Road Clearance Issue

I took delivery of my GT40 Mk2 (P/2171) in April of 2008. I live in Maine and travel the roads of Southern Maine and Central New Hampshire. Many of these roads can be unforgiving in terms of left over frost heaves, dips, and uneven pavement.
I always attempt to be cautious and avoid road hazards but regret to say I've nicked-up and scraped the underneath nose of the front lid.
The car was delivered with the following tires:
Front - Yokohama 225/50R15 91V ES100
Rear - Yokohama P295/50R15 105T AVID S/T

Here's my question.

What options, if any, exist to increase the road worthiness (get the car higher off the ground) of the vehicle?
For instance, perhaps: different tires, suspension modification.
Do all Superformance GT40s come delivered with the same extremely low road clearance, and there's no avoiding it?

Thanks,
Don in Maine
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
Your shock/spring steup is an adjustable coil over system and thus you can crank up the lock rings on the shocks for more road clerarance.

Be sure to re-check your alignment after raising the car.
 
Hi Don The roads in PA. Have the same issues, I haven't ordered these yet, But do plan on installing them over the winter. Home Wally
 
Don, two things come to mind:

1. raise the suspension somewhat as Rick says. I'd try 1/2 inch front and rear to start. In other words, move the lock rings on each corner 1/2 inch to allow for a slightly higher ride height. It would be best to get a four wheel alignment after adjusting up the ride height.

2. Perhaps consider a taller front tire. I have the same dimension tires on my GT40 as you except the fronts are actually a 60 series tire. A 60 series tire should give you about another 3/4 inch of clearance at the front. She rides a little softer with a 60 series tire too, which can be nice for street driving.

Cheers!
 
I agree with bill on the tyre size making a difference.
I went from 633mm dia to a 648 and my wife even noticed it when she drove it.

Jim
 

Seymour Snerd

Lifetime Supporter
Your shock/spring steup is an adjustable coil over system and thus you can crank up the lock rings on the shocks for more road clerarance..

Also make sure you actually have the intended ground clearance. From the owner's manual:
"Ride Height
Front 4.125 – 4.5 inches
Rear 4.5 – 4.75 inches"
Mine was set significantly lower than that from the factory.
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
Also make sure you actually have the intended ground clearance. From the owner's manual:
"Ride Height
Front 4.125 – 4.5 inches
Rear 4.5 – 4.75 inches"
Mine was set significantly lower than that from the factory.

The chassis' are not set at recommended ride height from the factory as the final ride setting will depend upon the type of engine, etc. installed and they don't know what it will be.

Ride height and alignment MUST be set after completion.
 
Hi guys,
I can see the suggested "Ride Height" on page 32 of the Owners Manual.
How is "Ride Height" determined? That is, where and what should I be measuring to determine my existing ride height?
After taking measurements once I know the answer to the question above, are the lock rings on the adjustable coil over system my only suspension option to increase the height?
Please consider that I am still a ROOKIE when it comes to things concerning the ownership of this vehicle; and I simply think my height must be too low.
Also, the lower joints on the front wheel stabilizer links (hope I have the terms described correctly) are approximately 1 1/2 inches off the floor. These two portions of the stabilizer that are just inside each front wheel, are the lowest thing on the vehicle. Is this normal?
I really appreciate the feedback. This forum is the only contact I have within the GT40 universe.
Thanks,
Don in Maine
 

Jack Houpe

GT40s Supporter
Taller tires is my vote, would be nice to have two sets, one for tract and one for street. This way you don't change the alignment.
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
Hi guys,
I can see the suggested "Ride Height" on page 32 of the Owners Manual.
How is "Ride Height" determined? That is, where and what should I be measuring to determine my existing ride height?
After taking measurements once I know the answer to the question above, are the lock rings on the adjustable coil over system my only suspension option to increase the height?
Please consider that I am still a ROOKIE when it comes to things concerning the ownership of this vehicle; and I simply think my height must be too low.
Also, the lower joints on the front wheel stabilizer links (hope I have the terms described correctly) are approximately 1 1/2 inches off the floor. These two portions of the stabilizer that are just inside each front wheel, are the lowest thing on the vehicle. Is this normal?
I really appreciate the feedback. This forum is the only contact I have within the GT40 universe.
Thanks,
Don in Maine

Yes,

The lock rings on the coil overs are the way to adjust ride height. The amount the rings are moved is not proportional to the ride height change, i.e. a 1/4" change in the rings is more then 1/4" on the chassis. It will take some trial and error to find the settings. ride hieght is measured at the lower point of the tub front and rear, that is the steel floor in front and the bottom of the horsecollar in the rear.

The front stabilizer bar links do normally hang down and are the lowest point on the chassis. We are working on a revised setup that would put the stab bar ends and link above the lower control arm but have not pwrfected or tested this yet. I'll post if it works........
 
The front stabilizer bar links do normally hang down and are the lowest point on the chassis. We are working on a revised setup that would put the stab bar ends and link above the lower control arm but have not pwrfected or tested this yet. I'll post if it works........

Elsewhere on this forum I've seen this problem discussed and fixed. I believe it was a simple matter of removing them and shortening them, but I can't remember it specifically now.

Where is that thread? :huh:
 

Seymour Snerd

Lifetime Supporter
Have current-production SPF cars addressed this issue or are they still requiring owner modification?

I don't know the answer to that question (Rick probably does).

However, since we're on the subject...

Looking at page S of the JWA parts book I see that the "original" attachment method is no different (in shape and parts type) although our lower rod end is rotated ~90 degrees about it's vertical axis. So, did the originals have the same kind of ground clearance to the lower rod-end and nut? Are we committing a crime against historical accuracy by "fixing" this? :)
 

Rick Muck- Mark IV

GT40s Sponsor
Supporter
I don't know the answer to that question (Rick probably does).

However, since we're on the subject...

Looking at page S of the JWA parts book I see that the "original" attachment method is no different (in shape and parts type) although our lower rod end is rotated ~90 degrees about it's vertical axis. So, did the originals have the same kind of ground clearance to the lower rod-end and nut? Are we committing a crime against historical accuracy by "fixing" this? :)

In a word...no and yes.

The factory still does it like FAV with the rod end hanging lower than the suspension arm. So yes, it is "original" and no, it is not a crime to change it as it is "bolt-on" modifications that can be returned to original configuration if desired.

And no, I have no idea why Broadley/Ford/FAV did it that way.
 
And no, I have no idea why Broadley/Ford/FAV did it that way.

It's great that the SPF chassis replicates the original. Having only glanced at the underside of originals, I can't recall them having such low-hanging fruit, as it were. So the question remains--does the SPF model the original perfectly, or are they using too-long rod end hardware which forces the bits to hang lower than originals?

In other words, is the modification described above bringing the car in line with historical accuracy, as well as practicality? Or does it represent a deviation from original, for the sake of practicality?
 

Terry Oxandale

Skinny Man
Onless one were trying to avoid snagging a turtle, isn't the this clearance issue with the linkage a non-issue in that it will follow the road contour much as the tire?
 
Onless one were trying to avoid snagging a turtle, isn't the this clearance issue with the linkage a non-issue in that it will follow the road contour much as the tire?

Yes, however there is real danger of damage, at least in my part of the world, from dropping a front wheel in a pothole or other similar depression.
 

Dave Hood

Lifetime Supporter
A partial solution would be to install a hydraulic lift system on your front springs. I had Dennis Olthoff install a RamLift system (Home) on my MK1 and it at least helps me address potential issues when I'm pulling into driveways, crossing railroad tracks, etc. The kit was around $1,800 and I'm sure I've saved that in bodywork to this point. The kit raises my front end by about 2 inches.
 
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