up and he commented he hated their head in the sand approach, and that he didn't see an issue with doing the car as a "Modified Production" which would see it finally fitted with a QLD Transport Blue Plate! Airbags, yup easy if you fit the right system, the guy does air systems as part of his business. There are some freedoms that you loose by not going the ASRF route, like forced induction is kind of difficult or simply out, but for cars that many people would build, a stout cruiser and reasonable HP, then its the old power vs weight calculator and you're good to go.

So I'm seriously looking at that route, and, its less than the half the cost as far as the approval process is concerned.

I should ask this in another thread, or keep searching the archives, but, anyone want to tell me what Tubing everyone is using for the centre Chassis bracing to achive the 34mm minimum Dia, seeing as 25NB is actually 33.7mm OD! Thoughts and suggestions???

[47chevyvan]

if you go with the HG HT front end use the rubber bushes not the nylon ones i put the nylon one in and had to replace them all to stiff and hard for road work good for track work !! i think my old DODGE still has the rubbers in it ?? they work fine and a lot cheaper in the long run ! you can replace a lot of rubber bushes for the same money as one set of nylon ones !!

[monte]

Mick the TAC are governed by the TMR and they were told no more air bags in hotrods ,end of story .I cant really comment on the modified production blue plate idea but to say I have been the road with the TAC on a few cars now and I found the system is simple and inexpensive ,considering we live in the bush like you and the Inspectors have to travel ,even better if you can get a few cars to be done together anyway good luck with the build and always some good advice on this forum