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914World.com _ 914World Garage _ Hypothetical Q..adding subframes to the 914
Posted by: Mueller Aug 10 2006, 02:54 PM
Ideally it would seem that tying to a central cage would be best, but what if you have no cage?
Does anyone think the firewalls are suffiecient to weld plates to that the subframe could be bolted/welded to it?
Looked an a Ultima frame and suspension* yesterday which got my pea-brain thinking and dreaming 
*not impressed, seemed "cheap" for that kind of money...
Posted by: TonyAKAVW Aug 10 2006, 03:17 PM
If you welded a plate across the bottom half of the firewall, and then plates over the longitudinals from the firewall up to where it meets the rear trunk, and used heavy enough material that might be one way to go. Basically box in the engine compartment with 1/4 inch plate. Kind of like a reverse Engman reinforcement kit, this time for the engine bay.
You could use the rear suspension mount points as well, also the shock towers. Between all of those spots you should be able to come up with something.
I'm welding in 1/4 inch plates at the upper end of the longs (at the trunk firewall) for my Subaru engine mount. That steel is pretty thick there, but for a whole suspension you'd definitely need more.
-Tony (not a structural engineer, nor an experienced racecar builder)
Posted by: bondo Aug 10 2006, 03:57 PM
Do you mean as in "subframe connectors"? They sell subframe connectors for 60s Mustangs because they have a front subframe and a rear subframe. Because of the unibody design, the subframes dissapear once they've overlapped into the passenger compartment a little ways. The subframe connectors connect the front and rear subframes, so they effectively run the entire length of the car. You wouldn't really need to do that in a 914 because the subframe (longs) already runs through most of the car. Perhaps there would be some benefit to tying the front suspension mounts more directly to the longs, but the front end seems pretty strong already. I think the big benefit on subframe connectors on cars like 60s mustangs is the unibody part they're relying on to tie them together has big holes for doors and windows. 914s have one really big hole, but it's spanned by the longs, which are actually quite strong. The engman long kit is probably enough, and if for some reason it isn't, you probably won't benefit much more from anything short of a full cage.
Posted by: ChrisNPDrider Aug 10 2006, 08:17 PM
Maybe the rear suspension stiffening kit from RacerChris is along the lines of what you are thinking...I think it directly connects that floating ear to the long with a metal rod = "mini frame"....I though it looked like a good idea and at least that peice would be a fairly easy DIY project. Are you looking for another new 914 project? 
Posted by: john rogers Aug 10 2006, 08:25 PM
You might want to see if you can find some pictures of Ron Mistak's GT-1/914 center seater race car. It has everything from the firewall back cut off and late model suspension added, etc. I think it took several months of having the car sit on a steel plate to get everything setup correctly.
Posted by: URY914 Aug 11 2006, 06:29 AM
If you welded a plate across the bottom half of the firewall, and then plates over the longitudinals from the firewall up to where it meets the rear trunk, and used heavy enough material that might be one way to go. Basically box in the engine compartment with 1/4 inch plate. Kind of like a reverse Engman reinforcement kit, this time for the engine bay.
You could use the rear suspension mount points as well, also the shock towers. Between all of those spots you should be able to come up with something.
I'm welding in 1/4 inch plates at the upper end of the longs (at the trunk firewall) for my Subaru engine mount. That steel is pretty thick there, but for a whole suspension you'd definitely need more.
-Tony (not a structural engineer, nor an experienced racecar builder)
1/4 plate is WAY too thick to properly weld to the thin sheetmetal of the car. And the weight of 1/4 is a little over 10 pounds per square foot . You should use 10 gage sheetmetal which is about 1/8" and drill it for spot welds. Building a 1/4 " box around the engine is a bit too much.
But getting back to the original question I don't think you could properly add sub frames to the front and rear w/o having a cage. The connection points of tubing to sheetmetal would not be ideal. I'm not saying it can't be done, but I won't.
Posted by: Mueller Aug 11 2006, 09:20 AM
But getting back to the original question I don't think you could properly add sub frames to the front and rear w/o having a cage. The connection points of tubing to sheetmetal would not be ideal. I'm not saying it can't be done, but I won't.
yea, I think at a minimum a properly supported roll bar would be ideal to tie into for the rear (mounted to longs, as well as have the bar firmly attach to the seatbelt mounting area on the targa bar)
Chris, the subframe would have to go further back to attach/support the transmission...similar to this:
Posted by: JOHNMAN Aug 11 2006, 10:43 AM
I thought he was trying to stop bullets or build an anchor.
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