Race Cars and Motorsports

We're back at working on the car, Steve got here yesterday afternoon. We put it on the lift, pulled the front suspension and swapped in the early crossmember and have been putting all that back together. A couple of interesting points. The inner fenders have to be dimpled up maybe 1/4" above the shocks. The front crossmember bolts have to be swapped out for shorter ones, or as we did, turn them down and cut new threads. The steering pinion gets shortened 1-7/16". Nothing special there but we did find dust in the steering rack, not a nice thing to see. The assembly will eventually have to be replaced.

I think we'll put the new brake pads on and finish that up this morning, then move on to the engine and tranny mounts. We installed my old set of Huffaker -1" front springs so the front end will come down noticeably. There is no front swaybar but Steve has a 7/8" bar at home. I think we will split the rear bar and use it for traction control, and then we'll have to decide how to deal with lowering the rear. Maybe a main leaf with reversed eyes will do the trick. We will also bolt up the T5 before the engine goes back in, and if we manage, we might finish up the bottom welds on the driver's floor.

I'll try to get some photos today.

Jim

This weekend we swapped in an early front crossmember, which also involved shortening and rethreading the two rear bolts plus shortening the rack pinion 1-7/16", installed the T5 plus a new S10 slave cylinder, positioned the shifter at the rear shifter hole position which required liberal application of a BFH th the tunnel for bell bolt clearance, made up motor mounts and have the damper maybe 3/4" off the crossmember. Photos below.



There is a bit more work on the mounts but you can see how it will go. The driver's side riser will be boxed, the other left open for a pass through.


With the Huffaker -1" competition springs the front will sit about 2" lower than the stock '74-1/2. Thinking about having the rear springs de-arched and adding a leaf.


Steering shaft splice.


Exhaust port clearance is a little tight here. We are considering cast manifolds.


Jim

you're planning on taking a stagger tape or gauge, right?

Could be. If I knew what it was...

Jim

Do they really measure tire stagger for a road course car running street tires? I thought it was only used with racing slicks & oval tracks.

Could be. If I knew what it was...


Stagger is difference in tire dia between the left and right side. You can use a tailor's tape or US race shops sell special "tire tapes" OR sliding gauges demarcated in ( inches / pi ).

[racecareng.com]

Stagger gauges are pretty hard to mishandle. Stagger TAPE measurements, on the other hand, should always be done by the same crewman with attention to repeatable procedure. It's very easy to induce variations in tape measurement.


It would be part of your post-pit tire analysis. Tire pressures and temps should be taken as soon as possible after the tires come off the car. Tread wear and stagger could wait a little bit.




I thought it was only used with racing slicks & oval tracks.



That was originally my thought as well. I've reconsidered though. In a 24hr race, you might burn tire sets bald. The delta in wear between L and R could be not inconsiderable by the end of the run.

It's not a bad idea, it'd give us something to do during those long mandatory pit stops.

Jim

Another Pit Stop coming up this weekend. Steve gets here Thursday afternoon, Dan will be here Friday evening. We will be fitting the radiator, finishing up the motor mounts, and perhaps installing the driveshaft and exhaust manifolds among other things. Matt will be here over the weekend and Dave will come over when he is free. Carl, and Scott, if either of you guys can make it that'd be great, and we'll not turn away any others who want to stop by.

As well as working on the racer, we will be trying to get Dan's TR7/1UZ conversion to where it can be fired up and driven if we can by the time he leaves on Tuesday.

My car is driveable but still needs wiring done on the transmission controller and a paddle shifter built. I don't expect to spend any time on that, but if I do get the bottom connectors done by then and I like the way it is acting I may take it down the street a time or two.

Jim

Here's a trick I missed that we could do.

That rear suspension has a number of what you might call creative solutions and a good bit of out-of-the-box thinking. I love to see those sort of solutions, innovations in suspension design tend to come slowly. I'm not real sure at this point exactly which solution we will use in lowering the car but it sure is nice to have options.

Jim

Quote:

Trying to build it to be approved for ChumpCar/Lemons racing.
Here's the gist of it.

At minimum, cage must include: Full front and rear hoop, appropriately braced to each other along the roofline (halo type and side/downbar type are also acceptable); two driver-side door bars (X-design is acceptable); appropriate main-hoop backstays with no bends, located as close to 45 degrees from horizontal as practical; one main-hoop diagonal; appropriate spreader plates and gussets; complete 360-degree welds at all joints, including all car-to-cage joints. Each major loadbearing member must be formed from a single, continuous tube. On all sides, all drivers' helmeted heads must be at least two inches inside the area enclosed by the cage.

I know I'm probably going to need to make a few modifications, but I wanted to avoid starting completely from scratch.

[www.mgexp.com]

We installed the driveshaft, re-packed the wheel bearings, cleaned up the brake rotors, got the calipers ready to install, put in the rear flex line, installed rear slave cylinders, plumbed the clutch hydraulics and bled the lines and even routed a bleeder line up close to the master. (In theory we could bleed the slave back into the master but at this point the fluid isn't clean enough for that.) We also shortened and installed the shifter, installed a water pump and carb, plumbed the fuel line and installed the valve covers. We decided to go with a stock MGB seat because the APC seat we have is just too big, sits too high, and we lose all front/rear adjustment. We got radiator hoses but haven't mounted the radiator yet so those weren't installed.

We need the front engine pulleys (2.8L), could use an MGB radiator support (I have no idea where the original one might have gone) and some sort of an air cleaner for the odd 2 bbl carb that was used on the 2.8, also an exhaust manifold for the driver's side. I expect we will have to cut and weld a stock one but we need a good starting point, which would be a stock rear dump manifold.

We have yet to lower the rear suspension also but we found a set of front swaybar links and reinforced them. We do not however, have the front lower control arm links that they attach to. The '74.5 had no swaybar and therefore used the plain links without the reinforcing plate and mounting hole. My last set went in modified form to Raliegh to be put on the MG-Roadmaster so I don't have any more of them. Took me quite awhile to figure out where the last pair had gone.

We also have a 13" TR7 steering wheel we are considering using, though it will require some sort of an adapter. The leather is stripped off but we are thinking of wrapping it with baseball bat grip wrap. Obviously open to an easier solution as I'm not seriously keen on more custom machine work at the moment.

All in all a good weekend. What doesn't really get conveyed by these reports is the sense of comraderie and brotherhood shared in these sessions, but it was without any doubt a bonding experience, and a good one.

Jim

Next work weekend, post ahead of time. Maybe I can make it down.

Quote:

We do not however, have the front lower control arm links that they attach to.

A set of negative camber lower A-arms would be nice!

I have a line on a set of negative camber lower A-arms with V8 bushings already installed.

Great Carl, those should work fine. We can try them and see how well we like them, and it'll be a good opportunity to evaluate them anyway, this being an endurance event. I know a lot of owners have considered using them.

I think Steve has a stock seat we can use.

We need to decide on how we are going to lower the rear suspension but I'm inclined to just try flipping the main leaf of the spring pack and see what that does before moving on to something more difficult. Maybe de-arch it if we need to, or even reverse the arch. I'm not sure how much of that it'll take without breaking, but I do know I've seen leaf springs badly bent up in junkyards so we might be OK.

Once we have pulleys we can make the alternator mount, then once we install the brake flex lines and bleed the brakes we should be about ready to run. Oh yes, we need another exhaust manifold first so we can hook uo the exhaust.

I'm going to try to schedule a weekend between now and June 15 to give Dan a chance to get his wiring done. I don't know if you guys will be able to make another trip up here that soon, but let me know.

Jim

I still have my original seats if you want.

I really think this leaf spring mod & restoring to the CB leaf spring mounts will do all we need for now.

Bent Leaf Spring





Edited 4 time(s). Last edit at 05/15/2015 04:27PM by MGBV8.

Stock


Modified

Stock


Modified





Tube is 1 1/16" mild steel pipe.



Edited 1 time(s). Last edit at 05/15/2015 05:19PM by MGBV8.

Finished raised shackle