New A-Arm Kit

[Ian Clark]

Hi Guys,

I replied to Ray Maras' post about CAV Canadas new lower A-Arms http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/80694/an/0/page/0#80694 These are very cool and solve a lot of issues, check them out and give me a call

 

[JackW]

Do you know if they will be using these on the CAV's from South Africa? The side profile shot of, I think Bob Childress's guardsmen blue car is one of the most beautifully positioned in terms of wheel setting (IMO anyway) that I have seen. I personally love everything about the CAV cars except that weird wheel position - particularly at the back.

Cheers

Jack

 

[Ian Clark]

Hi Jack,

Autofutura has changed the rear uprights and lower control arms on new production. I expect the wheelbase would be adjusted at the same time. Bob has my arm's on his car by the way, getting the wheel into the middle of the wheel arch and more adjustability did it for him.

Cheers

 

[JackW]

That is excellent to hear. I was thinking to myself after my post last night that in fairness, a lot of the CAV photos I have seen have been of cars that have no engine in them which I am sure, when added, would drop the back down a bit.

Regards

Jack

 

[Jean]

Hi Guys
Just to confirm that the chassis #100 and further runs with our new suspension, and needless to say all the components are of the best quality and design.The work that Ian is involved in , would be a upgrade for the pre #100 cars.
Attached photo showing the CAV GT stance.
Please contact me if you need further information or specs.
Regards
Jean

 

[Jean]

and another side view...

 

[Bill Musarra]

Jean,
Are my eyes playing tricks on me, or these 2 cars are setup differently. Are the aspect raios different on the two cars? Is the suspension setup different with the yellow car sitting lower? Maybe the rear clip is different? Kinda looks different in the second photo in that the wheel arch looks higher??? I love the way the yellow car sits. Looks much racier than the blue car.
With the setup of the yellow car, are the spring rates stiffer for less wheel travel? Any fender rub issues? Just curious.

Bill

 

[Jean]

Hi Bill
Fair question. The yellow car is built with Race-spec....wide tail and lowered suspension. The wheel does not touch the arch.( 12" wide rims at rear. Second car is standard road spec, standard tail, 10.5" rims. ( 408 producing 565hp...) A beast!
Jean

 

[Strobe]

Bill,
I am sitting with chassis 109 three after Johann's blue one here. I have the new chassis/std body and 10.5" rims with 335 at back onn 600lb springs on the back with the CAV std. spring spacer. I have messed with the setup with Jeans guys and can get the 40 to sit right down in the arch with good ample shock travel capacity. I have excellent clearance in the arch and no experience of rubbing. What you see here is my compromise position to handle all the bleedin speed bumps in my street.

Would be interested to find out what is peoples perception of correctness wrt ride height....

Cheers

 

[Ian Clark]

Hi Steve,

Ah, the speed bumps! Ride height is like "limbo" how low can you go? 4" would be the minimum used on GT40 race cars in the sixtes. Our cars are happier on the road and over the bumps with 4.5>5.0" especially when running larger than 24"dia. front tires. Here's a pic of Johns right hand drive car, the first equipped with the new arms. Is that beautiful or what

Cheers

 

[Ian Clark]

Another pic from behind, note the vents above the tailights, nice touch although we elected not to cut out the licence plate recess.

 

[David Briggs]

I have installed this kit on my car, it worked out very well, suspension moves more freely and the wheel is centered in the well. I removed the spring spacer from the shock and now the ride height is correct. It is way quicker and easier to adjust the rear toe. All in all worth the price of admission.

 

[Bob Childress]

Hey Ian,

Even your up grades have upgrades!! Nice looking pieces.
I have the CAV-Canada A-arms on my car also and they are sure the key to easy alignment and precise set up.

Here are my questions.
What front and rear caster, camber and toe-in settings would you recommend for use with these parts?
Are there any alignment tricks or helpful procedures you have found?

Keep up the good work, you are a huge asset for CAV owners.

Bob

 

[Bill Musarra]

Steve
I would be interested in some upclose photos of your suspension setup, wheels and tires. I would like to know all the numbers associated with your wheels(back spacing and others) and tires as I want to use the 335s as well on my DRB. I would like some body and suspension measurements as well, like from edge of wheel arch to opposite arch, wheel hub to oposite hub etc. As my car is an older one, I am having issues with trying to get the proper wheels and tires to fit under my arches without rubbing and having to send the wheels back and forth to the manufacturer.(I have the Gulf flares)
The other question I have is your spring rates. 600!!! I was under the impression that 300-350 was about what was needed to give good ride control and not shake your teeth out. Since all the coil overs are adjustable, the ride height is just a user referdnce. No?

 

[Ian Clark]

Hi Bob,

Thanks and as for alignment, if it's primarily a street use car with occasional lapping days, I'd go 1/16" total toe-in front and rear, half a degree negative camber front and rear with four degrees castor front and three degrees rear. Of course you should set the ride height with the sway bars disconnected before going for alignment settings.

This would be with the car weighted to operating conditions as in ballast for gas and driver/passenger in. Disconnect the sway bars and set your ride heights. If your front tires are 25" dia or larger then 5" is about your miminum ride height, the back should be a quarter inch higher. Now set your alignment then reconnect the sway bars, adjust the drop links to eliminate any preload tension on the sway bars.

For the track it's zero toe up front, one degree more negative camber front and rear, crank up the shock stiffness and hold on tight!

Cheers

 

[Pat]

As a reference, the original CAV factory settings were:

Castor 4 degrees
Camber front 1/2 degree
Camber rear 1/2 degree
Toe-in front 1/2 degree

I've done a number of laps and based on tire temps, these are pretty close. I tried going to zero on the front toe-in and the squat under hard braking was too unstable over about 140 mph.

 

[Bob Childress]

Veek and Ian,

Thanks for the alignment and setting numbers.

I agree with Veek that the ultimate criteria will be driver impressions of performance handling and the temperature spreads across the tire treads. I am a proponent of getting stability by setting up a car so that the relationship between control input and car response is very linear. As a result, my cars tend to be tight as opposed to loose and twitchy. I can already tell you from previous experience with Ian's A-arms that being able to set caster in the rear uprights made a noticeable difference in straight line stability. I plan to start Part VI of my CAV modification thread tonight or Monday and I will use these initial settings. Hopefully I will get my car back on the street this week and to the track at the first opportunity.

Bob

 

[Strobe]

Bill
I will post some photos but to answer some of your questions,

The springs are as metioned 600lbs running on the SPAX for the GT, uncompressed 197mm and 172 under load, spacer 20mm and 5 threads exposed to the lock nuts. Right now (because of speed bumps) I am running with tyre top 45mm beneath the wheel arch. Correct me if I am wrong but assuming you are running the tyres close to the edge you want very little compressive movement to avoid impacting the arch. Ths is kind of why I chose the 600lbs.....But the cost of springs wont prohibit changing as required.

The distance from the outside of the bevel on the knock on to the outside of the upper arch is 95mm from the same point from the knock on adapter to the inside wheel arch bulkhead is 270mm.
The distance from inside bulkhead to upper wheel arch inside is 365mm. The distance from the inside of the wheel to the inside arch is 80mm.

The car clearance I am running is 112mm and the tyres are 335/35 17's

Let me know what else you need
Steve

 

[JCoop]

After installing CAV Canada (Ian's) lower arms kit, and machining the shock spacer/spring perch to 1/2", this is how she currently sits at the lowest setting. Still about 1.5" high for me. Shock's already sitting on the rubber bump stops.

 

[JCoop]

Shorter spring perches

After machining spacers...