Ford Focus ST Forum banner

WMI on stock turbo

32K views 24 replies 16 participants last post by  jumeirah 
Without a big turbo I wouldn't bother. Here's why:
  1. With your Depo FMIC and snorkel, you are already keeping the charge air temps close to ambient in most cases.
  2. WMI introduces more potential boost leak locations.
  3. A failed check valve or solenoid could lead to engine hydro lock.
  4. Getting the intake valves hot cleans them reasonably well (although long-term WMI does better), but...
  5. No one has documented that (unlike some of the BMWs) gunk buildup on our valves causes noticeable performance degradation nor increased risk of LSPI or other potential bad things.

IOW, I just don't see the risk:reward benefit when running a stock turbo. You said you want to increase safety; sure, keeping the charge air temps cooler even after a long pull all the way up through the gears will help. But getting that benefit means increasing other risks from failure of the WMI system.

Unless you are tracking your car most weekends... But for a daily driver driven aggressively on the stock turbo, I wouldn't bother.

I'm sure you'll get opposing opinions! :)

All the best,
Mark
 
How does the inter-cooler and snorkel accounts for higher than normal ambient temperatures? It won't, it doesn't and that's false.
I never said that. I said a snorkel and the Depo FMIC together do a good job of keeping charge air temps close to ambient.


A W/I system will always make more power than just an inter-cooler upgrade period and that isn't up for debate. It will also allow the car with the same aggressive timing map that it does when conditions are ideal; the problem is conditions are hardly ever ideal.
I never said WMI wouldn't allow for more power. I tried to say that in my view, for a daily driver, the gain comes with risk. What I didn't say was that you need a custom tune to maximize the gain over an OTS tune. I believe you think the risks are less than what I think. So let's clarify "under what circumstances."

If you have an OTS tune, the risks are not huge, especially if you inject pre-throttle body. Most tuners limit max load to ~2.4 or thereabouts for OTS tunes and you can run the car there without WMI no problem. IOW, you don't need WMI to output load to 2.4, so the gain is minimal. You get some better knock protection, and some help keeping charge air temps down (which, with the snorkel and the FMIC are already close to ambient most of the time), so the tune really won't be able to add much timing in too many places -- hence, little gain.

If you have custom tune, then IMHO the risks are bigger, because your tune may target a higher maximum load, and will have more aggressive tables impacting timing. So, if you are in the middle of a pull and you run out of fluid, you are likely going to get some extra knock events and some pulled timing. Enough to cause engine damage? Dunno. Depends. But it's a bigger risk I hope you will agree than running an OTS tune which is calibrated to be ignorant of any WMI system that may be present.


How would it introduce boost leaks? Post inter cooler is a good location and as long as you used thread tape it won't leak.
Any additional joints post-turbo are a potential boost leak source. How big of a risk? Dunno. Depends. Depends on the quality of the kit and the workmanship of the installer. Plenty of threads on this board where experienced, well-intentioned enthusiasts installed a new FMIC and shortly thereafter post that they've got a boost leak.

FWIW I wouldn't use teflon thread tape if that's what you are referring to. Teflon tape doesn't like acid and solvents, like in oil. Some of the sound symposer delete kits that come with a T and a blanking plug for the NPT hole in the blanking plate come with instructions specifically recommending not to use teflon tape.


You can get way more out of the stock turbo with W/I than with just an inter-cooler upgrade, I'll show you, stay tuned...
Sure! Post up a build thread! That's what this forum is for, right? Different people using different ways of pushing the envelope benefits everyone!

All the best,
Mark
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top