My '04 X50's mission is street performance (car is not tracked - yet). Thus far, mods have been the most basic ones - tune and higher flow exhaust. What the best next step after these mods? Any other easy gainers, or is the next step where the increments become increasingly expensive?

 

if you work on weight savings it helps both street and track. cost is minmal if you do the work yourself.

fueling is always a mod to address before looking for larger power

 

You are kind of at a jumping off point. The next worth while thing is bigger turbos. Once you go down this road it gets expensive. You will need a bigger clutch, better fuel system, ect... and you could break things. I thought I was just going to do turbos and and boltons but now I am deep into an engine build. You could do an upgraded intake tract but you wouldn't see much of a gain without bigger turbos. IMO at this point you need to decide if you are up for spending a lot on mods and do it the right way or just enjoy the car as is.

 

I would argue that you want to increase efficiency. Anything to free up the intake side or to cool the air charge better. Intercoolers would be my next step and perhaps a MAFless tune with improved intake? I'd stick with those turbos until you have a need to increase airflow further. After that things become more serious and you might even need a clutch at this point. If the clutch has to be done look at the gt2 slave etc.

 

When I was at your point with my 2003 X50, I did the following.

1) wastegate actuators (helped low end a bit and helps the stock K24s hold more boost at peak). Will be selling mine shortly if you're interested.

2) SRM 4.5" intercoolers and silicone hoses. Won't "make" a ton of power, but it will make your car much more consistent and not pull timing in the higher gears. Even in 38* F ambient temps, my car was hitting over 100* air intake temps during a third gear pull. Now my car is generally within 5 degrees of ambient and intake temps only increase 10* during a third gear pull.

3) mafless tune and filters on turbos. This helped a ton. Car is more responsive and builds full boost to 1.3 bar (couldn't hit full boost before this because I'm at 4,500 ft elevation in Utah and the stock intake pipes suck)

Best of luck, have fun... it's addictive! (I will be upgrading turbos next)

 

^ This...Until you go full ****** you are looking at a nice gain and reduction in lag.
Let me know if I can help!

 

Here's my before and after dyno for the three mods above (and 60k mile service). Same dyno, roughly same conditions, pretty much 40awhp/40awtq gained on a Mustang dyno at 4,500 ft.

 

its not going to be cheap, and your tuner has to be able make proper adjustments...
most likely you need wgs, a 5 bar fpr, and matching tune.. then ICs as well as turbo upgrades to follow...
good luck
markski

 

I would listed to Sambo and Markski. If you are going to track at some point I would say coilovers as well.

 

intercoolers

MAFless and tune (you'll like this)

injectors, FP and E85.

 

GT3 sway bars or a good tire if you're planning to get into tracking the car.

You don't really need more power yet unless you've already got a lot of experience on track in powerful cars.

 

Consider upgrading your suspension and brakes before you dial in too much power. Call Sambo for sure.

 

Lots of good advice above; I appreciate the responses.

No one mentioned the IPD plenum, so I guess that's a "don't bother" on that one?

I've been eyeing the PSS10 kit and it's a likely future mod.

With brakes, what's the largest diameter disc that works with the factory 18" rims? 350mm? Caliper upgrade required? if so, to what?

 

IPD has netted proven gains as well as faster spool and you can install the larger T-body. A consult is best to make sure you meet your goals and budget.

 

I felt 0 hp increase on the butt dyno with 74mm ipd plenum and throttle body. Perhaps the 68 mm adds more to the midrange compared to mine and is easier to feel.