Going to Thunderhill in Willows this weekend

[Jerry]

Lemons race. If anyone is going, stop by # 67 a rusty looking Ford Cortina. We will have some fun, but they are putting too many people on the track these days. Keeps everyone slower, but some of those people are crazy.

Jerry

 

[Billm]

By "crazy" you are not referring to a weird VW beetle are you? (He is a friend)
BillM

 

[Jerry]

You mean crazy Mike! Of course not. I have raced with him many times. But there are some people that forget the race is for fun and cut you off or tap you. Even when they get black flagged, they drive the same. I am just out to have fun, so they can have the road if it is that important.

Jerry

 

[dougie]

I love the track, hope to get back there soon. Here's a view of the track after it rain all night a couple of springs ago. This is my morning practice session during the dry.
https://www.youtube.com/watch?v=YGqpo-PG9Zc&feature=share&list=UUKgBelHspm4MhfouAnzLrXQ

 

[Billm]

Jerry
Yes I did mean Mike- have fun and tell him that Bill M said Hi!

 

[Jerry]

Dougie,

I sent your video to one of our drivers that has not been to Thunderhill before. Good lessons. I like the track, even better than Infenion.

Jerry

 

[dougie]

Thanks Jerry, I got a new favorite track myself. I just got back from a 4000 mile trip to Elkheart Lake and Road American for their vintage festival. Here's nothing like a 4-mile road course.....
https://www.youtube.com/watch?v=jtdcyguUv5g&feature=share&list=UUKgBelHspm4MhfouAnzLrXQ

 

[Jerry]

Well, we did finish the race but had a few problems. The car was overheating, outside temps were 95-97. We had to take the grill off and remount the radiator fan to get more cooling. This may have had something to do with replacing two alternators over the weekend. The closest auto parts store was an Autozone and both only put out 13.2 volts which seems strange.
Crazy Mike did some off road racing in turn 1. One of out guys got off the track in turn 5.
One car caught on fire during the race, but the driver was already out and way.

Our Cortina can get enought speed but does not corner well yet. There is something wrong with the front suspension. We had it aligned but when you jack up the car the wheels toe out away from each other. So it is aligned when sitting on the tires, but as the suspension moves the alignment moves. I watched the guy align the car and the toe was correct, camber was minus 1. Castor was set at 1.25 per tire. Any ideas??

Jerry

 

[DRKizer]

Jerry, what you are describing about your front suspension is called "bump steer". Yours seems to be pretty severe if the toe change is that noticeable. Yes, it can make for evil handling. But the good news is that it can be corrected if you put your mind to it. Which model Cortina do you have? MkI? MkII? Do you know any Cortina gurus that may be able to tell you what you are up against to "bump steer" the car?

Cheers,
David

 

[Jerry]

While it is a MK 2, the front steering has been converted to rack and pinion via an english kit. We aligned as per instructions but it still has problems. Know any experts around Sacramento?

 

[DRKizer]

Hmm. Did that kit come with installation instructions that address bump steer? Or, are you just "on your own"?

The mounting point elevation of the steering rack is critical. The length of the steering links that connect the rack to the steering arms at the wheel hub is also critical (To completely neutralize bump steer, the steering rack may have to be either narrowed or widened between the inner ball joints in order to lengthen or shorten the steering links).

You may be able to get at least a feel for what will be involved. You have severe bump toe-in/ droop toe-out. Whether the steering rack needs to be mounted higher up or lower, depends on whether the steering rack is forward of the axle center line or aft of the axle center line. If the rack is forward of the axles, the rack would have to be raised. If the rack is aft of the axles, the rack would have to be lowered. As a wild guess from the severity you describe, the rack may have to be moved up or down an inch or more. You have to get the rack in the right elevation (trial and error) before you can begin to tell if or how much the length of the steering links have to be changed.

I've done a fair amount of bump steer work on production based race cars in my time. I'm located near Medford, OR and will be coming down to Sears Point to crew for a friend at the CSRG Charity Challenge, Oct 5-7. If you will be there, I'll be glad to look at your car and see if there is any more advice that I can offer.

Cheers,
David

 

[AngliaGT]

Jerry,

I think that your problems stem from converting to
rack & pinion.
I think that you need to conact Mike Drouin in Lodi.
He knows more about Cortinas than anyone in the Sacto area.

- Doug

 

[aeronca65t]

A decent example of bump steer can be seen HERE

Very basically, place your car on the ground and your tie rod should be approximately horizontal (when you are sitting on the ground looking back at the front of the car).
In order to achieve this, you may have to raise or lower your rack.

This is not a precise solution. There are a number of other factors with the suspension geometry.
But it should get you reasonably close.

READ THIS for a decent, simple explanation.

 

[Jerry]

Thanks group, this is interesting reading and describes the problem well. Now I get to take some measurements. I will try to find someone local to help. Our car is actually in Loomis CA. It was sitting on the ground in a field for years and the original steering was quite rusty. The "kit" we bought was from a guy who races in England and of course came with no instructions. We called him 3 times for more details but what we really bought was a triangle diagram with heim joints and found out that talking to him over the phone was not worthwhile.
The video is describing perfectly what is happening with the car. Makes for interesting driving.

thanks for the suggestions. If you have more, keep posting please. October 6th is out for us to meeting at Sears Point (or whatever the new name is).

Jerry

 

[Jerry]

Just wanted to give you an update on the Bump Steer issue. We bought some different end rods and were able to flip the connection to under the attachement arm instead of on top. This made the wheel and arm in line with the use of spacers. I also found a old wheel alignment tool that I inherited from my dad and used that to measure the toe changes as the wheel moves up and down. With a little adjustment of the spacers, there is now now movement! Much better. Now we are going to take it to a track test day at either Infinion or Thunderhill and see how it drives. We also were fixing the carb problems and had the opportunity to get the car on a dyno for free. The expert helping us had some changes in timing and adjustments which showed an improvement in horsepower of 18%. Not that it will every be a speedster but we will be entering the next Lemons race at Infinion in March and see how it does.
Thanks for the help!

Jerry

 

[dougie]

Nice improvements, keep us posted on your next outing.