Hey guys since our cars are developing more and more everyday with great aftermarket support it’s becoming easier to make a reliable, daily driven 400whp Speed. To make this power reliably the two most important things are a solid tune and proper maintenance to your vehicle! I can’t stress this enough guys. To check out you can do on stock internals see this thread.
big turbo stock block thread - Mazdaspeed Forums
Everyone’s results are going to vary due to tunes, dyno’s, hard parts, motor health, weather, and elevation etc.
Now this can be accomplished on just the stock injectors and an upgraded high pressure fuel pump. You will be very close to maxing out anywhere from 390whp-410whp depending on the tune and fuel choice. Please don’t ask if you can use less than 91 octane, the answer is no. Let’s get on to the parts that make this possible! Remember when building a car to this level do it once correctly and you will never have to do it again so don’t skimp on anything! Lol
Hard Parts
• Intake (Big MAF recommended, but not necessary in some cases)
• Big turbo inlet pipe
• Intercooler (Front mount recommended but TMIC will be able to get you there)
• Downpipe ( 3”)
• Catback Exhaust
• Bigger turbo (Choice of turbo varies on everyone’s desires of the drivability of the car)
• Colder spark plugs
• Motor mounts- You are definitely going to need a RMM but the PMM & TMM are something to seriously consider at this power level
• Injector Seals ( These are highly recommended but not necessary. The factory seals will wear over time so it’s better to upgrade before they go bad.)
• Manifold (Recommended but not needed, there are many stock manifold 400whp cars)
• Upgraded boost controller is highly recommended
Fueling- Don’t be this guy
• HPFP/HPFP Internals
Tuning
• Cobb AccessPort or Versa Tune (do yourself a favor and spend a few hundred bucks to have an experienced tuner tune your car)
• The tune is very key to all this power and to do it safely and reliably so make sure your tuner knows what’s going on and preferably has a good history with tuning speeds
Turbo
• To make this clear, there is not a best turbo. ANY GT30R turbo will easily get you 400whp including non-GTX versions. If anything, the GTX turbos seem to shine with higher boost levels than with low to medium boost levels. So if you’re planning on 400whp and that’s it, a GTX30R might be too much turbo.
If you want 400whp now and know that later on, you want to take advantage of future advancements in the platform to get even more power, a GTX30R would be great. There’s no right or wrong here. A GT2871R in theory has the ability to get there but the turbo will be pushing harder than a GT30R.
There are too many other variables to discuss. There are tons of ways to get it, but this is the most practical way to get 400whp.
Once you have done all of this hard work go enjoy your monster of a car. Don’t be afraid to drive it either, enjoy all the hard work you did to get it here.