Hi,
I have a set of GTS rear wheel arches which I am fitting to a scratch build locost and would appreciate some advice on alignment. The arches I have are the 9" wide ones not the 11" wide ones if that makes any difference.

Here are my queries:
1. Should the leading edge of the arch be aligned with the bottom edge of the chassis or should the trailing edge of the arch be aligned with the bottom edge of the chassis? I can't align both otherwise my suspension turret becomes exposed.

2. Longitudinally, where should the arch be positioned? Should it simply be set so that the radius of the arch has its centre at the centre of the wheel or are there some other alignment reference points?

3. Has anyone else had trouble getting the flange of the arch to butt up nicely with the rear panel on the car? I find that if I put the arch where I think it needs to go I get a large gap between the arch and chassis for the last 8 inches or so. I am using tadpole trim but it will not fill the gap as it stands and I'd rather not use body filler if I can help it.

Any tips on fitting the arches would be very welcome as would any tips on fitting the GTS light clusters (Carbon Effect ABS type). These appear to be too wide to fit the 9" arches as things stand and appear to need some fettling to fit the curvature of the arch otherwise the light clusters will be pointing slightly outward.

Thanks,
Craig.

quote:

---

Originally posted by craig1410
Hi,
I have a set of GTS rear wheel arches which I am fitting to a scratch build locost and would appreciate some advice on alignment. The arches I have are the 9" wide ones not the 11" wide ones if that makes any difference.

Here are my queries:
1. Should the leading edge of the arch be aligned with the bottom edge of the chassis or should the trailing edge of the arch be aligned with the bottom edge of the chassis? I can't align both otherwise my suspension turret becomes exposed.
I'd align the rear as it is most obvious - though both should be... odd

2. Longitudinally, where should the arch be positioned? Should it simply be set so that the radius of the arch has its centre at the centre of the wheel or are there some other alignment reference points?
Central

3. Has anyone else had trouble getting the flange of the arch to butt up nicely with the rear panel on the car? I find that if I put the arch where I think it needs to go I get a large gap between the arch and chassis for the last 8 inches or so. I am using tadpole trim but it will not fill the gap as it stands and I'd rather not use body filler if I can help it.
I've seen rear panels - if the panel is wider than the chassis and creates a toe in effect when looking at it from the rear. This produces an other than flat joint with the side panels... so when you offer up the arch, you have a gap. Not a lot you can do about it now... we had to chop our rear panel narrower - see our website for more details

Any tips on fitting the arches would be very welcome as would any tips on fitting the GTS light clusters (Carbon Effect ABS type). These appear to be too wide to fit the 9" arches as things stand and appear to need some fettling to fit the curvature of the arch otherwise the light clusters will be pointing slightly outward.

Thanks,
Craig.

---

When I fitted my rear arches they looked like they would not meet the aluminium panel at the sides. I fitted them with M6 bolts and penny washers through the flange and before I tightened them up I cut slots in the tadpole beading to pass the bolts. I tightened them gradually and ignored the creaking and they pulled in more than I thought they would.

Hellfire/Peteff, thanks for the replies.

After seeing your reply last night Hellfire I decided to just bite the bullet and drill some holes... I have now fitted one of my arches and it seems fairly good. I still have too large a gap at the trailing edge but I can work on that. I've pretty much decided that I'm going to end up painting my aluminium body panels now anyway which makes things like this much easier as you can use body filler and other materials without worrying about how to get a clean transition from Ally to GRP. I'll still use the tadpole trim but I'll use body filler to fill the gap on the GRP side of the interface.

Peteff, I did try pulling the panels together with the said method but the GTS arches have a very stiff flange and it's going to break before it bends I think. The problem is mainly that my ally back panel starts to curve just before the joint which is why I was asking about longitudinal position. If I was to move the entire arch forward about 1.5" then the gap is minimal but then the wheel looks silly in the arch and the rear lighting cluster will be too close to the tyre on the inside of the arch.

It would be interesting to hear from any GTS builders who have got to the stage of fitting the rear arches as I have not yet seen a photo of the GTS Locost from the rear. Darren has a few pics showing that the rear arch does indeed sit level with the chassis sides at the leading edge but I can't see how it could possibly sit level at the trailing edge unless the chassis slopes up much more steeply at the back. I can always fit some very short mudguards I suppose. (and cup holders and floor mats of course...)

Well I'm off out to see how on earth I'm going to fit my lights so that they are square to both the vertical and lateral axes. The vertical axis isn't a big deal as the light housings are designed to correct for the slope of the wheel arch but the lateral axis correction will require some fettling of the housing at the inboard edge.
Anyone who has used the GTS Carbon Effect light clusters care to comment?

Cheers,
Craig.

I had the same problem with my Stuart taylor arches, i eventually built up the Grp flange by laminating some more layers of glass tapering down from the widest gap to where it fitted.I then finished off with filler and fitted the tadpole trim. It looks ok but i do now have a few stress cracks where i used the bolts to pull the last bit into position , so would advise getting the best fit possible before bolting.
Paul.

quote:

---

Originally posted by craig1410
Hellfire/Peteff, thanks for the replies.

I still have too large a gap at the trailing edge but I can work on that. I've pretty much decided that I'm going to end up painting my aluminium body panels now anyway which makes things like this much easier as you can use body filler and other materials without worrying about how to get a clean transition from Ally to GRP. I'll still use the tadpole trim but I'll use body filler to fill the gap on the GRP side of the interface.

---

craig1410 - 16/1/05 at 04:12 PM

Thanks Paul,
Yes I'd rather it all went together unstressed with just the bolts nipped up uniformly to compress the tadpole trim. My plan is to just use filler as the gap isn't large enough to require matting. I might use that chopped matting filler (P40) but I think normal smooth stuff will be fine to be honest. I might screw some short self tappers through the flange where the gap is to grip the filler better.

Anyway, I've been busy working on fitting my light clusters and it's going reasonably well. I just came in to the house on my way to B&Q or Halfords to get some M5 x 30mm bolts to hold the clusters in place. Once I've done that I'll need to cut the large holes in the arches to accommodate the connectors for the lights and the back of the reflectors. I'm a bit concerned that the back of the light clusters are going to fill up with all sorts of crap from the road. I'm not sure if it's better to cut a larger hole to let the crap drain out or cut a smaller one and try to cover it with a plastic cover or something. Any ideas anyone?

Cheers,
Craig.

---

craig1410 - 16/1/05 at 11:23 PM

Okay, here are a few pics to show my progress over the last day or so. Still a few bits to tidy up and carbon effect plastic still has clear covering stuck on hence rough edges but not too bad. I'm not 100% happy and I keep thinking it is squint despite considerable scrutiny with my spirit level... I have made the mounting holes big enough to allow final adjustment once I've fitted the edging strip and once I've filled the gap between the arch and the chassis.



Rear Arch and Light 1


Rear Arch and Light 2


Rear Arch and Light 3

Thanks for all your help!
Craig.

---