boost problem

[THensley]

Having trouble just all of a sudden. A quick look I don't see an exhaust leak, and I swiped out boost solenoid. Im using a TurboSmart Street. no improvement
Ill be removing all the exhaust to get a good look at everything and Im thinking of installing some copper exhaust gasket I have. What's your thoughts?
I have not ran gaskets for a very long time and all the bolts are tight.
This is the 1st pass and 2ed 15 minutes later

 

[Mr.Spool]

Having trouble just all of a sudden. A quick look I don't see an exhaust leak, and I swiped out boost solenoid. Im using a TurboSmart Street. no improvement
Ill be removing all the exhaust to get a good look at everything and Im thinking of installing some copper exhaust gasket I have. What's your thoughts?
I have not ran gaskets for a very long time and all the bolts are tight.
This is the 1st pass and 2ed 15 minutes later

So your losing boost with the same dome pressure and bottle pressure?

 

[THensley]

No I have not switched over to external gate yet. as you can see from the two pic. the blue line is not flat,27 high 25 low, but was control I was living with.
But 15 min later the boost was all over the place 25 high 18 low.
I think it's an exhaust leak just have not had time to remove all the exhaust to do good investigation. Actuator is OK no leaks gat appears to work properly
I will be replacing the downpipe if no leak found.
Has anyone used the copper gaskets between the heads and headers. should I continue with no gasket?

 

[626gn]

Has anyone used the copper gaskets between the heads and headers. should I continue with no gasket?

If you currently have no leak at the header, I would avoid using a gasket there. One less thing to fail.

I have tried copper header gaskets on a freshly machined head and new headers, but could never get them to seal properly. Probably an installation error on my part as I tend to over tighten things. Others have had success with them though...

 

[dynoman]

Smoke test the exhaust system , it will show you where any leaks are .

 

[Mr.Spool]

No I have not switched over to external gate yet. as you can see from the two pic. the blue line is not flat,27 high 25 low, but was control I was living with.
But 15 min later the boost was all over the place 25 high 18 low.
I think it's an exhaust leak just have not had time to remove all the exhaust to do good investigation. Actuator is OK no leaks gat appears to work properly
I will be replacing the downpipe if no leak found.
Has anyone used the copper gaskets between the heads and headers. should I continue with no gasket?

If the flanges are flat we use orange rtv and call it a day
I've used all the gaskets at one time or another.
Stock headers?

 

[Mr.Spool]

I would smoke like dynoman said so you don't chase your tail

 

[THensley]

Smoking the short distance from the turbo flange to exhaust valve is just to much for my little smoke machine.
I tried smoking the intake side first, could not get any PSI and had smoke coming from the IAC. I did not think it could leak that much boost..
I changed it and boost solenoid no change with a small pull on the street. I also checked turbo flange at the same time.
so ill be chasing my tail.I do fill its more controller , actuator or down pipe because it falls to heavy duty actuator spring pressure. I have considered a manual boost controller if someone has one to lone me.

 

[dynoman]

Plug your exhaust outlets , pull out the O2 sensor and inject smoke there . I inject smoke at one side of the exhaust outlet and plug the other and it will show any leaks in the complete system . You could have a preturbo leak anywhere in the system effecting boost .
I made my smoke machine from a YouTube video and it will supply plenty of smoke for the complete system .

 

[dynoman]

www.bing.com/videos/riverview/relatedvideo?q=smoke+machine+automotive+diy
This is what I made , but I churched it up with digital pressure gauge , regulator and on/off switch .
If you decide to build one let me know and I'll send you the Nichrome wire & wick .

 

[THensley]

www.bing.com/videos/riverview/relatedvideo?q=smoke+machine+automotive+diy
This is what I made , but I churched it up with digital pressure gauge , regulator and on/off switch .
If you decide to build one let me know and I'll send you the Nichrome wire & wick .

thanks ill be putting some thought into that. I will probably just look at per turbo the two headers and crossover

 

[Nigel]

Hey THensley,

Was the first screen shot the first test run, i.e. was the car started cold and this was the first full boost run?

Is the boost control an open loop pulse width modulation from the Holly ECU?

By the way, nice job on the 10 second pass with the 5857.

 

[THensley]

No, second screen shot was the first pass( blue line is boost) 11.1 pass@ 125
first screen shot with blue line up and down was second pass 10.8 @124
Yes car was cold as leave the pits get in line cold car it had sate 4 hrs not started.
Made first pass 11.1. rolled around, download log make a timing change get back in line went 10.8 that pass. . Got back in line but I felled to look at the log closely because they said that were closing the track. and I wanted to make one more pass. Last pass car went 11.2 @122 but I did not look at the loges tell I got home.that log showed after 2-3 shift boost tapered of faster than second pass. All 3 pass took place in 45 minutes

No I use a EBoost Street It has been very reliable

I did remove the turbo and headers Thursday and found 5 small leaks drivers side #5 was small passenger side #6 was the biggest had small leaks at crossover on both sides and #2. Friday I ran to Phoenix and grabbed a set of race headers, it was a knee jerk reaction that was not needed. Ta street headers are very good set of headers.

Thank you It is a great privilege to receive the words nice job from a member I have great respect for. I have been trying to best your 11,0 time for some time.
You gave me a ET and MPH to shot for, next I have to hit that !.5? 60 foot you laid down.

 

[THensley]

If the flanges are flat we use orange rtv and call it a day
I've used all the gaskets at one time or another.
Stock headers?

The header were TA stock replacement about 12 years old and yes the high temp orange RTV has held up the best. the flanges are good and flat.
Boost as always been at 25 I Don't know what changed but it has crept up to 27. I wonder if the back pressure jumped up with the 2 extra lb boost. Like I said in the thread above all the Leakes were small the larger one was width of the bottom of the port the rest were less than a 1/4 wide.
I did pull the ALKY back a little that weekend and the MAT actually stayed about the same and the car went faster, Plugs look good and AFR's are tracking much better
I don't have a handle on Holley knock sensor but Im airing on the rich side and kipping timing in the safer side too.
I sprung for a set of race headers bigger flanges at the ports and the crossover Vband and better slip fitting should help.
I have myself stretched thin and probably won't return to the track tell early in April.

 

[Nigel]

No, second screen shot was the first pass( blue line is boost) 11.1 pass@ 125
first screen shot with blue line up and down was second pass 10.8 @124
Yes car was cold as leave the pits get in line cold car it had sate 4 hrs not started.
Made first pass 11.1. rolled around, download log make a timing change get back in line went 10.8 that pass. . Got back in line but I felled to look at the log closely because they said that were closing the track. and I wanted to make one more pass. Last pass car went 11.2 @122 but I did not look at the loges tell I got home.that log showed after 2-3 shift boost tapered of faster than second pass. All 3 pass took place in 45 minutes

No I use a EBoost Street It has been very reliable

I did remove the turbo and headers Thursday and found 5 small leaks drivers side #5 was small passenger side #6 was the biggest had small leaks at crossover on both sides and #2. Friday I ran to Phoenix and grabbed a set of race headers, it was a knee jerk reaction that was not needed. Ta street headers are very good set of headers.

Thank you It is a great privilege to receive the words nice job from a member I have great respect for. I have been trying to best your 11,0 time for some time.
You gave me a ET and MPH to shot for, next I have to hit that !.5? 60 foot you laid down.

Thinking out loud, whatever is causing the problems is resulting in fluctuations. An exhaust leak would result in a steady drop, unless it was acting like a relief valve opening up under a certain pressure and then seals back up. Or the leak would have to cause something else to change intermittently. Is that boost control closed loop?
Do you know what the waste gate duty cycle was doing, with a small turbo on an engine that flows well like yours, I would think it was 100% based on the way the boost drops as rpm increases.
Was the AFR steady or moving around? This will effect EGT and if the waste gate is 100% open, could be contributing to the fluctuations.
It looks like the rpm is following the boost fluctuations, which would imply the power output is following the boost changes.

 

[Mr.Spool]

The header were TA stock replacement about 12 years old and yes the high temp orange RTV has held up the best. the flanges are good and flat.
Boost as always been at 25 I Don't know what changed but it has crept up to 27. I wonder if the back pressure jumped up with the 2 extra lb boost. Like I said in the thread above all the Leakes were small the larger one was width of the bottom of the port the rest were less than a 1/4 wide.
I did pull the ALKY back a little that weekend and the MAT actually stayed about the same and the car went faster, Plugs look good and AFR's are tracking much better
I don't have a handle on Holley knock sensor but Im airing on the rich side and kipping timing in the safer side too.
I sprung for a set of race headers bigger flanges at the ports and the crossover Vband and better slip fitting should help.
I have myself stretched thin and probably won't return to the track tell early in April.

I would also like to see an external
gate on that car
It's a great time since the headers are coming off

 

[THensley]

I had to look it up yes, BUT it stays closed loop tell I get to gate pressure, set at 20 psi. then to duty cycle that is 75%= around 25 psi boost with a small boost spike of 27 for a few millie seconds at shift. No I don't log the duty cycle on the turbo smart But it should stay at 75% above 20 psi I did change the solenoid and did a small pull on the street and could only get 19 20 boost I did purchase a MAC solenoid and not a Turbosmart
AFR tracking +- 1% the full pass just one or two cells at the lower RPM -3% just off the break at 3000RPM
I see no voltage ,timing or sensor glitches, I wish the new ALKY pump was smoother it really swings 40 to 60 +- lbs more than the old one. I did change snubber

 

[THensley]

I would also like to see an external
gate on that car
It's a great time since the headers are coming off

Ta was out of stock on Friday one is on order.