DRB spring rates

Rossba · #1 (**permalink**) 12-29-2013, 04:42 AM

What spring rates have people found to work best?
I have 200lbs in the rear and 650lbs in the front.
The front feels to hard and the ride height is high whilst the rear is lower and scrubs the tyres on bigger bumps.

Just checking what I have compared to others.

Tim Brewer · #2 (**permalink**) 12-29-2013, 08:16 AM

Your spring rates are way off. I don't know if you have a small or big block, but a good start would be 300-325 for the rear and 375-400 for the front.

Gav · #3 (**permalink**) 12-29-2013, 01:54 PM

Tim, unless you have a US built DRB with US Torana suspension how could you know?

Towmaster · #4 (**permalink**) 12-29-2013, 03:36 PM

Quote:

Originally Posted by Rossba

What spring rates have people found to work best?
I have 200lbs in the rear and 650lbs in the front.
The front feels to hard and the ride height is high whilst the rear is lower and scrubs the tyres on bigger bumps.

Just checking what I have compared to others.

Must be Jag suspension? Mine is Torana so that information is useless... Did you ring DRB?

Towmaster · #5 (**permalink**) 12-29-2013, 03:48 PM

Actually I just saw a photo in another thread, yep Torana..... Just use the factory King Springs as specified by DRB. I have a set of the original taller rear springs if you want them, only had them on the car for a month or two. I wanted mine as low as possible so got the lower ones that you prob have.

Towmaster · #6 (**permalink**) 12-29-2013, 03:50 PM

Another option if you just want to raise the ride height at the rear by about 10mm to stop it rubbing just buy a cheap cutting board (plastic) and cut out a spacer with a jigsaw. Trust me, it works.

Rossba · #7 (**permalink**) 12-30-2013, 05:15 AM

Thanks Towmaster

The springs in the DRB build book state, king spring part numbers are KHFL-14

front, KHRR-12. The car came with KHFL-14 650lb KHRL-12 200lb so the rear springs are lowered instead of raised.

Are the ones you have standard height or the raised height? Part number maybe?
Wouldn't mind trying them, if you want to sell them let me know a price.

Cheers Ross

Tim Brewer · #8 (**permalink**) 12-30-2013, 07:57 AM

Relax Gav..... I didn't say I knew, I only suggested what should be a good starting point. Last I heard, a pound equals a pound on all sides of the earth. So unless a shock is canted, 650#'s is fairly stiff for a street car.

Towmaster · #9 (**permalink**) 12-30-2013, 08:20 PM

I don't have the springs here but the rear ones I had were raised and stiffer so the rear was really tail happy. I put in the ones you have on the car and it fixed a lot of the over steer problems. Check the King springs website, there are 6cyl versions that would have a softer ride but don't know about the handling. You really want to keep it reasonably stiff in the front and softer in the rear or you will have problems keeping the tail in line around corners. I will try and get some part numbers for you.

Legless · #10 (**permalink**) 12-31-2013, 03:01 PM

Hi Ross and Ash,
Good topic Ross, I'm pretty confident that there would be a few more people keen to know your spring specs Ash, including me.

Rossba · #11 (**permalink**) 01-01-2014, 12:38 AM

Thanks Tim,

I agree the front is to hard and looking to sort it out.
I have a small block and the shocks are in the middle of the spring.

Cheers

Ross

Rossba · #12 (**permalink**) 01-01-2014, 12:47 AM

Towmaster,

I was tinkering with the rear end today and noticed the tag on the spring was KHRR-12.
So i have the raised ones, probably the same as the one's you took out.
Dont know how low you got yours without rubbing as mine rubs on the inner guard and outer.
I jammed a piece of 20mm box tube under the spring to get some measurements and the ride height still looks good so I am going to try and make the chopping board spacers as you suggested and do some test driving.

Once I get the spring rate right in the front it may be lower.

Do you know your front spring rates?

Cheers

Ross

Towmaster · #13 (**permalink**) 01-01-2014, 04:08 AM

I think my fronts are a KHFSL something.... Front Super Low... I know they were the ones recommended in the build manual by DRB... Nothing special really. They are the original springs I put in the car in 2001....

Rossba · #14 (**permalink**) 01-01-2014, 05:04 AM

The King catalogue doesn't list any superlow for the Torana so the numbers on the end would be good.
K is for King H is for Holden F is for front SL is for super low and the number determines what car they suit.

Are you happy with yours now?

Towmaster · #15 (**permalink**) 01-01-2014, 08:45 PM

They didn't list the super low because they are too low to be legal I think... I will have to try and find a part number on them. They might be too old for that. I looked through my receipts and can't find a part number on that either. Happy with mine, I adjusted the sway bar back to 27mm and wound the shockies off a little and have a road tyre on it now so it rides a lot better, still rough on our Qld rough potholed roads.

Towmaster · #16 (**permalink**) 01-01-2014, 08:48 PM

Also depends what body shape yours is... What chassis number is yours?

Rossba · #17 (**permalink**) 01-02-2014, 02:08 AM

My chassis number is 194.
I couldn't get the sway bar on mine because the sump is in the way so would be interested to see what you did with yours.
What shocks you using front and rear?
My assembly book states the superlow which is what I have.
The number at the end of the spring part number stipulates what car they are for so it got me thinking if they changed the specs later and used a off the shelf spring from a different car. I know pedders can do that.
You may have a later chassis than me and/0r run the watts link.
Glad you have yours sorted to a stage that you are happy with.
Don't think our roads are better!

Rossba · #18 (**permalink**) 01-05-2014, 02:35 AM

Made up some spacers to try the height.
Will see how 20mm goes.

Towmaster · #19 (**permalink**) 01-05-2014, 04:59 PM

Quote:

Originally Posted by Rossba

My chassis number is 194.
I couldn't get the sway bar on mine because the sump is in the way so would be interested to see what you did with yours.
What shocks you using front and rear?
My assembly book states the superlow which is what I have.
The number at the end of the spring part number stipulates what car they are for so it got me thinking if they changed the specs later and used a off the shelf spring from a different car. I know pedders can do that.
You may have a later chassis than me and/0r run the watts link.
Glad you have yours sorted to a stage that you are happy with.
Don't think our roads are better!

Yep. Mine is chassis 250 which means I think the rear suspension is a bit different. I am not sure when they changed the rear upper mounts for the rear suspension. Yours also doesn't have as much wheel arch flare as mine does which is probably why it is rubbing. Also your body will sit lower over the chassis than mine. Mine is the 'efi' body so it has bigger front and rear flares and the body is 25mm higher on the chassis to allow fitment of the efi manifolds. The front springs will be torana and I think the rear are HQ.
I am off to Japan skiing for 10 days tomorrow so I won't get the chance to pull it apart to have a better look to compare. Send a PM to TUF427, he is more of the 'guru' than I am. He has the same body shape as yours and runs big wheels so he may be of more assistance.

Rossba · #20 (**permalink**) 01-11-2014, 03:43 AM

Quote:

Originally Posted by Towmaster

Yep. Mine is chassis 250 which means I think the rear suspension is a bit different. I am not sure when they changed the rear upper mounts for the rear suspension. Yours also doesn't have as much wheel arch flare as mine does which is probably why it is rubbing. Also your body will sit lower over the chassis than mine. Mine is the 'efi' body so it has bigger front and rear flares and the body is 25mm higher on the chassis to allow fitment of the efi manifolds. The front springs will be torana and I think the rear are HQ.
I am off to Japan skiing for 10 days tomorrow so I won't get the chance to pull it apart to have a better look to compare. Send a PM to TUF427, he is more of the 'guru' than I am. He has the same body shape as yours and runs big wheels so he may be of more assistance.

Hope you had a good time in Japan and made it home safe. (jealous)
Interesting the differences you point out between your chassis and mine.
Would be fun putting them together and play spot the difference. lol

Mine had a 2" high scoop that I fitted then had to raise it 2" further to stop the engine hitting the bonnet. Looked stupid.
After engineering I looked into it better and calculated that if I drop the engine 2" and move it back 3" I could get all of it under the bonnet without any scoop. So I did that before paint and worked out pretty well.
Another issue I had was the exhaust hit the side of the tunnel on both side when the engine still had 1" to drop further. Had to cut the side panels out, reshape them and weld them back in on the inside of the box tube. This gave me enough room to get my hand between the pipes and tunnel.
Even now that I have moved the engine back there is still room. And no scoop, ya.
Check out some before and after pics.
I made up these spacers to try and see what difference 20mm makes.
Done about 150kms so far and no scrapes. I am still happy with the ride height appearance and it works better.

I am spending the day on Tuesday with a retired suspension technician from Ford Geelong who has offered to help weigh the 4 corners, calculate the unsprung weight, calculate the spring rate for each corner and shock rate.
He is then keen to come to Winton raceway with us a work on the over/understeer.
Looking forward to learning a lot and sorting the car out.