Ironhead Posted December 18, 2019 Author Share Posted December 18, 2019 8 minutes ago, HuD 91gt said: Nice job. You only say it’s idiot proof until you have a resin filled hand, and fibreglass Matt strings everywhere! Already there. God awful mess. I wish I had a "dirty room" in the shop to do this sort of thing. As it is the sanding dust gets everywhere. Quote Link to comment Share on other sites More sharing options...
brittbogle Posted December 19, 2019 Share Posted December 19, 2019 i assume those fender kits are typically used for track/race cars and aren't manufactured from a precision standpoint. You may have covered so apologize if so, but just curious if your plan is to complete the build then tear apart for paint. Then one final assembly. It seems you have many eyes on your build. Keep up the great work. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted December 19, 2019 Author Share Posted December 19, 2019 34 minutes ago, brittbogle said: i assume those fender kits are typically used for track/race cars and aren't manufactured from a precision standpoint. You may have covered so apologize if so, but just curious if your plan is to complete the build then tear apart for paint. Then one final assembly. It seems you have many eyes on your build. Keep up the great work. Exactly right, I hope to dial in everything I possibly can before paint. Mechanical/electrical are done, just doing bodywork and final details now. Hope to start painting when the weather warms up in the spring. Thanks much. Quote Link to comment Share on other sites More sharing options...
LLave Posted December 19, 2019 Share Posted December 19, 2019 Great work. Love the attention to detail. Darius did a car with that kit finished out to a high level, I am sure they had to go to great lengths to get the fitment dialed. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted December 26, 2019 Author Share Posted December 26, 2019 (edited) I test fit the modified RF fender and found the fit to be vastly better. Not "perfect" yet, but definitely workable now. I had the fuel cell mount powder coated black, then sprayed the inside with Lizard Skin noise control, Lizard Skin temp control, then covered that with black Raptor Liner. I was of course interested in the Lizard Skin products to minimize noise and heat transfer, since the fuel cell will sit directly above the mufflers, but it was also an experiment to see if the Raptor Liner appeared to be compatible with the Lizard Skin products, since this is the combination I plan to use on pretty much the entire interior of the car. Everything went well with the coverings. The reddish strips are just adhesive backed silicone rubber strips, to cushion the cell a bit and prevent metal to metal contact. Edited December 26, 2019 by Ironhead Quote Link to comment Share on other sites More sharing options...
Ironhead Posted December 31, 2019 Author Share Posted December 31, 2019 (edited) Still messing around with the fiberglass fenders. The RF fender lined up slightly shallow next to the door, so I built up approximately .100" thickness additional fiberglass in that area to sand it to a closer match. It has been fairly cold here and the resin is curing slowly, so I have not been able to sand it yet (still gummy). I'm not opposed to using filler for some of this, and I'm sure I will before I am finished. But for the more significant alignment errors I am trying to build up the fiberglass where I can, just to keep the inevitable use of filler to a minimum thickness. I made the cutouts for the inspection doors, and doing so required me to remove the edge ridge that was molded into the fiberglass. On the driver's side I had to remove the ridge all the way back to the windshield, to slightly narrow the fender to make it fit on that side. Without the ridge, the parts lost a lot of structural strength and sort of sagged. So I made a couple of stiffeners out of 1/8" aluminum angle stock to straighten the parts and restore their rigidity. Bonded in place with 3M #08219 urethane structural adhesive. I will probably add a couple of layers of fiberglass over the outer portion of the brackets once the adhesive has cured, just to make everything one solid piece again. Sorry for the dull photos/mundane updates, but it's all I have.... Edited December 31, 2019 by Ironhead Quote Link to comment Share on other sites More sharing options...
grannyknot Posted December 31, 2019 Share Posted December 31, 2019 4 hours ago, Ironhead said: Sorry for the dull photos/mundane updates, but it's all I have.... But always good. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 8, 2020 Author Share Posted January 8, 2020 (edited) So last post I was pleased with myself about reinforcing with aluminum the sagging cutout area around the inspection panels. After that good feeling wore off and I started thinking, it actually seemed like a poor idea. Aluminum and fiberglass are bound to have radically different rates of expansion, and I figured that at best the bond would soon fail, crack the paint, and be a mess. At worst I feared it would crack the fiberglass. After reading some opinions from people who actually know what they are doing working with fiberglass, this fear was confirmed: Bonding metal to reinforce fiberglass is a bad idea, generally. So I inquired of a local plastics supplier of a product to bond to the fiberglass and provide some rigidity. He recommended G10/FR4 fiberglass reinforced epoxy composite. So I used some 3/8" thick. The stuff is crazy strong and rigid, and hopefully will have similar expansion/contraction to the fiberglass fenders and will remain bonded for eternity. After a ton of work, the fit between all the front end components is actually approaching kind of decent. Keep in mind I am not shooting for SEMA quality panel gaps, this isn't that kind of car, but I wanted it to fit together/look halfway acceptable. The "sparkly" appearance in some of the photographs is from the camera flash bouncing off the massive quantity of airborne fiberglass dust....LOL. Edited January 8, 2020 by Ironhead Quote Link to comment Share on other sites More sharing options...
LooseRocks Posted January 8, 2020 Share Posted January 8, 2020 FR4 is basically PCB glass. Really dense, strong and has a low coefficient of thermal expansion. Not sure how the properties compare to what your panel provider uses. Quote Link to comment Share on other sites More sharing options...
rossman Posted January 9, 2020 Share Posted January 9, 2020 (edited) The CTE's of FR4 and glass fiber reinforced epoxy (fiberglass) are very close to the same and about 1/2 that of unfilled epoxy but about 2x that of steel. Love the build - impressive work!👍 Edited January 9, 2020 by rossman Quote Link to comment Share on other sites More sharing options...
Nelsonian Posted January 9, 2020 Share Posted January 9, 2020 Love seeing the progress pictures as it gives me motivation for my intended (yz) rear quarters swap from the current (subtle z) on it now. I had a little bit of work in the driver's side front fender, but nothing as in depth as you have had to deal with. Keep up the progress.. Quote Link to comment Share on other sites More sharing options...
LLave Posted January 10, 2020 Share Posted January 10, 2020 This build is so good. Your posts inspire me on my own project. Thanks man. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 10, 2020 Author Share Posted January 10, 2020 Thanks for the kind words gents. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 20, 2020 Author Share Posted January 20, 2020 (edited) Working on fitting the air dam/bumper. The Ztrix piece is of course just a fiberglass shell, without much rigidity, so it is going to require a fairly elaborate support structure to be fabbed up to mount and support it. I made two brackets to bolt inside the wheel wells to support both the sides of the fenders and the sides of the air dam. I also included a piece to strengthen the fiberglass headlamp mounting panel, as it was pretty flexible and I don't want the headlights to vibrate excessively. This larger tube structure (it bolts into what I think used to be the OEM bumper mounts....but don't remember for sure) will be the foundation for the rest of the support for the air dam, and I also need to conjure up some structure to support a front splitter. All the tubing I am using for these parts is very thin wall. My hope is that in a minor front end collision the tubes will bend before they transfer damage to the car unibody structure. Not sure it will pan out that way, but that is my hope. Edited January 20, 2020 by Ironhead Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 22, 2020 Author Share Posted January 22, 2020 Support structure for the front bumper: Quote Link to comment Share on other sites More sharing options...
calZ Posted January 22, 2020 Share Posted January 22, 2020 If you want to make sure the support structure crushes before the unibody, some pie cuts out of the tubes would ensure that. Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 22, 2020 Author Share Posted January 22, 2020 2 hours ago, calZ said: If you want to make sure the support structure crushes before the unibody, some pie cuts out of the tubes would ensure that. Good idea. But the structure also has to support a lot of force, as I am also going to use it to mount a splitter... I wouldn't want the down-force to start bending things. Not being an engineer, this stuff is hard for me to calculate. I'm pretty much just guessing. Quote Link to comment Share on other sites More sharing options...
LooseRocks Posted January 23, 2020 Share Posted January 23, 2020 You're overestimating how much force a splitter can generate. Even with a very efficient splitter you're going to be generating very little force compared to the strength of that monster of a front beam you created. Unless you're going to do some crazy front wing like a hill climb car, I doubt you would be able to overcome 1" angle much less something like rollbar tube. You could go with something more flimsy and add support the "wings" of the bumper from the body panels with some of those fancy fasteners for removable body panels. There's a guy on youtube (kyle.engineers). He has some really videos on how much force automotive aerodynamics really generate. Quote Link to comment Share on other sites More sharing options...
jpndave Posted January 23, 2020 Share Posted January 23, 2020 Other than a little reinforcement and a few gussets aren't the front subframe rails pretty much stock? They should collapse at a more or less stock rate. I would be more inclined to keep the strength you have up there. Just my opinion though. I would keep in mind the collapse in an accident but you want all those bits to stay rigid and aligned. I think you are headed in the right direction and progress looks great. 👍 Quote Link to comment Share on other sites More sharing options...
Ironhead Posted January 23, 2020 Author Share Posted January 23, 2020 1 hour ago, LooseRocks said: You're overestimating how much force a splitter can generate. Even with a very efficient splitter you're going to be generating very little force compared to the strength of that monster of a front beam you created. Unless you're going to do some crazy front wing like a hill climb car, I doubt you would be able to overcome 1" angle much less something like rollbar tube. You could go with something more flimsy and add support the "wings" of the bumper from the body panels with some of those fancy fasteners for removable body panels. There's a guy on youtube (kyle.engineers). He has some really videos on how much force automotive aerodynamics really generate. Yeah, it's one of those things, when not sure of the forces involved, the tendency is to overbuild....at least that is my tendency. I hope I don't wind up with a 3000# car. On assorted amateur motorsports resources, I read that you should be able to stand on a properly supported splitter. And I'm a big f***. So, that's what I was aiming for. The bumper needs a surprising amount of support or it is literally going to flap in the wind. It is supported now in multiple places, and the lower rear corners (front of wheel arches) still move all over the place. The framework I built I think looks beefier than it really is. The tubing is .035" wall. I would be surprised if the whole thing weighs more than five pounds. But it is 4130 tube, which is pretty strong stuff. Quote Link to comment Share on other sites More sharing options...
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