New Service: Custom 928 Roll Cages
08-21-2012, 01:48 PM
#1
Developer
Thread Starter
New Service: Custom 928 Roll Cages
Just a note to make you aware that we have opened our shop to racers that need a full welded-in custom roll cage for their 928.
This is a complete, welded-in 6-point or 8-point roll cage to meet or exceed your race sanctioning body's safety requirements.
At some point in your racing of the 928, the bolt-in 4-point roll bars just wont cut it. Usually this is at the point where you are racing wheel-to-wheel. Then the rules books require welded in roll cages with side-impact door bars installed. Also, a bolt-in 4-point bar does little to stiffen the car against uni-body twist - where a 6 or 8-point cage does a LOT. This will make lap times faster! Finally, the bolt-in bars are all mild steel, where the roll cage can be chrome-moly steel (optional) which is lighter and stronger.
Unique to our cage construction is that we tie the roll cage directly to the rear shock tops, and we tie the rear shock tops to each other for maximum frame stiffness. Access to the shock top for adjustment is retained. Also: our forward bars (8-point cage option only) are under the engine, not over the engine, allowing maximum access to the motor for ease of service. See photos.
All welding is performed by our professional and certified welder with more than 12 years of custom race car cage experience. Top quality welds and fitment.
You must provide: Your 928 to us with the actual racing seat to be used already fitted and adjusted to your liking.
This is required so we can then locate the main hoop, the shoulder harness mounts, and the door
side bars. You need to also provide us with the rules book for your race sanctioning body so we can
be sure to build to their roll cage specs.
Optional: Before the roll cage can be fitted and welded, the entire interior, dash, and headliner have to be removed.
All the sound-deadening mat must be removed from the floor of the car. We can do these things for you,
or save some money and do them yourself BEFORE you bring your car to us. We also recommend the
interior door panels be removed, which allows us to bend the door side-bars out and further from the driver.
It is best if the windshield is removed also.
Pricing: Base roll cage: 6-point (Main hoop, dash hoop, and two rear braces as shown with gusseting and bracing
in DOM mild steel. Includes two drivers door side bars and one passenger door side bar). $3720.00
Upgrades: For each additional door bar, add $175.00 (includes Gussets between bars)
For Upgrade of "X" brace added in rear down bars add $225.00
For upgrade to 8-point cage (two additional bars added through the firewall to the front frame), add $275.00
For upgrade to all Chrome-moly tubing, add $500.00
For gutting the interior, removal of dash, and removal of sound deadening material: Shop rate at $120/hr
Painting interior when finished: Shop rate at $120/hr
Note: Pictures shown is from a 928 with all options shown. Extra door side bars, 8-point mounts in front of firewall,
chrome-moly tubing, an "X" brace in rear down bars, and interior painted.
For more pictures and information, see our webpage for this item here:
http://www.928motorsports.com/parts/..._roll_cage.php
Thank you for you interest!
This is a complete, welded-in 6-point or 8-point roll cage to meet or exceed your race sanctioning body's safety requirements.
At some point in your racing of the 928, the bolt-in 4-point roll bars just wont cut it. Usually this is at the point where you are racing wheel-to-wheel. Then the rules books require welded in roll cages with side-impact door bars installed. Also, a bolt-in 4-point bar does little to stiffen the car against uni-body twist - where a 6 or 8-point cage does a LOT. This will make lap times faster! Finally, the bolt-in bars are all mild steel, where the roll cage can be chrome-moly steel (optional) which is lighter and stronger.
Unique to our cage construction is that we tie the roll cage directly to the rear shock tops, and we tie the rear shock tops to each other for maximum frame stiffness. Access to the shock top for adjustment is retained. Also: our forward bars (8-point cage option only) are under the engine, not over the engine, allowing maximum access to the motor for ease of service. See photos.
All welding is performed by our professional and certified welder with more than 12 years of custom race car cage experience. Top quality welds and fitment.
You must provide: Your 928 to us with the actual racing seat to be used already fitted and adjusted to your liking.
This is required so we can then locate the main hoop, the shoulder harness mounts, and the door
side bars. You need to also provide us with the rules book for your race sanctioning body so we can
be sure to build to their roll cage specs.
Optional: Before the roll cage can be fitted and welded, the entire interior, dash, and headliner have to be removed.
All the sound-deadening mat must be removed from the floor of the car. We can do these things for you,
or save some money and do them yourself BEFORE you bring your car to us. We also recommend the
interior door panels be removed, which allows us to bend the door side-bars out and further from the driver.
It is best if the windshield is removed also.
Pricing: Base roll cage: 6-point (Main hoop, dash hoop, and two rear braces as shown with gusseting and bracing
in DOM mild steel. Includes two drivers door side bars and one passenger door side bar). $3720.00
Upgrades: For each additional door bar, add $175.00 (includes Gussets between bars)
For Upgrade of "X" brace added in rear down bars add $225.00
For upgrade to 8-point cage (two additional bars added through the firewall to the front frame), add $275.00
For upgrade to all Chrome-moly tubing, add $500.00
For gutting the interior, removal of dash, and removal of sound deadening material: Shop rate at $120/hr
Painting interior when finished: Shop rate at $120/hr
Note: Pictures shown is from a 928 with all options shown. Extra door side bars, 8-point mounts in front of firewall,
chrome-moly tubing, an "X" brace in rear down bars, and interior painted.
For more pictures and information, see our webpage for this item here:
http://www.928motorsports.com/parts/..._roll_cage.php
Thank you for you interest!
Last edited by Carl Fausett; 08-21-2012 at 04:01 PM.
08-21-2012, 03:53 PM
#3
Developer
Thread Starter
Thanks. I'm expecting a question about forward strengtheining bars into the engine compartment.
Two thoughts, preceded by the statement: This is a custom roll cage build. If the customer wants over-motor strengthening bars, we can make that happen. No problem.
But I don't default to adding them for these two reasons:
1) Because the 928 uses a dual-wishbone front suspension and not a single lower-arm with coil-over shock like others... we do not have the same loads on our shock tops, and the top of our shock moving in or out does not affect our Camber.
It certainly has a large effect on Camber on any car that uses McPherson strut or single-wishbone with coil-overs - so a roll cage that is tied into the front shock top makes a loft of sense for them. But, as I said, on the 928 flexing of the uni-body at the shock top does not change our camber...
Twisting of the forward frame rails does.
So I prefer to take the forward roll cage bars direct to the problem and try to reduce frame twist and flex directly where it occurs - the frame that our lower wishbone is mounted to.
That's why our (optional) 8-point cage goes from the Drivers forward hoop through the firewall and to the front frame as shown. Direct to the problem area to stiffen it.
2) Engine access. If you have crewed for a race team before, you know how much a PITA the forward cage over the motor can be. And in our case - we have supercharging, tubing, intercooler and such already occupying anywhere you would like to run a strengthening bar through.
So the lower, frame mounted front bars makes more sense for us.
If you are going to race an NA motor, you'd have more room than we do. We can add over-engine front bars if you like, but the car should be delivered to us with complete engine installed, so we know what space envelope we have available.
Two thoughts, preceded by the statement: This is a custom roll cage build. If the customer wants over-motor strengthening bars, we can make that happen. No problem.
But I don't default to adding them for these two reasons:
1) Because the 928 uses a dual-wishbone front suspension and not a single lower-arm with coil-over shock like others... we do not have the same loads on our shock tops, and the top of our shock moving in or out does not affect our Camber.
It certainly has a large effect on Camber on any car that uses McPherson strut or single-wishbone with coil-overs - so a roll cage that is tied into the front shock top makes a loft of sense for them. But, as I said, on the 928 flexing of the uni-body at the shock top does not change our camber...
Twisting of the forward frame rails does.
So I prefer to take the forward roll cage bars direct to the problem and try to reduce frame twist and flex directly where it occurs - the frame that our lower wishbone is mounted to.
That's why our (optional) 8-point cage goes from the Drivers forward hoop through the firewall and to the front frame as shown. Direct to the problem area to stiffen it.
2) Engine access. If you have crewed for a race team before, you know how much a PITA the forward cage over the motor can be. And in our case - we have supercharging, tubing, intercooler and such already occupying anywhere you would like to run a strengthening bar through.
So the lower, frame mounted front bars makes more sense for us.
If you are going to race an NA motor, you'd have more room than we do. We can add over-engine front bars if you like, but the car should be delivered to us with complete engine installed, so we know what space envelope we have available.
08-21-2012, 07:53 PM
#4
Rennlist Member
The few things that would make it a BETTER cage...like NASCAR bars that go OUT from the A and B pillar attachments to sit out over the edge of the lower frame rail..would add a number of hours of cost..so it should also be considered as an option.
This leaves room for a wider more enveloping seat, easier (much) driver access into/out of the car, and critical impact absorbtion as the point of impact..instead of 4-6" closer to you (from which point there will be additional intrusion)..plus ive seen door bars out to the edge of the sill keep car from becoming absolutely bent with that extra energy being given to the cage, and not the chassis.
Not a complaint that its not IN the quoted build, but its an option that should not be lightly discounted by anyone lookin to do this.
Its -hard- to build a -full- cage right, for under 3500-4000 these days as the rules on cage prep have tightened up over the years to discourage cost cutting..and some ORGs have started actually getting cages inspected where for years, they were incomplete (missing welds) cages but nobody cared.
And..if you think you did enough prep for your guy to start a cage, you didnt. Thats a cost sinkhole as well if you dont have dozens of your own hours prepping the car.
This leaves room for a wider more enveloping seat, easier (much) driver access into/out of the car, and critical impact absorbtion as the point of impact..instead of 4-6" closer to you (from which point there will be additional intrusion)..plus ive seen door bars out to the edge of the sill keep car from becoming absolutely bent with that extra energy being given to the cage, and not the chassis.
Not a complaint that its not IN the quoted build, but its an option that should not be lightly discounted by anyone lookin to do this.
Its -hard- to build a -full- cage right, for under 3500-4000 these days as the rules on cage prep have tightened up over the years to discourage cost cutting..and some ORGs have started actually getting cages inspected where for years, they were incomplete (missing welds) cages but nobody cared.
And..if you think you did enough prep for your guy to start a cage, you didnt. Thats a cost sinkhole as well if you dont have dozens of your own hours prepping the car.
08-22-2012, 11:17 AM
#5
Developer
Thread Starter
Right. When we had this cage made, we still had glass in the doors and a flat inner door panel. So the fabricator could not extend the side bars out into the door.
The safety inspectors like to see some distance between the bar and the occupant, so bending the side bars outward so they actually are close to the outer door panel is suggested.
We offer that service.
The task he had with our car was unusual. I needed to pass SCCA safety regs, PCA, and Pikes Peak rulebooks. Making one cage to please all 3 was a trip - but he did it. Since then, this cage has been inspected by NASA and the USFRA (Utak Salt Flats racing Association) and passed them as well.
The safety inspectors like to see some distance between the bar and the occupant, so bending the side bars outward so they actually are close to the outer door panel is suggested.
We offer that service.
The task he had with our car was unusual. I needed to pass SCCA safety regs, PCA, and Pikes Peak rulebooks. Making one cage to please all 3 was a trip - but he did it. Since then, this cage has been inspected by NASA and the USFRA (Utak Salt Flats racing Association) and passed them as well.
