Still can't boost above stock level...

[unwrittenLaw]

Perfworks gave me this info on an earlier post about my CEL:

VTCS (variable tumble control system). There are a set of throttle plates right before head port. and right before the fuel injectors. under cold start up and until the engine reaches at least 65 degreesF, they stay closed. there is a small slit that allows a "tumbled" air charge to pass thru and mix with the fuel injected. This tumbling continues down the intake port and thru to the combustion chamber. Is it supposed to help with cold start emmisions by creating a more complete and efficient burn . That along with the first cat are supposed to make the vehucle a 50 state legal smog emmiting vehicle.
the plates open when vaccum is allowed to pass the VTCS control solenoid mounted on the intake manifold.

 

[zzooomm]

At the tee pull the line that goes to your wastegate and see how much boost you get. Before flash I was at 22 but after flash I can only get 12.

 

[MazdaDryvr]

thanks unwritten!

 

[unwrittenLaw]

At the tee pull the line that goes to your wastegate and see how much boost you get. Before flash I was at 22 but after flash I can only get 12.

You had 22 pounds of boost?

 

[Notorious]

I highly recommend that you don't do that. Driving without a wastegate is bad.

 

[SpicyMchaggis]

yo go to mazda and be like..look bud..im ******* punk rock..fix the s*** or i'll mosh on your face.

 

[unwrittenLaw]

I highly recommend that you don't do that. Driving without a wastegate is bad.

yeah i know..i was wondering where he got 22 pounds, if that's what he meant

 

[unwrittenLaw]

yo go to mazda and be like..look bud..im ******* punk rock..fix the s*** or i'll mosh on your face.

lol...huh?

 

[unwrittenLaw]

update:

I went to Mazda and told them to "fix the s*** or i'll mosh on your face"..but no luck.

 

[unwrittenLaw]

another update:

I was driving on the freeway for a couple hours, and all of the sudden when I went into wot, the boost on my Blitz TT started increasing....its like all of the sudden, the MBC started to work...maybe something was clogged in the vacuum lines and the high pressure from a lot of freeway driving forced it out..I really have no idea.

Anyway, I adjusted the mbc to spike at around 10 and level off at around 8. I did notice that I could still hear faint metallic rattling when it was under full load in 4/5th gear, even with the colder NGK spark plugs. It's not consistent and only seem to be audible around 10psi and higher. But since I've lowered it to 8 I sometimes hear rattling, but I don't know if its detonation or not. I'm paranoid and thought the colder copper plugs would help....It might not even be detonation, maybe the heatshield or wastegate was rattling or something...I dunno. But now that I've turned down the boost some it doesnt happen, so I'm assuming its detonation....I wish I could know for sure whats going on in there, but I should assume the worst and be cautious. I just don't get how a lot of people are boosting so high w/o out any major mods and dont hear any knocking, etc...and then sometimes detonation isnt even audible...

 

[505zoom]

Crazy All that nothing for weeks and then the boost just decided to come on??? Was it noticeably faster or was there maybe just something wrong with your TT???

 

[unwrittenLaw]

No the boost guage on the Blitz TT is accurate, and yes my car was noticeably faster when it started boosting more. It was a cool night out and I was doing about 75 when I floored it in 5th gear...it felt like I downshifted to 4th...although its fun..I know my engine wont last long doing that all the time, thats when it would ping, so had to turn it down some..

 

[unwrittenLaw]

Does anyone else notice any different noises when running higher boost? It seems sometimes I hear slight rattling noises when its boosting....I'm not sure if its detonation or not, but I think if it was and I've been hearing it this long, my engine would have blown by now...so I'm thinking it's the heatshield, or wastegate or something...

any suggestions?

 

[II-Savy]

What octain gas are you using?

 

[dj JINX]

I took my joe p mbc off once and reinstalled it a day later. I tried to adjust the mbc and redo the lines after i couldnt get the boost past stock. I couldnt figure it out why no boost past stock. Then i realized i was turning the knob the wrong way. lol

 

[1sty]

Try welding the waste gate shut (thumb)

 

[unwrittenLaw]

Great idea 1st..!!, I'm gonna go do that right now....then I'm gonna punch myself in the face.

 

[unwrittenLaw]

What octain gas are you using?

Mobil or Shell 91 Octane...all we can get out here in Cali is crappy 91..

 

[1sty]

Great idea 1st..!!, I'm gonna go do that right now....then I'm gonna punch myself in the face.

Punch me while your at it

 

[unwrittenLaw]

Update:

Today when I got in my car and started driving, I noticed on my boost gauge that the car is at stock boost again. I checked the MBC, vacum lines, etc...readjusted the MBC, and it stays at stock boost like it was doing before. The boost holds steady but its not where it was at the day before.. WTF is going on? This is really frustrating. How can it go from not boosting above 6-7psi, then all the sudden go up to 9-10...now back to stock? Is Joe P's MBC defective? I have another MBC i could try, but i put it in there before when i was having this problem, and it didnt let me increase boost either. I mean what else could it be? The MBC is connected in line w/ the WG and the T fitting to the bpv.....I dunno what's happening....Someone help me before I go insane.