Diff gears swap.

[DaveW]

Dave,
Whats your gear ratios?
I found heaps of T56 versions, some with 0.50 ratio 6th gear.
Whats your current rear tyres?

With the VE GTS and the Lower 1st gear of 3:01 in the TR6060, they raised the ratio from 3.91 to 3.70

[Aussie Mike]

Originally Posted by stiffy

Aussie,




That would have been when petrol was 95 cents a litre

STIFFY

Yep, and a fella would run out and pump the gas for you and wash your windscreen. Ahh the good old days....

[AC-460]

Try this calculator you'll now what speed you doing in each gear


Speed/RPM Calculator

[Rog246]

Originally Posted by Aussie Mike

Yep, and a fella would run out and pump the gas for you and wash your windscreen. Ahh the good old days....

Mike, if I remember correctly BP had a gingle that went "Windscreen,Water, Battery, Oil and your tyres! " and all the staff ran out in sparkling white overalls

But then petrol was about 1/6 a gallon so, thats errr $0.15 for 4.54 ltrs and I got about 5 bob for working pretty much all day Saturday for that !! LOL

[Aussie Mike]

Originally Posted by Rog246

Mike, if I remember correctly BP had a gingle that went "Windscreen,Water, Battery, Oil and your tyres! " and all the staff ran out in sparkling white overalls

But then petrol was about 1/6 a gallon so, thats errr $0.15 for 4.54 ltrs and I got about 5 bob for working pretty much all day Saturday for that !! LOL

One of my first after school and weekend jobs was working in a service station. That was when service actually meant something. Our overalls were brown. We would pump gas, wash windscreens, check and pump up tyres, check and top up oil and battery as required. All at no charge to the customer (except for oil top ups). The bell would ring as they drove in and we'd be out there to meet the customer. Everyone there took a lot of pride in their work (I know I did). I have to say I really enjoyed that job at the time. It beat doing a paper round hands down.

This was in about 1983. What happened in the years since....

Cheers

[Jaydee]

Boxy. My chassis number is 3169. What rack do they use. The one in mine is rubbing on the chassis. I'll have to space it. I have 4 piston jag calipers and 280mm disc. In depth manual? Not sure if 20 pages qualifies that, as in depth.
Some basic pictures. Do you prefer the high seats? I would like something safer and that holds me in better. What's rear bump steer?
JD

[Aussie Mike]

Bump steer is the change in toe as the suspension moves through it's travel. My chassis had about 40mm change in toe from top to bottom. You can check yours easy enough. Take a spring off a rear shock and move the suspension through it's full travel and you can see it plain as day.

Some info on some of my mods to the CR Rear end. CR Rear suspension mods

I make a bump steer kit that fixes the rear geometry with the stock arms too.

The 4130 track rod with rod ends and steel clevis replace the stock track rod on the AU arms. This works on full width and shortened rears.



It improves the rear bump steer no end. Here's the before and after graphs.



Sorry for the Hi-Jack David

[Tenrocca]

jaydee, space your rack 25mm, improves bump steer on the front and gives the boots a bit more clearance. consider putting extra mounting tabs below the rack as well. top tabs only not enough imo.

consider power steering. I drove one without and one with and its a no brainer.
cheers

[Jaydee]

So is yours power steering? Which rack are you using, and what mods are necesary? Are they really that heavy, without it?
JD

[Tenrocca]

vn or vl rack - cant remember. PS pump and lines of course. Different steering shaft and uni - get one off a commodore and modify

Not heavy without, just a lot more refined with.

[boxhead]

The CR uses the VL commodore rack, you need to shorten the tie rods and cut a new thread on them.
I do not have power steering currently, but it is something I am thinking of fitting.
Power steering is not needed to make the steering lighter, but is beneficial for circuit racing due to better steering ratio (less turning of the steering wheel).
My car is also square tube, chassis number 3181.
I also added a lower tab to steering rack mount for added strength.
The seats in my avatar picture are long gone, I had them for rego (to give required back rest length). I now have low back buckets with removeable headrest (headrest always removed)
This is my car now (at 2012 Shelbyfest)


And at 2011 Nationals hill limb.


Waiting in pits at Nationals, side view.

[gjkrv8]

Hi Jaydee, I have power steering on my "round tube" CR chassis and it is great. The rack we use in the later chassis is VP, so not sure if that suits Square tube or not. Also with 6-8 degree caster it tracks well and steering is not too light.
Rgds Gregg

[gjkrv8]

Dave, I want to some day move to 3.7 diff ratio as I find 3.45 too tall for take offs and around winton I found I was too high for 2nd and too low for 3rd on corners. rgds Gregg

P.S. I made up a neat Excel Spreadsheet for trye/diff/gear ratios etc that shows youo speeds in different gears at different RPMs. All you do is enter in the gear, tyre,diff ratios and it plots it out for you. PM me if you want a copy.

[Bruce M]

I have a 502 Chevy w/super T10 wide box 2.52 first gear w/3.70 rear. Great from the dg and lower revs on highway. Check the overall reduction w/your tranny.

[Modena]

I have put a diff/gear/tyre calculator on the CCCV club website;

http://www.cobracarclubvic.org.au/

Click on "Cobra Tools" in the left-hand menu bar