RCR GT40 FRONT WHEEL CENTERING

[STEVE71]

hi gang , i m new on the forum i buy a gt40 from rcr40 i try the fit the front end and i realise the front wheel are not centered with the body and they rub on the lower panel and fuel tank , somebody see this problem with rcr ? need help thks

 

[Bill Kearley]

Sounds strange, Check the install of your control arms.

 

[STEVE71]

rcr install the control arm , and i have no adjustement to play with

 

[Randy V]

Welcome to GT40s, Steve.
Unless you bought a “Turn-Key” or otherwise partially finished car from RCR, they”re typically only assembled in rough state to transport. It is up to the owner/builder of the car to assemble properly and align.
You will need to space the lower control arms as far forward in the pockets as they will go in order to get the wheelbase set properly and to get the positive castor angle. Numerous build logs in the build log forum as well as my own online build log and RCR’s manual will go over this.

 

[STEVE71]

thanks randy , but all ajustment is forward than i can , the wheel is not center of wheel arch , the rocker is 1 1/4 from the tire and its rub on fuel tank and the nose dont fit with the spyder , i make rough alignement and its horrible

 

[STEVE71]

hi gang , i m new on the forum i buy a gt40 from rcr40 i try the fit the front end and i realise the front wheel are not centered with the body and they rub on the lower panel and fuel tank , somebody see this problem with rcr ? need help thks

Welcome to GT40s, Steve.
Unless you bought a “Turn-Key” or otherwise partially finished car from RCR, they”re typically only assembled in rough state to transport. It is up to the owner/builder of the car to assemble properly and align.
You will need to space the lower control arms as far forward in the pockets as they will go in order to get the wheelbase set properly and to get the positive castor angle. Numerous build logs in the build log forum as well as my own online build log and RCR’s manual will go over this.

 

[STEVE71]

 

[Rich Kruger]

Before you do any suspension analysis and or adjustments the car needs to be close if not exactly at it’s wet weight. Engine, transaxle, cooling system, fluids and weight in the drivers seat. The picture looks like an unladen chassis.

 

[Randy V]

Steve - you need to lift the suspension so that the lower control arm is perfectly level - this will be very close to where the axles will be at ride height. At that point, you should have the increased clearance you are looking for. Also - I don't know what size tires you are running on the front - I think I recall mine being very close and they were 225-60-15.

 

[Randy V]

This thread may well help you ---

General Build Help thread

Post your questions and answers about general build help here. This will help keep individual build threads centric to those builds...

www.gt40s.com

^^^^^^^^^^^^^^^^^^LINK^^^^^^^^^^^^^^^^^^^^^

 

[Chris Kouba]

Before you do any suspension analysis and or adjustments the car needs to be close if not exactly at it’s wet weight. Engine, transaxle, cooling system, fluids and weight in the drivers seat. The picture looks like an unladen chassis.

Better yet, find a flat floor, cut wood blocks to your desired ride height, jack up chassis, slip them under, remove spring/shock units (front and rear), and lower chassis onto blocks. Now you can align your suspension. THEN start your body alignment. It may be an iterative process if you have interference at the sills. Start as Randy indicates, with the lower arm all the way forward.

 

[Ryan L]

There is spacers that sit inside the suspension mounts at the chassis end that can be changed over to alter the spacing of the control arms on the chassis.
I know Jason Ferraro got some other ones made up for some reason. Photos were in his build diary at some stage.

 

[STEVE71]

Steve - you need to lift the suspension so that the lower control arm is perfectly level - this will be very close to where the axles will be at ride height. At that point, you should have the increased clearance you are looking for. Also - I don't know what size tires you are running on the front - I think I recall mine being very close and they were 225-60-15.

hi big foot , what do you mean when you say lca perfectly level ? and i have 205/60/15 front tire , when i drop the suspension the wheel come really close then the rocker something like 1/4 inch the tire rub evrerything .i mesure the center of ball joint to gas tank it give me 14 3/4 how is your ? thks

 

[STEVE71]

problem solve !!! i talk to fran he is a busy guy but take time to help thks

 

[Mike Pass]

One of the things we do, with race cars in particular is to centreline the car. This means marking a line down the centre of the chassis - usually on the bottom of the car as that is the flattest surface. This line can be drawn in several ways but usually drawn from the midpoints of front and rear suspension mounts. once this centreline is established then it can be used to measure to the location of any any point on the car relative to the centreline. The most important are the locations of the uprights and wheel centres. Very often the bodies in fibreglass are not accurate or symmetrical. In fitting GT40 bodies we usually fit the suspension first, taking care to adjust it so it is accurately spaced from the centreline. We then bolt down the spider and then fit the front clip to the spider. We then drop a plumb line down from the edges of each front wheel arch to see if the body is centred to the suspension position. If its is out we then unbolt the front of the spider and move to a new position by slotting the mounting holes and then repeat the plumb line test. This is done until the body is centred on the car. Usually very little movement on the spider is needed to get the front body centred relative to the centred suspension. Check the windscreen fit. The rear clip is done the same way.
Cheers
Mike