Roadracer's #997 build

[Mastertech5]

Nice! Having fun yet? Haha.

[RoadRacer]

Nice! Having fun yet? Haha.

SO MUCH FUN!

This time was kinda important- it’s the first time (in nearly 3 years of tweaking) the cars suspension worked how I wanted it to. The roll was finally controlled and there was still negative camber on the outside tire on the fast sweepers. That sounds obvious but it’s taken a lot of mechanical tweaks and alignments (and 3.5° static camber, 10° caster!)

[RoadRacer]

This was my fastest run at Porsche Club of America (PCA) event on Saturday - my 6th run after we'd moved most of the water off the track! It was a lot of fun but felt more like skid pan training ��



In the early runs there was so much standing water! But by the time we'd all done 8 runs, the second session was almost dry.

standing-water.jpg

[RoadRacer]

My fastest run at spokes #9, best for second place in class (XB) today - this were a few pretty tight corners so a prepped miata won

[RoadRacer]

I wasn’t happy with the way I fitted my seats so I ripped them out and fabricated a new mounting method based on the breeze brackets I had. Much nicer, more stable and easy to remove when needed.

It’s amazing how much better the car is to drive fast with these seats.

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[RoadRacer]

ok, steering again. There have been a few of us experimenting with various UJ's that connect to the steering rack.

I've had 3 different ones now. The factory one stripped its splines (leaving the splines on the rack in perfect condition btw, they must be much harder). So I then went for a 'clamping' style below:

clamping UJ.jpg

Steering is pretty important (!) so you'll see I added two extra things too over the years. One is a clamp that stops the UJ slipping down the spline (the factory one did this once). More importantly there's a bearing (here) to hold everything in exactly the correct place in 3D space - the lack of this is what allowed the slop to strip the splines originally.

If you have PS, I don't think you'll need this support bearing, but manual steering does, IMO.

Anyway, yesterday I was driving and it got to the point that my UJ #2, the clamping one above, finally crossed the threshold of too much slop again. I could move the steering wheel far too much without anything getting to the wheels. The slop is always at this UJ.

On closer examination the clamp just doesn't work. It seems obviously better, but in practice, there's too much metal to squeeze and an insufficient bolt to squeeze it. In fact I stripped the Allen head, trying to tighten it.

This might be a better picture, showing what I mean by 'clamping'

clamp uj.jpg

Hence attempt #3. I had bought another style a while back (here), so today I had to drill off the old one (stripped allen head) and quickly fitted the new one:

UJ3.jpg

I have to say, first impressions are great. The spline was tight.. I had to gently tap the UJ up the spline. None of the others were that tight. I did everything back up and will be testing after lunch..

[RoadRacer]

Quick update after a quick 60miles.. the steering is transformed. So far so good.

The low speed steering is a lot easier. There’s a lot less slop in it.. I won’t say “none” but I can turn the steering wheel and it seems immediate now that the tire moves. And that’s great through so many uj’s, splines etc.

The spline so far is the best yet.. and remember this was a cheapy Chinese part from Amazon with 17 reviews. ����*♂️


Watch this space and we’ll see what 1,000 stiffly sprung miles does to it.

[TxMike64]

'clamping'
clamp uj.jpg

I wonder about taking this one, chucking it up in a lathe and turning it down so that the clamping bolt can actually "squeeze" onto the shaft. I ask because my kit includes to of these style UJs with the PS Kit. I have access to a lathe - we can test it...

[RoadRacer]

I wonder about taking this one, chucking it up in a lathe and turning it down so that the clamping bolt can actually "squeeze" onto the shaft. I ask because my kit includes to of these style UJs with the PS Kit. I have access to a lathe - we can test it...

Yes, good idea. I tightened to 45ftlbs (IIRC) as stated in instructions but it didnt seem to do a damn thing. Then I looked at the thickness of the metal (it appears to be steel) and I was like, well duh.

If you want this one to test with, happy to share.. I won't be using it

[wrp]

Sorry to sound like a broken record, short of welding all the u joints, I personally do not think you are going to solve the problem. With the reasonably solid front axle mount and fixed mount on the steering column, every time you hit a bump, some almost imperceptible chassis flex is going to result in stress from the steering wheel to the pinion input shaft. even if you do solve the problem on the pinion input shaft, the stress will continue up and down the shaft assembly and simply find, then work loose another UJoint. I've kind of refrained from saying this much but after nearly 100,000 miles or more, and dozens of reinstalls, along with a number of differing joint types running the entire length of the steering assembly, the Borgeson slip joint is the only thing I have found to work with any degree of confidence. The slip joint allows that pulling and pushing pressure on the D-shafts to exhaust itself without pressuring the UJoints. I may not have done mine correctly, but after nearly a year of hard driving on poorly maintained Texas roads, my piñon input shaft is still firmly mounted and mated to the Borgenson UJoint. I am no expert on this, just the guy that says oh **** when the steering wheel starts to spin without effect and then who ultimately h as to fix whatever the problem was. But, I went to this all Borgenson Solution. Because of the problems I have had, I open the hood, rock the wheel and then physically test the pinion input shaft for play every time I drive the car. I am not advocating that anyone modify what they have to try my solution, just saying that this is the only way/thing that has worked for me.

GOPR0223.jpg
Probably should have put slip join along the lower shaft to pinion input shaft run. However, the sip joint shaft uses a 1 inch UJoint. So far this has done well. I did not lock down the intermediate support bearing shaft position. I let it slide through the bearing in both directions to direct the flex to the slip joint.

GOPR0224.jpg
One issue right away was the angled joint exiting the firewall is right at its maximum bend and tended to hang up. I called Borgenson and they have a greater than 40 degree joint that is much heavier, that they do not advertise. Solved the problem and increased the stability feeling of the entire assembly.

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Compares the Borgenson 3/4 D Shaft/9/16 spline to original FFR joint Borgenson is heavier and less problem binding.

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Package for the pinion shaft to D Shaft U Joint. Sorry I've misplaced the D Shaft/slip joint part number and the greater than 40 degree joint. Call borgenson and ask they were pretty helpful.

[wrp]

Not sure there is a lot of value, but interesting look at the steering assembly components in use.

[RoadRacer]

Thanks Bill, I totally get it, but I love the journey too! You're still a few miles ahead of my journey

You can smile when I catch up to your solution

[wrp]

Be careful out there, I'm pulling for you

[RoadRacer]

I do need to drive up there one day. Would be fun. Can you think of an excuse?

[wrp]

We need an event to get together. there are at least 3-4 of us in the area, with another 2-3 reasonably close by. It would be fun to congregate at XTreme Raceway in Farris TX and have a FFR shootout. Or meet at Cresson, Eagles Canyon, or LG2 for an event. Anyone else in the DFW area or within a reasonable drive interested?

[wrp]

The build map doesn't exist anymore does it?

[RoadRacer]

No unfortunately not. Google killed the service one day ¯\_(ツ)_/¯

[RoadRacer]

You may remember that I blow the fuse whenever I use the left turn signal. Well, today was the day that task got to the top of my todo list!

It was pretty consistent recently, which made it easier. It seemed to coming on after a rain storm, but now I'm not sure that wasn't just a coincidence.

I had previously confirmed the problem isn't in the steering column, or under the dash. So that left the front harness, and taking it apart. I could have run a new wire but I enjoy wiring and thought I had done a great job with connections, wrapping/shrink tubing, tie wraps, supporting often, etc, etc. So I had to find out.

I took all the wires out the front harness and unclipped from the chassis, but could see no damage or any way the main runs could be a problem. No scuffing, it all looked pristine. I inspected the few connections that I had made under by the X, and they looked good.

I moved up to the headlight. As you know, the headlight wiring is a bit odd in that you have to connect the wires on the other side of a hollow bolt into the headlight bucket, so once connected you can't remove the headlight without cutting off the connections. The wires go through the hollow bolt unwrapped, so I did wonder if something had happened there. I cut off the connections and removed the headlight to inspect it.

blownfuse1.jpg

And found the problem!

It wasn't the bare wires going through the hollow bolt, but the wires inside must move around, and over time it wore a hole in the insulation. I couldn't believe it, but here you are:

blownfuse2.jpg

I don't see a perfect way to fix this (ideas?) so I wrapped the blue wire to the other wires with 3 layers of electrical tape and a couple layers of duct tape. I also put some duct tape on the inside of the headlight bucket.

But of course, the wires will always be able to move around in there, so eventually, I'll be doing this again.. but hopefully in many years.

BTW, I did improve the failure point of wires going through the hollow bolt, by shrink-wrapping them. I didn't think it would fit through, but it will if you're persistent.

blownfuse3.jpg

[progmgr1]

Yup. I'm running DRL so I had 2 extra wires to go through the hollow bolt. I had to drill out the holes to a larger diameter and then put Weather Pack connectors down near the X frame. (The wires with terminals crimped on now fit, sequentially. with a little persuasion.) I chamfered and polished the ends so the wire bend radius was a little larger and there were no sharp edges to rub on. I also added a little electrical tape, since I couldn't fit shrink tubing. I guess the message is: be wary of sharp edges and especially burrs wherever you run wiring.

Keith HR #894

[RoadRacer]

Yup. I'm running DRL so I had 2 extra wires to go through the hollow bolt. I had to drill out the holes to a larger diameter and then put Weather Pack connectors down near the X frame. (The wires with terminals crimped on now fit, sequentially. with a little persuasion.) I chamfered and polished the ends so the wire bend radius was a little larger and there were no sharp edges to rub on. I also added a little electrical tape, since I couldn't fit shrink tubing. I guess the message is: be wary of sharp edges and especially burrs wherever you run wiring.

Keith HR #894

Did you find a way for the wires inside the bucket not to rub over time?

[progmgr1]

Nothing special - a little tape wherever I could reach. These cars are a rolling high vibration environment and things are going to move around. I just tried to eliminate any wear points to delay the inevitable as long as possible.

Keith HR #894

[JimLev]

The LED headlights don’t draw a lot of current. I spliced both black wires together inside the bucket so there was more room in the hollow bolt for insulation, only one black wire going thru the bolt.
I mounted terminal strips on each side of the fan shroud so I don’t need to cut any wires if I need to remove the headlights.

[Mastertech5]

Great idea with the terminal strips Jim. I've been pondering that wiring situation for a while now. Are they weather proof and if so where did you get them?

[JimLev]

Not weather proof, but should be fine.
The terminal strips came from Amazon. The wire ends I’ve had for years, maybe get them on Amazon too.
I put ring lugs on the harness and the red & yellow on the wires to the headlight.

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[RoadRacer]

The dashboard lights I had for my turn signal and main beam were always too dim to notice, and the other day I was driving for a while with a turn signal on, so I figured time to change.

I tried my luck on some "brighter" LED lights from amazon and they showed up today. MUCH better. I can see these even in strong sunshine, but they aren't dazzling. A very soft brightness. Like a satin finish lens, it isn't a "spot" of light like some LED's are.

dash-lights.jpg 2023-11-04 15.16.01.jpg

[progmgr1]

Good info. That one goes in my "Build Tips" file for future reference. Thanks for posting!

Keith HR #894

[Mastertech5]

The dashboard lights I had for my turn signal and main beam were always too dim to notice, and the other day I was driving for a while with a turn signal on, so I figured time to change.

I tried my luck on some "brighter" LED lights from amazon and they showed up today. MUCH better. I can see these even in strong sunshine, but they aren't dazzling. A very soft brightness. Like a satin finish lens, it isn't a "spot" of light like some LED's are.

dash-lights.jpg 2023-11-04 15.16.01.jpg

I bought similar ones from Amazon but they are black with arrows for the directional and a headlight for the high beams.

[RoadRacer]

A couple of things today - first, I finished the frame-mounted alternator and tested it - it worked great and showed 15v the whole time.

Here's the final picture showing a bracket welded on the frame for the adjuster. There's more photos in this thread.

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Second, I got my new QA1's from Gordon Levy and fitted the front set.

qa1-front.jpg

I really need to get some helper springs this time around, since not only are my springs too short on full droop (always have been) but the QA1 hats don't work the same way as the Koni's. So these are on the way from summit:

spring helpers.jpg

[RoadRacer]

Got the QA1's on. Some notes:

If using helper springs (the ones I bought above work great), add them to the opposite end to the adjusters. Otherwise they won't collapse all the way

After reading lots of documentation from shock manufacturers and racers and GRM, the consensus is that QA1's for cars like mine should have low compression setting (for bumps), a higher rebound setting (helps cornering), and much lower numbers than what you expect. These are light cars!

I started at 12 out of 18 and it was like a rock . Then I researched and found I should be like 3 or 4 compression, 6 or 7 rebound. I'm now experimenting, but that's my starting point.

Curious what others started at or ended at

[RoadRacer]

One more thing.. Gordon Levy at https://www.lrclassicsllc.com/ deserves another shout-out.

TLDR; Call Gordon, he's very knowledgable and very helpful.

Longer version:

My car's a little different and not really a road car, even though I use it that way. But I really have it built as close to insane as my budget allows, and it'll get more insane over time!

So when Gordon sent me the shocks, he sent the normal size. 401's and 501's. But my car has shorter, stiffer springs and is lower than normal so the front shocks were too long. And he knows I'm running a track sprint at the weekend, that I really wanted the new shocks installed for. There was an easy fix, replace the long rod ends with short rod ends.. but it needed Gordon to be able to respond quickly.

He did, answering my email within the hour and offering to overnight the new parts to me. I had them in my hand midday the following day, and everything now fits and works like a dream.

We don't often say the GOOD things that happen with vendors, all we normally hear is very upset people, so I wanted to say again that I've never had a bad experience with a FFR vendor, and we should share those stories too!

[Just 1 More]

Can you explain the helper springs? Why do you need them? What do they provide?

[RoadRacer]

Can you explain the helper springs? Why do you need them? What do they provide?

Yes, for sure.

In my case I'm using 7" springs now. This certainly makes the problem worse, but you also may still have this problem with longer springs.

If you jack your car up and you see a significant (>1"?) gap between the top of the spring and the tophat, you should ideally use helper springs (sometimes called tender springs) to fill that gap.

Without them, if you went over a sufficiently large bump the spring may not re-seat to the tophat properly. Imagine the spring falls sideways a little, and then the car drops down. (You could tie wrap the spring to the top hat, but then you move the problem to the bottom of the shock)

This is even worse on the QA1 than the Koni, because the top hat isn't held in place by a circlip, so it could (in theory) just fall off the car while airborne. And I think you can imagine what happens next.

The helper spring just flattens to solid when sitting or running normally, so no harm done, but will hold everything in place under droop.

[Just 1 More]

Yes, for sure.

In my case I'm using 7" springs now. This certainly makes the problem worse, but you also may still have this problem with longer springs.

If you jack your car up and you see a significant (>1"?) gap between the top of the spring and the tophat, you should ideally use helper springs (sometimes called tender springs) to fill that gap.

Without them, if you went over a sufficiently large bump the spring may not re-seat to the tophat properly. Imagine the spring falls sideways a little, and then the car drops down. (You could tie wrap the spring to the top hat, but then you move the problem to the bottom of the shock)

This is even worse on the QA1 than the Koni, because the top hat isn't held in place by a circlip, so it could (in theory) just fall off the car while airborne. And I think you can imagine what happens next.

The helper spring just flattens to solid when sitting or running normally, so no harm done, but will hold everything in place under droop.

Great explanation, Thank you

[progmgr1]

Thanks for posting this great information. Copies going into the file for future reference.

Keith HR #894

[RoadRacer]

As I posted elsewhere, I'm trying to educate myself on the "proper" way to set up a car using math, not the seat of my pants. I was fed up not knowing things like suspension frequencies, motion ratios, etc.

I know about corner weights and the basics of car dynamics, but I wanted to go deeper. So I read a few books and subscribed to "Suspension Set-Up With the "Weight Transfer Worksheet (WTW)"" amongst others. I'm going to post about my journey into learning how to measure or calculate the inputs into Dale's spreadsheet (the WTW).

First step was to measure corner weights again. I did it last year, but this time I wanted to go further and measure enough to calculate the Center of Gravity of the car.

To walk you through my process though.. first I don't have corner weight scales, so I wanted to experiment with the idea of using bathroom scales The scales I bought were 400lb scales for $15 each on Amazon, but I needed to use a lever to measure more like 600-700lbs per corner. So I fabricated these levers and when I place a weight half way along the scales weight half the weight. I calibrated each one by standing on the "center" and making sure each scale measured half my weight.

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I made sure they were level too, of course. Then I lowered the car onto the scales.. and it was a dismal failure. I did get a couple measurements, but there are some big problems with this method.

1. The car does not want to balance on these.. and falling off is painful
2. The car cannot effectively be lowered onto these scales using a quickjack.. because a quickjack lowers sideways, not vertically. So as it touches the scales.. everything falls over.
3. The scales turn off 15s after weighing! You have to really run around the car writing down the answers!

LOL. So a $60 experiment that i do NOT recommend, but I did use the scales later to measure unsprung weight.. and worse case my kids each get a nice digital scale for Christmas.

[RoadRacer]

Next, I called my friend and he was free to help me use his proper Longacre scales. So next day off I went with an expensive bottle of bourbon..

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Measuring corner weights was straightforward. here are my results. Same as last year, I just had to raise the front right shock by an inch or so to get perfect 50/50 cross weights. The 2581lbs was with me (255lbs) so the car in racing trim was 2326lbs.

Corner_Weights.jpg

Next, we needed to raise one end of the car at least 10", and measure the weight at the wheels again. You only need to measure the weight of the lower wheels, but we raised the scales by 11" and measured all 4 wheel weights again. (It's red because we "lost" a few lbs when raising the car, so my sheet highlights that potential error)

raised corner weight.jpg

This data allows you to calculate the COG using this calculator: Car Center of Mass Calculator

The biggest surprise of the whole process was that this was so high- it showed the COG was 24" off the ground. More than I expected, although a few people had told me that it was normal to use the height of the camshaft as a "rough guess" on race cars with a big v8.

So at this stage I have balanced corner weights and a COG.

[RoadRacer]

Measuring motion ratios was next. This is the ratio between wheel movement and shock/spring movement.

BTW, this is a good time to say again that this is all pretty new to me, so forgive me if I use a wrong term, or make a mistake, or describe something poorly.. just let me know and I'll fix it

On the front suspension you can remove the spring and then jack up the wheel and measure how much the shock travel was. E.g. mark shock, raise wheel 100mm, and measure distance shock moved. Doing it this way is the best because it takes out all angles and variables, and directly measures you exactly what you want.

I, of course, didn't do it this way. Having just installed the new QA1 shocks and springs the previous weekend I was all done with farting around with the shocks, so I just measured the cantilever suspension, and factored in the angle of the shocks. Ended up with a motion ratio of ~0.78.

At the live rear, I used a commonly used ratio of 1.05 because the shocks are behind the axle. The shocks are at 3º so only applied a 0.99863 correction, which left the ratio at.. still 1.05

[RoadRacer]

I measured unsprung weights next. I disconnected the top shock mount and (with car at ride height) lowered the wheel directly onto the bathroom scale. The unsprung weight was 96lbs each side at front.

At the rear, I jacked up the car and lowered the chassis onto some wood that was a couple of inches above ride height. Then jacked up the live axle, slid the scales under and lowered the wheels to weight them. I made sure the springs were unloaded (I could turn them by hand), so I was just weighing the live rear, and roughly half the control arms, driveshaft, etc.

The rear unsprung weight was 454lbs total.

[RoadRacer]

Motion Ratio of the rear, in roll, is calculated from the ratio between the track width (centerline of tires) and the distance between shocks. That was (for me) 40" / 61.5", so 0.65

[RoadRacer]

Next was the Motion Ratios of the ARB's (sway bars). This is the ratio of how much the ARB moves in relation to the wheel movement. I just measured the distance along the UCA where the ARB connects, and divided by the total UCA length. This was 6.375" / 10", or 0.64.

At the rear, the ARB motion ratio was dictated by the angle of the ARB lever arm from vertical, which worked out to be 0.88

I also had to measure the ARB width, diameter and lever arms to calculate the effective ARB spring rates. The units are inch lbs per degree. ARB rate adds to wheel rate in roll.

Mine worked out to be 239.87 (front) and 109.32 (rear)