Questions

I see many people coming to my site from Google or other search engines. Theses people are asking questions. Questions like: Why does my ladder bar car turn left when I launch? What is the correct pinion angle for a dragster? How to pre-load a rear suspension? and similar.

I have tried to sit down and answer these questions in a blog post as they come in, but I have found that the articles become almost huge as there are so many variables that need to be addressed.

I have an idea.

I encourage you to ask  your question directly to me. You can email me through the contacts page at the back, and I will reply, most likely with more questions so I can answer your question as it pertains to your needs.

I have many customers who email me with all sorts of questions, they send me photos and specs and I guide them through the process they are trying to accomplish. The cool thing about this sport is it is hands on, most of you guys and girls build the car, and set it up yourself. That is fantastic, and if I can help I am more than happy to.

So, don’t be shy or embarrassed, ask away, and I will respond in a timely manner, (you won’t be waiting a week for a reply). You can ask anything to do with Drag racing, from chassis design and setup, engine building and tuning, gas, alcohol, and nitro, gear ratios, tires, driving techniques, sponsorship, or rules, or any thing else.

Saturday January 9

Well, Saturday appears to be turning into a rather casual “open house”. With several people and cars coming by, so I thought, “why not run with it.” Come on by on Saturday, say Hi and see what’s happening around here. Looks like around 11:00 is the popular time. You are all welcome. Unit 18 Raceway Park, 32929 Mission Way, Mission BC

I’ve moved.

I have re-located to unit 18 Raceway Park, 32929 Mission Way Mission BC. My new phone number is: 604 814 1320

It has been a very big move from the Sunshine Coast, but I am mostly settled now, and Telus finally got my phone connected today, 18 days after it was supposed to be connected, how is that for service?

I invite everyone to drop by and say hi. For the next little while I will be busy getting caught up on work and getting more organized, so I will be here pretty much seven days a week, so stop in on the weekend, or over the holidays.

Ladder Bar Setup. Part one, center and square.

Ok, everyone seems to want to know how to setup their ladder bars, so I will see if I can shed some light on the subject. For those of you with four links. . . work it out yourself. No, no, I promise, I will do four links too, but they are a little more involved, and in effect build on the ladder bar principles, so I will start with ladder bars, and do four links at a later date.

I have given a lot of thought to how to approach this. I have decided that I will try to keep away from the engineering and physics as much as possible, and try to make this a “practical” guide. This is aimed at what I would consider the average bracket racer, with basic understanding, and tools.

First, you need a mostly level surface. Ok, here it comes already, the ‘experts’ out there are going to tell me it has to be perfectly level. Yes, perfectly level would be nice, but tell me this; how level is the startline at your dragstrip? Do you even know?  If you want ideal, you will set your car up on the startline, and the lane, of the track you are about to race on. That is most likely not possible, so we will settle with mostly level. Dragstrip startlines are generally pretty good, some much better than others. They usually have a very slight amount of camber to the outside for drainage, which is why you always start your burnout a little to the inside right? I will assume you are using your garage or workshop floor to work on here. To get mostly level, put the car in nose first, and centered in the doorway. The floor will usually have some drainage built into the floor so liquid will drain out. By nosing the car in, it puts the front end on the high side, more like a wheels up launch, and centering the car should have it pretty close left and right. What you want to do now, is make some marks on the floor, or take some measurements, so you can park the car in the same spot in the future to get the same results. You will want a reference of some sort.

Next, you do want some weight on the driver’s seat to simulate the driver. It does make a difference. You know how much you weigh, add that amount. Within twenty pounds is fine. Set your tire pressures to where you would normally run the car.  Now you get to get dirty.

The very first step is to square the axle in the car. And see, it is already getting tricky. What will you square it to? Is the chassis square? No sense squaring the axle to the rear cross-member  if the cross-member was installed out of square, how will you ever know? Let’s triangulate. No, it is not physics, it’s geometry.

Head up to the front end, at the front cross-member, between the front wheels, measure the distance between the front wheels, this can be inside to inside, or to straightedges held on the outside by your assistant, whatever is easiest, but be accurate, a sixteenth of an inch accurate. If you are measuring from the wheel or the tire spin the wheel an measure from a couple different points to make sure you are getting consistent measurements. Take that measurement, find the middle, the exact middle, and make a lark on your front cross-member at this distance. Sometimes I will use a plumb bob and drop points to the floor, or use a carpenter’s square. Once I have a mark in the centre of the front cross-member I am confident is in the exact centre of my front wheel track, I will make a permanent mark, usually a centre punch mark, then it is always there. When I am building a car I mark it while it is still on the jig. Now you have the centre of the front. Perfect.

Next. To use this procedure to square the rear axle, you need the rear axle to be centered in the car. The best bet is to center to the chassis, as the body may be a little offset. From under the car, measure from the inside of the tire or wheel, to the chassis rail where it goes up and over the rear axle. Sometimes it is way too tight  to get in there, in that case you will have to pull the wheels off  to get this measurement.  So now you find your rear axle is half an inch offset one way or the other, not at all unusual. Sometimes it is less, sometimes more, but we can fix it. You will most likely have a panhard bar, or a wishbone setup to center the housing. Loosen the jam nuts and adjust the housing from side to side. A wishbone is a little more involved as you will have to remove the bar from the brackets to make the adjustments. Another note on the wishbone, if you wind one rod end in, wind the other one out the same number of turns to keep the width the same so you can get the bolts back in. (a little pet peeve of mine, the rod ends should be parallel). If any of your rod ends are difficult to turn, remove them from the car, clean the threads, inside and out, spray some good oil up inside the tube, (I use engine store fogging oil) to prevent corrosion, and grease the threads. I don’t use never seize, it is dirty and abrasive, I use good quality grease. Now next time you need to make an adjustment, there will be less cursing.

Back to squaring the axle in the car. Ok, now you have the rear axle centered between the rear chassis rails, and a center mark on the front cross-member. The next step is to choose a point on the ends of the rear axle to measure forward to the front cross-member center mark. You can use the front edge of the brake drum, or disc, the backing plate, or the backing plate flange. The important thing is to use the same spot on both sides. measure from your chosen point to the center mark on your front cross-member, (again you can use a plumb bob, or carpenter’s square to drop marks onto the floor if it makes things easier). The objective here is to have the dimension the same on both sides, right rear brake drum to front cross-member center the same distance as the left rear brake drum to front cross-member centre. Again, be as accurate as possible, a sixteenth of an inch or better.

They’re not the same are they. That means one rear wheel is further forward than the other. Now it is time to look at your ladder bars and see if one is adjusted longer or shorter than the other. What we are concerned about here is the bottom of the bar, we will use the top to adjust pinion angle later, but for now we want the axle square. I generally start by removing the ladder bars, remove and inspect all the rod ends, and the bars themselves for any damage, rust, cracks etc. Lubricate everything, and assemble the bars with all adjustments in the middle of their range, (which is about six threads showing on the rod end). Before re-installing the bars I will adjust the bottoms to the same length, if the chassis is all square and true, the housing will be square. Back to your car, if you have adjustable ladder bars, set the adjusters, (which are normally on the bottom and rear of the bar) in the middle of their adjustment range, and adjust the front of the bar, the front rod end, to square the housing in the chassis, to make both dimensions from the rear brake drum to the front cross-member center mark equal. Ideally you want both front rod ends in or out of the tube the same amount, and preferably with about six threads showing, (that is above the jam nut). A couple threads either way is not too bad. If you are finding that you have to have much more difference than that, either your housing or chassis brackets are on crooked, or your chassis is crooked. I am going to assume that everything is pretty close.

Now you have a rear axle that is centered, and square in your car.

A brief overview:

Car mostly level.

Find the center of the car at the front.

Center the rear housing in the chassis.

Measure from either end of the rear housing to the front center mark to square the housing in the car.

See, this is easy.

Next we get to talk about pinion angle.

Weekend update

Was it cold in Ashcroft!

Well this weekend was disappointing on one level, but a whole lot of fun on another. As you know I was supposed to be running the 1936 International pickup retro rod from Boomers this weekend but unfortunately it was not to be. The mechanical gods figured I had had more than enough fun this year and decided to put a stop to it. The engine in the Boomers rod is a 1964 Buick “Nailhead”. I know, you want to know why they are called a nailhead. These engines use very small valves, which look like nails, so the term, “Nailhead”. Small valves mean small ports, which in those days lead to high torque, these engines can pull. Anyway, back to the story. The oil filter is held on the side of the engine with a small aluminum casting, an oil filter adapter. After forty five years of trouble free service, it decided to crack as soon as we took it to the racetrack. A very very small crack, that could not be seen when we removed the adapter to replace the gasket, thinking/hoping, it was just a gasket leak. Unfortunately it was not. As I am sure you can appreciate, an oil filter adapter for a forty five year old nailhead motor is not the easiest part to find, let alone in a small town like Ashcroft. We did consider trying epoxy, or some similar product, but because it is under pressure I simply didn’t want to take the chance. This weekend was all about fun, pumping oil out of the engine at half track is not fun. Add to that the nasty weather on Saturday. . . we went to the bakery for coffee.

The awards Banquet on Saturday night was great fun. It was a huge pleasure to surprise Dennis Hicks with a Wally of his own. When I won my Wally earlier this year, I ordered another so Dennis could have one, I felt he, as car owner, was as deserving of the award as me. So while I was up collecting my award for winning the series, I was able to thank my crew, and present Dennis with a trophy of his own. Thank you Dennis, for  the opportunity to drive your car. We will have another great season next year.

Sunday was spent saying goodbyes to everyone at the track, seeing everyone as often as we do through the summer means the next six months will be pretty quiet.

Well. . . not all that quiet. The shop is very busy, I have many articles planned for this blog, and a few other things in the works. A jet Funny car that needs some work for next season, and maybe a Nitro Dragster or two.

Writing

Well thank you to all of you. I am really enjoying this blog, learning how to watch it, and track it and such. I am sincerely flattered by the huge number of people who are out there looking for me specifically on Google or other search engines. And what is really cool as that when you find me, you read through my whole site, and then, even better, you keep on coming back. Thank you.

I will continue writing for you. I enjoy it. Sometimes I simply ramble on, like this morning, and of course other times I have something more specific to say. I have many ideas for articles that will be coming. I still intend to break the blog into three sections: a technical section, for the racers and fans who really want to get into the nuts and bolts of race cars. There will be what I like to call the personal growth section, in which I will discuss things mostly about my training and motivation. Things like meditation techniques I use, diet, exercise, and other things I use, or have tried or heard of, in that area. The third section will be about my own racing program. At this point I have two different cars lined up to drive next season, Dennis Hicks’ Mountain Brew dragster of course, and a jet funny car. I am also discussing options with two different top fuel teams, one running in IHRA out of Florida, and a local nostalgia top fuel car. So although the season is winding down for me, there will be plenty to watch out for.

This last week has been very busy on the phone and in meetings with team owners and sponsors, I apologize for not updating my blog as promptly as I would have liked.

By far the most popular articles I have written are the technical articles. I promise many more, starting with an in-depth how to on ladder bars and four links. The technical articles are much more involved to write. My objective is to make them as easy to read and understand as possible. I have yet to work out how to add decent drawings to my blog, so I may simply draw them then take a photo, probably much faster. It is also important to me that you are getting the correct information, in the correct order. So I will often do some research into specific details, which in turn leads me to a distraction, and hence it takes much longer to write a technical article. But they are coming, I promise. Of course if there are other technical subjects you would like to hear about, please, let me know. I will continue with the rear suspension theme for now. But there is very few aspects of the drag race car I cannot enlighten you on, from blown alcohol or nitro motor setup, clutch, carburetors too. Also things that one might consider simple, yet I often see them done incorrectly.

One thing in particular which was brought to my attention this weekend after a nasty incident, is the need for correct throttle linkage setups, with good strong toe hooks so the driver can pull the throttle back if he needs to. And in reality he should be pulling the throttle back whenever he closes it, not simply lifting his foot, but pulling back on it. As a driver, throttle control is very important to me. Having a correctly designed throttle linkage is mandatory if you want me to do a good job driving.

The unfortunate thing is that the small details do not get noticed until they are needed. And when they are needed is when it is a bad situation. When these cars are running right, when the tuneup is spot on, traction is ideal, they are almost easy to drive. It is when things are not right that you need all your ducks in a row, that toe hook on the throttle pedal only needs to work properly when the throttle is stuck open, until then you will never notice if it is strong enough or not. . . or will you. I hope you are off to the car right now to check on it.

Internet Explorer

Sorry all. I have just discovered that the slide-show on my homepage does not work with internet explorer. I would have thought that the people who made the website would have checked that, but obviously they missed that too. Anyway, I have someone working on it now, and it should be fixed soon. In the meantime, try using Mozilla Firefox as a browser, my website works great there, and far fewer security issues too.

Welcome!

I am very excited to welcome Boomers Hot Rod Shop as a sponsor. These guys build world class hot rods. Show winners. It is a pleasure to bring them on board because I can recommend their work without hesitation. Their standards are as high as mine, and that is rare. Jim Hilstad and the guys at Boomers can build a complete show winning hotrod from the ground up, from sourcing the original parts and pieces to the final polish. This is the important part, when I say world class, I mean “world” class. This is the shop to call if you want to win the biggest hot rod shows in the world, or if you just want to know that your car was built right the first time. They not only do hot rods, but rare and classic car restorations and repairs as well. Do you have a numbers matching car? As much an investment as a cool toy, these guys can repair it without risk to your investment. They understand the subtleties needed to maintain the status of your rare vehicle. Did your baby get damaged in an accident? They can do the repairs to the highest standard. Is it time to upgrade your hotrod, or classic car with some new suspension or fresh paint or interior? They can do that too. Want a rat rod? They will build you one. Don’t be intimidated by the high standards they keep though. These are down to earth hot rodders who understand exactly where you are coming from if you like your hotrod to be a daily driver too. These things are meant to be enjoyed, and driving them is a big part of that enjoyment.

Give Jim Hilstad a call at 1 604 886 4546 to discuss your hotrod needs. Tell him you got your number here.

I have a lot of fans over in the East of the continent too, if you want a world class hotrod, these guys will build it for you, it is worth calling them even if you are on the other side of the continent, they have many long distance clients and work with them very easily.

I just ran over to their shop and took a couple quick photos of the things they are working on today to give you an idea of their scope.

For fun, at the last race in Ashcroft on October 3, we are going to take their little International retro rod pickup up and I am going to give it a few laps down the quarter mile. I encourage all of you to come by and take a look. This is one cool little truck.

They are in the process of building a website, watch this space for the link as soon as they have it up and running.

Rear Suspension

This whole website is pretty cool. By watching the stats I can see that the most popular tags for searches which end up on my site is rear suspension setup, in particular four link setups.

I will, in the next couple weeks, publish a very in depth post on adjusting your four link correctly. It will be a long post to be sure I cover it properly. But to begin with, let’s cover some basics.

As I am sure you have deduced, I am a drag racer, so this discussion refers to drag racing setups. If you want info for a street setup, or something to go around corners, send me an email and I can help you individually.

Let’s start with some basic high school physics. Newton’s law of motion states that for every action there is an equal and opposite reaction. This applies to almost everything we are doing while trying to accelerate a car down the quarter mile, and is very handy to remember when designing or modifying anything on the car.

Pistons are pushing down on the connecting rods, and the crankshaft, most of us understand that, but what are they pushing against? They push up against the cylinder heads, and, here it comes, they push up the same amount that they are pushing down, Newton got it right. That is an example for you, back to the rear suspension.

Your driveshaft is rotating, clockwise when viewed from the front. This turns the pinion gear in the front of your rear axle, the pinion gear is meshed with the ring gear, turning the rotation ninety degrees to drive the rear wheels. Try to picture the following, it can be tricky, but once you get it you will have a better understanding of what is happening in the rear suspension. As the pinion gear is rotating, meshed with the ring gear, if the slicks are stuck hard to the track, in effect preventing the ring gear from turning, or at least impeding the ring gear from turning, the pinion gear is literally trying to “climb up” the ring gear. Picture the ring gear as stationary, the pinion then climbs up the ring. Back to Newton, even when the tires start to rotate as the car accelerates forward, the pinion gear is still trying to climb up the ring gear, by an equal amount of force. Equal to, and opposite the amount of force trying to drive the car forward, (ok, there are some minute losses, friction and such, but for this discussion we can forget about them). And it is a huge amount of force, (torque). Think about that 750 ft lbs of torque your engine makes, multiplied through the torque converter, before hitting your first gearset which multiplies it even more, it is a huge amount of torque, (I am saving the calculations for another post). Now if the pinion is trying to climb up the ring gear, what is stopping it? The axle housing stops it, and in turn, whatever is holding the axle housing in the car. . . four links, ladder bar, leaf spring, etc.

Now, rather than visualizing the pinion climbing the ring gear, picture the whole axle housing trying to rotate up and around the rear axle, in the opposite direction to tire rotation, (and with an equal amount of force, Newton again). The housing is being driven around the rear axle by the pinion gear. It is this rotational force that we are harnessing with a four link or ladder bar or any other rear suspension setup.

A four link has two bars per side, a top bar and bottom bar. Pictured from the side, and under acceleration, (people often forget that under braking, or deceleration, everything happens the other way, ever see a car try to turn when backing off at the top end?), the bottom bar is being pushed forward, and being compressed by the rotational force of the axle housing, while the top bar is being pulled backwards and upwards in tension, trying to lift the chassis of the car. Adjusting the angle of the bars, controls the direction of the push and the pull, pushing the car forward, pulling up on the chassis, lifting the chassis, in turn transferring weight to the rear tires.

This all refers to the basic load directions in a four link rear suspension, so that you can picture what is happening back there when you release the trans brake, or mash the throttle. I have tried to make it basic enough to follow, yet assume the reader has a bit of an understanding of the terms I am using. These loads are all similar in a ladder bar setup, or leaf springs. Stock coil spring rear end setups, like some Mustangs and Camaros are in one form or another a four link, but with different geometry for anti-squat and anti-dive, as well as general passenger comfort. This is the first time I have ever really written a technical article, and hope I am making the concepts clear and understandable. I will work out how to add drawings in future articles to help clarify some of the concepts. If you have any questions, don’t quite understand what it is I am trying to get across, or want some clarification, please send me an email, I would love to hear. If you have any ideas for future posts, I would love to hear them too.

I will continue this discussion on rear suspensions soon, so check back often.

Ladder bars.

Why not a four link?

I am a big fan of ladder bars. For the majority of racers out there a ladder bar will do everything they require. But a four link is better, I hear this all the time, and yes in some perspectives a four link is a much better drag racing rear suspension setup. The biggest advantage to a four link is it’s adjust-ability.  This can be a great advantage. . .  if you know how to adjust it. When I look around the track, I see very few people adjusting their four links. Generally what I see are four links that have been setup, either by someone who knows how to tune them, or after a certain amount of aggravation, or “that’s how I bought the car, and I am not going to touch it ’cause it is working just fine the way it is”., and because the car is going straight, and running consistent, the owner leaves it alone.

The problem with a four link is that very few people have spent the time to work out how to make adjustments. I am not going to get into how to adjust a four link here, but I will tell you that the procedure starts when the car is being built. The chassis builder should have given you a chart of instant centres. If you don’t have one, you need to get one. You can generate one yourself. There are computer programs you can buy that make it easier, or you can do it the old fashioned way on the floor. I have done both. I now have a computer program I find reasonably easy to use although it does not allow for as many holes as we are using in newer four link setups, so I have to run the program twice. Once you have your instant centre chart, you then need some sort of preload reference. How much weight, does a quarter turn on the bar add, or subtract, form each corner. Of course this will change with a change in instant centre, so if you change bar locations, you then need to know the preload adjustments for that location. The point I am trying to make here is that although a four link is a great rear suspension setup, the adjustment procedure is too involved many drag racers. They generally get it working, then never adjust it.

If that is going to be the case, why not use a ladder bar then? A ladder bar generally has three choices for instant centre, and you can see them all on the car, you don’t need a chart. Preload can be set with a ruler if you want, although I do prefer to weigh the car so I have a reference point for preload adjustments. Often, unless it is a very high horsepower car, little or no preload is required with a ladder bar.

Ladder bars do take up a little more space forward in the chassis, if you are building a car with a lot of rearward driver position it can be a challenge to get a long enough bar in the car.

One of the cars I am currently building is a ladder bar setup. It is a very short wheelbase at 100.5 inches, so getting bars in there can be done. This one is interesting in that the owner wanted to use his rear axle housing which was already setup for a four link. It has a range of holes on the axle housing that could be used, and they are not in the usual location for a ladder bar. I had to get creative. One problem the typical ladder bar has is because of the angle of the two bars, as soon as you adjust the rear of the bar for pinion angle, the hole spacing changes, causing a side load on the rod ends, this is not good at all. It can also cause a certain amount of stress and cursing when trying to install the bars after making an adjustment.

For this car, I wanted to take advantage of the range of holes in the housing. I accomplished this by putting a pivot in the top tube, allowing the hole spacing at the rear to be adjustable. This solves two problems, first there is now no side loading on the rear rod ends after adjustment, and second, because I made the top bar adjustable, pinion angle can be changed very easily. Now that I have built these bars, I wouldn’t build them any other way. They are a little more expensive, but worth it. They offer a large range of adjust-ability, without the confusion of a four link. They are very strong, with large diameter thick wall 4130 tubing. And they can be built to suit any set of brackets you may already have.

Questions? Ask away, at the contacts page

Since I published this post a few days ago, it is interesting to note that people are finding it when searching “how to adjust four links”. I will compose an in depth look at how to adjust a four link suspension for future post. It may take a while so check back often. If you have any specific questions concerning your setup, my email is on my contacts page.

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