STEP 3 - PERFORMANCE UPGRADES
-Now that your maintenance is all caught up, you can start adding power. And there is alot of it hiding inside waiting to come out. Most of it is in the intake. It is like no other. It's secondary air inlets allow the SHO to make a very impressive power curve...actually, it's not a curve at all, it's a line. The higher you rev, the higher the line goes, and it doesn't fall off until you let off. Here is a dyno graph of a stock 3.0; You can really tell when the secondaries open up.
Power is all about moving air (and fuel) through the engine. The more air that goes through, the more power. Each engine was precision built, and can spin an incredible 9,000 RPMs with no fear. Only problem is that the external accessories (power steering pump, A/C compressor, water pump) can't handle that kind of speed.
1-However, with an under-drive pulley from SHO Source, you can safely push it to 8,000 RPMs. Of course, a tune will be required to do that. But even without the tune, it adds 5-8 hp.
2-A tune is going to be necessary if you want to get the most out of your engine. The only option now is the twEECer from SHO NUT. It is a bit pricey, but you can do anything you want with it. There used to be a place that sold the considerably cheaper LPM (otherwise known as a chip). Unfortunately, these are hard to find as the original supplier is no longer in business. You may be able to find one on e-bay and have it programmed to suit you by SHO Source...good luck with that. But a good tune will provide another 20+ hp.
3-K&N stock replacement filter is worth about 10-12 hp. It is the best "bang for your buck" as far as upgrades go. A cold air intake is more costly, but moderately more effective, especially in the higher RPMs. Avoid the ones that draw air from inside the engine compartment, as these are not pulling in cold air regardless of a makeshift box with weatherstripping. Cold air is denser, thus more air in a given volume area. Try to find one that draws the air from outside like the stock air box does. These used to be easy to find, but again, the only place known to me that sold them is no longer in business...keep checking ebay. If you can't find one, I'd stick with the K&N stock replacement and stock air box.
4-80mm Mass Air Flow Sensor (MAF). This simply replaces the stock 65mm unit to allow more airflow. This will require a twEECer or LPM to work properly. It's worth about 5-10 hp on a stock motor. More with intake porting.
5-Big bore butterflies. These are available from SHO Source ready to bolt on. They add at least 10 hp once they open. With intake porting you can expect alot more.
6-Intake porting. There is alot of metal that can come out of the tanks and runners. Put a gasket up to the these parts and you'll see just how much. This is no small task though. It took me a few weeks to port everything on mine. If you want to do this to your daily driver, find a spare intake and have it sandblasted. Then start grinding. That way you can work on it at your leisure and have the whole intake ready to just swap out. You can expect 15-20 hp from this. While your at it, paint the parts with some high temp engine paint, or have them powder coated. Go ahead and finish it off with some new silicone hoses, new clamps and new stainless steel bolts and washers. Make sure you use blue Locktite on the new bolts to the heads.
7-Head porting. There is a considerable amount of metal to be removed from the intake side of the heads. However, they need to be removed from the car to do this. You don't want those shavings falling into the combustion chamber and damaging the valve seats. The valve seals could probably stand to be replaced, anyway. Head porting is highly recommended if you do all the intake porting, otherwise, the air flow you freed up from the intake will hit a bottleneck here. The exhaust side is already gasket matched, so just polish that side.
8-Now you need an escape for all that air. Pick up a high flow Y-pipe from SHO Source. They are available with or without cats.
9-Follow that up with a cat back system to complete the exhaust. Together they will produce another 15+ hp.
10-With all of the above done, you're going to need a high flow fuel pump to keep up with fuel demand.
-Catch can. This is necessary to filter out the crap ton of oil that will come from the crankcase back to the intake during normal operation and clog up all that free space you just opened up. Also, it gums up the plugs and what not. Not critical, but highly recommended. The better the can, the more expensive.
-Rod shifter. These came stock in the 92-95 cars, But the 89-91s had cable shifters. They are ok until they break, and they probably will. If you have a gen 1 try to find one of these to upgrade to. Bushing kits are also available to give it that like new feel.
-If you do all the mods listed above, you will have a 300 hp car that is a thrill to drive, is still comfortable as a daily driver, and the transmission can handle whatever you throw at it. You can even add a 100 hp nitrous kit if you want. The only thing left to do now, other than a 3.2 swap (for a little more torque) or cams (very expensive) is add boost (Turbo or Supercharger). Just remember, these transmissions aren't designed to handle more than 400 hp, so if you do add boost, have a few spares lying around.
-I hope this guide helps you new owners out there. Happy modding.
