GTR Body Alignment Tips
Discussion
On the edge of the subject, my new GTR project had an issue with the forward mount points for the front hood. On close inspection of the glassed in steel pivot bushings there was a large air bubble under the top layer of glass, in fact part of the bushing was not secured by fiber glass. We ground out the area and laid several layers of glass from the bushing out to the body. Lot of stress on two little points. lee
As the body comes from the factory it is pre-aligned and attached to the frame. Then we install all kinds of hoses and other such things in close proximity to the body be extra careful that you don't accidentally let the body touch something and be pushed out of alignment. until it is attached to the frame the center section is very flexible and will easily twist to go around a heater hose for an example that is partially obstructing the body frame fitment.
where the down braces from the rear shock to the cockpit roll bar enters the body a "seals it" brand flat rubber seal is worth the effort. A surprising amount of heat and noise can enter through that gap. Lee
where the down braces from the rear shock to the cockpit roll bar enters the body a "seals it" brand flat rubber seal is worth the effort. A surprising amount of heat and noise can enter through that gap. Lee
ROWDYRENAULT said:
As the body comes from the factory it is pre-aligned and attached to the frame.....................
What you say is true (I believe) for those kits crated for delivery abroad as it is the way the Factory can ensure it all stays in place during transport. Kits bought in the UK are only body aligned if you pay for it.I can only assume the basic body alignment has remained the same with the new Evo.
The build instructions talk of making sure flanges etc. do not have high spots in the layup GF but I don’t believe enough emphasis is placed on this as it will make a very big difference is wrong.
They also advise fitting all body panels including the front and rear clips and the wheels/tyres but I doubt many builders will want to be buying tyres that early in what could be a drawn out build.
Start with the side pods positioned as the build says but not fixed yet.
Position the body tub as far back as it will go with the GF down the front of the ali skin on the front bulkhead. You did remember not to fit rivets along the top edge of the front bulkhead skin didn't you? (Remove them now.. I’ll not tell). Make sure it is positioned hard back against the bulkhead and equal side to side. Once happy with its position you can drill a pop rivet hole through it into the top of the front bulkhead cross tube and secure the tub with skin pins. It fits over M6 studs sticking up from the top of the side pods. You may need to slot the holes in the tub to allow the tub to sit where you want it without influencing your alignment. They will have large washers fitted later so no issue.
With the front clip closed you can adjust its height, fore/aft & side to side to get the correct shut lines clip to front of tub and clip to top of side pod. It’s a pain in the arse to do and may take hours but is the only way to do the next bit of alignment.
Next is to see if the back of the clips ‘wheel arch/arc’ aligns with the ‘wheel arch/arc’ of the side pod front. If they don’t align you may have to bin the Factory dimension you started with when positioning the side pod. Sit down cross legged on the floor and look at the shut line ‘Front clip/Tub’, ‘Front clip/top of side pod’ and the arch alignment you will see that the clip is dimensionally fixed so if the other two parts are not correctly aligned now no amount of front clip realignment will fix it.
The top of the side pod can now also be moved in or out to align with the tub provided your slotted/enlarged holes were large enough. You can fit a washer and nut on the front stud of the side pod and nip it up to keep your alignment (use plain nuts as you may need to come back for another tweak).
Moving back you can now align the B post edge. Nothing special here as it is a straight line down the back of the door opening….but. Fit the rear clip and again adjust the shut lines. More hours later have a look at the shut line ‘side pod top/rear clip’ you are going to make life difficult for yourself if you try and make this too tight and there will be rubber buffers in there two. Now look at the joint ‘tub/top of side pod’ and you will see it looks odd as it is much narrower than the shut line alongside it so I make a spacer to fit between the tub and side pod and paint it body colour.
With the rear clip on you can align the side pod where it fits to a vertical plate on the chassis. If you just riveted it on it will likely pull the side pod in too far and not align with the clip so again you may need to make a spacer. The spacer may also be thinner top or bottom to get the alignment right.
Last part is how far in or out the bottom edge of the side pod is. The only alignment here is to get it vertical so just make sure the car is level first.
You were doing the other side at the same time weren’t you?
Now go around and check/tweak it all again.
Don’t fit/trim the doors until the windscreen is in.
Steve
Edited by Steve_D on Sunday 24th December 18:29
Steve_D said:
What you say is true (I believe) for those kits crated for delivery abroad as it is the way the Factory can ensure it all stays in place during transport. Kits bought in the UK are only body aligned if you pay for it.
I can only assume the basic body alignment has remained the same with the new Evo.
The build instructions talk of making sure flanges etc. do not have high spots in the layup GF but I don’t believe enough emphasis is placed on this as it will make a very big difference is wrong.
They also advise fitting all body panels including the front and rear clips and the wheels/tyres but I doubt many builders will want to be buying tyres that early in what could be a drawn out build.
Start with the side pods positioned as the build says but not fixed yet.
Position the body tub as far back as it will go with the GF down the front of the ali skin on the front bulkhead. You did remember not to fit rivets along the top edge of the front bulkhead skin didn't you? (Remove them now.. I’ll not tell). Make sure it is positioned hard back against the bulkhead and equal side to side. Once happy with its position you can drill a pop rivet hole through it into the top of the front bulkhead cross tube and secure the tub with skin pins. It fits over M6 studs sticking up from the top of the side pods. You may need to slot the holes in the tub to allow the tub to sit where you want it without influencing your alignment. They will have large washers fitted later so no issue.
With the front clip closed you can adjust its height, fore/aft & side to side to get the correct shut lines clip to front of tub and clip to top of side pod. It’s a pain in the arse to do and may take hours but is the only way to do the next bit of alignment.
Next is to see if the back of the clips ‘wheel arch/arc’ aligns with the ‘wheel arch/arc’ of the side pod front. If they don’t align you may have to bin the Factory dimension you started with when positioning the side pod. Sit down cross legged on the floor and look at the shut line ‘Front clip/Tub’, ‘Front clip/top of side pod’ and the arch alignment you will see that the clip is dimensionally fixed so if the other two parts are not correctly aligned now no amount of front clip realignment will fix it.
The top of the side pod can now also be moved in or out to align with the tub provided your slotted/enlarged holes were large enough. You can fit a washer and nut on the front stud of the side pod and nip it up to keep your alignment (use plain nuts as you may need to come back for another tweak).
Moving back you can now align the B post edge. Nothing special here as it is a straight line down the back of the door opening….but. Fit the rear clip and again adjust the shut lines. More hours later have a look at the shut line ‘side pod top/rear clip’ you are going to make life difficult for yourself if you try and make this too tight and there will be rubber buffers in there two. Now look at the joint ‘tub/top of side pod’ and you will see it looks odd as it is much narrower than the shut line alongside it so I make a spacer to fit between the tub and side pod and paint it body colour.
With the rear clip on you can align the side pod where it fits to a vertical plate on the chassis. If you just riveted it on it will likely pull the side pod in too far and not align with the clip so again you may need to make a spacer. The spacer may also be thinner top or bottom to get the alignment right.
Last part is how far in or out the bottom edge of the side pod is. The only alignment here is to get it vertical so just make sure the car is level first.
You were doing the other side at the same time weren’t you?
Now go around and check/tweak it all again.
Don’t fit/trim the doors until the windscreen is in.
Steve
Don't fit doors until the windscreen is in? Factory usually fit doors first and then windscreen. Why do you recommend fitting the screen first?I can only assume the basic body alignment has remained the same with the new Evo.
The build instructions talk of making sure flanges etc. do not have high spots in the layup GF but I don’t believe enough emphasis is placed on this as it will make a very big difference is wrong.
They also advise fitting all body panels including the front and rear clips and the wheels/tyres but I doubt many builders will want to be buying tyres that early in what could be a drawn out build.
Start with the side pods positioned as the build says but not fixed yet.
Position the body tub as far back as it will go with the GF down the front of the ali skin on the front bulkhead. You did remember not to fit rivets along the top edge of the front bulkhead skin didn't you? (Remove them now.. I’ll not tell). Make sure it is positioned hard back against the bulkhead and equal side to side. Once happy with its position you can drill a pop rivet hole through it into the top of the front bulkhead cross tube and secure the tub with skin pins. It fits over M6 studs sticking up from the top of the side pods. You may need to slot the holes in the tub to allow the tub to sit where you want it without influencing your alignment. They will have large washers fitted later so no issue.
With the front clip closed you can adjust its height, fore/aft & side to side to get the correct shut lines clip to front of tub and clip to top of side pod. It’s a pain in the arse to do and may take hours but is the only way to do the next bit of alignment.
Next is to see if the back of the clips ‘wheel arch/arc’ aligns with the ‘wheel arch/arc’ of the side pod front. If they don’t align you may have to bin the Factory dimension you started with when positioning the side pod. Sit down cross legged on the floor and look at the shut line ‘Front clip/Tub’, ‘Front clip/top of side pod’ and the arch alignment you will see that the clip is dimensionally fixed so if the other two parts are not correctly aligned now no amount of front clip realignment will fix it.
The top of the side pod can now also be moved in or out to align with the tub provided your slotted/enlarged holes were large enough. You can fit a washer and nut on the front stud of the side pod and nip it up to keep your alignment (use plain nuts as you may need to come back for another tweak).
Moving back you can now align the B post edge. Nothing special here as it is a straight line down the back of the door opening….but. Fit the rear clip and again adjust the shut lines. More hours later have a look at the shut line ‘side pod top/rear clip’ you are going to make life difficult for yourself if you try and make this too tight and there will be rubber buffers in there two. Now look at the joint ‘tub/top of side pod’ and you will see it looks odd as it is much narrower than the shut line alongside it so I make a spacer to fit between the tub and side pod and paint it body colour.
With the rear clip on you can align the side pod where it fits to a vertical plate on the chassis. If you just riveted it on it will likely pull the side pod in too far and not align with the clip so again you may need to make a spacer. The spacer may also be thinner top or bottom to get the alignment right.
Last part is how far in or out the bottom edge of the side pod is. The only alignment here is to get it vertical so just make sure the car is level first.
You were doing the other side at the same time weren’t you?
Now go around and check/tweak it all again.
Don’t fit/trim the doors until the windscreen is in.
Steve
Edited by Steve_D on Sunday 24th December 18:29
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