Let’s Talk Downpipes!

Hello everyone! Today we will be talking about downpipes! Enjoy!

What are Downpipes?

Downpipes are what connect the turbos to the exhaust. Downpipes also usually contain the catalytic convertors. The turbochargers on the ExST are bolted directly to the head, and the downpipes are then attached right downstream from them. The downpipes then connect to the mid-pipes, and then to the exhaust.

Stock Downpipes Problems

The stock downpipes have a really serious problem with their welds. They are prone to cracking. Symptoms of a cracked downpipe is visible cracking (obviously) or egg or gas smell. The heat shields also have problems with rattling.

Aftermarket vs Stock Downpipes

There are some very nice gains to be had with aftermarket downpipes. The normal gain is around 15-20awhp on average and cut down a couple tenths off the quarter mile. Paired with an aftermarket exhaust, they also add some fun turbo spooling noises as well as sound.

Catted vs Catless

There is only one catless downpipes offering, and that is FenFab’s test pipes. I do not recommend them at all. Catless downpipes will have minimal gains compared to catted units, and their disparities outweigh those little gains. Catless downpipes will have an unpleasant smell, and take a lot of work to find an custom exhaust that will sound good. The normal cat-back offerings would rasp, drone, and sound horrible with catless downpipes. Most importantly, any reputable tuner will not tune for catless setups. For 2025 ExST vehicles especially, since you can’t tune them, catless downpipes are even more useless.

Defoulers

All the downpipes include a pair of defoulers for the O2 sensors. You will need to use them to avoid a check engine light.

Aftermarket Downpipe Comparison

SPD, CV-Fabrication, Whoosh Motorsports, Kooks Headers, and Fenfabrication all offer very good quality downpipes. There are a few things to note about the following downpipes:

-SPD unit includes mid-pipes, reason why they are more expensive then the other offerings that don’t include the mid pipes. Earlier builds had a few cracking occurrences due to their bracing, but later builds fixed that problem.

-CV-Fabrication: Tent to be the cheapest with Tyler Clark’s code (TYLERCODE1)

-Kooks Headers: Most expensive offering because they are the only ones CARB-certified

-FenFabrication: Offer both catted and catless downpipes

Install

Install for downpipes is a pain, especially if you don’t have a lift. Most people drop the subframe a little to assist with the removal and install of the downpipes. Unless you have a lot of time, patience, and mechanical knowhow, it is probably best to leave the install to an shop.

Hope you found this article informative. Thanks for reading and be sure to subscribe to keep up with all our latest content!