What kind of Boost Levels are MS3 owners seeing?

[Vixen]

I think I've read something about this somewhere. Interesting, but can you get a boost reading post-fix to see if it's pushing more than 12 psi? You want a gauge anyway don't you? I can provide detailed instructions on the install if you pull the trigger.

Thanks!
I'm pulling the trigger......

 

[Speedy3]

Fantastico!

Ok, I did 2 runs today.

Run #1:
Roll on boost in 4th gear at 46 MPH and 3k RPM, then shifting to 5th gear at 5500 RPM and letting off the gas at 4400 RPM @90 MPH.

Ambient Temp: 44 deg F
Intake Temp: 41 deg F (dropped to 39 halfway through 4th gear boost)

4th gear: 14.4 psi initial peak boost, dropped steadily to 11.2 psi.
During shift: Dropped to -12.7 psi
5th gear: 18.3 psi initial peak boost, dropped quickly to 14.4 psi, then dropped slowly to 12.9 psi until I let off the gas.

Run #2:
Roll on boost in 4th gear at 50 MPH and 3k RPM, then shifting to 5th gear at 5500 RPM, then shifting to 6th gear at 5100 RPM and letting off the gas at 3900 RPM @101 MPH.

Ambient Temp: 44 deg F
Intake Temp: 41 deg F (throughout entire run)

4th gear: 15.0 psi initial peak boost, dropped steadily to 10.9 psi.
During shift: Dropped to -11.5 psi
5th gear: Rapidly hit 14.1 psi then at a slower rate climbed to 16.8 psi initial peak boost, dropped quickly to 15.0 psi, then dropped slowly to 12.6
During shift: Dropped to -11.3 psi
6th gear: 17.3 psi initial boost, dropped quickly to 15.1 psi, then dropped slowly to 14.8 psi until I let off the gas.

I uploaded the graphs, but don't know how to put them into a message here.

 

[desperado-c]

Thanks!
I'm pulling the trigger......

I took some pix yesterday and put together a post in the next day or so. It's a great first mod. Especially for people like me who haven't had a turboed engine before.

 

[desperado-c]

Ok, I did 2 runs today.

Run #1:
Roll on boost in 4th gear at 46 MPH and 3k RPM, then shifting to 5th gear at 5500 RPM and letting off the gas at 4400 RPM @90 MPH.

Ambient Temp: 44 deg F
Intake Temp: 41 deg F (dropped to 39 halfway through 4th gear boost)

4th gear: 14.4 psi initial peak boost, dropped steadily to 11.2 psi.
During shift: Dropped to -12.7 psi
5th gear: 18.3 psi initial peak boost, dropped quickly to 14.4 psi, then dropped slowly to 12.9 psi until I let off the gas.

Run #2:
Roll on boost in 4th gear at 50 MPH and 3k RPM, then shifting to 5th gear at 5500 RPM, then shifting to 6th gear at 5100 RPM and letting off the gas at 3900 RPM @101 MPH.

Ambient Temp: 44 deg F
Intake Temp: 41 deg F (throughout entire run)

4th gear: 15.0 psi initial peak boost, dropped steadily to 10.9 psi.
During shift: Dropped to -11.5 psi
5th gear: Rapidly hit 14.1 psi then at a slower rate climbed to 16.8 psi initial peak boost, dropped quickly to 15.0 psi, then dropped slowly to 12.6
During shift: Dropped to -11.3 psi
6th gear: 17.3 psi initial boost, dropped quickly to 15.1 psi, then dropped slowly to 14.8 psi until I let off the gas.

I uploaded the graphs, but don't know how to put them into a message here.

Those numbers look good to me and show that it is running 16 psi and more when the load is there. I'm now thinking that what people refer as a initial spike is really a peak that decreases as the load the decreases. The higher your gear, the higher the peak and the longer it takes to come down from the peak. Add an incline like I did and it will hold the higher psi for even longer.

It would be good to see the graphs. Unfortunately, you can't upload files to the forum. Instead you need a host since the image option requires a URL. I use Photobucket and it's fairly easy to setup and use. If you don't want to bother, you can PM me and I'll post them for you.

 

[Speedy3]

Those numbers look good to me and show that it is running 16 psi and more when the load is there. I'm now thinking that what people refer as a initial spike is really a peak that decreases as the load the decreases. The higher your gear, the higher the peak and the longer it takes to come down from the peak. Add an incline like I did and it will hold the higher psi for even longer.

It would be good to see the graphs. Unfortunately, you can't upload files to the forum. Instead you need a host since the image option requires a URL. I use Photobucket and it's fairly easy to setup and use. If you don't want to bother, you can PM me and I'll post them for you.

I'll do it tonight when I get home from work. The images are at home.

 

[Speedy3]

Those numbers look good to me and show that it is running 16 psi and more when the load is there. I'm now thinking that what people refer as a initial spike is really a peak that decreases as the load the decreases. The higher your gear, the higher the peak and the longer it takes to come down from the peak. Add an incline like I did and it will hold the higher psi for even longer.

It would be good to see the graphs. Unfortunately, you can't upload files to the forum. Instead you need a host since the image option requires a URL. I use Photobucket and it's fairly easy to setup and use. If you don't want to bother, you can PM me and I'll post them for you.

Ok, here are the graphs of Run 1 and Run 2. I added labels to the peaks and valleys.

 

[Speedy3]

I'll do more runs, but actually shift at 5500. Some of my shifts were lower RPM cause of traffic.

 

[desperado-c]

I'll do more runs, but actually shift at 5500. Some of my shifts were lower RPM cause of traffic.

You were hauling butsky, bo. Thanks for putting those up. Good stuff. I got to look at them some when I get some more time.

 

[redms3gt]

Boost is lower in 4th also. I would like to see the graphs of a ms3 with exed on it. Then a camparison per gear. Hopefull power will be full from 2nd to 6th.

 

[tru-boost]

i would like to see the same graphs but powershift the gears instead.
i would love see how much higher the boost stays

 

[Speedy3]

i would like to see the same graphs but powershift the gears instead.
i would love see how much higher the boost stays

I have this data from a drag run on Jan 15th. I didn't do a good job shifting, so I'm gonna do another run soon, shifting at 5500 rpms per gear. Notice how the boost dramatically starts to drop off in second gear when It hit 6040 RPMs. Not sure if this was me or the PCM.

 

[redms3gt]

Pcm cut th% to 80% at 6k. Anyone know where the factory sensor is located or exactly how accurate it is. There is no way I ever get close to 15psi spike in second but measuring at the BOV might be the issue.

 

[desperado-c]

i would like to see the same graphs but powershift the gears instead.
i would love see how much higher the boost stays

You think you're gonna get this guy to flatshift just so you can prove your point on on m3forums about maintaining boost?

Anyhow, I think it's interesting that the decreases in slope of the boost line mirror the slope of the RPM increases. Maybe this the closing down of the throttle plate in gears 1-4 that AMS and others have talked about?

Also on the boost being lower in 4th, it got up to 16.7 on this graph before Speedy3 pulled the plug. And in the earlier graphs it had a lower peak than in 5th/6th, but they all settled down to the same level of right around 15. I'll do another run up an incline in 4th to check, but I think it will hold 16 under load.

 

[tru-boost]

yes i would like to see it !!
if i had the ability to get the data myself i would...but i dont.
i think it would be interesting to see.

 

[Speedy3]

yes i would like to see it !!
if i had the ability to get the data myself i would...but i dont.
i think it would be interesting to see.

I'm gonna log the data during a drag run with flat-shifting, but probably only up to 4th gear.

You think you're gonna get this guy to flatshift just so you can prove your point on on m3forums about maintaining boost?

Thanks Desperado-c for looking out for my car's health! I think I'm gonna do this test anyways. I'm curious too.

Anyhow, I think it's interesting that the decreases in slope of the boost line mirror the slope of the RPM increases. Maybe this the closing down of the throttle plate in gears 1-4 that AMS and others have talked about?

I can plot the throttle selenoid position vs boost if you want.

I'll do another run up an incline in 4th to check, but I think it will hold 16 under load.

I'll do a load boost test too when I get a chance and post the graphs.

 

[tru-boost]

I'm gonna log the data during a drag run with flat-shifting, but probably only up to 4th gear.

thatta boy !!! (drive)

 

[desperado-c]

thatta boy !!! (drive)

+100! After all Mazda suggested this to Car and Driver as a way to get a better drag time out of the MS3 even though Car and Driver compared it to dropping a grand piano on your tranny.

Also looking forward to the graphing of throttle position to boost and boost under load in 4th. MUCH more reliable than me looking at my boost gauge. What diagnostic tool are you using again?

 

[Speedy3]

+100! After all Mazda suggested this to Car and Driver as a way to get a better drag time out of the MS3 even though Car and Driver compared it to dropping a grand piano on your tranny.

Also looking forward to the graphing of throttle position to boost and boost under load in 4th. MUCH more reliable than me looking at my boost gauge. What diagnostic tool are you using again?

Auterra Dyno-Scan.

 

[Rotus8]

Auterra Dyno-Scan.

Can you tell me which real-time sensor readings the Auterra can access on the MS3? I am considering purchasing one and would like to know what I am getting.

 

[clos561]

flat shift? what is that? power shift? how do u do that? i jstu chagne gears really fast..........is it jsut clutch work?