LOWERING an RX-7 causes so many PROBLEMS. Here’s how we fix them. 

The main two things with the welds would be that sinking in (concave) welds is not really a sign of penetration, it just means you are running too hot/ not feeding it as much filler as it likes. The Japanese aluminum casts are notoriously dirty(at least on motorcycles, which is most of that I've done) And have a ton of air pockets which is why it seems like you're adding a lot of filler but not getting proper convex beads, also with the bevels you want to try and get both bevels the same, otherwise you'll have a tendency not to get the penetration on the part with the lesser bevel (unless you purposely focus on it). The last thing is to get some acetone for cleaning the aluminum, as the die grinder gets rid of the metal but still leaves oils on the surface, and with the cast, you need all the cleaning you can handle.

Major cojones Rob for modifying knuckles at each corner. Highly recommend x-ray or magnaflux of welds for safety.

Not gonna lie, I'm REALLY impressed if these guys manage to put the car together in time. They're cutting it CLOSE.

I'm a journeyman welder 18 years experience. Just wanted to say your welding has gotten much better. Isaiah no doubt has taught you a lot, he is a great fabricator. My dream was to weld custom cars like you guys do, but I got sucked into the oil and gas sector lol

NO GLOVES ON SPINNING TOOLS!!! You NEED to grow a great mustache before Pikes Peak. Look like a pilot while flying low!

Rob PLEASE stop using gloves on the drill press. My dad explained it to me once he saw a guys thumb taken off, said it looked like a tendon hanging out of a crab leg when you crack it. Not a pretty picture.

Who else is proud of Rob? He went from trusting his life in others and figuring it out small bit by small bit, to trusting his life in his own work and making leaps and bounds in advancement in his work. Bravo entirely!

I'm extremely interested in the rear wheel stuff for my RX7, actually for all 3 of them. Yeah, I have 3 RX7's and want the Rob Dahm sauce. Gimme your sauce, Rob.

I really don’t want to see you fly off the side of pikes peak!, these knuckle modifications are extremely important! Please get them x ray’d,and I hope you will be taking the car to a racetrack for testing before pikes peak. Stay safe.

Steve Morris did a great video with a welder who welds water filled copper power lines for steel plants. Very informative

Please Rob don't lose digits due to gloves. I am currently working on becoming an aircraft mechanic. This was the first thing they taught is to not wear things that can get cuaght and suck digits in. Your work is amazing so keep it up!

I am terrified for those cast aluminum welds. I wish you all the luck you can carry.

8:24 BMW mechanic here. Whenever I work on suspension I use a pole jack to place the hub at ride height before tightening the bushings. Forgetting this step will cause the new bushing to tear when you hit the first or second bump. Ideally you final tighten the bolts when its on a 4 post lift while doing the alignment but a pole jack works just fine.

"The bigger the globe, the better the job" is usually a saying reserved for anti-sieze and grease, but here we are assigning it to welding 😂

Man has a mad cnc set up and welds bits on to something he could just machine for the race of his life. That’s what I call a man who wants to learn the wild way and I love it 💪🏼🤛🏼👍🏼

You should invest in some temp-sensors to put around on the tires, on pikes peak grip is EVERYTHING! Knowing if your tires are warm/normal or where the heat (grip) is and isnt on the HUD would be super beneficial i think! Anyway, keep it up Dahminator!

Rob: We want those in billet too, for your safety. I closed my eyes when you started welding alum. haha Isiah, .look away

11:50 on the rear geometry considerations- Caster (and kingpin) angle don't really matter on the rear because you're not turning, like you said, and it's best to just get the points as far from each other as possible to minimize overall deflection. but there is often some intentionality in the positioning of the "steering axis" (virtual axis passing through upper and lower links; still present even if there's no intentional steering) and in particular the mechanical trail and scrub radius which are impacted by those angles. Having a little bit of mechanical trail is a good thing at the rear as it keeps the tire self-centering and reduces potential compliance in the toe link, and minimizing scrub radius at the rear helps reduce the forces through the toe link during a typical bump load case. Packaging and other considerations often take priority anyway in rear suspension design, especially bump steer like you say, but there are things you can do with the rear outer geometry that dont seem immediately beneficial but can help you out in general

Good thing you mentioned the heat treatment so it's like you know what you are dealing with, billet would be the ultimate best solution since you have a cnc machine and it doesn't need heat treatment and it's way stronger than cast, but I can only wonder what would be the overall cost of it at the end of the day, but overall it's a major upgrade for everything considered!

9:09 rob starts doing some kind of dance with shimmer hands 😂

this build is my favorite youtube content right now. Probably the best content i've seen all year actually

Real trust in ability to redo all knuckles. Be safe up there Rob, hope you finish the build with no issues!

/Makes key suspension pieces with eyeballed measures and welds. "I trust it with my life."

As a forklift operator, stress risers form where the cross-section of a structural member changes so Im looking for the smoothest transition from old to new on a weld like that.

It's kind of beyond me that with all the equipment in the shop Rob didn't make a jig for welding rear uprights

I can really appreciate ur learned knowledge of suspension geometry and ur ability to fabricate these arms

scan the hubs and machine billet ones .. outsource it for quickness

Rob seems like such a geniune guy, really makes the content more entertaining

Rob, can you PLEASE grow out an Iron man/Tony Stark mustache-beard combo? It would suit you so well, as well as the Stark-like genius part ;)

Haha teasing us with that ending! 😂lol. Can't wait to see it all come together, but enjoying watching the journey

That stash makes you look like a Mario character 😂

The sneak peak of the front knuckles is inspiring for my dreams of improving the super strut suspension on my ST205 Celica. Love your work, your mind, and the art you and your team continue to produce.

"This glorious mustache doesnt belong on my face" - Rob even though big bushy fireman mustaches are totally in style right now.

Keeps got me here because this builds Keeps getting better

Fun fact: the snap ring retained friction ring for 2 piece rotors was patented by PFC, their patent only recently expired which is why Wilwood and some others are following suit with their own versions. It really is the best way to do a 2 piece rotor

I just got certified as TIG welder about a month ago. My instructor always told me it never hurts to add a couple more beads on your weld bead. It helps a lot more with strength and durability. So in short I think you’re alright with the idea of putting more beads on top of the other.

I believe the "caster" is part of the rear steer geometry. When the rear suspension droops under braking, you get toe-in to add stability. On a turn, the inside rear droops and has less weight over the contact patch and I think the toe-in on one side reduces the slip angle to keep the tire in stiction.

We could tell it wasn't the Fab Daddy in the welding coat, cause you don't have on the requisite Croc safety shoes.

I love watching welds but the certified welding side of me want to cry 😭 at least he’s got 10/10 prep

Dude you gotta get those Knuckles X-Ray'd or Fluxed or something, thats CRAZY

Thank you Mr Wilwood Racing!

2:13 "the biggest snap ring in the world" Laughing in railway wheel snap ring😂😂😂😂

Those adjustable Arms with spherical bearings look like Parts Shop Max.

Listen. You make those billet knuckles, I’ll buy a set. I don’t even own an rx7, but I’ll still buy a set to support one of my favorite RU-vidrs.

We've known each other since before your garage was blue, so I'll tell you something that you may not know... With new welders, you don't have to preheat. When you preheat, you get the material way too hot and you lose strength, as you've mentioned in the video. One of the best welders in the world is in Michigan. Steve Morris made a couple of videos with that guy (he shared some tips in the video and it's well worth the watch in my opinion).

Glad you mentioned making the parts out of billot after testing the proof of concept. The entire video I was wondering why you hadn't just gotten the pieces drawn out in CAD then made in your CNC

As you noted, all of that welding on the aluminum upright has anealed and softened it. But you can take it to a forge and have it heat treated back to T6.

Vibrational frequency may get the better of you here Rob but good luck hope it holds up. 🇦🇺

8:15 To my understanding, bearings/ bushings are to be tightened with the car on the ground, right?

That Parts Shop Maxx rose colored anodize is hard to hide. I hope they work well for you!

I swwitched my old FD track car to manual, non-ABS brakes back in 1999. Went to twin primary (nee: master) cylinders, Porshce d996 front calipers and WILLWOOD rear caiipers and discs on the rear. A fabricator named David Breslau machined the adaptor brackets for the rear caiipers. You are on the right track.

I would smooth every mm of those rear hubs. Remove minimal material but remove all risers and surface imperfections until it looks like it was almost grown organically, any surface imperfection is stress riser waiting to happen and the cast aluminum you are modifying would make me want every safety base covered. One of the welders in here probably commented but you can use the torch to bring the contaminants to the surface of the cast aluminum to ensure the best weld. Love the content, be safe.

THANK YOU for wearing gloves while welding, finally a good exemple of health and safety on this channel.

this build has been so awesome !! I can't wait to see the finished car, and I have never looked forward to Pikes Peak more !!!

Has a CNC set up, has design software.. Cuts and welds uprights by eye with hope and prayers that they hold under load. Mental.

Next time you try the timesert thing you did, first install the timesert then do the extra tapping of the aluminum so it's 100% lined up

I'd recognize that rose gold and gold scheme anywhere. Parts Shop MAX is the shit.

Please test your brake fluid before every race. Racing brake fluid absorbs water very quickly, which significantly lowers the boiling point. Personally, I use Rowe SuperDOT5.1, which is also used by many race taxis on the Nürburgring Nordschleife, a track famous for its brake destruction. Unfortunately, I don't know if Rowe is available in the USA.

I guess my movie can wait

nothing better than a Rob video in the evening

Yes, we want to see you play with suspension things. Dude, I'd watch you rebuild power wheels if you want. You do some crazy, cool shit and I'm here for it.

Definitely interested in billet drop spindles! Even better if we could see just where it places the roll center compared to the COG. Even more better if the steering rack arm connections on the front were shorter to give a faster steering ratio.

I would definitely buy some billit spindles from you Rob. Can't wait to see the Rob Dahm Performance parts for sale

24:26 good boy. -engineer

So glad Rob uses ppe when welding. idk why people like barehanding filler metal

That’s a terrible modification. Just a dangerously weak spindle. Do what you want but on the mountain you will find out. I would suggest you CNC that design out. I like your videos and I’m sure you enjoy your life.

She getting low, down to the floor... Rotary get low low low low low low From the Throttle! to the firewall! with regards to T-Pain who also loves cars

Just a quick materials note, that spindle is more likely to be A356 casting aluminum which has a higher silicon content to aid in flow of the material in the mold. A356 is weaker from 6061-T6(51). Also, good catch on knowing that the welding would de-temper the aluminum. Above 140C the temper decreases rapidly (a couple hours), but at welding temps it is nearly instantaneous.

Negative caster also allows you to roll over bumps easier where as positive caster would push the suspension in on itself upon impacting a bump.

Rob I agree have the welds x-rayed and magnafluxed. Making cnc would be best.

Can't wait to see the testing on track!!!

Definitely interested in billet drop knuckles. Josiah over at fdf did a one off rear grip kit. Doesn’t offer it to the public yet tho

I wish there was a shop that did stuff like this that needed a good mechanic that wants to learn all this and get his foot in the door near northern indiana

@6:20 in vid-ish, I also like to use a good "chucking reamer" to get the perfect size and shape out of the threads for the best bite. Just in case that helps Rob.

7:13 I don't get, how you achieve a continuous thread between the insert and the lower aluminium part. Wouldn't you have to "clock in" the insert to fit the lower thread?

Your hair is getting more luscious every upload.

No, we don’t want the individual billet suspension. We want a Dahm store front. All the parts!

You have a cnc i hope you recreate those knuckles in billet. The amount of safety and money and time gone into this car you should definitely do it. The last thing you want is one of those "i trust it" welds cracking at the top of the mountain. Also those bronze arms are Powered By Max arms.

Nice jig for the knuckles Rob!

25:14 By lateral force, I think he means side to side. As the car moves forward or brakes, the control arms/knuckles/subframe sees forces moving front-to-back of the car (side to side of the knuckles)

Absolutely should build some billet versions, Don't trust those welds on cast material for the sake of fatigue cracking and the crash that would result.

That classic copper and gold, powered by max 🤙🏻

Rob for the win again ❤️ I’m interested in a 13B built and bridgeported with a VW type 1 adapter plate for a 1960 to run NA carbureted. 🙏🏽

We're interested in the spindles!

I know it's unlikely but I wanna see your rx-7 up against other rx-7s like in Hot version. looking forward to seeing all the progress Excited to see everything else you'll be doing to it Excited to see what you'll find when you're in the testing stage.

I once bought a wilwood rotor without mounting holes. Prob was it was supposed to have them 😂. They are nice looking calipers btw. 👍

Trust the weld with a complete bevel all the way to 1/16 then weld til flush.

Dahm’s doing the Reno 911 ‘stache alls he needs now is new boots 😂

Loving these mods, it's above my knowledge and I'm learning!

And maybe a good idea to leave the old bearing in place whilst welding to have a better chance of no distortion.

And always keep your filler material in the shielding gas. You are killing it Rob!

Broski, shouldn’t have used TimeSerts. I mean they’re not bad by any means but there are some that are cheaper but more importantly much stronger. Torque Test Channel made a video on comparing different inserts on 10th of July 2022 and TimeSerts turned out to be in the bottom of the ranking (18:02 of that video). Top two places were PermaCoil and VCoil inserts. I suggest using those next time especially on custom brake mounts 💪🏻.

I don't own an RX7, but all the sudden I feel very interested in buying a billet spindle for an rx7 from Rob Dahm

Aside: Have you considered using Chrome finish on an engine, from "crankshaft" to rotors, housing, even bolts. It is supposed to be durable as well as very thin and nearly as slick as Teflon. Not to mention the LOOKS!

Parts Shop Max makes those control arms

Seems you have a functional solution, you can lower the outer wishbone mount or raise the inner wishbone mounts. If packaging is an issue, pushrod and rocker allows you to use leverage multiplication to choose a smaller coilover package mounted either transverse or longitudinally.

Shout out to Dave Racing - he's a man!

Without a doubt , considering the initial strength compromise .. it would HAVE to be worth cadding, then machining from billet . But hey , this is R'nD ... wow ..I think you could even file a patent and give Mad Mike a free set !

When doing full pen weldss you need to grind down to the root from the other side or you have a void that will potentially start a crack

Precision engineering!