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per 11-17 GCR pg 88 "Cars competing in Improved Touring, Spec Miata, Touring, and B-Spec may extend one tube, from each front down tube, forward to the firewall, bulkhead or wheel well, but not penetrating any panel."
nor do I believe that what he intended it to be .... to that point however, unless there's another section that I missed I do not believe that Touring requires footwell bars.
Originally Posted by 3X2
The oem dash bar does not meet the tubing spec for material, pg 88, or size, pg 89, for cars over 2700 pounds.
Agreed, and was my point if it doesn't meet 1.5 x .120. I don't recall that bar being ERW, however that would be another point of potential concern.
I'd be interested to know of those points had been vetted out initially or if there's been some agreement so far, however I believe we're on the same page as far as area of concern.
F. TUBING
1. Seamless or DOM mild steel tubing (SAE 1020 or 1025 recommended) or alloy steel tubing (SAE 4130 or T45) , or Docol R8 tubing must be used for all roll cage structures. Alloy and mild steel tubing may not be mixed. ERW tubing is not allowed.
2. The following table shows the minimum allowed tubing outer diameter and wall thickness by vehicle weight:
<chart summarized>
2700 lbs and up
1.50 x .120
1.750 x .095
2.00 x .080
I build my own cages. I TIG, MIG, and plasmacut own tube bender's too. People need to read the rules for their sanctioning bodies. People also need to know that every cage design is a compromise and that compromise starts with cost vs. goals. Someone mentioned T4 needing no dashbar. Well yes those little underpowered cars are lucky to go 120 while a restricted T2 C5 vette with 300lbs more than factory weight will still do a bit over 160mph at Daytona.
So the spec vette cage is a good basic design for its purpose. PMS has done a great job at an unbeatable price. If you want to take the PMS cage to the next level it is very easy to pull the dash and add a true dashbar. It is also very easy to add in the footbox intrusion bars or attachment points of door bars to the door sill. All that add money and today you are lucky to find a cage under $5000 and many are $7500! So for $3000 PMS is really doing us all a great service and it shows he really loves the sport wanting to help make SpecVette happen because he isn't getting rich making SpecVette cages.
I would have a SCCA tech inspector look at and approve that cage. Of course, just because one inspector approves it, doesn't mean the next one will. Does spec corvette require some sort of a logbook? Personally, I believe the cage does not meet T1 or T2 rules.
I would have a SCCA tech inspector look at and approve that cage. Of course, just because one inspector approves it, doesn't mean the next one will. Does spec corvette require some sort of a logbook? Personally, I believe the cage does not meet T1 or T2 rules.
There are no T1 or T2 rules just the SCCA GCR that applies to all cars with minor modifications per class regarding things like attachment point number and piercing the firewall. Sanctioning bodies balance what is in their best interest and what is best for drivers in attracting drivers. For example SVRA mandates a fuel cell for all except the legacy 1st gen spec miata class that runs as the old spec rule with no fuel cell. The old formula was safe and SVRA accepted that and so those miatas get to run in SVRA. When specCorvette proves itself and the class grows the closest SCCA class to the SpecCorvette is SCCA T2. Most likely , SCCA will welcome the SpecCorvette car counts with very little if any modification from SpecCorvette format. If anything SCCA might change restrictor plates and weights to ensure parity which is their typical MO. It is extremely unlikely IMO that SCCA with mandate cage modifications despite how close Spec Corvette cages are to the SCCA spec.. Looking at SCCA's allowance of the Porsche spec Boxster into SCCA T3 with no cage modification is precedent of what I say might be true. And if anyone wants to add a stout dash bar, thicken their tubing, go 4130 chromoly, docol R8,or NASCAR bars increasing attachment points to the sill plate that's your choice. Increased safety is never denied.
Last edited by fatbillybob; 11-02-2017 at 12:12 AM.
I don't think the speccorvette rules could be more clearer: "The safety rules within the SCCA GCR are the over-riding guidelines with regards to safety specifications listed below." and "Cage must meet SCCA spec's for T1".
Personally, I would build the cage to SCCA T1 specs, if in the future, one would want to go SCCA T1/2 racing.
I checked back with my cage builder and they confirmed the cage in my spec corvette is compliant with NASA/SCCA and will not have an issue with tech inspection.
I checked back with my cage builder and they confirmed the cage in my spec corvette is compliant with NASA/SCCA and will not have an issue with tech inspection.
Regardless of whether the cage is nasa/scca compliant or not it still looks like a good way to lose your legs in a crash in it's current form.
In order to keep the cars water temps low I decided to replace the stock radiator with an aftermarket one from ECP Radiators. It's an all aluminum radiator and is about twice as thick as the OEM radiator.
Overall it appears to have a pretty decent build quality and the install was fairly simple. I did have to make some small cuts/mods on the OEM plastic fan mounts piece that silps onto the backside of the radiator.
It was priced really well at $250.
I forgot to take pics of it before I put it in but here is a pic from their website.
There are no T1 or T2 rules just the SCCA GCR that applies to all cars with minor modifications per class regarding things like attachment point number and piercing the firewall. Sanctioning bodies balance what is in their best interest and what is best for drivers in attracting drivers. For example SVRA mandates a fuel cell for all except the legacy 1st gen spec miata class that runs as the old spec rule with no fuel cell. The old formula was safe and SVRA accepted that and so those miatas get to run in SVRA. When specCorvette proves itself and the class grows the closest SCCA class to the SpecCorvette is SCCA T2. Most likely , SCCA will welcome the SpecCorvette car counts with very little if any modification from SpecCorvette format. If anything SCCA might change restrictor plates and weights to ensure parity which is their typical MO. It is extremely unlikely IMO that SCCA with mandate cage modifications despite how close Spec Corvette cages are to the SCCA spec.. Looking at SCCA's allowance of the Porsche spec Boxster into SCCA T3 with no cage modification is precedent of what I say might be true. And if anyone wants to add a stout dash bar, thicken their tubing, go 4130 chromoly, docol R8,or NASCAR bars increasing attachment points to the sill plate that's your choice. Increased safety is never denied.
The inclusion of a class offered by another sanctioning body does not necessarily give it a pass on the SCCA GCR cage specs. In the case of SMG (Mustangs) they are allowed additional attachment points, but not fewer. SE46 (BMW) uses standard SCCA GCR spec for production based cars. Spec Boxster must use the SPB rules in the PCA rulebook.
If Spec Corvette has no specification by a recognized sanctioning body it will have to meet the GCR spec to run with SCCA. That means a dash bar. *unless the OE dash bar meets the material specs good luck getting that approved. Additionally, if you were to incorporate the OE dash bar, and it attaches to the chassis at additional points you may find yourself exceeding the allowed number of cage attachment points for Touring.
The front/forward feet are not required in Touring
c. Front Hoop Bracing
GCR - 87
9. Cars and Equipment
General
All open cars with a high front hoop and all closed cars except those competing in the T4,
Improved Touring, Spec Miata, and B-Spec classes must incorporate a horizontal front hoop
brace at the approximate level of the dashboard. It is recommended that cars competing in T4,
Improved Touring, and Spec Miata classes also have the front hoop brace.
2. One tube must extend, from each front down tube, forward to the firewall or through the firewall except in vehicles in Improved Touring, Spec Miata, Touring, and B-Spec. This tube, one on each
side, must connect to the chassis at a point not more than 12 inches forward of the front axle
centerline.
3. Cars competing in Improved Touring, Spec Miata, Touring, and B-Spec may extend one tube, from
each front down tube, forward to the firewall, bulkhead or wheel well, but not penetrating any
panel.
Those cages look nicely done, but I would not show up without a proper dash bar.
Those cages look nicely done, but I would not show up without a proper dash bar.
RX7, you happen to have any pics you can share that show a proper dash bar? I'm just trying to visualize where that would be or how I would have that added in. Thanks for you input on this.
RX7, you happen to have any pics you can share that show a proper dash bar? I'm just trying to visualize where that would be or how I would have that added in. Thanks for you input on this.
Looks like there may be room to run it inside the C5 dash.
Those cages look nicely done, but I would not show up without a proper dash bar.
I'm not involved with the specCorvette rules or the organization. It is funny how everyone wants cheap racing but then make no compromises to get there. Who knows how specCorvette will evolve but some of the comments here are the exact kind of "rules creep" that keep racers out of the series. People have to understand compromise and that you can't please every driver. As a DIY guy it is easy to add a dashbar but it is extra time and cost to those who can't DIY. I just fabricated and welded a whole frame for $65 bucks in materials to hold the C5 sriveline so I can lift the chassis off the driveline to service it. If you commission someone to make one for you they would be $500 bucks easy. This is where specCorvette decided to drawn the line. We only have a couple of pictures and it appears that there is no dashbar. No problem add it if the other class you race demands it. You see if specCorvette put the dashbar inside the dash some would complain they loose the HVAC or HUD and have to cut some dash. There is someone in this thread already not wanting to cut the door panels and this is a racecar! If you follow the OEM facotry dashbar some would say while legal the "S" bend is not as strong as a straight bar. You can't please everyone...ever. So the smart play is what SpecCorvette has done. You have a basic $3000 cage and if you want NASCAR bars you can pay for those. You want a dashbar you can pay for that too. No one is going to deny an increased level of safety.
Congrats to the racer who found the $250 big radiator. Keep us posted on how it works. This is the kind of thinking we need to race corvettes at miata prices. If people want the $1000 ron davis with right side oil cooler go for it!
That curved dash bar is interesting in that it is probably barely effective. My dad was a structures engineer on planes that ran the gamut from the F5 fighter to the B2 bomber. I don't have to consult with him to know he would frown on a curved bar like that. It is already partially pretzeled. The stock straight dash bar is stronger than that curved one. The white straight bar in the other photo is the strongest.
11-01-2017, 12:58 PM
