Dyno graph inside Why is my boost falling off on the big end?
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Dyno graph inside Why is my boost falling off on the big end? Made a trip to the dyno today. On 13 psi I made 609 rwhp/ 647 rwtq. I'm happy with these numbers but my car bled the boost off and dropped and held at 10 psi. Is it because of my tsp228r cam? http://m.imgur.com/l2pxpYF
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From: Bowling Green KY
Benita, Benita, Benita, Twin Benitas commin soon!
But seriously that is a reasonable number for that setup. I agree the cam is fine. You should use the boost line off the compressor housing to control the wastegate. A wastegate should never be controlled off the manifold. A wastegate shouldn't vacuum, only boost. Vacuum is not good for the seal on the piston on the wastegate. It should be held closed by the spring, or pressure on the back side of the piston, and pushed open by boost on the underside of the piston. That is from reading the instructions that came with one of my wastegates said anyhow. There is a reason why compressor housings are drilled and tapped here.
You should compensate for your pressure drop through the inlet piping, the intercooler and the throttle body. For example I have my gate set at 16.5 PSI and I data log 15 PSI on the MAP sensor. Thus I loose 1.5 PSI in my system, this is a very normal number considering my setup. My boost is flatlined, well within 1 PSI from 4000 through 7000 rpm, and I only use a spring, no controller.
Benita!! Benita!!
Benita, haha
But seriously that is a reasonable number for that setup. I agree the cam is fine. You should use the boost line off the compressor housing to control the wastegate. A wastegate should never be controlled off the manifold. A wastegate shouldn't vacuum, only boost. Vacuum is not good for the seal on the piston on the wastegate. It should be held closed by the spring, or pressure on the back side of the piston, and pushed open by boost on the underside of the piston. That is from reading the instructions that came with one of my wastegates said anyhow. There is a reason why compressor housings are drilled and tapped here.
You should compensate for your pressure drop through the inlet piping, the intercooler and the throttle body. For example I have my gate set at 16.5 PSI and I data log 15 PSI on the MAP sensor. Thus I loose 1.5 PSI in my system, this is a very normal number considering my setup. My boost is flatlined, well within 1 PSI from 4000 through 7000 rpm, and I only use a spring, no controller.
Benita!! Benita!!
Benita, haha
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So where do I go with for my boost solenoid ? The top port of my gate is open, and the other port goes to the solenoid . I believe the vacuum comes from my booster . Is there a link to a diagram that would show me where it should be setup ? I used the diagram with the eboost controller and hooked it up that way. They claim there are several ways too do it so i didn't dwell on it too much
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From: Bowling Green KY
You have it installed incorrectly I believe. Normally the line from the compressor goes to the bottom side of the piston, down by the valve and seat, and the controller attached to that port on the top of the piston. I think you ran on spring only if your plumbing is like that. You usually put a light spring in the gate and it is supplemented by pressure working with the spring from the boost controller. The balances against the pressure from the line off the compressor housing against the bottom of the piston.
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You have it installed incorrectly I believe. Normally the line from the compressor goes to the bottom side of the piston, down by the valve and seat, and the controller attached to that port on the top of the piston. I think you ran on spring only if your plumbing is like that. You usually put a light spring in the gate and it is supplemented by pressure working with the spring from the boost controller. The balances against the pressure from the line off the compressor housing against the bottom of the piston.
this is exactly how it's hooked up
8 psi spring 44mm xspower wastegate
Last edited by Dennis5374; Mar 1, 2017 at 06:19 PM.
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From: Bowling Green KY
I would recommend you try the 2 port, single solenoid, single turbo setup, like on the top of page 10 of your manual. Does that make sense to you? That way the high pressure in the exhaust side doesn't affect control as much.
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yeah I'll give it a try . I'm gonna turn the controller way down though . If it works as it should I'll be making 60% of 40 psi which will be bad news lol . Is this gonna help where my car peaks or just allow me to hold higher pressure too my shift point ,
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could the back pressure cause the turbo to fail prematurely ? And I was referring to where I shift at , hold more boost too redline so to speak . I'd like to add more fuel , water meth and shoot for 700 next week. If I pop the ls1 it gives me an excuse to build a bad *** motor with the wife
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From: Bowling Green KY
could the back pressure cause the turbo to fail prematurely ? And I was referring to where I shift at , hold more boost too redline so to speak . I'd like to add more fuel , water meth and shoot for 700 next week. If I pop the ls1 it gives me an excuse to build a bad *** motor with the wife
. That should 'splain it. Forgiveness not permission. If I didn't go that way, I probably be driving a Taurus, and not a new SHO, probably something like a '96 bubble mobile. No disrespect to my wife she is a great person, but people only behave the way you let them. Show her you have a .Oh yeah, and tell her you have a Benita, and you need another one. Actually scratch that, don't tell her anything about Benita, that could get you in more trouble than building a motor.
I think using the setup on page 10 will give you better boost control. How big of a spring do you have in your gate? I'd put about a 10psi spring in it.
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One more question , I'm still getting light smoke after installing a Mighty Mouse ls Wild setup, and all new -10 an drains with a turbo werx exa pump and brand spanking new turbo ! This is the most frustrating thing as I battled this problem all last fall and still can't seem to figure it out . I've read some people clock their turbo an inch forward or clockwise? I really don't understand why I'm still getting smoke when I let off, or come to a stop . All new valve stem seals, the right pcv setup, a proper drain. Could my turbo possibly need a restrictor? This is the most frustrating issue I've had since switching over to turbo! I see 65-70 psi oil pressure at wot . But it never smokes under boost , it's always when I back off or at low Rpms . Could there be excessive blow by in the motor causing it ? That doesn't make sense though considering it doesn't ever do it under wot and only when I'm babying the car ...
8 psi spring as stated above also
8 psi spring as stated above also