One of our customers, Corin, just participated in a dyno day and sent back his sheet and a photo. This is a 2008 MS3 on 93 octane with the following mods:
jbr 3.5″ intake
gs 3 port ebcs (2 port mode)
cobb xle bpv
tb coolant bypass and tig
cp-e catted dp
STRATIFIED tune
Very consistent numbers at 295whp and 350ft lbs of torque! Looking forward to the E85 tune that should put this car well above 300whp. Awesome car Corin!
MS3 aftermarket catless downpipe versus the stock downpipe. Credit: ATP turbo
A downpipe on any turbocharged engine, if well designed, can have a positive effect on performance. If it is a better flowing unit (less restrictive) than what it replaces it will increase the pressure differential across the turbine and reduce the pumping losses of the motor. This means that the turbo will spool faster, possibly hold more boost, and the motor should also move more air per stroke. In theory this sound great but numbers are even better.
We’ve had a customer who is very consistent with his logging meaning the data logs are taken at similar ambient temperatures and the same altitude. He was able to provide several back to back logs showing the difference between a stock downpipe and a stock downpipe with a gutted catalytic converter.
As a general rule of thumb, a catalytic converter should always be used (a high flow one is fine) but this comparison shows the ballpark difference we can expect from adding a downpipe (or gutting the stock one) on a stock turbo (k04) vehicle.
The results are below. In a nutshell, the turbo will spool faster but more importantly the engine flowed on average 5 g/s more mass air past 5500 RPM. This is worth about 5-7 horsepower at the wheels all else being equal and the gains are coming from a reduction in pumping losses alone – not an increase in boost.
Is this worth it for you?? Well that depends on your perspective. On the same vehicle, the air filter can be worth about the same in terms of power, and a 3″ intake to the turbo is worth TWICE this. That being said, the improved spool and throttle response (as well as sound) from installing a downpipe are much harder to measure and these can make for a more pleasant driving experience.
Happy Tuning!
To facilitate one-stop shopping and offer a discount for the “tuning essentials” for the MazdaSpeed platform we are now offering COBB AccessPort and Stratified Custom Tune bundles. You can further customize your order with Autotech HPFP (fuel pump) internals if you need these as well. The HPFP internals are needed for maximizing the power potential even on the stock turbocharger!
Happy Tuning!
Completed a local install of the Guardian Angel in a 2007 MS3 yesterday. He was having some overboosting issues and wanted the added safety and protection. A very smooth and OEM like installation that took about 45 minutes.
Here is the unit installed in the engine bay
And here is the warning LED installed in the spare button plug beside the steering wheel. Make sure you keep an eye on this to make sure the unit is functioning every time you start the car (It flashes on for 2 seconds).
The BNR Stage3 turbo is a great upgrade for the DISI engine in the MS3 and MS6 cars. It flows a lot more than the stock K04 and is as bolt in as it can be. Under the skin it is a Garrett 2871 and it maintains the great spool of the stock turbo but carries power much deeper into the RPM band.
The challenge with tuning this turbo is controlling boost. Using a 3 port electronic boost control solenoid connected to the stock ECU we were able to achieve a beautiful boost curve on this customer’s 2010 MazdaSpeed3. This car was running 3 gallons of E85 as well and in spite of the 90+ ambient heat in California made some very good and consistent numbers. The power curve is beautiful and he should see these numbers go up nicely as temperatures drop!
