Building our Lemons/Chumpcar (Page 26/29)
DonP FEB 15, 11:13 AM

quote
Originally posted by wftb:

(I think women call us losers ......



Well thanks. I think.

It has been great fun working through each of the problems or challenges as we get to them.

Don
DonP FEB 15, 12:29 PM
The camber on the rear of our '88 has long been a point of concern for us. Really, the stock setup needs help to make the car work better. Particularly on the track. And we are not allowed to use those really sticky tires that other racers can use. The coil-over conversion was a good place to start in taming the rear because it enables us to use different spring rates. And it had been obvious to an experienced observer at the track that the rear end "wasn't happy."

What to do?

The stock setup at the rear obviously uses a strut attaching the upright to the shock/strut tower. Bloozberry has posted a really nice photo of some really clean suspension pieces in another thread. If you don't know how the strut attaches to the upright, I suggest you take a look at the 9th picture on this page. http://www.fiero.nl/forum/F...L/000116-9.html#p331 Bet you stop at all the other photos as well.

Fierosound has already posted some pictures that show the stock adjustment here http://www.fiero.nl/forum/F.../HTML/129289.html#p8 You'll note that he has a picture of a new "cam" bolt used in the slotted (lower) mounting hole. Turning the bolt head works the cam against stops on the strut body. This alters the relation to the rear upright and controls how much camber is introduced into the rear suspension. Most of the reading seems to indicate that it is possible to gain between 1 and 1 1/2 degrees of static negative camber. Fair, but not as much as the racers want.

BTW, I am referencing actual threads found on the forum instead of just copying pictures. That's because I haven't taken time to get permission from contributors like Bloozberry, Fieroguru, SCCAFiero and others. Hopefully you can just follow the links and check out their photos.

Having said that, here is a picture I pilfered from the internet



So what's to be concerned about? Here SCCAFiero posted some pictures showing rear camber problems on his build thread http://www.fiero.nl/forum/F...HTML/084322.html#p26 Note pictures 4 and 5. The rear tire not only does not exhibit negative camber so important for maximizing cornering forces, but actually lean out at the top - positive camber.
BTW, he is exhibiting great form in the second picture on that page by looking ahead to where he's going and not at the back of the car he's following.


We aren't trying to obtain excessive amounts of negative camber here. Just enough to be helpful.



This is a picture taken after we converted to rear coilovers on the car.


Now we started researching how others have accomplished this. The first thing we found was something we had already seen on other performance machines. Camber caster adjuster plates.



These adjusters bolt to the top of the strut and to the strut tower. You can see how the top mounting point can be moved along an axis (towards the center of the car or towards the outside) and therefore change the amount of camber in the setup. Actually, they change the relationship between the lower ball joint, or in the case of our '88 the lower bolt attaching the lower arms to the upright and the strut mounting point. This "tilting" effects the angle of the attached hub and wheel mounting flange. That means the camber or tilt in or out of the tire is changed.

On the forum, we found references to caster camber adjuster plates available from that purveyor of great automotive technology, E-bay. But there were lots of responses along the lines of "I tried it and found it lacking."

Besides, we had seen this type of thing on other Lemons cars - the Mustang guys from Reno come to mind - and they are always penalized for the "high tech" "cheaty" parts. Nothing attracts attention like a new aluminum part or the outlandishly anodized parts so popular with all these tuner cars.

Fieroguru had a nice write-up on relocating the upper mount here. http://www.fiero.nl/forum/A...130314-2-121291.html This approach looked closer to a stock solution and might make it past the tech inspectors, but we finally decided to look elsewhere.

Here on the forum Vince - AKA Snapperhead started down the road of producing some adjustable devices for use with coilovers, but ultimately abandoned the project in 2011. http://www.fiero.nl/forum/A...130314-2-117370.html It looked as though they might have been a bit stealthy which appeals to us. But....


An even more elaborate solution was created by Fieroguru. He actually attempted to address the inherent problem of a less than optimal suspension geometry. Fieroguru created some "lateral link relocation kits" http://www.fiero.nl/forum/Forum4/HTML/060635.html Cool but not totally unobtrusive. If we had the money, we might have gone this route anyway.

As I mentioned in the last post, Rich had an inspiration in the shower. This appears to be such a common occurrence that I suspect he has a waterproof white board in there. Don't know. Don't want to know.

Okay to understand what Rich thought up, I would recommend that you look at image #4 entitled "1988 Fiero Rear Suspension Rear View" on Bloozberry's thread here. http://www.fiero.nl/forum/F...L/000116-9.html#p345 Again, I do not have permission to copy the image, but it's magnificent. Now, let's assume that the face of the wheel hub is exactly perpendicular. That would mean that the rear camber is zero. Now, draw a line between the bolt that attaches the lower control rod(s) to the upright and the bolt at the top of the strut. Where the strut attaches to the tower. These two points are fixed. See those two bolts where the upright attaches to the strut bracket? The ones in the red crosshatching. Now, if you recall, the lower hole is actually slotted. And the bolt goes through a cam which can therefore move the attaching point. If you turn the head of the bolt, turning the cam, - pivoting on the upper fixed bolt - you can move the top of the upright towards the imaginary line we drew earlier or away from that line. In this case, moving towards that line, towards the center of the car, changes the angle of the whole upright, changing the angle on the attached wheel flange on the hub to create negative camber. Turning the cam to move the upright out adds positive camber.

In each case above, turning the cam pivots the upright/strut interface around the upper bolt.
Why is the upper bolt hole fixed? What if we move the upper pivot point? Not through drilling the upright which might be a bit questionable. But what if we could place the upper pivot bolt on a cam like the lower adjustable bolt had? We might be able to effectively move that pivot point in or out as well.



We purchased a couple more of the camber adjustment bolts from NAPA and went about modifying the brackets on our struts. We slotted the upper holes to start.









We found that it was necessary to relieve the back surface of the strut bracket. Most of you who have replaced the back struts have had to do similar modifications to relieve an interference fit. Very common.









The interesting thing was that we had to turn the upper bolt in the opposite direction than the lower bolt required. So Rich had to add a stop on both sides of the cam.





The results? We were able to dial in just over 3 degrees of static camber. We did limit ourselves to three degrees, just because.

At one point we had the car professionally aligned. Rich bought the extended service which allowed us to bring the car back in at any time to have it re-aligned. Great deal. So we started by scaling the car so everything would be as we intended to run.





















The very first time we took the car in, we were lucky and one of the old-timers was there. Our desired alignment specs were a bit unusual and he had no problem. He understood what was desired, why, and how to get there. This time when we showed up, that guy had moved on. Frankly, the new guys knew nothing about alignment. They knew how to read a computer but couldn't help on anything out of the box. We no longer used shims. Rather it was necessary to adjust heim joints. Huh? The computer doesn't say nothing about that. Ultimately, we ended up redoing the whole thing ourselves. Oh, and they suggested we not come back with that modified car.

We were able to run on the track once again, and the results were very good. In this photo, you can clearly see that we have signs on negative camber at the back.



The Reno-Fernley track has some nifty elevation changes that can really load the suspension. The car definitely felt significantly more stable with the front and rear suspension changes. And the additional rear camber gave the car a more planted feeling. Even with the wore out tires we were testing with, the feeling of always being on the edge or fearing the sudden change into massive oversteer wasn't there. I think there was no doubt about the front end after the re-design and construction. The rear now felt much closer.

So we tweaked the spring choices and were ready for our next race at ThunderHill.
davylong86 FEB 15, 12:53 PM
You guys are doing a hell of a job on this race car. I really enjoy reading this thread. And as for as finding old school mechanics, I have one about 4 miles from my house and I told him he can not retire as long as I have my Fiero. He worked for a Pontiac dealer in the 70's thru the 80's. He thought he was done working on Fiero's lol !

[This message has been edited by davylong86 (edited 02-15-2015).]

DonP FEB 16, 12:23 PM

quote
Originally posted by davylong86:

You guys are doing a hell of a job on this race car.




Thank you. It's always a struggle to A.) do what needs to be done and B.) remain a LeMons car with all those constraints. Build it instead of purchase it.

I hope all those ads I see on Velocity for places like Wyotech are producing actual mechanics and not just computer operators. My brother repairs heavy equipment and tells me that everything is computerized even there. And it has become a "read the computer and replace the indicated module" world as opposed to days when you broke down a failed component and repaired it. Surely those skills are retained somewhere.

Wait, I'm sounding old enough to justify this gray beard.
zkhennings FEB 17, 02:43 PM
Awesome thread, I especially enjoyed reading the whole process behind designing your front suspension, I am planning on making something very similar for my front end.

I would look into raising the roll center in the rear, similar to Fierogurus relocation brackets. You could also raise the inner pivot points if you have room. I bet your lateral links are near parallel to the ground or pointing upwards at your ride height, which means that every bit the suspension compresses that roll center keeps migrating down causing the car to roll more. That is probably why all that static camber helped so much, but it is probably very worth while to do something about the rear roll center.

I have been reading through this at work the past few days, now I need to go through it at home to watch all the videos, thank you for taking the time and the effort to thoroughly document everything!
DonP FEB 21, 09:25 PM
The entire team was really stoked to be taking the "new" Fiero to Thunderhill. At our last race on Buttonwillow, we had finally experienced good power with the 3800SC. The car had handled quite well. But just a few test laps had us convinced that we would be on a whole 'nother plane.

This was the last time that LeMons would be running on Thunderhill Raceway in it's original 3-mile configuration. Even as we were racing, we could see signs of ground being cut for a new addition to the track that added 2 more miles and resulted in a full 5- long road course. The next race was scheduled to run on the new 5 mile configuration.

184 cars were entered into the race. That meant that we had a minimum of 736 drivers for the two day event. At the end of Saturday, we were running in 81st position having completed 126 laps with a fast time of 2:29:206. Not as good as we had hoped. Unfortunately, the Mustang guys had really got their act together and finished Saturday in 44th position, having completed 146 laps with a fast time of 2:29:922. So they were way ahead of us despite our faster top speed. Our only excuse was that they were killing us on pit stops. They had added a new fuel cell (and I suspect practiced between races) and could pull of a 3-4 minute pit stop. We were giving them as much as 4 laps per fuel stop. And they carried a lot more fuel, requiring fewer actual stops.

Worse yet was a new entry from Reno. Grant and Dante had put together a 1981 BMW 320i. Grant had been aware of us as he owns a "84 Fiero that is autocrossed in the area. They finished Saturday ahead of us in 74th position having completed 129 laps at a top lap time of 2:37:633. Thos pit stops and a bogus black flag were really killing us.

Oh, the leader in a 1983 BMW 533i was four laps ahead of second place Porsche 944 with 168 laps in the books.

For some unknown reason, I didn't get very many photos of the weekend. But I do have a couple which clearly demonstrate the rear camber gains.






Chasing down the (yellow) Mustang.




If I was totally ruthless, I would say that our Sunday prospects looked better. The Reno-based BMW lost a rear hub.







Thunderhill at Willows Ca is roughly 12 miles from the middle of nowhere with regards to car parts. The local parts guys had nothing for the BMW except maybe some oil. So, like any good racers, Grant unloaded the race car and drove 117 miles into a suburb of Sacramento, purchased another BMW off of Craigslist and canabalized it for the necessary parts.



During Sundays race session, one of the guys hauled the now disabled BMW to Pick-N-Pull.
Great effort guys.

Some of the competition.






[IMG]http://i1222.photobucket.com/albums/dd483/DonP87/Build%20Lemons%20Car/1238751_10151727192894495_220640354_n_zps3b8ad89c .jpg[/IMG]

Our most serious incident, surprisingly, involved Rich. He was moving forward through the pack. And of course that meant he was observing several cars in front of him to see what they were doing. One car in particular always took a, uh, sub-optimal line down the front straight-away. As Rich was moving up to pass entering turn one, the driver grenaded his brakes way, way too early in response to a car entering the track. Rich braked and took evasive action. I never said we fully removed the infamous snap over-steer. And Rich went spinning through the inside of turn one at a high speed. Luckily, he missed the flag stand. Unfortunately the GoPro had quit.......

Things were going great. The car felt much more stable. We could drive it in places and ways that would have been disastrous before changing front suspension design and gaining the rear camber. The only thing that we all observed was that the engine seemed slightly soft. Running at 235 plus degrees at Buttonwillow may have had an impact on the engine. We were still ahead of the stock 2.8 liter. But we weren't pulling as hard as expected.

Over all, things were going good.

THEN DISASTER STRUCK!





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No, not for us. The BMW guys lost a rod. And who knows where the wrist pin got to.





We motored on.



Robert and Paula watching the Fiero leave the pit.








So, we finished in 69th place out of 184 entries. The Fiero Libre guys finished 17th overall. And the Mustang guys with their new found range finished in 45th place 18 laps ahead of us. We definitely needed to deal with slow pit stops.

This link will show several laps from the ultimate winners car. Very quick. Very aggressive (but appropriately so.) Definitely experienced drivers making the correct decisions. You can see the Fiero Libre guys at 40 seconds in. https://www.youtube.com/wat...mcI&feature=youtu.be

And the official LeMons wrap-up commentary on the race can be found here. https://www.youtube.com/wat...5ZQ&feature=youtu.be

We were really looking forward to getting onto the full 5-mile configuration next year. And we had some thought on improvements.
doublec4 FEB 22, 09:33 AM
Great work!

I watched that video... around the 8 minute mark a GTO goes flying by. I thought there was a limit on how expensive the entry cars could be?
Bridgetown FEB 22, 10:05 AM
Could one of these steering ratio quickeners be adapted to a stock steering shaft without power steering?
http://www.speedwaymotors.c...36-Spline,24447.html
DonP FEB 22, 11:38 AM

quote
Originally posted by doublec4:

Great work!

I watched that video... around the 8 minute mark a GTO goes flying by. I thought there was a limit on how expensive the entry cars could be?




#79 was listed as a 2004 Holden Mondaro, the basis for the GTO. Looked like more than $500 driving down the track. I guess you have to convince the judges that the rusty and twisted unibody/frame made it possible to buy this car from the underwater salvage company for less than $500 but more than the $50 scrap value that it was going to sell for. I've seen a couple instances where someone shows up with a "real" prepared car. Sometimes they are allowed to run with a high number of penalty laps guaranteeing they cannot win. I recall a prepared BMW where the BS tech officials asked for his VIN. That number was the number of penalty laps he was assigned.

At that same track, there was a guy who showed up with a Mustang (in a hauler) obviously prepared for something like the NASA Mustang series. The story that I heard is that he's allowed to run though not really scored. The car owner evidently uses this as a training session for new drivers being cultivated for other duties. So he pays the fees as well as a healthy donation to a charity and the driver gets LOTS of on track seat time in race conditions. At least that's the story his crew told us as we were parked next to them.
DonP FEB 22, 10:15 PM

quote
Originally posted by Bridgetown:

Could one of these steering ratio quickeners be adapted to a stock steering shaft without power steering?
http://www.speedwaymotors.c...36-Spline,24447.html



Talking with Rich, we believe that the quickener MAY be adaptable to the stock steering column. That's the short answer. But it has been like two years since we have even seen the stock column. That was as we were yarding it out. I suspect that the quickener would need to be mounted outside the firewall. And more than likely you would need to eliminate the "collapsible" tubing connector which is an important safety feature in the case of a front end collision. In our case we used a couple u-joints that built in some angled connection points. In the event of a front end collision we anticipate that the different angles would more or less accordion instead of driving directly through to the driver's spine.

If you can gain access to the steering shaft coming through the firewall make sure you add probably a good 3 inches to the required room for the quickener. I would anticipate needing to add u-joint adapters to mate the quickener's splines to whatever you feel safe in attaching to. A simple good quality 3/4" inch spline to 3/4" inch spline u-joint (which is almost certainly NOT the one you will need) will cost more than half of the quickener cost. http://www.summitracing.com...r=steering%20u-joint

I'm sure you are aware that adding a quickener will require more effort to turn the car. That's why we elected to add power steering.