There seem to be several conflicting reports on what the boost pressure is on these vehicles; I've seen 8-18 psi, with most saying around 16 psi when in full throttle in third and beyond, 12 psi in first and second. Does anyone know for sure? What kind of boost can these engines handle (relatively safely)? I'd really like to know.....

 

With stock parts, the limit seems to be 22 psi. If you get upgraded cams, vavles, stroker kit, etc, you can probably get in the 29-33 psi range (and getting tons of horsepower).

 

Where did you get those figures from?
I'm no boost expert, but that seems exceedingly high for anything butperhaps a top fuel engine.
The few stock engine that I'm familiar w, including the MSP, are set between 6-8psi in stock configuration. Some can be modified for up to 12psi, but let the buyer beware.
33psi would be rediculous!!
And what effectwould a stroker kit have on the boost level?

 

[:'(][:'(]No way is the Speed3 running 22-30 lbs of boost.

I'd say probably around 15 psi...let me do a little snooping around and see what I can find.

 

yeah, i would say that if you wanted to go up above 18-20 psi, you would be risking internal damage. these cars are built to take punishment, but there is only so far that you can push them. remember, no matter how well they are built, they are still stock.

also, i would say that in my experience with turbocharged cars, you will probably get about 8-10 pounds of boost stock out of these. i say this because i have driven it and felt the lag/boost. the speed6 has been noted by mazda to produce 16.9 psi stock but there is definitely a difference between the two. the 6 boosts a lot more and a lot harder than the 3.

 

I'd say stock 15 psi is about right based on the majority of MS3 owners that have installed boost gauges, you'd be pushing it at 20 psi.

http://www.mazda3forums.com/index.php?topic=71034.0

You'd have to o-ring your heads and do a ton of work to run 30 psi...those are turbo diesel pressures and their cylinders are like pressure vessels (8 bolts around each cylinder.)

 

I'm sorry! I forgot to mention that you'd have to have a turbo upgrade to get 22 psi! Sorry for confusion!

"And what effectwould a stroker kit have on the boost level?"

Not really any added boost, just a crankshaft and pistons that would be able to widthstand that amount of pressure.

 

Look at it this way...Lotus used to use 100 hp/Liter as their design benchmark.

The MS3 has 114 hp/Liter....It's already tuned to a fairly high degree.

I would think reliability would go down fairly quickly with increased power output.

 

The mazdaspeed3 is supposed to be pushing 15.6 lbs max boost as stated in MotorTrend Nov. 2006. It's also known that 1st and 2nd are lessened already and that with DSC on any wheel spin will result in bleeding boost. Boost gauges have shown low boost in 1-2 and then oddly in at least 3-4 the boost will rise to full, showing 16 on the guage and then drop. Though traction conditions, were'nt stated. A boost controller, fine tune and all would get more power sooner i'm sure with even just the same top psi, but it'll lose that practicality. Mazda also stated that there are different boost maps for each gear. The car is tuned, not just boosted. it's tuned the way mazda wanted, taking everything into consideration including drivability, so I'm sure theres much to be gained by re-teaching the computer.

 

I recorded 5.4 hkpa using blitz turbo timer (it's japan spec) but when converted to psi it's 8psi. Maybe that's all the small turbo can spew out. I dont thinkms3's turbo can reach20psi. If anyone here got some other analog boost gauge ( mine is digital) let us know what you clockin. I'll be happy if I can reach 300 hp to the wheels. cai, cbe, accessport whould do it. When I reach 300hp then a bov will come on. Dont flame me for wantin my ms3 to go faster. Dont worry I wont drive like a maniac on public roads or drink and drive.ok? ok.