Need Boost Guru;s Help
#1
Thread Starter
Burning Brakes
Need Boost Guru;s Help
Ok, I'm chasing my tail it seems.
I installed a Lindsey 3" exhaust (with cat), and I have a Vitesse chip (2 shims - not sure that means anything) and a 3 bar fuel regulator - the PO said the boost was suppose to limited to 15psi.
Before the exhaust I was hitting 1.75 bar (on the car gauge).
After I installed the exhaust on my car pulled it pulled like a bull and the needle on my OEM boost gauge hit 2 for about 1 second or so before falling off.
Then for some a few days later I'm only able to get to about 1.8 +/- bar (on the car gauge) and it doesn't pull hard. The car revs to red line and I don't think the clutch is slipping.
I had the car leak down and compression checked and it all turned up good, so no problems there. I replaced all the small vacuum lines. I replaced the pop off valve on the J boot.
the only thing that might be contributing to boost loss is the crossover pipe. I notice the other day, after replacing the cam housing and oil dripping down the headers onto the collector and crossover pipe, that when I started the car oil must have soaked past the gaskets and I say puff of smoke coming from between the crossover pipe and what looks like a metal heat shield. Not massive amounts of smoke, just little puffs. I realize this could be a cause of boost loss, but that should have been there before as well. IDK.
I pulled the waste gate exhaust pipe off and the valve was fully seated though I don't have a tool to pressure test it other than compressed air tank. Not sure its a good idea to use that.
I know the OEM gauges are not that acurate, but it is a constant I've been working with.
I bought a cycling valve, but have not tried installing that yet since from what I've read if it fails I should only be able to hit 1.2 bar. I have a hard time getting past 1.2bar unless I just floor the throttle.
I need to check to see if my throttle is opening all the way, but I suspect it is since I didn't muck around with that before or after the exhaust went on.
I was going to try and wrap the crossover pipe with exhaust tape to see if it helps with the boost. Does that make sense?
Can a partially bad cycling valve cause this?
Also I know there is an aftermarket Tial or LR waste gate, but don't they need some type of controller? I really don't want to get into all that. If I end up needing a WG do they make one that is spring adjustable without having to have a controller?
Thanks for any help you all can give.
I installed a Lindsey 3" exhaust (with cat), and I have a Vitesse chip (2 shims - not sure that means anything) and a 3 bar fuel regulator - the PO said the boost was suppose to limited to 15psi.
Before the exhaust I was hitting 1.75 bar (on the car gauge).
After I installed the exhaust on my car pulled it pulled like a bull and the needle on my OEM boost gauge hit 2 for about 1 second or so before falling off.
Then for some a few days later I'm only able to get to about 1.8 +/- bar (on the car gauge) and it doesn't pull hard. The car revs to red line and I don't think the clutch is slipping.
I had the car leak down and compression checked and it all turned up good, so no problems there. I replaced all the small vacuum lines. I replaced the pop off valve on the J boot.
the only thing that might be contributing to boost loss is the crossover pipe. I notice the other day, after replacing the cam housing and oil dripping down the headers onto the collector and crossover pipe, that when I started the car oil must have soaked past the gaskets and I say puff of smoke coming from between the crossover pipe and what looks like a metal heat shield. Not massive amounts of smoke, just little puffs. I realize this could be a cause of boost loss, but that should have been there before as well. IDK.
I pulled the waste gate exhaust pipe off and the valve was fully seated though I don't have a tool to pressure test it other than compressed air tank. Not sure its a good idea to use that.
I know the OEM gauges are not that acurate, but it is a constant I've been working with.
I bought a cycling valve, but have not tried installing that yet since from what I've read if it fails I should only be able to hit 1.2 bar. I have a hard time getting past 1.2bar unless I just floor the throttle.
I need to check to see if my throttle is opening all the way, but I suspect it is since I didn't muck around with that before or after the exhaust went on.
I was going to try and wrap the crossover pipe with exhaust tape to see if it helps with the boost. Does that make sense?
Can a partially bad cycling valve cause this?
Also I know there is an aftermarket Tial or LR waste gate, but don't they need some type of controller? I really don't want to get into all that. If I end up needing a WG do they make one that is spring adjustable without having to have a controller?
Thanks for any help you all can give.
#2
Race Car
A quick test is to pinch off the line to the wg and take for a run being careful as it should overboost. If it still doesn't hit good pressure then there is a problem in the wg or exhaust parts.
Edit; I suppose it could be a boost leak too. Check the bottom side of the ic couplers or the turbo outlet. A smoke machine is good for finding leaks.
Edit; I suppose it could be a boost leak too. Check the bottom side of the ic couplers or the turbo outlet. A smoke machine is good for finding leaks.
#5
Thread Starter
Burning Brakes
Ok I pinched off the line to the WG and drove it up and down my street. I didn't go fast, maybe 30 mph. I tried 1st, 2nd and 3rd gear and the most boost I saw was 1.2 on the gauge. I went up to 4k maybe 4.5k rpm.
#7
Thread Starter
Burning Brakes
ok, from what I'm reading on Clark's it seems the WG may not be the issue if I'm not making boost. I'm only getting to 1.2bar and according to Clark's that indicates a sensor issue. How do you test the TPS sensor? That's something I'm suppose to check.
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#9
Thread Starter
Burning Brakes
If I understand correct if I pinch off the WG line then I take it out of as a variable correct? So something else is limiting my boost.
When I had the J boot off the cold side spun freely and I felt no play.
#10
Rennlist Member
So, you're saying you went from 2 bar on the stock gauge, to 1.8+/- bar, and now 1.2 bar. Are you sure you took the line to the cycling valve (it eventually goes to the wastegate) out of the loop? Because that would be a huge mother coincidence that you're only getting 1.2 bar now. (Because that's exactly the amount of boost you would get if the TPS or the CV failed).
When I delete that boost line I always take the banjo fitting bolt out of the charge pipe, take the line off, and reinstall the bolt; to make sure that boost is absolutely deleted to the wastegate.
When I delete that boost line I always take the banjo fitting bolt out of the charge pipe, take the line off, and reinstall the bolt; to make sure that boost is absolutely deleted to the wastegate.
#11
Instructor
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From: Lafayette+New Orleans, LA
It's sounds like a coupler wasn't tightened down all the way when you changed out the vacuum lines.
I'm located in Lafayette, let me know if you need any help tracking it down.
Jonathan
I'm located in Lafayette, let me know if you need any help tracking it down.
Jonathan
#12
Thread Starter
Burning Brakes
So, you're saying you went from 2 bar on the stock gauge, to 1.8+/- bar, and now 1.2 bar. Are you sure you took the line to the cycling valve (it eventually goes to the wastegate) out of the loop? Because that would be a huge mother coincidence that you're only getting 1.2 bar now. (Because that's exactly the amount of boost you would get if the TPS or the CV failed).
When I delete that boost line I always take the banjo fitting bolt out of the charge pipe, take the line off, and reinstall the bolt; to make sure that boost is absolutely deleted to the wastegate.
When I delete that boost line I always take the banjo fitting bolt out of the charge pipe, take the line off, and reinstall the bolt; to make sure that boost is absolutely deleted to the wastegate.
Thing is I'm getting boost, just not quickly, meaning I have to stomp on it to get the boost to hit 1.8 bar. If I just give medium effort on the gas peddle and run it to 5k I'll hit maybe 1.2+/- bar. Use to be that would get me near 1.7 or so.
What has me puzzled is when I pinched off the line I could only manage to get the boost up to 1.2. That's even revving to 4.5k. It didn't even get to about 1k if I slowly went up to 3k. I read on clarks that the exhaust pressure will open the valve at 1.2 bar if the cycling valve fails. But this confuses me.
What also puzzles me is that why can I boost to 1.8 with the line not pinched and only 1.2 with it pinched.
The only other thing of note is that after I took the pliers off I noticed the outer casing of the hose cracked. It is indeed dry rotted.
Tonight I went and got a coolant tester and pulled the connector off that you put on the coolant tank to I could connect it to the top of the WG. When I pumped it up the valve unseated at an indicated 4psi. But when I connected the pump up to an air gauge and pumped it to the 4 psi the other gauge it was connected to read 7 psi. Not sure which one is right now though the one on the pump seems of higher quality.
Last edited by Last Lemming; 02-01-2014 at 12:09 AM.
#13
Thread Starter
Burning Brakes