As for the right diameter, it depends on your spec. A wider downpipe diameter always increases flow rate and therefore boosts performance and response.
Upgraded downpipes provide great increases in horsepower and torque on turbocharged vehicles by allowing exhaust gasses to flow easier as they leave the turbo. Paired with the appropriate software, a downpipe can provide significant gains and make a vehicle more fun and engaging to drive.
Pipe diameter does have an effect on flow rates but is not the major factor in most cases. 2.5″ may flow enough for 300-350 horsepower without being a restriction. 3″ is usually capable of flowing 500-600 horsepower before becoming a restriction.
Do downpipes add horsepower? Yes. Performance catted downpipes nowadays have been shown to increase horsepower. An aftermarket downpipe with catalytic converters will add 10 to 20 horsepower on average, and that gain is noticeable anytime the turbo spools.
Aftermarket downpipes usually feature wider capacities, and they are less restrictive than the stock option. This increase in diameter allows for greater space for a faster turbo spin. The increased spin makes a huge difference. It decreases turbo lag and generates more spool.
Yes it will be louder, not too much though. Does catless-downpipes makes you car sounds any diffient?
EXPERT TIP: Downpipes will never be a major drawcard for your home and you won't want them to attract too much attention, so it's best to pick a coating that is the same shade as the gutters and fascia or one which is close to the same colour as the exterior walls so they blend into those.
The most obvious disadvantage is the environmental impact of unrestricted exhaust flow. There is also the terrible exhaust smell, failed emissions and a switched-on check engine light. In effect, the difference in power gain between a catted and catless downpipe is small.
Even though 68mm round and 65mm square downpipes are among the most common, most rainwater systems are available in multiple sizes. For example, this might be 75mm, 87mm, 100mm and 120mm for a certain range, with corresponding gutter sizes to match.
Yes, catless downpipe is required for stage 2 flash tune. Otherwise there is no point of going stage 2 with stock cat where its super restrictive. Yes they are and we have them in stock. Yes they are and we have them in stock.
- Nothing catless is legal in Aust.
In other words, a restrictive exhaust/downpipe will require the turbo to work harder to achieve its requested load, therefore reducing performance or at the very least, more wear and tear due to heat.
Does Downpipe Increase Sound? The downpipe system itself does not increase sound. There isn't a noticeable decibel difference when you add a downpipe, unlike the straight pipe. Of course, you can still do other alterations to change your vehicle's sound.
Most gutters and downpipes, including steel and aluminium gutters, are expected to last for approximately 20 years. Copper gutters are the strongest option and they offer lifespans of almost twice as long.
Downpipe is the biggest bottleneck in the exhaust system and it will change the sound of the car significantly (from what others have said).
Downpipe does not damage engine. But it can affect failing emmisions (especially smog) in some states, to solve that, you need to play around with o2 sensors. If you JUST run downpipe with either stock or stage 1, you will get a CEL, if you flash stage 2, it goes away.
100 x 75mm
Flow Capacity 4.4 litres per second.
Dividing the total "effective" roof catchment area by the catchment area for the gutter selected, will give the number of downpipes required. This is not normally a whole number, so it is rounded up to the nearest whole number.
Furthermore, aftermarket downpipes help your vehicle even more. They're less restrictive, increasing power and fuel economy. Plus, you can notice a better engine lifespan since it'll reduce the engine temperature. You'll likely even enjoy your ride more with a non-factory-issued downpipe.
Downpipes (catless) will make the exhaust sound more aggressive and deep.
A downpipe is a pipe carrying rainwater from a gutter to a sub-surface drainage system or ground level. They are part of a roof drainage system. One downpipe must serve no more than a 12 m length of gutter and must be located as close as possible to valley gutters.
Black: Black is a more traditional colour, but it is more expensive than white. Grey: Grey is the most modern colour for fascias, and it is slowly being introduced to the UPVC suppliers. Fascia Board: Fascia boards are what your gutters are attached to.
We recommend choosing a color that is the same as your siding, the same as your trim, or the same as your roof. Matching gutter color to siding color is usually the safest choice and it will blend in with your home the most this way. Black or dark-colored gutters will generally look better longer.
Downpipe colours should be made to match whichever part of the house they are closest to. If close to the siding, they should match the siding colour; if close to the trim, they should match the trim colour. If downpipes are equally close to the siding and the trim, then it's your call.