Red Bull 1968 Charger AWD Hemi 6 speed

[dhutton]

Fiberglass front fenders, steel rear quarters.

Thanks, I just assumed they were steel.

Don

[jlcustomz]

Having done both fiberglass & steel construction, I originally was going to make fiberglass layovers for my rear widebody before changing my mind to steel. Was going to make a shape with expanding foam, fine tune & coat it, then make or possibly have made bucks to make quality parts that can be repeated & possibly pay a shop to make parts off buck. But for an off 1 project that's a lot of work. Was experimenting with something in the middle of the process such as kitchen cling wrap type stuff for release paper over my reasonably tuned & quickly done spray foam, then spraying harder expanding foam thickly & embedding reinforcements to make a mold.
Wouldn't be a great mold & would still need a bit of bodywork, but this could still produce a reasonable part much quicker & cheaper.
Other option was to make the part on top of the foam, remove foam , & then bodywork the hell out of it. Been there, done that on stuff before.
What's your plan Steve?

[Motorcitydak]

Exactly what peanut said. I do have OEM steel fenders for this car but I have been wanting to use the fiberglass ones to save about 30 pounds per side

Just thinking out loud here, but I was recently watching a prototype car being built. They always use a big CNC router to carve out the clay shape before getting to the hand work. Im thinking that maybe a small hand held router would be a good way to hog out a lot of the material quickly. Just checking out a 1/4hp trim router from Harbor Freight for $30...

jl, my plan here is to shape this foam exactly how I want it then simply lay the cloth over it. I am using epoxy resin so that will not eat the foam, therefore no need to coat it. This foam I am using is just a 2 inch thick 4x8 sheet of insulation from Home Depot for $30. I have 2 of em left over from a project I did around the house. One thing I really like about the stuff is that is sands VERY nice. The expanding foam, and green floral foam, I have used in the past is very much the opposite. I think that once I get my shapes close, some block sanding will have this foam looking just like a finished surface ready for primer. I hit a section of it with a DA just to see how it comes out, impressive is the answer to that one

Ill add that once the fiberglass is laid over the foam mold, Ill just remove the whole assembly from the car and break/grid away the foam from the back side. Ill add in some reinforcements back there to keep everything in shape and then work out some more details to attach these to the car

[jlcustomz]

Honestly a router isn't what you want here. Cnc equipment uses routers partly because they can have the types of cutterheads to cut harder materials & control it as needed.
I kinda quit with the spray foam experiment because I didn't have affordable & easy access to the harder foams that would have worked better.
I've glued up & used the pink foam, it is consistent & finishes decent. My preferred tool for this out of my tool collection is an old Festool ro150 6" sander which is both random orbital & random rotary , variable speed, and has a vacuum connection. With 36 grit woodworking paper it hogged the foam down in a hurry. Also a great tool for roughing in coarse body work like you'll be doing. Not cheap at over $600 these days. Think Bosch has a similar knockoff of this sander for a little over $200 now.

Epoxy is messier & more expensive than poly resin, but it is definitely better. Far less future shrinkage. If you can keep the resin to fiber ratio down to as little as possible, that'll help the strength & weight.
You mentioned cloth. Cloth is ok for first layers, but you really want to finish with matt material to not have checkering appearing in the future.
If you have any uv lights, that would definitely speed up the drying process. A spray on poly primer like evercoat g-2 definitely sped me up on getting coarse handmade off one fiberglass projects ready for final primer after a little traditional body filler.

[Lurch]

One thing to keep in mind when considering tires however is that wider is not always better. It is very hard if not impossible for a consumer to find this information, but a tire traction dyno graph would be helpful here. It will show how much grip a tire can give with a certain weight on it. There is a limit and area where you will get less traction with a wider tire, you just cannot make it work unless you increase its weight load (ideally with added aero downforce). My 2000lb Lotus has 195s and 225s on it. Folks will go wider as the cars get more extreme but you then need to balance that with bigger and bigger aero packages to push those meats into the road.

Another issue is simply cost. It is relatively cheap for me to come up with 18x10, 10.5 and some 11 inch wide wheels. A 13 inch wide is going to be custom three piece units at $3000 per set and then add in the number of offerings for a tire that large, it becomes cost limiting for a 20mm tire gain. Not saying it is not necessary or a good idea, just always something to consider.

The trend lately for wheels and tires has definitely been wider and wider. Especially on these new super 200TW compounds that get up to temp quick (I think these supersoft compounds negate the weight factor somewhat. The wider tires don't seem to have as much trouble getting up to temp as they did years ago).

I get the Lotus having skinnier tires up front since there's not much weight up there. My Honda is similar weight but with the distribution of that weight and the tire stagger basically reversed (225's on 9's up front, 205's on 8's in the back). I'd assume an AWD Charger with everything pushed back is going to be close enough to 50/50 to want a square setup.

No idea on how much interior this thing will have, so excuse me if I'm wrong. but I figure this car will probably be in 3500-3800 range? That's around what a newer Mustang weighs and they're starting to run the exact setup I described. https://trackmustangsonline.com/thre...fenders.13378/ Definitely expensive tires, but it seems like no one but BFG makes a wide (300+mm) 18" sticky street tire anymore. Hankook hasn't in years.

I think if there was any real disadvantage of wider tires, it might be on track. Having enough power to overcome the drag of them in really high speed parts. You might have enough power for that not to be an issue.

As for cost, Forgestar could build you a custom set of 18x13's for $1600ish. It's been a while since I've really read back to see if this thing was 5x4.5 or 5x4.75, but if it's the former, I think Rota makes some fairly affordable 18x12's for it. 13's are definitely a custom item though.

[Zachalanche]

Consider economies of scale. Dont accidentally build your car around the most expensive tire out there. You might also limit yourself to a single brand of tire by going with a specific size.

Also you can fit a pretty wide tire on a narrower rim. 305s easily fit on a 10.5 rim. And you can also trade width fir diameter and maintain a similar contact patch. With AWD you shouldn't need the world's widest tire for acceleration. Sure you can run a 335 on the front for max cornering, but with what compromises?

Maybe find the tire size that is the best bang for the buck, then plan around that.

[speedfreakcobra]

I agree with zach. Since our builds are going in the same direction I'll throw in my 2 cents. I will use 2 sets of wheels and tires. The set that will be used for ax, rc and car shows will be 18x12 on the bfg rival s tires ($950 per wheel/tire) and for daily driving I will run Americanmuscle.coms combo of. Fr500 17x10.5 wheels on Mickey-T street comp 315 tires ($350ish per wheel tire). I just feel that such wide tires are useless unless you use it like you are supposed to. Having 2 sets can save you some money in the long run by only using the wide tires when you need to. Plus mt 315s go for like 150 bucks at 300 tread wear rating.

[Lurch]

I can definitely get behind the multiple sets of wheels and tires as I do that for my cars as well. More because I like to still drive my cars during the winter and store my 200TW tires inside during the cold months. 300TW's aren't really as picky about being out in the cold. Still that gives you something "normal" to drive around on when you're not driving the car in anger.

The 13 wide does kind of limit you to 335's and 345s (of which BFG, Toyo, and Nitto are about the only ones that make a 335 18 plus some full on R comps). You can get a 305 or 315 on a 12 and that opens up you options a bit more. My original comment about the flares was more just to allow yourself the option to fit the huge wheels/tires if you wanted.

[Motorcitydak]

Lurch, the car won't have much of an interior. It'll have the front seats, a center console for switches and cup holders and a rear bench. Not much for trim or cushions....at least not any time soon. I weighed the car when I was getting my suspension and it's just a hair over 3000# right now. I think the rear might have a bit more weight than the front but it will be close to 50/50. I do want to run a square wheel and tire setup. 315s look and fit pretty well. I'll have to look more into forgestar and rota.

Zach and speedfreak, I agree with you guys too. I do want good performance from the car but if I lose a tenth off a lap from smaller tires that Dave a few grand, I'll live. That being said I wouldn't mind having two sets so I don't waste good sticky tires on the street

Also to answer a question from earlier, the car has 5x4.5 bolt pattern. I had the c5 corvette drilled out because I preferred that so I can run Mustang wheels

[Lurch]

Does it need super high Corvette offsets or can lower stuff be used? Maybe not exactly what you'd expect to see on a Charger, but I've seen some people running these on some serious 240sx's (aero, big power, 315 Hoosiers, etc) as a "cheap" wide wheel. 18x12 +20 Rota P45R3. 25ish lbs so not the lightest out there, but not terrible. And you wouldn't be out a ton of money or be waiting for another if you mess one up.

http://www.wheeltech360.com/ROTA-Whe...Hub_p_300.html




I'm not sure there's any getting around tire prices these days when it comes to wide 18's. I think the cheapest are probably 315 Toyo R888R and they're still $1200 a set. MT does the street comp and Nitto does the NT05 in 315's that are cheap, but only in 17's.

[Sbeck09]

I'll throw in my 2 cents here from some real world experience. I worked at Vorshlag Motorsports for a while and also built some cars for road racing on the side. I've yet to ever see a disadvantage when going to wider wheels/tires. It's a trend because it works. Even a 200hp car can benefit from 335s if they fit. I'm not saying it's financially worth it, but with a fairly light wheel setup it only improves lap times. That said...I went with 315s on my build since they are around $200/tire cheaper than 335s. The wheels also average $150 each less.

Absolutely take cost into consideration here, but fit the biggest you can plan to run while you are building this thing. And unless there is a class reason for it, I don't recommend running a narrower wheel than the tire calls for. It squishes the tire up and narrows the contact patch while also encouraging the sidewall to want to roll under in hard corners. In fact the opposite is preferred if you must. It was a trick in autox to run a 1 size wider than necessary wheel with the widest tire allowed by that class. It essentially adds a few mm to the width of the tire. It doesn't seem like you are in that situation so I would just match the tire size to the proper wheel width.

For wheels I would backup the suggestion for Forgestar as they are among the better wheels for the money. Don't try to save too much on your wheels as you largely get what you pay for.

[Lurch]

In fact the opposite is preferred if you must. It was a trick in autox to run a 1 size wider than necessary wheel with the widest tire allowed by that class. It essentially adds a few mm to the width of the tire.

The same holds true for road course stuff for the most part. Before NASA implemented their current mounted tire gauge rules, the faster way was to take the tire you were limited to and stretch it out on wider wheels. TTE Miatas with 205's on 15x9's. TT4 M3's with 245's or 255's on 10.5's.

A little stretch certainly doesn't hurt anything and the 12 wide does allow you to cram 305's or 315's on as well as 335's. So from a tire selection perspective, I think that size would make more sense and give more grip than a 10.5 or 11.

[Motorcitydak]

Thanks for the info and input guys! Lurch, to keep the scrub in the front close to ideal the wheels I have are +45mm. Turning on a dirty surface shows they rotate just about exactly in the center of the tire tread. I do have the ability to run either a 5x4.5 or 4.75 bolt pattern front and rear. I do need to order another two wheels very soon so all this input is greatly appreciated

[Lurch]

That's basically Corvette offsets then. Forgestar F14's might be your best bet at that point. Looks like around $1600 a set.

https://www.forgestar.com/wheels/rot...ck-series/f14/

Just take into consideration that they're custom wheels so they're is some lead time on getting them made.

Forgestar D5's are right there too. I'm not sure if these are more ready to ship straight from Summit.

https://www.summitracing.com/parts/F...BoCEwcQAvD_BwE

[Motorcitydak]

Thanks lurch! I was just looking around on their site. Looks like I can go with a CF5 as well. That lead time isn't great but I can get two more wheels to match the ones I already have for $300 from American muscle. Then the forgestar ones can be my nice second set

[Motorcitydak]

Hey guys, it has been a long time since my last update but I’m still slowly working on the car. I decided I’m no good at fiberglass so now I’m building the front fenders in steel. I’ve had a pair of oem fenders this whole time and finally decided I needed to use ‘em. Here is where I am now, this is a 4 inch glare over stock, the rear I think I did 2.5. That’s a big question for me right now tho, the front and rear don’t match. What do you guys think about how it looks? I’m not sure if I want to keep it this way, or rip the backs off and push the flares out to match the front..... let me know what you all think

[Motorcitydak]

The drivers side fender is done as well. I did some mock up work to match the way shape I had on the rear but I did not like it because the wheel lip had to extend way out to allow the tire to turn, thus the girth had to increase.





This was the revised version, prior to sheet metal



It is all welded up now, I just did take any pics.

[iadr]

As far as the lip goes, you know, clearance vs the "ideal" appearance (namely: of flush offset *and* with a half inch upper circumference clearance, ...well I have to say I am losing my inhibitions about running air. IDK about you, but in my dream build it recently just tipped over the odds from about 66/33 no to 60/40 yes. As long as the geometry is right, why resist, is kind of where I got to.

But yeah I like it. Bit of a bulge in the lip to my eyes that I see without you having to have pointed it out. But it all works.
I like how you extended a "bumper" area to the wheel well. Interesting way to "update" it ! Moves the visual "weight" a little lower.
Though it might emphasize the long overhangs which I've always seen as a potential weakness of that body style.

[FormTA]

What about raising the top of the flair to match the body line of the door? Maybe that would help to blend it in so it doesn't look so much like its tacked on.

Still, it's looking much better.

[FormTA]

This is a garbage sketch I did on my phone quickly. But you get the idea. The top portion of the current rendition I really to flat IMO.