Roll Cage Ideas
No work was done on Blue over the weekend. As you all know, I promised the Missus that I would finish the nightstands I’ve been building for her prior to wrenching on the MR2’s. Well, with her permission I did a little work on the MR2’s, but I’m outta rope. I got the first bit of stain/color work done on the nightstands over the weekend and plan to get the last step on the color work done this evening. Then it will be onto more MR2 work until I can spray final finish on her tables.
That said, I’m obsessively thinking about our LeMons racer all the time. I know that we have a roll cage issue pending, that being the fact that Matt is quite tall (6′5″-ish) and will be a tight squeeze in the car even without the helmet. But I may have a solution, as shown in the photos below.
Before you look at the pictures, remember this: we are taking a street-legal vehicle and are turning it into a race car. It will not be subject to a reverse vasectomy. If we can find a way to keep the roll cage inside the frame, all the better, but this is at least an alternative (credit to Free Range Racing):
Brilliant! And we’d even get to do a make-your-own-T-tops project! I guess the rollcage will subsitute for whatever stiffness is lost by removing the sides of the roof btn the A and B pillars?
Is that rollcage welded to the strut towers near the engine?
I suspect that the car in this photo was already a t-top ride, but yes, that would be true. And it does look as if it is welded to the strut towers. Once we get the engine running, I think one of our must-do projects is a DIY brace between the strut towers to minimize rear end flexing. There’s no rear antiroll brace in the ‘89 MR2, or so I’ve read. I think a DIY brace that works with the welded rollbar brace would be excellent and would earn us mucho LeMons points.
@Pat
Oh yeah. I saw a few pics of that setup (homemade anti-sway bar) on one of the MR2 forums. Angle-iron and some spot welds. And if the engine cover is permanently removed (how bad is it if the engine bay gets rained on while running?) we wouldn’t have to worry about any clearance issues.
Once we get the engine running, that is. The devil’s in the details.
@Matt
I think that what we should do in regard to the engine cover is to establish a couple of large electric fans running such that they are exhausting out the top of the engine bay, like these, if we can find some in the junkyard:
This accomplishes several goals at the same time:
1. Extra engine cooling — always a good thing in an endurance race;
2. The windforce will redirect any rainfall away from the engine area; and;
3. Finally and most importantly, the fans will provide Blue with additional downforce a la Jim Hall’s 1970 Chaparral 2J Can Am racer.
rain won’t hurt as long as the ignition and ecu stay dry. tuberware and silicone is your friend.
as for the cage I think it can be done “in house” i have some friends over in murphy that could help out. He has a really nice bender. One better than the one in the pick could be turned out in a weekend.
@Grayson
Cage: that is fan-freaking-tastic. The exterior cage will also protect me if we need to cut a hole in the roof to accommodate the crown of my helmet!
@Pat, I think I had one of those kinds of fans in my dorm room. One side blows stale air out and one side brings fresh air in, right? I’ll look in the attic to see if I still have it.
Now go get those damn tables done so we can figure out if we have a working car!
@Matt
Those are both blowing-out fans. An inny-outy fan wouldn’t do us much good on the fan-downforce idea, would it?
@Grayson
Awesome. All-around awesome.
Pat, an inny-outy would be even better–we could set it up on an axis with a counterweight so that whichever way the car’s turning it could provide extra suckage on the inboard side and extra boost on the outboard side! Just have to convert the motor from 120vAC to 12vDC. Definitely worthwhile.
It’s been done..the fan thing and with success…google BT46 fan car in images for pics
Brabham fan car
Brabham BT46B with its fan covered by a dustbin lid!Having witnessed what ground-effect could do for cornering speeds, Gordon Murray, who would later design the awesome McLaren F1, decided to take the principle one step further. Because the Brabham BT46 used an Alfa Romeo flat-12, it couldn’t use Venturi Tunnels to naturally speed up air flow beneath the car, so Murray got round this by simply installing a large engine-driven fan under the rear wing. This literally sucked it down onto the road, even in the pits the car visibly squatted when drivers blipped the throttle. F1 regulations banned ‘movable aerodynamic devices’ so Murray claimed the fan was simply for cooling purposes. On its debut at the 1978 Swedish Grand Prix the car won easily in the hands of Niki Lauda and the other teams were in uproar. Mario Andretti said it was like being behind, ‘a bloody great vacuum cleaner. It throws muck and rubbish at you at a hell of a rate’. The car was declared legal but Brabham owner Bernie Ecclestone decided to voluntarily withdraw it.
That’s why Hall’s design was superior. He ran the fan on the Chaparral car off a separate 5 HP motor so that the downforce was consistent at all times, for the very reason identified on the Brabham car.
I think we need to figure out how to add on monopoly money shooters. Even if just for tech inspection/pregame, the sight of the TARP car driving along spewing out money would be one for the ages.
ala potato gun?
Or have a bag attached to the top of the cage and at the beginning of or during the parade laps each day, have some sort of ripcord the driver can pull that releases the “money” into the air. That way we’re not really at speed, creating a hazard/distraction during racing.
I was thinking about the potato gun idea, actually. Or maybe some sort of loader and fan setup that would utilize the trunk and the holes that will be left when we remove the rear taillights. So it would spew money out the back as it went down the road.
Of course, that may be a metaphor that cuts too close to the bone, depending on how things go with this car.
There are some guys up in Denton who are working up two MR2’s for the Houston race, one MK1 and one MK2. They have a couple of MK1 cages that they are using as templates for their MK1 roll cage. Grayson, do you think that it would be of any benefit for us to get measurements off those cages before starting our cage? Or would it be just as fast for us to just measure before we cut?
I’m really looking forward to doing the cage. I’ve been wanting to learn to weld for several years. I’ve watched a ton of training videos (thanks, YouTube!) but haven’t actually given it a shot yet.
It would be even better if we could borrow one for a while. That way when you bend a piece you just go lay it over there next to it to see if it is right. measurements would definitely help or just a visual will help. There are some things we can do before we actually go over to fab up a cage. We could get all the re-enforcement plates welded to the pan and on the back along the shock tower.
Grayson, they said that we’re welcome to come out and measure it anytime we like, so we just need to figure out a good time for us to do that sometime during business hours (or probably on a Saturday, too, they’re a race shop getting their own LeMons racer ready too). It might work if we showed up with a couple of cases of beer and asked if we could borrow one of them
My contact is Aaron at ATS Racing, his number is 940-293-1338 if you want to call him yourself. I’ve been communicating with him on MR2oc.com, he’s prepping a MKI and a MKII to run at Houston in February also.
And here’s a link to a big photo gallery from some guys who ran an MR2 in last year’s LeMons South race in South Carolina. They totally chopped the top off the car. Our car looks about that gutted now. I thought this might give us some good tips about the roll cage, especially the mounting brackets that they built off the floor.