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Posted by: jhelgesen May 20 2010, 06:35 AM

We started cage work for a vintage racer 914-6...

Customer brought in a decent stripped tub, fitted for a complete fiberglass fender setup.





We started in with the main hoop



We'll be tying in all the suspension points.



Trial fit the door bars last night.

Posted by: JmuRiz May 20 2010, 09:07 AM

Looks good, but damn, you have my wall stripe idea before I did mine...is it paint (if so, VERY nice) or a vinyl decal?

Posted by: jhelgesen May 20 2010, 09:10 AM

Thanks. It is paint. 5 rolls of painters tape, 3 colors, and 5 nights of work.

Posted by: Racer Chris May 20 2010, 11:24 AM

I hope you're not welding the roll cage together with that little Lincoln in one of your pictures!

Posted by: jhelgesen May 20 2010, 11:34 AM

Our equipment works just fine, more than enough amps....



We just finished up this Acura TSX for the Continental Tire Challenge series

Posted by: jimkelly May 20 2010, 12:22 PM

if you can - pls be descriptive on the install of the fiberglass fenders - photos would be nice too. i assume they get epoxied in place? i see you cut away a decent amount of sheetmetal near the near lights.

Posted by: quadracerx May 20 2010, 02:09 PM

I was wondering about those fenders and how they attach too....

Posted by: carr914 May 21 2010, 04:16 AM

It says NASCAR on it, doesn't that mean it's good ?

Posted by: jhelgesen May 21 2010, 04:22 AM

We have to weld in little circles only to the left with it...hehehe

Posted by: quadracerx Sep 20 2010, 09:59 PM

Anyone have any suggestions on how to fasten these fenders properly?

Posted by: carr914 Sep 21 2010, 04:37 AM

The fact that it is a race car, I would think that they used DZus Fasteners

Posted by: scotty b Sep 21 2010, 05:22 AM

Dzus

Posted by: jhelgesen Sep 21 2010, 05:46 AM

Quick release fasteners were not allowed by the sanctioning body, the panels were glued on with 3M panel adhesive. After several track events and some contact, the panels are still on and not going any where.

Posted by: carr914 Sep 21 2010, 06:21 AM

I was just starting my 2nd favorite beverage

Posted by: arkitect Sep 21 2010, 06:59 AM

Keep the picts coming, want to see the process of connecting full fiberglass fenders.

Dave

Posted by: sean_v8_914 Sep 21 2010, 08:01 AM

OT: I was watching monster truck jam. Blue Thunder hit some jumps and both rear shock consoles came apart. then they showed the carnage...WTF? it all came apart at the welds. can someone with real welding experience explain that? I say cold joints and poor penetration.

Posted by: rick 918-S Sep 21 2010, 08:21 AM

If it was 4130 it is likely poor penetration. (monster trucks likely would use light 4130) The other problem with welding 4130 is the rate of cooling. Mig welding 4130 can result in a concentrated local heating of the tubes with a quick flash cooling. This will cause a brittle condition and lock in stress. IIRC Tig welding can even be worse as the heat concentration is even more concentrated with a faster cooling cycle. In welding body panel seams tig is ideal because of the small heating and your ability to concentrate the work to a smaller area minimizing the warp factor.
That's why experimental air frames are gas welded. The molecules expand slower with the torch and further down the tubes. The tubes hold heat longer after the welding process is completed. Cooling is slower allowing the tubes to naturalize (tube and weld metal) restoring the strength.

Mild steel DOM can be mig welded with great success. It's a little heavier.

Posted by: sean_v8_914 Sep 21 2010, 09:58 AM

does pre heating help?

Posted by: rick 918-S Sep 21 2010, 11:36 AM

Yes. No problemo. I'm note sure they still do this but NASCAR I think used to require the cages be placed in an oven after welding to be cycled up in heat and slow cooled to naturalize the cage. It doesn't take alot of heat I don't think. (can't remember all the little details it's been awhile..) But a rosebud with a low flame moving over and away from the joint several inches should accomplish a nice slow cooling cycle. IIRC it doesn't even have to be red or cherry, just heated and not overheated. There should be alot of info on the airframe builders forums. I always gas weld 4130. There is a specific filler rod for 4130. I have some in the garage. Can't remember the part number.

Sorry for the hi-jack I tend to ramble. Hopefully some of this dribble will be useful..

Posted by: msglaigaie Sep 21 2010, 11:46 AM

I have the same fenders and I am very interested in how you cut and fitted. Share more photos please.

Posted by: campbellcj Sep 21 2010, 11:32 PM

I'm surprised that the sanctioning organization won't allow dzus fasteners but they allow a full fiberglass body ?!?!

Definitely please keep us posted as the build moves forward

Posted by: quadracerx Nov 23 2010, 03:04 PM

Any progress updates?

Posted by: Silverstreak Nov 23 2010, 06:45 PM

Great job on the Acura, but god I hate seeing 4 door saloons being used for racing cars.

Posted by: jhelgesen Nov 23 2010, 07:52 PM

I'll have to dig up the completed pictures, car was racing and winning in August....