Buying the Right Down Pipe for Your Turbocharged Automobile
Turbocharged vehicles aren't a common sight. You'd normally only see them in video games, on TV, or in movies. If you've got one sitting on your garage, then consider yourself very fortunate; you've got a high-performing ride after all. While a turbocharged automobile is already great as is, there are plenty of ways to make it even greater. You can add all sorts of accessories and replace various stock parts. One surefire way to get more horsepower for your car is to replace your stock catalytic converter with a downpipe.
What does a downpipe do, exactly?
Simply put, a downpipe directs the exhaust from the turbo charger to the exhaust pipe. A downpipe provides better exhaust capabilities, allowing for an improved performance in your car. In fact, you can get as much as 15-20 more horsepower with a downpipe equipped to your car.
If you're wondering what may be the possible downsides of using a downpipe, the answer to your question is none. There haven't been any reports of downpipes causing other areas of performance to suffer, unlike other performance modifications. That's the very reason why a downpipe is one of the best ways to upgrade your car.
What downpipe should you buy?
There are several kinds of downpipes in the market. You'll find plenty of brands that offer them. However, there's really not much difference among all of them in terms of function. They basically perform equally. With those said, we advise you to get a downpipe that's made of stainless steel. There are also mild steel variants, but they naturally won't last as long as the stainless steel versions.
Getting a stainless steel downpipe is our only recommendation. The style/construction of the downpipe that you're going to purchase is up to you. Stick with your preferred style as long as it fits your car. Again, there aren't notable differences among them. Below are the descriptions of the various downpipe styles.
- Blank plate ? This is the most similar to stock downpipes. The wastegate portion of the pipe is covered. Generally, this is also the cheapest of type of downpipe.
- Twin dump/Divorced ? This looks like the blank plate-style downpipe except for the fact that it has a hole for the wastegate portion.
- Bellmouth ? It's a downpipe that's completely open.
- Split Bellmouth ? It's a bellmouth-style downpipe with a divider in the middle.
How to Install a Down Pipe to a 2004 Subaru STi
If you've got a turbocharged 2004 Subaru STi, then you're one lucky man. While your ride is already impressive as is, there's a good chance that you'd want to boost its performance even further. And one of the best ways to do just that is by installing a new downpipe to your automobile.
Time: 1-2 hours
- Jack (although a ramp or a lift would be better)
- Jack stands
- Open-ended wrenches
- PB Blaster
Step 1: Before getting to work, make sure that the engine isn't hot anymore.
Step 2: Jack up your car. Again, a ramp or a lift would be more preferable if you have one.
Step 3: Unbolt the heatshield. Use a PB Blaster to have an easier time doing that (do this for all the bolts that you'd have to remove throughout this process). You can do this without having to remove the intercooler as well, but it may prove to be difficult.
Step 4: Once the heatshield is out of the way, a small turbo should be in plain view. This is attached to the stock downpipe via bolts and studs, which you'll have to remove.
Step 5: Next, find the two bolts that attach the stock downpipe to the transmission. They're kind of hard to reach but you'll have to remove them.
Step 6: It's time to go under your car. There should be bolts that connect the downpipe to the cat-back. As usual, remove them. Afterwards, do the same for the bolts that attach the downpipe to the hanger.
Step 7: By this time, all the bolts that hold the downpipe should be gone. Find the sensor that sits on top of the stock downpipe. It should be easy to spot as it has yellow wrapping around its wires. Unscrew this from the downpipe.
Step 8: Detach the downpipe from the hook of the hanger.
Step 9: Now that all the attachments to the downpipe are gone, you can easily slide it out of there. Finally, you can install the new downpipe.
Step 10: Start by attaching the sensor that you took out earlier to your new downpipe. Afterwards, go under your car with your new downpipe. Find the location of your old downpipe and place the new one there. Secure it with the nuts and bolts that you removed earlier. Hook it to the hanger as well. Apply a new gasket, although you can also opt to use your old gasket instead if it's still in good condition.
Step 11: Now put everything else that you removed earlier.