I've always been curious about chassis rigidity offered from the different door bar options. NASCAR vs an X that protrudes into the door vs a flat X. One or two friends have sent me pictures of modern TA cars using a straight X. Doesn't seem like it would offer the same protection. Any thoughts?

Little clarity on the post above about A-pillar tubes. I prefer a continuous tube from the floor of the a-pillar to the main hoop but the gusset locations stay the same as mentioned above whether a continuous tube or a halo style cage. I may start a thread for tips on layout and bending tube, but haven't gotten around to it yet.

On to cooling system! Road racing in Texas is a definite challenge for cooling and its a problem I really didn't want. I knew that I wanted as big of a radiator/oil cooler as I could handle and close off the front of the car as much as I could. It may be an aero brick but at least try to make it better. Here's where the problem started - ducting. Sure, the engine is moved back and its a big car, but having the front closed off and a duct to feed a vertical or near vertical radiator just wasn't in the cards space wise. More used race parts! I found a PWR/C&R radiator/oil cooler module from DEI that was in excellent shape for an absolute steal but it is a freakin unit. Probably north of 60lbs when full of fluid. Here's were I started. Huge front area, mounted with a slight angle, taking up about as much space is available




How am I going to make a duct for that? Being so heavy and so far outside the axle made me start to think - if you're going to start laying the radiator down for a duct, might as well keep going and get the weight as low as possible. Here's where I ended up. The face of the radiator is level with the bottom of the bumper.




Now this I can work with. Weight as low as possible, and an uninterrupted path for airflow. Cut some more factory frame rail off, build some 1x1 framing, and here we are.


Only thing left now is how to fill this thing. Used race parts! I found a fabricated pressurized cooling system reservoir that came with an inline pressure relief valve (PRV) that would do nicely. Here it is mounted on the firewall making it the highest point of the cooling system by a fair amount. There will be more on this item when it gets plumbed.



This brings up a topic - why not just put a filler neck somewhere in the upper hose(s) from the heads or TStat housing like so many people do, even OEM's? Downflow radiator anyone? Location matters! The radiator I found is about as badass as I could have hoped for, having extruded tubes. Even with the nice tubes there is still a flow restriction created by the radiator. Just for argument sake lets say 1.5psi and you have the filler neck in the upper hose with a 25psi cap. As soon as the water pump is moving water, that cap immediately sees 1.5psi. You have just lowered the effectiveness of that cap by 1.5psi. Sure, doesn't sound like much but when its the difference between water and steam...it matters. Feeding the lower hose is the only way to go IMO, if you're able.

Here's the lower coolant pipe feeding the water pump. Notice the -10 welded bung on the top of the coolant pipe bend. This is how the cooling system fills - also something to keep in mind. All the areas that are higher than this point have air bleeds - cylinder heads and top of radiator.




A quick note on welded on fittings - obviously this is a welded on -10AN. Koul Tools offers a really neat setup to recondition the flare on this fitting should it get damaged. If you're in a situation where you cannot recondition or don't have the tool, you're cutting that fitting off and welding a new one on. O-ring Boss (ORB) weld on bungs definitely don't have as large a variety of options as far as venders and sizes go, but they're getting better all the time as more people incorporate them. If I were to make that pipe again today it would be a ORB welded on and a straight fitting coming off the top of it. Yes, that oring is another leak point, but not an event ending leak point like a damaged flare.

Anyone notice the welded on AN fittings in the cylinder heads? Prime example of "why". The heads are a late casting C3 and only one of a couple pairs I've seen with a fitting welded in - most of them are tapped for NPT. As much as NPT makes me mad depending on the use, I would much rather have preferred an NPT. One day while working on the car, I'll damage that fitting. And life will suck.

Did anyone notice the lack of a lower ball joint in the control arm?