The engine is already fairly well optimized, so the most practical upgrades are an underdrive pulley, cold air intake, exhaust system upgrade (contact Dynomax for a local dealer), and K&N air filter, which is a controversial item. Some claim the K&N increases air flow without loss of protection; others say it is a waste of money, and at worst, that it lets more dirt into the engine. If the K&N does make a difference, it is at the highest rpms when airflow becomes critical. There are performance computers of varying utility and generally overstated claims, as well.
The first step is to replace the stock tires, which are often the car's main problem. For those on a budget, we would recommend Yokohama's AVID series. Tire Rack can sell them to you at bargain prices. We also tested the highly rated Bridgestone Potenza RE93, but found that these tires tend to chirp more on acceleration, which can bring trouble with the law. We recommend getting better tires immediately, as the stock Goodyears can be slippery in water; better tires also reduce stopping distances. (Other commonly recommended, inexpensive tires are the Goodyear Aquatred, Dunlop D60A2, and Goodrich Comp T/A. Try Tire Rack for good prices).
"One cheap way to get extra power and fuel economy is to wrap your exhaust manifold/header with heat resistant exhaust wrap/tape.
"When exhaust gases are pushed out of your cylinders to your exhaust manifold, the air surrounding the manifold begin to cool the gases. This cooling process reduces the velocity of the escaping gases and the engine must 'work' to push the gases through your exhaust system.
"Wrapping the exhaust headers with exhaust wrap maintains hotter exhaust gases that exit the system faster through decreased density. Increased exhaust scavenging is produced, along with lower underhood and intake temperatures. I would also venture to guess that my catalytic converter operates more efficiently since hotter gases would elevate burning of pollutants.
"I purchased the exhaust wrap by a company called Thermo Tec from a JC Whitney catalog for around $30. I installed the wrap on the header and a portion of the exhaust pipe leading from the catalytic converter to the muffler.
"This mild enhancement resulted in a 5 - 7 HP gain ... the power surge starts at around 3,000 rpm. I haven't had the chance to monitor the fuel economy gains."
David Fain wrote that he had added a cold air intake to his Corolla; his method is similar to that used by many enthusiasts on cars from PT Cruisers to pickup trucks. In his words:
The car seems to rev up faster. I did it by cutting a portion of the air intake hose (2 inch diameter intake plastic hose), attached a 90 degree 2" PVC coupling, cut and attached a PVC pipe and routed to the grill of the car. Since the opening of the pipe is pointing down, I made a 45 degree angle cut at the bottom of the pipe and faced it towards the grill. In this way, as air speed picks up, the air hits the 45 degree opening and 'rams' the air up the pipe. Since air has to move up the pipe, rain water doesn't seem to work it way up into the filter box.
To do this, you will need (from a hardware store) 2" PVC piping and a rubber 2" 90 degree coupler, with a hose clamp on each end. Use a tape measure and utility knife saber saw with angle cut adjustments.
Note: Ed Salisbury wrote, "My understanding is that PVC should not be used in the engine compartment, since it can give off poisonous fumes when heated too much. I've heard that ABS is the plumbing material of choice."
I own a 1998 Corolla CE. I recently purchased a generic short ram air intake kit on Ebay, and it was only a little over 30 dollars including shipping (which seems to be the going rate for most intakes for my year Corolla). The kit came with an aluminum tube, a hose, a red conical air filter, an adaptor to fit onto the engine, and an adaptor to fit the filter onto the aluminum tube.
I've never worked on my car, and yet it only took about 20 minutes to install. The tools you'll need: basic set of screw drivers, and a basic racheting wrench kit. I've noticed a slight, but noticeable gain in performance. From around mid-range rpms, the engine has a low rumble. In higher rpms, it has a nice raw sound. At 70k miles on the engine, and using 91 octane gas, my car passed with flying colors (with the aftermarket intake still installed).
There were two complications. The hose that came with the kit was much too short to reach the mass air sensor. A friend of mine, who was helping with installation, happened to have a 3" bit of hose that just happened to fit exactly over the stock hose and the hose that came with the kit. We secured it with fasteners to be safe, and we've had no problems with that so far.
At about the middle of the aluminum pipe, there is a hole about the size of a dime. This is usually used to connect a mass air sensor or OBD component of some sort, but my Corolla only required that single hose to be hooked up. I've temporarily covered it with a patch of duct tape to avoid getting dirt into the engine. I plan on purchasing some exhaust header wrap, or some kind of heat resistant tape, to properly cover the hole. Even after some rough driving, the duct tape is still perfectly secure, at least for now.
Inspect, and if needed, clean out the aluminum pipe before you put it in your car; small metal shavings inside your engine is a bad thing.
David Fain wrote: For anyone that's interested in supercharging their Corolla, EL Prototypes (626) 812-4358 will start working on one in a few weeks. Their price will be approximately $2,500. They will attempt to find one that works best with the Corolla (i.e. Roots or Compressor Type made by Toyota, Vortec, Eaton, etc.). Their setup may require repositioning of the battery to the trunk and replacement of the air filter box with a aftermarket air intake system. With the compression ratio of the Corolla being 10:1, the boost will probably be low; however, replacement of the pistons and connecting rods with aftermarket forged types and ball peening the crankshaft may allow higher boost for more power.
My preference would be to keep the engine stock and deal with a mild boost setup. Moreover, I'll replace the stock clutch and pressure plate with something more heavy duty.
As I had mentioned in a previous posting, EL Prototypes [also] has a Turbo kit for the Corolla for anyone that's interested. The unit doesn't spool up until you hit 2,000 rpm with a max boost of 5 to 6 psi. [Approx price: $2,500]
Cyberspace Auto sells the following: (prices as of August 2000)
David Fain wrote: Just had TRD stock struts and springs installed and the improvement in handling is incredible ... at least 100% and worth the investment! The ride is stiffer than stock but the car absorbs road imperfections without giving bone jarring feedback. In addition, the car is about 1 inch lower than before and the lowered stance conveys a sports car attitude. With this new setup, you have to push the car pretty hard to make it oversteer but its easy to get it back under control.
Sorry! Adam Trimble wrote: "A word of advice, the Corolla engine (1ZZ-FE) cannot have "G" series heads put on it. I have talked to both TRD and Toysport who say this is impossible."