What causes heavy steering at racing speeds
- Thread starter Russ Noble
- Start date
I have not compared either.
I have owned 2 escorts but that was a few years ago so you may be wright there Tim.
Cortina upright so it may be the same doner.
If you take the lock stops out that have been put in to reduce travel it has about 4 turns lock to lock.
Jim
I have owned 2 escorts but that was a few years ago so you may be wright there Tim.
Cortina upright so it may be the same doner.
If you take the lock stops out that have been put in to reduce travel it has about 4 turns lock to lock.
Jim
Ross Nicol
GT40s Supporter
Yes definitely an early Cortina rack, I have a spare one just in case I need it. I also have an Escort quick rack and the linear travel for steering wheel rotation is the same as the Cortina.Funny isn't it there used to be a denial from RF that there were any donor parts in the car.
Ross
Ross
Ross, I agree, reduce the 6.5 down to the 4.5 so they are equal. If not equal you can get the feeling that turning one way is really easier than turning the other. I once had this on my car. At Goodwood it was a breeze going through St Mary's but every right handed corner was heavy work. But boy was I quick through St Mary's. So much so I did consider staggering the car the other way but in the end I kept things equal.
By going back to 4.5 degrees you have a starting point that is fairly typical and you still have the option of loading it up by increasing back towards 6.5 as necessary. Also under braking did you find the car pulled up straight or was it trying to pull to one side?
I would be optimistic that sorting this unequalness out will give you quite some improvement from where you are now.
By going back to 4.5 degrees you have a starting point that is fairly typical and you still have the option of loading it up by increasing back towards 6.5 as necessary. Also under braking did you find the car pulled up straight or was it trying to pull to one side?
I would be optimistic that sorting this unequalness out will give you quite some improvement from where you are now.
Lynn Larsen
Lynn Larsen
Good Stuff! I am really enjoying this thread
Trevor, I caught the idle speed question and couldn't wait to hear the explanation !:squint:
Chris (Flatchat), I second the motion that you share some of your experiences with setting up the DRB for the track! I am assuming that you were using 'Vette front uprights.
Thanks to all contributors, :bow:
Lynn
Trevor, I caught the idle speed question and couldn't wait to hear the explanation !:squint:
Chris (Flatchat), I second the motion that you share some of your experiences with setting up the DRB for the track! I am assuming that you were using 'Vette front uprights.
Thanks to all contributors, :bow:
Lynn
Howard Jones
Supporter
Frank, I was wondering if you have the specs/data for a standard GTD front upright laying around somewhere.
A drawing of the granada upright would be really useful.
I had the camber change data and if I can find it, I'll post it. If I remember correctly it wasn't too bad (camber change) and so I started my program at the rear of the car where it really is excessive and these cars really need some help.
If you can help with this, Thank you,
Howard.
A drawing of the granada upright would be really useful.
I had the camber change data and if I can find it, I'll post it. If I remember correctly it wasn't too bad (camber change) and so I started my program at the rear of the car where it really is excessive and these cars really need some help.
If you can help with this, Thank you,
Howard.
Russ, funnily I have been out in a car with "my" suspension set up this afternoon on public roads, giving a demonstration ride to a Swiss friend.
At all speeds the steering is delightfully balanced and very light, the car runs straight and true with hands off the steering wheel completely at over 120mph, turns in with total accuracy and driver confidence, no bias to over or understeer at all -- just perfect. On the track it has exactly the same feel, its just so easy to drive. I must give all credit to Ray Christopher who started me on this fairly radical route, he has no fear of being considered conservative either. Frank
At all speeds the steering is delightfully balanced and very light, the car runs straight and true with hands off the steering wheel completely at over 120mph, turns in with total accuracy and driver confidence, no bias to over or understeer at all -- just perfect. On the track it has exactly the same feel, its just so easy to drive. I must give all credit to Ray Christopher who started me on this fairly radical route, he has no fear of being considered conservative either. Frank
Howard, first area to consider for your car is changing the length of the lower rear A arm, the rest will follow.
Ahhh Frank...... That's no challenge!! Who wants a car that's easy to drive? Takes away all the excitement and surprises! It's much more satisfying to tame an unpredictable wild beast than it is to lead Daisy the affable house cow. 'course with Daisy you might live to tell the tale.........
Trevor, are you suggesting the problem could possibly be something basic like the inclination of the roll axis? Possibly another problem generated from the rear of the car?
I take the point about idle speed, if it's too low it makes the car more difficult to drive around the pits:lol: That's why I went for the Ackerman instead, along with the overpaid pit crew:lol: .
Cheers
Trevor, are you suggesting the problem could possibly be something basic like the inclination of the roll axis? Possibly another problem generated from the rear of the car?
I take the point about idle speed, if it's too low it makes the car more difficult to drive around the pits:lol: That's why I went for the Ackerman instead, along with the overpaid pit crew:lol: .
Cheers
Noble, I hope your suspension geometry is not as warped as your sense of humour!! Archaic /Geriatric/Overpaid pit crew indeed- keep this up & Lim & I will jump ship to help Ross @ SFOS.
Can anyone confirm that the RF upright is modeled/borrowed from the Holden HQ/HZ series, if so I have dwgs somewhere from the old HQ race series when I was Tech Steward of the upright with angle's etc.
Jac Mac
Jac mac
It is a cortina TF -TE, they have 6.5kpi
part # 77BA3108AA are cast into knuckle.
They are not clear but I would say this # is OK.
Jim
It is a cortina TF -TE, they have 6.5kpi
part # 77BA3108AA are cast into knuckle.
They are not clear but I would say this # is OK.
Jim
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Ron Earp
Admin
The front uprights and spindles that were on my RF kit were clearly stamped "Ford" with the oval, that is, they were a stock Ford part. I think that jive's with Jim in it being a Cortina part with the Ford part number.
Ron
Pete McCluskey.
Lifetime Supporter
Yeah but there are some that sure sound stupid, like - Idle speed?
Tim.
Well here may be another dumb one. What is Akermann?
Ross Nicol
GT40s Supporter
I presume Trevor's Idle speed remark would be answered like this- If the idle speed is high when coming into a slow corner then the rear will be pushing you through the corner, much like a limited slip diff with a high breakaway or welded diff, makes it hard to turn the car. Pete - Ackerman is where the inside wheel is set to turn more sharply than the outer wheel in a turn. Been around since horse and cart days and said to work because the inside wheel travels along a shorter radius than the outside wheel.The reason for the Russ Noble/JacMac spat is that a car with Ackerman is easier to push around the pits and JacMac is nominated as Russ' crew chief.Now who was it that said "that's what motors are for" we are not allowed to start race engines till 9am at Phillip Island and similar at other circuits so a lot of pushing does have to happen.
I have 2 spare RF uprights Ford # 77BA3107AC 2.
My 2nd and 3rd piece of Data - upright steering pivot axis to tie rod attachment 125mm. I can take pictures if it helps.
King Pin Inclination- I measure 7.5 degrees but I could be out by a degree.
Ross
I have 2 spare RF uprights Ford # 77BA3107AC 2.
My 2nd and 3rd piece of Data - upright steering pivot axis to tie rod attachment 125mm. I can take pictures if it helps.
King Pin Inclination- I measure 7.5 degrees but I could be out by a degree.
Ross
Ross Nicol
GT40s Supporter
Jac Mac
Upright weight 3.5 kg. I thought the only variation in Aussie Cortinas was when they dumped the heavy 6 cyl motor in it.Upset the handling apparently and never worked in the handling dept.
Ross
Upright weight 3.5 kg. I thought the only variation in Aussie Cortinas was when they dumped the heavy 6 cyl motor in it.Upset the handling apparently and never worked in the handling dept.
Ross
Ross Nicol
GT40s Supporter
Jim C - I got my spare uprights from a TC/TD Cortina I'm pretty sure the TE/TF being the later cars had different uprights and power steering racks.I have w/shop manuals for TC/TD.Sorry for 3 posts in a row I'm not totally on all cylinders yet today.
Ross
Ross
Pete McCluskey.
Lifetime Supporter
Pete McCluskey.
Lifetime Supporter
Ross, I found this on google, an interesting read It talks about slip angle and tyre load also..http://www.racing-car-technology.com.au/Steering Ackerman4.doc.
Pete, Hope your coming over to watch this showdown, you can bring your fancy trolley thingamys with you too, better bring a metal detector as well cos if it rains at teretonga with the mud/grass pit area you will need it to find them !
Ross, the first ( Mk 3 Cortina 6) from Aust retained the english front uprights, the Mk4 which I assume is the TE/TF had an Aust only front clip from firewall forward and was much heavier all round. Now this is an area of concern if your car has the earlier uprights fitted as the inner wheel brg is very small & will possibly deflect/ bend with the loads you are getting while racing.
Jac Mac
Ross, the first ( Mk 3 Cortina 6) from Aust retained the english front uprights, the Mk4 which I assume is the TE/TF had an Aust only front clip from firewall forward and was much heavier all round. Now this is an area of concern if your car has the earlier uprights fitted as the inner wheel brg is very small & will possibly deflect/ bend with the loads you are getting while racing.
Jac Mac
