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FAQS

TECHNICAL FAQs

Folks often ask what auto parts we run on our Mazdas. Below are some of the answers.

Note that your ideal choices may be very different from ours, because other aspects of your Mazda are different, or your local conditions are very different, or what you do with your Mazda Miata, Mazda MX5, Mazda RX7, Mazda RX8, Mazda 3 and Mazda 6 is different, etc.

You can contact us with a brief description of your plans or call us to discuss your needs and application at (858) 775-2810. We will be happy to help you find what works for you.

For MUCH more information on many of these subjects, see our Mazda Forum.

Rim Weight

The 1990 through 2005 Mazda Miata is VERY sensitive to unsprung weight. The factory designed and sold it with factory rims that were as light as 10 pounds each! Our STRONG advice for owners of 1990-2005 Mazda Miatas is to only buy similarly light wheels and avoid any rims that are over 15 pounds each. The lighter the better! We sell 15 inch rims that are under 10 pounds and most users can feel a change as small as 3 pounds of unsprung weight per corner. Buying wheels over 15 pounds will seriously degrade the ride and performance of your Mazda Miata. We have had too many customers call us only AFTER their purchase of 15-20+ pound wheels elsewhere asking how their Miata can be fixed now that it rides rough, crashes over potholes, and is no longer fun to drive! Asking your Mazda Miata suspension to lift 15 to 20 pound rims with each bump and still feel fun to drive is like asking your own body to run with ankle weights and still be fast--heavy rims will hurt your Mazda Miata's performance just like the ankle weights would hurt yours. Don't accept the representation from the average tire shop that the rim they are trying to sell you is "light." Know exactly what the true weight is before you buy! Note that there is a lot marketing hype out there and few distributors bother to actually check the advertised weights of the wheels they sell, relying instead on exaggerated or atypical claims in the marketing materials produced by the wheel manufacturers. Because we actually weigh the wheels we sell, our weights will often be higher than what the wheel manufacturers list on their own websites. It is VERY COMMON to find other vendors selling 15 pound rims yet telling their customers those rims are 12 pounds and lower. Here, we weigh every rim we sell and report the actual weights in the product listing for each wheel.

The 2006 Mazda MX5 has a more sophisticated suspension but the user seeking to improve performance should nonetheless remember that weight is still the enemy. The brakes on the 2006 are too large to accommodate 15 inch rims which means that 16 inch rims are the minimum. We use 16 inch rims for both street and race track duty to keep the unsprung weight as light as possible.

Rim Sizes

Our preference for 1990-2005 Mazda Miatas is 15 inch rims for both street and race track use. For the pure street user the 15x6.5 size helps keep unsprung weight low and the user can select from a wide selection of 195/50/15 and 205/50/15 sizes. For the user planning track racing or autocross work we recommend a 15x7 and 205/50/15 as the starting setup. Feel free to consult with us on tire choices The 2006+ MX5 Miata has brakes that are too large for use of 15 inch wheels. On the 2006 Mazda Miata we use 16x8 inch rims with 225/50/16s for daily driving and 245s for track racing and autocross work. See our forum for details and pictures.

Wheel Offsets

This issue causes a lot of confusion. Here is a simple explanation. If the rim is 6 inches wide, and the mounting surface of that rim (backside of the bolt holes), is 3 inches from either outside edge, that rim has a 0 offset. To the extent that a rim's mounting plane is offset from that zero position, that offset is measured in millimeters for Japanese cars. For the 1990-2005 Mazda Miata the factory offsets are 45mm for 14 inch wheels and 40mm for factory 15s, 16s, and 17s. Street users should stick to the factory range of 40-45mm. Note that there is a popular book on the Mazda Miata still sold that indicates the factory offset is 45mm only...that book is a decade out of date and should be discarded. Moreover, you will notice offsets in our wheel section of 35mm, 30mm, etc., and those are for race application. Please consult with us if you have any questions on appropriate offset for your intended use.

Hubcentric Rings

We sell hubcentric rings for those that want them. They are not required. They are a convenience item. They are NOT a load bearing item which is why they are typically made from nylon reinforced plastic. Their job is to roughly center the wheel while the user tightens the lugs. The lugs do the final centering. Racers will often skip the hubcentric rings because they do not want to take the chance of them dislodging and getting stuck on a hot hub during a fast trackside tire change on race day. Racers will typically squat and use their knees to hold the wheel roughly centered while they spin the lugs on. Street users usually don't want to worry about it and pay the $18 for a set of rings.

Alignment

Depends on what you want to do with your Mazda Miata, Mazda MX5, Mazda RX7, Mazda RX8, Mazda 3 and Mazda 6. For race track driving and more aggressive street driving try a bit more negative camber. For performance street driving we like the front camber ranges from -1.0 to -2.0 depending on conditions, tire choice, etc.

Autocross. Autocross is not reality and ideal autocross alignments are not ideal street alignments. Much depends on your choice of tires, shock absorbers, etc. Tire life may suffer and you assume the risk if you try these settings and ruin a set of tires!!. For Autocross consider considerably more negative camber. We find the following works well on our Autocross Mazda Miata:

Front camber -2
Front toe zero to POSITIVE 1/8 (within factory range) Caster--As much positive as you can get with the above settings.

Rear camber -3
Rear toe zero to NEGATIVE 1/8 (within factory range)

The camber curve of the rear link suspension on the Mazda RX8 and 2006+ Mazda Miata is better and needs less negative camber (we run ranges of 1.8 to 2.2 typically).

Which Intake Fits with a Shock Tower Brace?

On 99 and newer Mazda Miatas the Racing Beat HighFlow intake will fit with a Freedom Design Shock Tower Brace--but it is tight and requires a bit of tinkering to get these two parts to play together nicely. For 90-93 cars, the HighFlow is not compatible with any shock tower brace. On 94-97, the Racing Beat HighFlow does not fit well with shock tower braces.

What Oil do we use?

Synthetic in our piston motors. We have opened engines with years of use that have run on nothing but synthetic and other engines that have run on regular dino and the comparison can be dramatic. We run synthetic here in our piston engines and so should you. You spend serious dollars on your Mazda car, why put cheap oil in it? Note that the Mazda RX8 rotary motor cannot use synthetic oil because it injects oil in the combustion process and the flash point of the synthetic oil is so much higher than regular oil it fails to fully burn and can destroy your catalytic converter, 02 sensors, etc.

Cleaning Your Muffler Tip

If you have our RoadsterSport, or a Racing Beat, or any other stainless steel muffler you should clean the tip. Stainless steel exposed to heat will discolor slightly. Use a little metal polish each time you wash your Mazda car to keep exhaust tips looking great. We like Mother's Aluminum Wheel Polish for this task but any metal polish should work fine.

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