Safety First - Building a NASA Rally Spec Cage
One of the driving forces behind building the OLC2 (vs upgrading the '67) was the desire to make the transition from a street car that is driven on the track to a true track capable car that happens to be street legal. In the four years since the OneLapCamaro was finished we have been fortunate to have been able to participate in a variety of unique and challenging events... but there were several which necessitated more safety equipment than we had in the '67. Hopefully the OLC2 will address those needs with a comprehensive roll cage, fire system, and full selection of safety equipment.
When it came time to build a roll cage the question we had to answer was"what rule set should it be built to?"
The Tire Rack One Lap of America has no rules but some of the other events that we want to run - The Silver State Classic Challenge, Targa Newfoundland, and the Chihuahua Express - have explicit but not necessarily consistent guidelines. Ultimately we chose to build the cage to the most stringent - and logical - rule set we could find:
NASA Rally Sport
. It meets or exceeds most all road course rule sets and essentially follows FIA guidelines. Going this route means that the OLC2 will not only have a cage that we can be confident in but also that we will (we should) qualify for a Log Book as an Open 2WD Heavy car under Rally Sport rules.
The NASA Rally Sport roll cage rules break the construction in to seven required elements with options for each provided within the rule set. Follow along with our design...
Required Element 1 - Main Roll Cage Structure & Backstays
Design 253-3: One piece main hoop, two forward bars tied across the top of the windshield and two straight rear backstays.
while not part of Element 1 we added a bar behind the dash that will tie forward and support the pedal block.
the front bars in to the engine compartment are also not part of Element 1 but we wanted to position them as our work on the front continued. These bars may cause some issues with RS compliance as some groups prefer to see more crumple zone in front of the suspension but we should be OK.
With the main cage framework in place we mocked up some of the future elements
Required Element 2 - Roof Bars
Required Element 3 - Backstay Diagonals
The design for Element 2 and Element 3 ultimately tie in to one another. We chose 253-14 for the roof bars which dictates 253-22 for the backstay diagonals. Essentially these two elements consist of two "V" shapes which meet at the top of the rear main hoop.
This first attempt at the backstay diagonals was quickly scrapped as the diagonals did not end in the proper position. In me mean time work commenced on the next element
Required Element 4 - Main Hoop Diagonal Members
Design 253-7 - an X across the hoop with a separate harness bar that will be behind the X
Backstay diagonals are now in the proper position terminating within 3" of the backstays
Required Element 5 - Sill bars
Required Element 7 - Door Bars
This design ultimately results in three door bars - one horizontal bar parallel to the sill and two bars making an X across the door entry. This design is a variation of 253-9 which uses two shallow U shaped bars which meet in the middle.
which also includes
Required Element 6 - A-pillar reinforcement
also known as an FIA bar.
Looks almost like a '67 with a vent window...
All of the elements are coming together now...
And will all of the required elements in place we added the required gussets - in this case we chose to use "Taco Gussets"
We chose to add some additional protection for the foot wells and will now begin welding everything together...
GM Performance Parts LSA
When it came time to figure out a powerplant for the OLC2 we knew that the new GM Performance Parts line of LS based engines was the logical choice. The LS7 in the OneLapCamaro had been a great foundation for the '67 but for the '69 we knew that we needed more power. The solution was the LSA Engine from GM Performance Parts.
With over 550 HP on tap stock and more than capable of making 700+ with some simple tweaks it was definitely the way to go. For our purposes it was more than just a simple installation. We wanted to set the engine back 5+ inches to give us a little bit better weight distribution. That was about the max we could work with the SpeedTech Subframe and Torque Arm and going back that far required some serious reworking of the firewall.
We started by gutting the stock dash and cleaning up the cowl.
I would be lying if I told you that I knew why the decision was made to completely remove the cowl; unfortunately it was done before I knew it. Now I tell myself that we're saving some weight while, in reality, I know that it's going to be a monumental PITA in the future.
But at this point it's too late to fuss over bad decisions. All I can suggest say is "don't try this at home."
The Supercharged GMPP LSA is will be by Tremec's T-56 Magnum - the aftermarket version of the OEM TR-6060. Rated for 700 ft.lbs. of torque it should be ideal for the OLC2.
A quicktime bellhousing is more compact and lighter than the McLeod piece we used on the OLC.
Locating the LSA back from it "stock" position required making some room in the firewall to get the lay of the land...
Back almost 5" from it's "stock" location the LSA needs some help around the firewall and at the subframe.
As always, there is more than one way to skin a cat. I would consider this, in hindsight, to be the wrong way. Too much time, labour, and headache to justify. Once again... live and learn...
After some discussion the decision was made to remove the old firewall and replace it in it's entirety...
We began by removing the old firewall and started its replacement with a flat sheet of metal...
Getting a flat plane far enough back meant removing the factory "tulips" and cutting in to the structure
To give the new firewall some stability a bit of work was put in with a bead roller...
Before the flat panel was curved to replace the now missing tulips
Our LSA looks right at home with the very tidy firewall...
Repositioning the firewall meant repositioning the fender mounts as well - you can see that we're about 2" further back with the new firewall...
The engine setback also required some new clearances be made for accessories...
With some finish work the new firewall looks like it could have been like that way from the factory
To ensure that the LSA could make every bit of horsepower we went with a custom set of Stainless Works headers from SpeedTech. With 1 7/8" tube they were only available unassembled... Ironworks created a jig and welded them up in house...
We're well on our way now...
Next up - the Roll Cage!
Making Some Room
With the SpeedTech front and rear suspension in place Ironworks went to work on the front fenders.
One of the biggest shortcomings of the original OLC was the restricted turning radius, narrow track width, and limited tire options which came a a result of the stock subframe and stock fenders. The SpeedTech subframe would help with the turning radius and some of the tire size but to optimize the track width and get some really big tires under the front we needed to tweak the front fenders "a bit".
The '67 has been running a 275/35-18 front tire in combination with a 305 or 325/30-19 rear tire with the front track width being over 3" narrower than the rear. OLC2 is going to run 305/30-19s front and rear with a balanced track width. Follow along as we make some space...
Starting with the stock fenders...
Cleaned up and marked for preliminary cuts:
Started with three basic cuts...
Pulled out to ensure lots of clearance
Leaving the back of the fender well out from the door
The choice was old school IMSA style or some kind of transition in to the door... we chose the latter
Starting to look like something...
More transition work to come but it was getting close...
With the basics together the doors got some work to make the transition
Now we're getting a look at what the OLC2 is going to look like...
It still need "finish work" on the sheetmetal - gaps, fit, etc. - but we're on our way...
With the outside coming together it's time to turn our attention to fitting the GM Performance Parts LSA engine and Tremec T-56 Magnum...
SpeedTech Performance Suspension
With the roof replacement done the OLC2 project made the trek from Escondido to Bakersfield, California and Ironworks Speed & Kustom. Ironworks was the logical choice for the sheetmetal and tube work that were next on our list for the OLC2 project.
Before we could get started with the modification we needed to get the new front and rear suspension under the car and for that we turned to
Our 1967 Camaro used SpeedTech's modified "Chicane" front subframe kit which is based on am OEM subframe. While we have been happy with the performance we knew that if we were going to step things up a notch then aftermarket was going to be the only way to go.
We decided on SpeedTech's
kit which combines their
Pro-Touring Front Subframe
Rear Torque Arm
A logical addition to the Track Time package was SpeedTech's new
Chicane 9" Floater Assembly
Speed Tech Chicane 9” Floater
incorporates the Corvette ZR1 rear drive hub and factory park brake kit along with a NASCAR quality 9” housing with floating axles. The housing end is precision CNC machined from Billet steel to ensure the highest strength possible. The ZR1 drive hub uses a forged housing and dual bearing packs with 31 splines. This is a fully sealed unit that eliminates the possibility of any contamination getting inside, it also incorporates the ZR1 Active wheel speed sensor. This feature allows the addition of
Anti-Lock Brakes and Traction Control
. Another benefit is that there is no regular maintenance required like all other floater assemblies that require bearing cleaning and preload adjustment."
Perfect for what we are thinking for the OLC2.
Next up will be some sheetmetal work on the front to allow for some big front tires and improved track width...
OLC2 - From Humble Beginnings
The foundation for our OLC2 project is a relatively rust free 1969 Camaro shell that was owned by a friend in Southern California. Work had been started on the car but as is often the case plans changed and the shell sat for a while before we picked it up.
It still needed some rust repairs but was a good starting point - not too nice but not to bad.
First stop will be to Best of Show Coachworks in Encondido, CA where the roof will be replaced as part of an article for Camaro Performers Magazine...
You can read the entire article in
Kicking Off Project: OLC2
So what’s the plan?
I guess the best description is a modern take on a Trans Am style car – hardly a new theme for (the collective) us but more or less correct – or probably more accurately, more of a Porsche RSR theme – light weight, streetable but really track oriented, and just a bit different. This car will be 90% track focused and 10% street oriented; basically it will be street legal by necessity but not by choice.
Much like the OneLapCamaro I’m building it with one clear goal - to be competitive against some of the more modern cars in the Tire Rack One Lap of America… and if the end result more or less overlaps with the “Unlimited Class” tech rules for the Silver State Classic… well, so much the better.
Big tires front and back are a given. We’re going to work with SpeedTech and use one of their subframes and torque arm rear suspensions. We’ll push the envelope a bit on the front wheels and tires maybe running something like a 305 front with a 325 out back…. maybe…
Right now the car is at Best of Show where we’re waiting on some parts. Once they arrive they’ll swap out a rear quarter and install the mini-tubs. Then the roof comes off and the car will be shipped to Rodger at Ironworks in Bakersfield for a complete 12-point roll cage and some other “subtle” ironworks touches. The SpeedTech front and rear suspensions will go on and then we’ll work to fit a light weight clip on the car and shed whatever unneeded weight that we can.
Hopefully this is half as fun as the OLC build (and aftermath) was.
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