GTR Stagea - Fitting the Front End (Patreon)

Following on with this, here is a super detailed account of everything that went into getting just the bonnet to work on this conversion, something that everybody I've ever seen has just skipped over.I figured that this whole front end swap is going to take a lot of back and forth, moving the parts around to get them all to play nicely with eachother and so it was tricky to figure out which panel to start with or to do them all at the same time. The only thing I knew for certain was that the bonnet had to be centered and so I started there.First up were the hinges. So unfortunately they didn't bolt straight up so there was straight away going to be some custom parts needed.The bolts on the GTR bonnet were about 120mm wider apart than the stagea ones and so adapter plates had to be made. The bolts on the GTR bonnet also taper in towards the front meaning that there was a bit of tricky measuring to figure out what angles the new bolts had to line up at.There was a lot of back and forth with the cardboard templates to get a design that worked. To determine how far back the bonnet was going to sit in this initial placement I did a rough test fit of the panels to see what sort of space there was for the front bumper and headlights.Conveniently it ended up working out that you want the bonnet about as far back as possible because the curve that matches up with the windshields are different on each bonnet, and by having the GTR bonnet as close as possible to the windshield you can hide most of that ugly gap. I used the windshield wipers to tell me how far back was too far and positioned the bonnet until they just barely opened without touching the paint.Then I was all good to make the adapter plates out of steel.For this I plug welded 2 M8 bolts to the backside of the plate and ground them flush so they would sit flat on the bonnet. I also had to drill out a rivet on each side but there were definitely more than necessary anyway.After finishing up the adapter plates I had front and back distance sorted, then I needed to make the bonnet latch to line it up in the center and also work with the existing Stagea latch mechanism.The main hoop was simply bent out of some 8mm mild steel rod and then heat treated and annealed after also being plug welded from the back side.As I mentioned, my goal with this car is to keep everything on it completely road legal and so after speaking to my certifier, I made sure to add the secondary catch as it is a legal requirement for any road car in NZ to have 2 independent bonnet catchments. (Ironically that also includes a pair of $20 eBay hoodpins) but we're doing things properly here.The latch was origami'd by hand using some 25mm mild steel box section, cut and folded to match the factory shape and then trimmed to the height that would work for the new bonnet.Then here is all the finished piecesFinally they could be test fit on the car to confirm everything was sweet before getting a coat of etch primer.Then it was all bolted up and aligned to dead center.For the height of the bonnet there were 2 main things that determined it. The downwards slope, (rake) and the resulting height of the front bumper. I could tell from the test fit that I would want the bumper as low as possible to get around the impact support beam that I will have to leave in place.In a perfect world I may have put the bumper slightly higher and have less rake on the front end but the goal is to keep it road legal and this is the best solution for that.But with that in mind, the bonnet was set up so that at it's lowest point it sit's 10mm above the highest point in the engine bay which from my investigation was a bolt on the top of the front composite core. (FYI to anybody doing this in the future, go ahead and cover those bolts in foam tape so they dont scratch the shit out of your bonnet while you're test fitting it all)The next thing to tackle will be front bumper and headlights as leaving this bumper wrapped up for 3 years has deformed it slightly and it needs some support to get it back into shape.So with the bonnet sorted out I shifted my focus to getting the front bumper and headlights test fitted. Since I expect that once the guards go on I might have to shift things around I'm putting off making anything permanent until everything has been test fit and I can confirm I don't need to shit things around.I made a quick and dirty wooden brace for this bumper and played around with shims till I had it lining up nice with the bonnet.And with that I was able to get a really good fit along the bonnet edge.At this point I realised I was missing the super fancy GTR rubber trim that seals the gap between the bonnet and the front bumper which mean that there should be about 5mm of space between these two. I made sure to leave the gap but I will be sourcing my own piece to go in there.Next challenge was to get the headlights to fit.They contacted a lot of this upper front core support so some of that would need to be trimmed to get them in.Luckily I have a donor chassis that I didn't have to be so careful with and so I used it to figure out how much I needed to cutThe top of the headlight presses hard against the upper frame rail in order to sit nicely. In the end only a small amount of the upper rail needed to be trimmed down.There is a small plastic mounting tab on the headlight that gets in the way of the upper core support. Since there's no real way to actually use it to mount the headlight it serves no purpose anymore and so it can get trimmed off.This was a bit of a concern regarding keeping the car road legal as frontal impact standards are a big deal here. After a bit of back and forth with my cert guy though we figured out how to do it in a way that would retain the factory strength and so then I transferred everything back over to the proper Stagea to trim it for real.This was all that needed to be trimmed of the upper frame rail in the end. Just a bolt point for the fender and a small part of the pinch welded tab.The goal was to leave as much of this core support as possible to I spent quite a while slowly trimming and test fitting to make sure I had a nice snug fit before tidying up the edges.Pretty happy with how tight the fit was.Then in order to keep the thing road legal I had to put in exactly 3 plug welds to join the upper rail back together where it was trimmed.The reason this whole thing was such a process was because there were 2 failure points designed in to the frame rail right where I had to trim and so the surrounding area had to be exactly as strong as designed originally. My initial plan was to trim the whole tab off and weld up the seam but this would have actually added to much strength to the join and acted as reinforcement which could have lead to the failure points not working as intended and shifting the point of failure further back towards the driver in the event of an accident.This is the level of stuff we have to deal with in NZ but at least if this shows the conversion is possible here it should be doable everywhere else in the world.The last step was to tidy up the welds and prime the panels with some epoxy primer and spray the inside of the rail with some cavity wax.And then the finished product:Next up will be making the custom fenders.It's going to be a bit of a relief since I know I'm going to be making widebody fenders that will cover these anyway, so I don't have to be perfect with the finished part. But knowing me I probably wont be able to help myself.