33 Coupe Adjusting and Tweaking 2        3/25/06

If you've been following along up to this point, you'll know what I'm going to be talking about but if you've just dropped in, let me catch you up on a thing or two. 

When I finally got the car on the road back in January, I had to find out how those big tires were going to work. The only way to find that out was to take the car out to some remote area and whack the throttle. The first thing I noticed was that those 16.5" wide tires spin real easy. The second thing is the car goes pretty straight with two people in it but doesn't go very straight with just me. I didn't know why the car was doing that so I talked with Gary and he said that it sounded like suspension. Gary said to put the car on a rack (I wish I had one) then adjust the 4-link bars so they're all in a neutral position and then preload the top-right bar (passenger side top) by shortening it by one half turn.

What you see below is a poor mans rack. It was just high enough off the ground to work under it and to have the cars weight on all four tires. With the car off the ground, I needed to get all four bars in that neutral position.  To me this sounded easy but was much harder than I expected because I only have one end that can be adjusted on each of my 4-link bars. That meant that I would have to remove the bolt from one end of the bar, turn the rod-end (the adjusting part) a few turns till I had all of them in there neutral position and then replace the bolts. Now to do all this I had to use my floor jack along with a soft-faced hammer to remove some of the bolts. This didn't work as planned because as I was trying to adjust one bar after removing it's bolt, I couldn't get the bolt back in after adjusting it. I tried removing both top bars and then tried it again. This seemed to work so it was time to do both bottom bars. After doing the same to the bottom two, the top were tight again. I did this back-and-forth a few times only to find myself with my pinion angle all wrong. I hade worked myself into a hole at this point.

What I ended up doing was adjusting the pinion angle back to where it was right again and said good enough for now. What I really need is a set of 4-link bars that adjust at both ends (right-hand on one end and left-hand on the other end) so I wouldn't have to remove any bolts. This might be something I'll do in the near future if I can't get the car to go straight.

I took the car back out after all this and it went a little straighter. This means I must have done something different, which is a good thing, but it still wants to go left. It's much better when there's someone else in the car still so I have more tweaking to do. 
 

 

 

3/26/06

After I was through testing the suspension out, I let the car sit for about three weeks because of all the rain we had. It rained two weekends in a row and I was gone on the next one so I didn't get a chance to do any cruising in that time. I thought this would be a good time to change the oil now that I have a few miles on it so back onto the "rack" it went. When I tried to start the engine, the battery was dead so out came the charger. That's the trouble with having modern electronics in a car these days, the battery has to run two things in my case. One is the radios presets and clock and the other is the computer for the transmission. The settings for the transmission are of greater importance to me than the presets on the radio but this is the price you pay to have a street rod.

While I was charging the battery, I figured that I would change the oil. I wanted to look at the old oil very carefully to see if there was anything else in it other than just oil, so I cleaned out my oil-drain-pan before I removed the drain plug on the car. After the oil pan on the car was empty, I poured most of that oil from the drain-pan into a five gallon container and then started my investigation for anything foreign. This left me with a thin layer of oil in the bottom of my oil-drain-pan to work with. I could see that there wasn't anything large, which was a good thing, so then I used my fingers to root around the remaining oil. I used my fingers to check out the remaining oil because they can feel the smallest of items. Everything looked good so the rest of the oil was drained into my five gallon container and I was a happy guy. The only thing I didn't check was the oil filter but I still have it and will check it very soon. By cutting open your used oil filter, you can find out a lot about what's going on inside your engine. If there were some kind of metal trapped inside it, this would be the time to find out where it came from and then maybe tear the motor down and find out what happened. If you were to let it go knowing that there was a problem, you might be playing with fire so this is a good way to see what's going on.
 

 

 

One other tweak that needed to be addressed was the carburetor. When I pressed hard on the throttle, it still had a slight hesitation (bog) to it and that needed to be fixed. I had bought two different sizes of accelerator pump discharge nozzles, or squirters for short, which were # 35's and # 37's but they didn't fix it completely so I was ready to change all that without buying any more. 

To give you a little history about the sizes of squirters, the # size refers to the diameter of the hole in the end of the nozzle, not a drill # size. What I'm going to do is drill out the nozzles in the squirters a little larger till I get the hesitation to go away. 

By using a pin-vise to hold your drill with, you end up with a lot of control while your drilling. If you were to use a drill motor to do this in place of a pin-vise, you could end up with a hole that isn't very true (larger on the side that your drilling from). It only takes a minute per nozzle so it's not a big deal using a pin-vice. I had a few squirters hanging around so I used one of them to do my surgery on. I started with a # 31 and drilled a .040" diameter hole through both nozzles which would make my new one a # 40. After driving the car around for a test drive, that made a big difference so now it's time to drill out another to the next drill size which would be .041" diameter. Why am I going to drill out another one when this one made the car work better?

Well, if you want to find out where the limit is when doing something like this, you have to go "over" the limit to find it first, so I'll continue drilling out squirters till I find the limit and then back off one notch and that should be the one to use. It's not rocket surgery but it's one way to do it that will work. The only thing you have to have while doing it this way is to have at least two squirters to work with. Once you have the right size that works on your on your engine, you should either write the numbers down on paper and keep the paper in a safe place or scribe the number on the squirter with something. I like to use a Dremel for a job like this because I might lose the paper. This way I can use the Dremel to cross out the original number and put the new one below the old number. Whatever works is what I say!
 

 

 

The last tweak that I did on the this test drive was adjust the transmission. The trans was shifting way too soon for my liking (at low RPM it shifted too early) and way to soft when I was up on the RPM so by playing with the Compushift electronics, you can set it just about anywhere you want. There are two areas that you can adjust: 1) when the engine is off and 2) when the engine is running. I wanted to adjust the shift pressure and the throttle position that the shift took place at. Lets say that you wanted the car to shift nice and easy while driving around town. No problem. Just adjust the throttle position so the trans shifts around 5% to 15% throttle and you should have a nice smooth shift while cruising. Tell it when your into the gas around 50% or more that you want a much firmer shift and it will bark the tires for you. It's like having a shift-kit in your trans but it only works when your on the gas hard and not all the time. After pushing a few buttons, the car was closer to what I wanted so I'll try it at these setting for a while and see if I like or not. If not, it's easy to change again. 

Drop back by in a week or two because I should have another couple of things that need tweaking on, plus I'll find if these changes worked or not.
 

 

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