Frame Welds

[Briansshop]

Watching some vids,and noticed some welds on a new coupe kit had welds that had been hit with a grinder. Is this common for FFR to do this?

[GoDadGo]

Heck Yes They Do A Little Weld Clean Up!

Check out the attached video about 8 minutes into it.

https://youtu.be/wVT6QHyBxDA

[Briansshop]

Thanks. That's disappointing.

[progmgr1]

I don't understand why that would be disappointing. Most of the grinding on my car was where flat parts (square tubes and/or steel sheet) were butt welded, and later sheet aluminum panels would be mounted. In my limited experience it's almost impossible to create a completely flat weld with any additive metal process (MIG, TIG, etc.) So, if you want your sheet metal panels to lay flat and seal up easily to the frame, the weld buildup has to be ground flat. Grinding off the tops takes away only a little strength from the joint, and some of that loss is offset by attaching the panel to the tube. IMHO, grinding welds is necessary and desirable.
Keith HR #894

[GoDadGo]

I don't understand why that would be disappointing. Most of the grinding on my car was where flat parts (square tubes and/or steel sheet) were butt welded, and later sheet aluminum panels would be mounted. In my limited experience it's almost impossible to create a completely flat weld with any additive metal process (MIG, TIG, etc.) So, if you want your sheet metal panels to lay flat and seal up easily to the frame, the weld buildup has to be ground flat. Grinding off the tops takes away only a little strength from the joint, and some of that loss is offset by attaching the panel to the tube. IMHO, grinding welds is necessary and desirable.
Keith HR #894

Ditto on my Dark Side MK4 #8,515
99% of the grinding was to allow the aluminum pans to sit flat against the 3/4" square tubes.
No visible grinding was done on the structural areas of the frame nor for any of the suspension mounting points.

[edwardb]

X3. It's done to allow fitment of other parts including panels flat on the frame as mentioned. Not remotely disappointing. Someone doesn't quite understand how these fit together.

[Briansshop]

I can see a little grinding where the tin mounts,but I've seen it in places where no tin is fitted. A good weld shouldn't need grinding,and a weld that has been hit with a grinder will not pass a chassis certification. Rest assured edwardb, I have a pretty good understanding how it works. I have a different plan for use,than most on here I'd imagine,so some different concerns.

[NAZ]

Some racing sanctioning bodies will not allow welds on certified roll cages and chassis to be ground. However, there are times when an engineering requirement dictates welds to be ground to improve fatigue resistance and structural integrity. Correctly grinding a butt weld such as discussed above, can actually improve the strength of the weldment, but if not done correctly can diminish the strength. During my time as a professional welder, I've seen some botched grinding jobs. And grinding of joints that should not have been ground. When I took my LA City Structural certification test, all butt welds were to be ground and if you screwed it up the coupon would fracture when the inspector would bend it.

[JohnK]

If chassis certification is your concern, I would call FFR and explain your need and see if they can specifically not grind any welds on your frame. Seems like a simple enough request. You could order the frame bare, and then have it powder coated locally after you clean up whatever welds you need cleaned up (if any). I had to get a new rear frame section for my Mk4 (long story) and I asked them if they could not weld on the little tabs above the RH fuel strap mount, since most people cut them off, and they were happy to accommodate that request.

[Logan]

I have to agree, I’m sure it would be as easy as a phone call to order a kit with no grinding of the chassis welds. Especially considering that would be LESS work on their part. As a RACING company, they would undoubtedly be happy to accommodate that request.

What branch of racing is this intended for which has this specific technical requirement? I’m guessing some form of drag racing.

[GoDadGo]

Brian,

What car do you plan to build?
What racing style do you plan to do?
Are you planning to buy a Challenge Car or Type 65/R to go road racing?
If you plan to go drag racing, in a 33 HR, then see if "THE NAZ MAN" will be willing to take on a project to do exactly that.
NAZ is the man when it comes to fabricating because nobody has even come close to what he's done with his 33.
As for me, I'm A-Okay with my Under Powered Prius Style MK-4 Cruiser shown below:

https://www.facebook.com/dlarmann/vi...&theater&ifg=1

Steve

[Briansshop]

Yes, drag racing. Plan is to get the chassis bare,since I'll be adding a driver's side door bar and a window net. Also figure there might be a few other things I might want to change along the way. Then like mentioned either sandblast/paint myself - my preference actually - or have it coated. Paint is easier to fix down the road if needed.

[GoDadGo]

Yes, drag racing. Plan is to get the chassis bare,since I'll be adding a driver's side door bar and a window net. Also figure there might be a few other things I might want to change along the way. Then like mentioned either sandblast/paint myself - my preference actually - or have it coated. Paint is easier to fix down the road if needed.

If you get the Type 65/R Coupe, you should have no issues, but if you want to go 100% custom;

Then Get The NAZ Man Involved If He Is Willing!

https://thefactoryfiveforum.com/albu...chmentid=77037

His 33 HR is 100% custom from the firewall back.

[Briansshop]

Daytona,I've considered the R chassis but leaning towards standard one.

[GoDadGo]

Daytona,I've considered the R chassis but leaning towards standard one.

How fast do you plan to traverse the 1,320 or are you planning to play at th 1/8 mile events has everything to do with the regulations.

[NAZ]

Brian, if you plan to drag race at a NHRA sanctioned track, I can share with you my experience building a FFR "kit car" into a NHRA compliant race car. The Coupe looks like a very well built car and if I was going to build a kit car I'd sure be attracted to that car. But do your homework before commit as NHRA has some really strict rules that make it difficult to comply with when using a FFR chassis.

If you use a coupe based build and want to run quicker than 11.50 (7.35 1/8-mile) you need a compliant roll bar. You won't need much power to get that ET and the roll bar requirement is going to make it difficult to get any FFR car to comply with. And quicker than 11.00 requires a cage and NHRA has some very specific requirements on how a cage is built. I'm not sure what size tubing the coupe is built from but I suspect it is crafted to meet SCCA specs which are very different (more lenient) than NHRA. The Hot Rod is the easiest to make compliant with NHRA rules but "easy" and "inexpensive" should be better defined. I read the rules and contacted NHRA to get some clarification on many of the requirements and still when it came down to certifying my custom chrome molly roll cage NHRA wouldn't cert the cage. Actually, they had no issue with my roll cage but they wouldn't approve the FFR chassis it was welded to. Long story short, I ended up scrapping everything from the firewall back and designing, engineering, and fabricating a custom chassis to meet NHRA's rules.

Not to scare you off -- just do your homework as changes start getting expensive. I'd been better off starting from scratch, which is how I've built cars in the past. But I thought the FFR "kit car" was going to save me lot's of time as the rules say you must weld your roll cage to the factory frame. But NHRA ruled that the FFR chassis is not a factory frame as it's not a Henry Ford original. Go figure -- the FFR chassis is far stronger than an original 1933 coupe.

[mike223]

But do your homework before commit as NHRA has some really strict rules that make it difficult to comply with when using a FFR chassis.


I read the rules and contacted NHRA to get some clarification on many of the requirements and still when it came down to certifying my custom chrome molly roll cage NHRA wouldn't cert the cage. Actually, they had no issue with my roll cage but they wouldn't approve the FFR chassis it was welded to. Long story short, I ended up scrapping everything from the firewall back and designing, engineering, and fabricating a custom chassis to meet NHRA's rules.

+1.

You don't need to worry about the welds because you're going to be doing them all yourself.

I'm pretty sure you're out of spec on the 1.5" tubing from the beginning (to serve as even an "approved" roll bar), and lord help you if you want a NHRA certified cage (needed for 11.00).


And for the roadster guys - you need a NHRA "approved" bar at 13.49, and good luck with that (not likely happening).

They also need a certified cage at 11.00, and if you get that it's not going to be safe to drive without a helmet on (bars going to be way too close to your melon in a roadster).



It's a mess - best recommendation - if you want to play that game, buy a used drag car that's already certified (way cheaper + easier).

[NAZ]

+1.

You don't need to worry about the welds because you're going to be doing them all yourself.

I'm pretty sure you're out of spec on the 1.5" tubing from the beginning (to serve as even an "approved" roll bar), and lord help you if you want a NHRA certified cage (needed for 11.00).


And for the roadster guys - you need a NHRA "approved" bar at 13.49, and good luck with that (not likely happening).

They also need a certified cage at 11.00, and if you get that it's not going to be safe to drive without a helmet on (bars going to be way too close to your melon in a roadster).



It's a mess - best recommendation - if you want to play that game, buy a used drag car that's already certified (way cheaper + easier).

That's the truth! Cheaper to buy a used DIALED IN race car than build one from scratch, and building one from a FFR kit car is more expensive than building from scratch. What was I thinking???

[mike223]

What was I thinking???

I always kind of wondered that.

And that was before I knew you had to go back and start over from the firewall...

[Briansshop]

I plan on mid 8 sec 1/4 mile passes. The Coupe cage portion of the chassis is 1 5/8" according to F5. The plan for the car is to build a fast street car that I can run at the track with minimal hassle from tech. Was thinking if I add a drivers side door bar and a window net,I'd be good. Around here, I don't see much of a prob, have buds running 8.0s at 170 with no cert,and they don't get hassled.

[GoDadGo]

I plan on mid 8 sec 1/4 mile passes. The Coupe cage portion of the chassis is 1 5/8" according to F5. The plan for the car is to build a fast street car that I can run at the track with minimal hassle from tech. Was thinking if I add a drivers side door bar and a window net,I'd be good. Around here, I don't see much of a prob, have buds running 8.0s at 170 with no cert,and they don't get hassled.

What power plant do you have in mind and what transmission too?
A BBC, LS, or SBC will be the easiest & most economical way to get there.
Mid-8 second passes is quite doable so please consider going with the R-Chassis since you plan to go that fast.
I'm assuming the car will get a four-link rear; however, playing around with the upper link of the three-link, possibly to the center, may work too.
Get with NAZ regarding your rear set up because I think he's already got that issue ironed out on his crazy 33.

Good Luck From The Dark Dart Side & Can't-Wait To Follow Your Build!

PS:...My goal is to run into the Mid-11's before the folks at Gulfport Dragway send me home, but my car is a Cruiser Not A Bruiser.
......https://www.facebook.com/dlarmann/vi...&theater&ifg=1

[mike223]

I plan on mid 8 sec 1/4 mile passes. The Coupe cage portion of the chassis is 1 5/8" according to F5. The plan for the car is to build a fast street car that I can run at the track with minimal hassle from tech. Was thinking if I add a drivers side door bar and a window net,I'd be good. Around here, I don't see much of a prob, have buds running 8.0s at 170 with no cert,and they don't get hassled.

Since the coupe has a roof and a roll cage (maybe even 1 5/8"), you at least have a reasonable chance of making an argument out of it with tech, should it ever come to that.

You probably ought to take a good look at one in person before you go far planning a door bar - that area is "extremely tight" in a roadster (I don't know about the coupe).

All I wanted was to build something close enough to an approved bar in my roadster to allow for the same sort of reasonable argument in tech.

But after years of research and prototyping I never came up with a design I felt was satisfactory enough to argue about (for a "street" roadster).

I tried to build mine to be capable of 10 seconds @ 140 (slicks would be required).

But frankly - at this point I've pretty much completely lost interest in spinning street tires in third and fourth gear.

Mine is much more of a street application and the next motor I build will be milder - I'm thinking a 9:1 351 would probably do the trick nicely.


8s @ 170 is deep into certified cage + parachute territory (and a lot of other things) in the NHRA + IHRA rulebooks.

And the insurance companies run the rulebooks (+ thereby -tech- when they want to, or suspect they have a problem).


Good luck,

Mike

[mike223]

8s @ 170 is deep into certified cage + parachute territory (and a lot of other things) in the NHRA + IHRA rulebooks.

And the insurance companies run the rulebooks (+ thereby -tech- when they want to, or suspect they have a problem).

Specifically, I happen to know that this guy's videos raised eyebrows and became the subject of some very specific national follow the rulebook / perform tech / "we'd better never see anything like this ever again" guidance edicts a few years ago...

https://www.youtube.com/watch?v=AQtmrxaRVTg


This guy too (I especially enjoy the snicker when he's telling about his "156,000 mile 302", lol): https://www.youtube.com/watch?v=pf_t...CA065F8F84002E

[NAZ]

Brian, that sounds like a fun project. I thought it would be really fun to build a quick "street" car, actually a race car licensed for the street that I would race and occasionally drive to town for cruise night. I have the quickest street car in my area and the most unpractical -- but it is a lot of fun. I can tell you from experience, you have a very aggressive goal so plan on your project costing at least double what the average Coupe build costs and take at least twice as long to build with many setbacks and diversions along the way. To get that kind of ET you will need to modify much of what FFR has designed (and that's if your roll cage complies with NHRA / IHRA).

Beside the car complying with the rulebook, you will need a competition license to run quicker than 10.00-seconds or faster than 135 MPH. I have a Level-4B Super Gas license and to qualify for the license I attended Frank Hawley's Drag Racing School at The Strip in Vegas. So plan on getting licensed as well as modifying your car to comply with the rules. It's really not a good idea to hope and assume you'll get through tech with a non-compliant car -- that's a lot of $$ and time spent to be turned away. Better to ensure the car and you are compliant with the rules. You can view the NHRA requirements here: http://www.nhraracer.com/

Our, you could buy a hot street car (like mine) and be money ahead while enjoying your new car immediately. Make me an offer -- maybe I'll let mine go to a new home.