Tag: Tips

Posted on

How to Modify an FC RX-7 CorkSport Style Part 2: Chassis & Drivetrain

Picking up where we left off last time, the chassis and drivetrain for the FC RX-7 has plenty of potential with minimal modifications. Chassis bracing is a good place to start.

CorkSport offers strut braces for the front and rear strut/shock towers. Some people have questioned the effectiveness of the tower braces in the FC. Speaking from first hand experience, they work very well, and they make a big difference. I have e seen the aftermath of a car hitting a guard rail at highway speeds sideways and what saved the car from crushing itself sideways was the front strut brace. The front is a simple bolt in, and while the rear requires some extra work and includes trimming some metal, it is well worth it.

For underneath the car CorkSport sells the AutoExe Member Brace Set. Think of this is an over the top strut tower brace set for the under side of your RX-7. The chassis brace set ties together multiple points of the suspension to make the chassis more rigid, including tying up the rear differential sub frame to the chassis.


AutoExe Member Brace Set

Next up is lowering the car. Lowering the car gives it a lower center of gravity and you should also stiffen the dampening of the suspension to go with the springs. Tokico Illumina shocks combined with Eibach springs are a good combination for street driven vehicles. With the installation of lowering springs you will need to address the camber for the rear suspension. The design of the RX-7 suspension requires a camber adjustment kit which CorkSport offers as well. The rear camber link kit adjusts the rear sub frame correcting the camber on both sides of the car.


Rear Camber Adjuster

If you are seeking maximum performance out of the suspension you can change out the suspension bushings with polyurethane parts. The good part about the bushings is the upgrade to urethane makes the suspension work without extra deflection. The trade off is extra vibration from the stiffer bushings into the chassis. CorkSport offers the Prothane bushing kit for the RX-7.

Drivetrain mounts will also need to be replaced. It is not really a choice anymore, the engine, transmission, and differential mounts will be worn out after ¼ century. CorkSport offers Mazdaspeed replacement mounts for all of the drivetrain. The stiffer rubber used in the engine and transmission mounts limit engine movement to help cope with the extra power and put the power out the drivetrain instead of moving the engine around. The rear differential mounts are needed to deal with the increased torque load of the drive train under hard acceleration. We have seen cars in the past come into the shop with a clunk noise from the rear end of the car only to find the front differential mount broken.


Mazdaspeed Engine Mounts

With the increased power made from the engine modifications in the first blog you will need to upgrade the clutch. For a street driven RX-7 the ACT street clutch kit is hard to beat. The reason for the street version of the clutch is that puck clutches tend to chatter when engaged from a stand still and make driving in stop and go traffic a pain. With the installation of the clutch a lightweight flywheel is a good idea as well. ACT also offers lightweight flywheels in two varieties, Streetlight and Prolight. The reason for a lighter flywheel is engine response. With a lighter flywheel the engine has less mass to spin and because of this engine revs build faster. The difference between the two is the weight. The street version weighs more which helps with keeping the inertia of the motor going. This is helpful with making smooth starts and stops while on hills. I would choose the pro light myself. Having a rev happy rotary engine just makes me smile. When purchasing a lightweight flywheel it is important to get a counterweight. The stock RX-7 flywheel has the counterweight built in but the aftermarket flywheels do not.

The last piece of the drive train puzzle is the shifter. It is something you are constantly using in the RX-7 and CorkSport offers a short throw shifter. The short throw shifter decreases the distance you have to move the handle to change gears resulting in quicker shifts. The CorkSport shifter includes all new bushings and seals which are a must since most RX-7s we have seen need to have all of the parts replaced. If you are wondering what I am talking about there check out the shifter in your RX-7. If you can move the shifter left to right while in gear, and it feels loose and vague when shifting, or it doesn’t return to the center while in neutral you need to replace the bushings and seals at a minimum.


CorkSport Short Shifter

Well, that is it for the chassis and drive train. In the next blog post I will cover the brakes and styling for your RX-7.

– Derrick

Posted on

How to Modify an FC RX-7 CorkSport Style, Part 1: The Engine

So you have an FC RX-7 and you want to upgrade the car both in engine performance and styling. We have a large range of CorkSport brand products to help you out, along with other products we carry. Today we’ll start with the engine performance modifications, and later on work our way to the exterior.

The example car I will use for the build is my 1987 RX-7 Turbo II, since I am very familiar with it. This build will be written as if the car is stock when we start the project.

The first thing you need to do is get rid of the stock exhaust since it is heavy and fairly restrictive. Since my car is a turbo model I chose the CorkSport 80mm Turbo Back Exhaust or TBE for short. There are several reasons to go with the turbo back system. First, the exhaust looks great and sounds even better. Second, the turbo back exhaust is straight-through and is as free-flowing as you can get (be careful, removing the catalytic converter can violate emissions laws, check your local laws before installing.) Third, the amount of power gained with the exhaust system can be close to 45 wheel horsepower.

With the installation of the exhaust you do need to defeat the over-boost safety device built into the stock computer. This can be done with an HKS Fuel Cut Defender (FCD). What it does is cap the voltage of the pressure sensor so the computer does not think it is boosting higher than stock. Without the FCD the factory computer will cut fuel to the rear engine rotor to try and control what it thinks is over boost. The fuel cut will cause the rear rotor to be lean and can result in detonation and engine damage.

CorkSport RX-7 Turbo Back Exhaust

With the increase in power and boost from the TBE we need to look at addressing the fuel system before we put anymore power out of the engine. Lets face it, the fuel pump has been in the tank for 24 years now and isn’t getting any younger. To keep supporting the power increases an upgraded fuel pump is going to be required. The two options CorkSport offers are the J-Spec Cosmo fuel pump and the Walbro 255lph pump and Screen kit. I personally would use the J-Spec Cosmo pump. It may be more expensive but it was designed to fuel the 20B 3 rotor engine which had six 550cc fuel injectors to feed, which is 1100cc more than the FC RX-7 Turbo has. The pump is a bolt in replacement for the stock fuel pump and it includes a new pickup screen. I also strongly recommend sending your fuel injectors out to be tested and cleaned when you upgrade the fuel pump. There is most likely 24 years of deposits built up in the injectors as well. There are several companies which offer the service, like Witchhunter Performance or Marren for example. Find a place to clean the injectors that is close to you to cut down on shipping time back and forth.

With the fuel injectors pulled out I am sure you noticed that the wiring harness is pretty crunchy and destroyed, especially on the turbocharger side of the engine. The options are to either fix the breaking connectors and splice in new plugs or replace the harness. I would opt for replacing the harness myself so there will be trouble free motoring in the future. The CorkSport Harness is a great setup with all of the short comings of the stock harness addressed and removed in this new part.

We improved the exhaust flow so now it’s time to go work on the intake side. The first part to remove is the stock rubber turbo inlet pipe, which undoubtedly needs attention. The heat from the turbo and time really play hell with the stock part, making it brittle and prone to cracking. The CorkSport Turbo Inlet Pipe or TIP for short gives you a good looking part which will last much longer and seal better than the stock rubber part. The CorkSport TIP also happens to be $60 less than the stock Mazda part, if you can even find one.

CorkSport Turbo Inlet Pipe

The second part to the intake side is adding the CorkSport Front Mount Intercooler Kit (FMIC). The stock intercooler is mounted on top of the engine and can get heat soaked easily. For more information on heat soak check out our technical article about upgraded intercoolers. The solution to this is to get the intercooler out of the engine bay and into the air flow of the cooler air coming into the engine bay. The intercooler really helps out with making power consistently, instead of worrying about performance variations because of intercooler temperatures. With a heat soaked stock intercooler you get almost none of the cooling effects and you are just pumping hot air into the engine.

Now that we’ve done a good job of upgrading the power potential of our car, we need to make sure it stays cool. The next item to upgrade then is the old stock radiator in the RX-7, and we have the perfect part or the job. The CorkSport Aluminum Radiator and Fan Shroud are bolt in replacements for the stock radiator and shroud. The reason the new shroud is required is that the thicker radiator places the shroud closer to the stock engine fan. The new fan shroud has extra clearance so the stock fan can still be utilized with the upgraded radiator. The original radiator uses an aluminum core with a plastic fiber end tank design. After heat cycling for 24 years the fiber end tanks get brittle and crack. When this happens it is game over for the stock radiator and your engine if you let the engine overheat. Remember if you hear that annoying buzzer go off, stop your car and check the coolant (let it cool off first). Mazda made it annoying on purpose; rotaries do not handle overheating well.

While we are on the topic of cooling, the stock oil cooler lines are something to look at. The stock parts are a rubber line with a braided cloth outer. The lines will get soft and start to develop leaks or possibly fail over time. This can be the end of your engine if this happens while you are driving and lose oil pressure, which can destroy your motor. The CorkSport Stainless Braided Oil Cooler Lines replace the stock line with completely new and upgraded parts. The lines are a stainless steel braided line which is more durable than the stock oil cooler lines. They are a little more difficult to install because of how tough they are, but the end results and peace of mind you get knowing they won’t fail are well worth it.

That’s all for this time, I will run through the drivetrain, chassis, and styling modifications in future blog posts.

– Derrick

Posted on

International Shipping Advice

In a typical week I’ll answer 5-6 emails asking about shipping parts outside of the United States and which method to choose. To hopefully clear up a few things for people I will discuss the options we offer and other important topics.

First things first, CorkSport will not under value shipments or label them as gifts. What you are asking us to do is to not be honest in declaring a shipments value to your government. This is like asking a US citizen to report something false to our IRS. It is something you just don’t do. The other catch on this subject is the USPS and UPS will not allow us to insure a shipment over the value of the declared parts. If you ordered a $500 part and asked us to declare it at $200 the maximum we could insure it would be $200. If the shipment gets lost or damaged there is no recourse with the carrier.

CorkSport has several options available for shipping overseas which boils down to two different carriers, the United States Postal Service aka USPS and United Parcel Service known as UPS. Each carrier has its own advantages compared to the other as I will explain below.

UPS delivers to most countries on the planet with the three options below.

UPS Express

is a 1-2 day shipment to most places on the planet. The only thing that can slow down the delivery for this option is customs in the country the shipment is going to. The brokerage fees when shipping by this method are included in the shipping cost. The duties and taxes for your country are not and UPS will collect them. Tracking is available and is updated often with UPS.

UPS Expedited

is a 3-5 day service. This is the economy service for air shipping via UPS. As with UPS Express, the brokerage fees are included in the shipping cost. The duties and taxes for your country are not and UPS will collect them. If you need something decently fast but it is not critical I recommend this option for most shipments. If you want to order something large like an exhaust system or larger, this is the shipment method we quote out. Tracking is available and is updated often with UPS.

UPS Standard

is a ground shipping option for Canada only. UPS Standard shipping takes from 3-10 days depending on where you are in Canada. CorkSport is located on the west coast in the USA. If you live on Prince Edward Island you can plan on the shipment taking 10 days to reach you. With UPS Standard the brokerage fees are NOT included in the shipping cost. The duties and taxes for your country are not as well and UPS will collect them. We get a phone call a week asking us why we did not change the shipping option from UPS Standard when someone places an order when UPS delivers a shipment and collects brokerage and duties. You the customer get to choose the shipping option. If you choose UPS for delivery we will ship it out via UPS.

USPS delivers everywhere on the planet and has multiple choices for shipping.

USPS Priority Mail International

is an option that takes 8-10 days to arrive to most countries. This does not include the time in customs once it arrives to the destination country. Sometimes customs can be quick with a 1-2 day delay. The worst case in customs I have seen was 10 days for Germany. This shipping option will require you to pay for duties and taxes for your country upon delivery. There is no brokerage fees charged. Tracking is available for Priority Mail services except for small flat rate envelope or box. Small flat rate will give us a customs form number but it is not traceable in the USPS system. Insurance is limited for Priority Mail in most countries to $600. If you have a shipment that is valued over $600 we will contact you about this to change shipping options. One drawback to Priority Mail is the maximum size limit which is 200 total centimeters length and girth.

USPS Express Mail Service

is a 5-6 day shipping option to most countries. Customs in your country can delay the shipment but we normally do not see this more than 1-2 days for Express Mail. When the Express Mail shipment arrives they will collect duties and taxes but there are no brokerage fees. Insurance levels are higher with Express Mail. For most countries the highest value for insurance is $2700. There are size limits with Express Mail which are similar to Priority Mail which limits the length and girth at 200 centimeters.

What I suggest for most shipments if the value is lower and the weight is less than 10 lbs, is to use USPS Priority Mail. It offers a decent shipping price for an international order and is very reliable. If you want to get an exhaust or intercooler kit shipped I recommend UPS Expedited. The shipment arrives quickly and insurance value covers the parts if there is damage or something goes missing. You also get your new exhaust or intercooler quickly with this method. If you order something large like a bumper or a quantity of a larger part I recommend you contact us for a shipping quote.

If you have any shipping questions feel free the contact us and we will help you with any shipping questions.

– Derrick

Posted on

Credit for Content: Tips & Tricks

We love to hear some of the ideas our customers have when it comes to product development. You have some great ideas that have been shared with us in the last few months.

In keeping with our goal of providing excellent customer service and technical support to our customers, we would love to hear some of the tips and tricks that you use when doing installations, modifications or routine maintenance of your Mazda. Could be great ways to keep the oil from spilling all over the rotor housings on your RX-7 during an oil change (that upside down filter is a gem, isn’t it!), solutions to removing or reinstalling the downpipe on the MS3 (those studs don’t like to stay put in the turbo, do they!), or even something as simple as methods on how to keep your tools organized or functioning to their fullest.

In return, we’ll give a 10% discount code (not to exceed $25) for use toward any CorkSport Brand Parts to the top three tips submitted in the next three months.

Feel free to submit video, photos or diagrams to support your ideas.* The clearer you make the content, the better your chances are of getting the discount. We’ll publish the best tips here in our blog and give credit to everyone who submitted ideas. Submit your content to: wrenchtips@corksport.com.

For Example:

Here’s an tip I learned from an Aircraft & Powerplant mechanic who spent countless hours slogging through the muck repairing Aircrane Helicopters that had broken down in the field (or more appropriately out in the middle of nowhere in the woods). This trick was so helpful that he kept a can of Bon Ami sink cleaner in his toolbox. Aircraft and automobile engineers love to use phillips drive screws to hold all sorts of things together. And whether we ourselves have ham-fisted an install and thrashed the phillips drive in the top of a screw or it was the fault of the DPO (Dip-$&*%Previous Owner) , the solution is often times to get out the dremel and make it worse before it gets any better.

Alas, there is a solution that works perfectly, especially in those applications where the Phillips drive is HUGE and holds something on with substantial amounts of torque and your ‘bash it with a hammer’ impact screwdriver has eaten the top of the screw for breakfast.

So before you put all your weight into your battery powered screwdriver and turn what still looks remotely like a usable screw into a finely machined cone…take a deep breath. Go into the kitchen or (if you’re a bachelor and don’t know what this room in your house is for other than storing giant garbage bags of empty natty light cans) grocery store and pick up a can of abrasive sink cleaner like Bon Ami or another abrasive polishing powder. Mix it up into a paste and dip the end of your screwdriver into it. The paste is aggressive and will grab uneven surfaces of the drive in the screw and it will come right out. Make sure to continue to use plenty of downward pressure as well so the driver doesn’t just jump out of the contour of the screw. This trick also works well on partially rounded off hex drive fasteners like those M8 head exhaust manifold heat shield bolts on the MS3/MS6/CX-7.

Just don’t let your wife know that you’ve been stealing things out of the kitchen for use in the shop.

They don’t like that.

– Jason

*All content submitted will become the property of CorkSport.

Posted on

CorkSport Events 2010

CorkSport attends Mazda events throughout each year which include some of the larger get togethers like the OCC Mazda Meet last May or Sevenstock in September. There are also smaller events like our local club Mazdas Northwest which has a monthly meeting. This is a chance for CorkSport to come out and meet our fellow like-minded Mazda enthusiasts. This is also a chance for us to show you, our customers some of our cars like the CorkSport project 2010 Mazdaspeed 3 and the RX-8.

With a new year coming up we are working on planning our schedule and are offering you all the chance to influence where we show up. So far we are planning on definitely attending Sevenstock XIII, the SEMA show in Las Vegas, various Mazdas Northwest events, Mazfest in SoCal, and RPNW monthly meets.

If you have a Mazda event you are working on planning in 2010 let me know about it. It can be local to us in Portland, OR or on the other side of the planet in Geneva, Switzerland. If you have an event or know of one that has Mazdas present let me know as I am open for suggestions. This does not mean that we will be able to make every event, but if we know about your event there is a much better chance of us supporting the event. Feel free to send me an email or a call me on the phone at 360-260-2675 with your suggestions and events!

– Derrick