One of the biggest perks of being on the Circle Track staff is being able to regularly talk to some pretty cool people and ask them whatever you want. Imagine being able to call up your mayor and request that he replace the stop sign with a light at that annoying intersection on your way to work. Or the general manager for your favorite sports team and ask him exactly what was going through his thick skull during the draft?
It’s sort of like that, but with racing.

We recently had a very enlightening conversation with Mike Mortensen of Quick Performance. Quick Performance builds complete rearends for racing, and also supplies racers with quality racing components. One of the strengths of Quick Performance is that it understands we all aren’t racing on NASCAR Sprint Cup budgets, and offers a line of products that are both affordable for the Street Stock-level racer that’s also much higher quality than the stock components many racers try to get by with.

We hit Mortensen with several of the questions that we most often hear from racers. The information he provided us was so good we thought we’d relay it to you as-is. One of the points Mortensen stressed is that Quick Performance doesn’t mind spending time on the phone with a racer to help them improve their performance. Each racer has unique needs, and Mortensen says if that means spending a few extra minutes on the phone to make sure that they can get him or her a rearend that’s exactly the way they needed, then that is what they are willing to do.

The Ford 9-inch rearend is easily the most popular in racing, but most Street Stock racers run a GM metric chassis like a Monte Carlo. What do they need to do when installing a new rear in to make sure all the suspension geometry is correct?

We can handle that for them. We build housings that are compatible with some of the GM chassis that are popular in circle track racing. So a customer can call up and tell us what he is working on, and we can jig up a suspension and build him a rearend housing that will be pretty straightforward when it comes to installing it into his race car. We typically spend enough time on the phone talking to the customers that we can get a pretty good idea what they need so we can set them up with a package that is going to be suitable for them. In most cases they can bolt the rearend into the car and be competitive right from the get-go.

Any advice finding what I need in a junkyard?

If you are trying to race with junkyard parts, it can be really hard to know what you are getting. If you are pulling a 9-inch rear out of a junkyard, that probably means it is been in service for decades by now. It could be 40, 50, maybe even 60 years old. A lot of times those rearends have been in and out of different vehicles, and they have been abused and neglected. And if you miss something it can leave you broken on the track and cost you a lot more than you saved by going to the junkyard in the first place. Plus, with older stock components, the manufacturing processes back then just weren’t as capable of maintaining quality like we have today. And often you will wind up with a setup that may not be up to the task for today’s racing conditions.

We build our own housings at Quick Performance. We do a whole new housing, or we can build a housing with a reconditioned centerpiece. That way you know everything is either brand-new or has been thoroughly inspected and brought back up to spec. We will build a rearend with all new DOM tubing, new laser cut brackets and billet steel housing ends. Now, not only do you know that everything is straight and fits in the race car like it should, but you also have the advantage of higher quality and newer technology that should help you race better with fewer failures. We can build a housing today with today’s technology that is so much better than anything Ford ever made all those years ago, and the cost really isn’t that much of a difference.

When can I get by with a cast center section and when should I upgrade to a nodular iron piece?

If you are running an entry-level class with lower horsepower levels you often can get by with a cast third member without any problems. A good example is the IMCA Hobby Stock division. We have had a lot of success helping those guys out running a reconditioned stock 9-inch third member case that we reassemble with new Temkin USA bearings, new Motive Performance gears, and either a spool or locker depending on how the car is being used. Then for guys that are a step up and beyond the entry-level divisions, we do have a new aftermarket nodular iron center section as well as even aluminum cases that we can use.

Often the rules will restrict what type of rearend you can use. If the rules say you have to run a stock rearend, that often limits you to the cast center section. But if you can choose, a general rule of thumb that I go by is if you have four hundred horsepower or more, then you are usually better off using an aftermarket nodular iron third member that can hold up to much higher levels of power and abuse.

Is spending the extra money on a lightweight ring-and-pinion set worth it?

If money is tight, we do have gearsets that are quite inexpensive. For the guys on a budget we do have a value line of gears that starts at $112, and they go on up from there. We have sets that are factory lightweight and they are typically about 2 pounds lighter than a standard set of gears. Then you can go on to REM polishing. Some guys use those in the lower levels, but if money is tight, quite often I will tell guys that they might be better off spending their money somewhere else.

However, a lot of guys really do like the lightweight gearsets. They say they can tell the difference in the efficiency of their drivetrain. Cutting out the 2 pounds of rotating mass does free things up quite a bit, and drivers often say that the car will get up to speed more quickly and is more responsive to the throttle.

What is a full floating 9-inch rear?

There are basically two main styles of 9-inch rearends. From the factory Ford made a semi-floating 9-inch rearend, which is the traditional style. That uses an axle shaft that is splined on one end and a flange with wheels studs on the other end. For that particular set up we do have a heavy-duty tapered wheel bearing that is highly recommended for circle track racing. It will withstand sideloading a lot better than a standard bearing. Sometimes your rules won’t allow a full-floating rearend, so you will have to go with this traditional style, but we even have guys on a tight budget that have raced these rearends with success. The main thing is to upgrade to the better bearing and it will allow the rearend to hold up a lot longer.

A full-floater style rearend really is not too much more expensive. It uses an axle shaft that is splined on both ends, and there is a splined hub that mates with the axle and the wheel bolts to that. The axle isn’t bolted to anything, so it just kind of floats between the third member and the hub. A lot of times it comes down to the rules. Some of the more entry-level classes will not allow you to run the full floater. But if you are allowed to run either, the full floater really is a no-brainer. It is safer, it is easy to work on, and for circle track applications it really is the better setup.

What axle should I run?

The 28- and 31-spline axles are going to be the two most common choices. Both are spline counts that Ford made from the factory. I always try to recommend the 31-spline axles whenever possible because they are stronger. Sometimes a guy may already have six or seven third member setups that are already 28-spline, so you can understand why he would want to switch over to the 31-spline axles. But if you don’t have anything to begin with, you are definitely better off going with the 31-spline axles to gain that extra strength. They do hold up better to racing than the smaller 28-spline axle.