Can anybody tell me what exactly happens at 4k rpm with the engine in the MSP?

[CustomMSP]

Everytime when I let off of gas anywhere from 3.8k-4.2k rpm the engine bogs/jerks. The severity of the bog/jerk depends on how much the throttle was open as I let go. In this case more gas=bigger jerk. I mentioned this on the forum before and we thing it has something to do with the switch over of the VICS. But I though that VICs doesn't switch over until like 4.7k rpm. When we disable VICS the engine stops jerking. I've noticed this switch over at 4k rpm on a few other MSPs I've drove as well so it's not just mine. Also, with the switch over, the power goes down as well, I can feel the car stops accelerating like it was prior to 4k rpm if I hold the throttle stead/not WOT and let it pass 4k. You can also hear the whistle/woosh of the turbo quit down right away. What I'm trying to say is I have to give a little more throttle for the car to keep accelerating the same it was prior to 4k. It still pulls hard, just with more throttle than before.

Thanks.

 

[2K3 MSP]

Holy s***..How can you possibly have this many posts and not know what this is???
Search for the "flash".....

 

[AutoBox]

all i know is that at 4k with wot the car takes off ......if i let of at 4k it bucks, im assumin the hesitation and boost lettin off rapidily

 

[CustomMSP]

Bro,

It's not a "flash" issue ok....I've gotten my car "flashed" twice already just for you info. I think it has something to do with the VICS. If it was an all boost issue than I would assume the same would happen at 5k rpm or 3k rpm etc etc...

 

[2K3 MSP]

Why did you get it flashed twice?

 

[CustomMSP]

Because the first time I had it flash I didn't feel any and i mean any difference, the second time I got it flash same thing. I don't think two different dealers would lie to me about flashing my car...

 

[jonnydoe48]

maybe your car was already flashed and the hesitation you think you feel is in your head?

the turbo spools up at around 4k and you should feel a slight increase in power.

 

[Heathen23]

http://mazdamp3.com/vbb230/showthread.php?s=&threadid=39126&highlight=VICS

 

[jersey_emt]

You got your car 'flashed' a second time and you're still feeling the hesitation? Like the same thing I felt when I drove your car at the meet, and that you mentioned you didn't feel in mine?

Hate to say it but maybe it still isn't flashed? My MSP does NOT do that...it definitely bucks if I let off the gas quickly from full throttle in that RPM range, but I feel MORE acceleration at WOT @ 4,000 RPMS, not a decrease.

 

[low_psi]

the turbo DOES NOT spool at 4K, its a damn t25 people.

you should start building boost around 2K and hit full boost at ~3K.

Sounds like you need to take it to the dealership and have them check out the VICS.

 

[gixermixer]

I am flashed and have this same issue, did not have it before the flash. I think it is just the fuel map. When i hit 4k and put the clutch in, i get the jerk/jolt/buck. I am not sure why, but if i go over 4k before shifting, i dont have this problem. I feel it most in 2nd.

 

[CustomMSP]

Can somebody explain what exactly happends at that rpm though? Justin, what dealership did you go to to get your car flashed?? Maybe I should go in for a third time hehe. Also, this happend before and after the "flash" for me

Thanks.

 

[jersey_emt]

Can somebody explain what exactly happends at that rpm though? Justin, what dealership did you go to to get your car flashed?? Maybe I should go in for a third time hehe. Also, this happend before and after the "flash" for me

Thanks.

Sansone's Rt. 1 Auto Mall on Rt. 1&9 in Avenel/Rahway. I'm going to check on the bucking/jerking with & without VICS tomorrow...I'll let you know what's going on.

 

[jflo]

maybe it's ur stock pipes...if u've been running ur car for a lil' to let the heat soak the engine compartment (not a very long time), the pipe flex can cause bogging. my car does that too. i don't knoe what it is for u, but most people i've talked to explained that it was just the plastic pipes flexing and expanding

 

[Notorious]

At 4k the ecu also goes into open loop operation. The weird thing is that its rpm based not throttle based.

 

[FrozenMazda]

Sorry guys, I'm just a guy who acts like he knows anything about cars.

What does VICS stand for?

 

[ONRAILS]

lol... I'm with you man, I am just starting to learn all these acronyms

 

[jersey_emt]

Variable Intake Control System

http://www.geocities.com/negatize/vics.htm

 

[BremertonMSP]

maybe it's ur stock pipes...if u've been running ur car for a lil' to let the heat soak the engine compartment (not a very long time), the pipe flex can cause bogging. my car does that too. i don't knoe what it is for u, but most people i've talked to explained that it was just the plastic pipes flexing and expanding

No offence, but until you can show me some cold hard facts for the "expanding pipe" phenomenon causing all of the problems with the MSP, please give it a rest!

 

[yashooa]

Bro,

It's not a "flash" issue ok....I've gotten my car "flashed" twice already just for you info. I think it has something to do with the VICS. If it was an all boost issue than I would assume the same would happen at 5k rpm or 3k rpm etc etc...

Dude sounds like they are blowing smoke up your skirt. That sounds exactly like 1MP3's pre-flash MSP behavior experience.