Free Raffle Car - Q45-2020 Challenge

To me, it's really fun to get the small stuff right. Whether it's just a simple bracket or the proper orientation of a zip tie, Ive learned I really enjoy having the time to do it right.

It doesn't look like it set you too far back. Great work.

Announcement. 

On Tues March 31st, this build will be featured an the The GRM Happy Hour video chat

Kudos to you for trying, finding problems, listening to advice, and pushing thru to the right answer.

This stuff isn't easy and I applaud you for sharing your mistakes.

In reply to TVR Scott :

Some might argue that this thread is 6 pages of mistakes, lol. I'm here it share, learn and have fun so its all good.

After the video call the other night Stampie asked for a link to the shocks I am using. I am assuming he meant the manufactures link as the for sale link is long gone. 

https://www.qa1.net/circle-track/suspension1/shocks/62-series-shocks

Here is a video showing how they are rebuilt

In reply to Fladiver64 :

Thanks.

Fladiver64 said:

In reply to TVR Scott :

Some might argue that this thread is 6 pages of mistakes, lol. I'm here it share, learn and have fun so its all good.

 

 

I so prefer seeing you working at it in real time, making mistakes, and having fun.  So much better thread than someone dumping 200 pics of what they did ten years ago, and acting like they're the best that ever was.

Back to work today, after the video call and many questions about the weight of the car I decided to try and get it on scales today. Now this is not the most accurate as I had to put some block in the suspension since there are not any springs or shocks installed, but it should give me an idea of where we are.

First a reminder of where we started 3289 lbs 42% rear

First time on scale today

WOW ! under two thousand pounds! but this is too good to be true. There are too many parts missing, suspension, brakes, wiring additional steel still needed, so I decided to start gathering up the parts and stacking them about where they belong. Put the front brakes, shocks and springs in a container and set it on the front cross member, got out the wiring harness and ecu and set them on the dash where they will be installed. Then I did the same for the rear suspension and stacked steel on the rear tail pan to represent the additional steel to be installed and added another box of 40 lbs to simulate radiator. We would still need to add body work so it is not all in but it is much closer.

2056 and almost perfect 50/50 front rear balance. You can ignore the cross weight as it is not sitting level so the cross weights are off. I think we can be race ready without a driver for under 2400 lbs.

We also got some work done on the rocker suspensions. Int he front I got the passenger side rocker pivot tacked in place. Decided to use a piece of 1.5" DOM tubing and a polyurethane bushing as a pivot.  Ended up biased toward the front to keep the link from the a arm as straight as possible.

For the rear we used sone 1.5" square tubing and made a base between the shock towers. The rocker arms will reach thought he shock towers and the shocks will be mounted very similar to up front. The plan is to tie the tops of the shock towers together with more square tubing and a couple of diagonals to tie everything together. The humps at the bottom of the hock towers is the unibody frame so we are tieing that together as well.

Mike sent me the above scale pictures today and my first thought was oh he's just setting up the scales cause there's no way it's that light.  Amazing what they've gotten it down to.  This car was 11th place before overall.  Image it 500lbs lighter and a shorter wheelbase plus way more berking cool engineering on it.

So tonight I built the first rocker arm for the front suspension. Probably would not have been the final part as test fitting there were some issues I would have liked to correct, but thought it was close enough to set it down on the spring for the first time.

In a phrase, epic fail (this should be another favorite post of TVR scott).  I had thought that a polyurethane bushing would work as a pivot point but even with a relatively small side load the bushing deforms rather than the spring compressing. The spring I have in there is 130 lb/in so it is very light.

From the front looks OK that is actually about half compressed height, with the spring all the way loose.

But then the side shot

That arm is supposed to be straight, I can move it so it is straight, but it is clear the bushing is too soft to carry that load. I think I need to go back to my original idea and that is to replace the bushing with a tapered roller bearing so it can take the side load and the rotational load at the same time. If it was easy then everyone would be doing it.

In reply to Fladiver64 (Forum Supporter) :

That does it! I'm sick of your antics!  Where's the professionalism?

In reply to Fladiver64 (Forum Supporter) :

Taper roller bearings are a big budget hit. If you extend the fulcrum tube a lot they will become un-necessary. Hard bronze will do, but you want them about 6" apart.

In reply to TurnerX19 :

I found these for $5.00 each shipped LM11949/LM11910 Tapered Cup and Cone Set. .750 id x 1.76 OD x .61. I was thinking two of these and using a 3/4" bolt as a shaft and a piece of 2" DOM tubing to mount them in. I have the tubing so that would be scrap price, $10 for bearings and $8 for a 3/4" bolt and nut. What do you think of that solution? Hard Bronze would be less than that at about $4 per bushing, so $8 per corner, but I would have to figure out a longer shaft solution, possibly just a longer bolt would be OK for that distance.

Advantages/Disadvantages to bearing vs bushings?

Just trying to think this through before making another attempt.

In reply to TVR Scott (Forum Supporter) :

Clearly you are in the wrong thread, I can think this crazy stuff up, I didn't say I was any good at pulling it off.

Fladiver64 (Forum Supporter) said:

In reply to TVR Scott (Forum Supporter) :

Clearly you are in the wrong thread, I can think this crazy stuff up, I didn't say I was any good at pulling it off.

In that case, carry on!

All old American cars have two tapered roller bearings in each front wheel. You might even be able to cut the "carrier" out if the drum or disk, and use the stub axle as your pivot.

In fact, just drill two holes at the right spots in a disk brake and cut away the rest. Instant rocker with built in bearings and pivot.

Just saying.

Heck, used bolt in wheel bearings for non driven wheels might be an easy ticket as well. Easy to attach to car, easy to attach rocker arms to.

In reply to Robbie (Forum Supporter) :

I thought about this as I have hubs from the original q45 that i could use. The issue I am having is how to mount that to the cradle near the arm. The spindle and bearing is designed to me mounted on one sie with the other open. That means the mount has to be able to take all of the torque load. So far I have not come up with a single sided mounting system I feel will withstand the load that I can build in the space available. I'm not saying it can't be done, just saying I have not been smart enough to figure one out as yet.

Might have to disassemble one of the Q45 struts and get the part down to basics and see what I can come up with

Keep the mount double shear. Even with the roller bearings you should extend the fulcrum. In an ideal long life situation the bronze bush might be better because roller bearings don't like shock loads, but the life span of a challenge car should be well shorter than the bearings in a worst case scenario. LM11949 is Chevy, Triumph and many others front outer wheel bearing.

Worked on a small project today. there is a patch of sheet metal that needs to be replaced due to the removal of the trunk

Looked around for so sheet metal to harvest and a section of the roof we cut our looks like it might work

A little trimming and it fits nicely. The gaps at the ends will get covered with the plates for the roll bar so no issues there.

Pardon my poor welding but its in.

This shows how the roll bar plate fits

Next patching the floors with more roof panels.

So got a little bit done this afternoon

First a little CAD

Then off to cut up some more roof to make floor panels.

Rinse and repeat on the other side.

Hot damn, why have I not been watching this closer?

Looks awesome, keep up the awesome fab work!

In reply to barefootskater :

Thanks, looking forward to seeing you do a walk around on your project.

Started on the rear suspension rocker system today. Going to go with wheel bearings in some 2" DOM tubing for the pivot. On the recommendation that we spread the pivot radius apart this is a 7" pin vs the 2 1/4". So the hinge will be the 3/4" rod that is there now, with a 1/2" bolt running through it. The wheel bearings are 3/4" id with a 1.76 OD. The OD is the same as the 2" DOM tubing ID but I don't think that will be enough of a press fit, so I have some 1 3/4 tubing left over from the roll bar that we will insert in the 2" for a back up to the bearing races.

Side View

There will be two uprights and a cross bar on the top, Then those will connect across to the other uprights and then a diagonal will tie the whole thing together.  I am going to wait on the upper portion of the system until I get the rocker pivot and shock mounting working through the correct trael. That way incase something needs to change I have less to redo. 

Time to repeat for the other side.