klapamos

Hey all,

So I apologize in advance about asking this question on the S2000 forums. I own a 2001 S, but my question is about my 2007 Mazdaspeed 3, I would ask on the Mazda forums, but they are rude and not very informative. So my 2007 MS3 engine is being rebuilt with forged Wiseco pistons and should be completed in about a week. I was planning on running the car on a stock tune during the break in period and then running a basic stage 1 map until I can have a custom tune and add the go fast parts. Most of the feedback I've received has said running the stock tune should be a none issue. Although I contacted Cobb and their support said the forged pistons will cause a sensor knock issue without a custom tune. I'm assuming this could be due to the increased cylinder wall clearance with the forged pistons?

The displacement and compression of the engine hasn't been changed

noodels

Thought the knock sensor detects detonation only ie through a weak mixture ignition advanced too much ect.
would it not through a code if there was a problem ?

Ecko_3420

What i have done for my previous motors:
1. Start up, make sure no leaks and all is good.
2. Drive to tuner, tune.
3. Drive it hard!!!!!
You want varied RMPs with engine braking.

AP1Chief

ECKO is correct, you want pressure on rings both ways with in the first 10-20 miles for a good ring seal. Not doing this will ensure glazed cylinder walls, crap ring seal, and blow by.

since I tune my self, I literally started it checked for leaks, maybe had it idle for 5-8 mins, turned off, drained oil, but fresh oil in, went out, base tune, low timing made sure AFRS where 11s, and ran about 8-10psi right out the gate with good positive and negative pulls on the rings. Did this with neon, and my B16 build. Neon made 640 ran for 45k miles and its still running with new owners, B16 made 480, 20k miles, and still running with new owners. Zero leaks.

You NEED a good AFR tune before u go ragging on it though, too rich will wash cylinder walls and create all kinda problems. too LEAN you could risk more stuff going wrong.

and YES forged pistons CAN create more noise that the knock sensor is not use to, so it will THINK its knock and pull timing. Youll need a new baseline on your knock Volts. Some cars/pistons do this, some don't. depends. Also depends how "loose" your P2W is.

AP1Chief

If you need help with tune and all lmk

HawkeyeGeoff

I've been on the disi platform for way longer than I'd like to admit...there are several break in procedures out there depending on how the car is supposed to perform. The advice I'm giving is based on me assuming you're going to use it as a street car.

What I'd recommend is the following though seeing as you are stock (I'm assuming from your language) minus the forged internals themselves:
1. Use this stuff: https://www.autozone.com/motor-oil-a...ive/674846_0_0
Add 3 OZ on each of the first few oil changes.
2. Use regular oil, do not use a synthetic oil during break in!!

Procedure I've used in the past:
1. Fresh oil w/ the additive, hold the throttle pedal to the floor and turn the engine over ~10 times to build pressure and fill all the items with oil. Cold start the engine. Let the motor warm up to operating temp (depending on the temperature outside this can range from 10-20min). Shut it off, change oil + break in additive again.
2. Go drive the car for 20 miles or so, varying RPM, lots of engine decel, do a few "Naturally aspirated" WOT's (little to no boosting, use the skinny pedal to achieve this)
3. Change the oil again + break in additive, drive for 200 miles varying RPM, lots of engine decel and a generous amount of WOT including boost.
4. Change the oil again and start tuning. Switch from dino to synthetic at 500-1000 miles and you're break in is complete.

You can also ask several tuners on that platform (Tuned by Nishan would be my recommendation) for their break in procedure.

If you have mods added to the car make sure you get a base map from one of the tuners first.

Let me know if you have any questions.

Also, use mazdaspeeds.org from now on if you need DISI advice; that is where all the OG's hangout.

Edit: As far as knock sensor values go, some built engines are noiser than others. As AP1Chief suggested you may need to reduce the sensitivity of the knock sensor in some areas especially if you decided to do a balance shaft delete when building the motor. Most of the time we just up the knock sensor load target so it doesn't become active before a certain load is reached; the part throttle knock is usually where you see built motors increase the KR activity. WOT the knock sensor seems to perform just fine unless there is something loose in the engine bay. Hope this helps.

Also, did you keep the Piston to Wall Clearance at around the .0003 range? If so you should have very little problems breaking it in anyway, assuming you didn't use like chrome rings or total seal rings. The newer forged pistons require much less expansion room than they did in the past. On my 600whp MS3, I ran .00045 and it was WAAAAAAAAAAAAAAAAAAY too much clearance.

HawkeyeGeoff

Nah it doesn't throw a code on this platform unless the knock sensor itself is defective. It'll let you see 8° all day without hesitation if it thinks its real. It's just a microphone on the block.