Are my wastegate springs big enough?

1Slow5PointOh

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Quick rundown of the setup : On3 twin turbo car, on3 wastegates, dual pump return system with DW 95# injectors, Turbosmart Eboost2 with a 3 port solenoid.

-Turned down the boost controller to gate pressure and it's showing as making roughly 5.5psi on a "6 psi spring"
-Turned the boost controller up to 10 pounds and it pulls hard throughout the rev range.
-Turned the boost controller up to ~11/12 psi and I feel hesitation/oscillation throughout the pull.

My first thought is that I'm running out of wastegate spring as 11/12psi is just about double gate pressure. Tuner says that AFR's/knock and everything else seem fine on his end. is the oscillation/hesitation a normal sign of "boost cut" or should I look elsewhere? I've had a couple people tell me it might be valve float (which I assumed was more of a gen1 problem then gen2), and another recommended upgrading to a 4 port solenoid (I don't have enough knowledge on this to know what difference that would make.)

 

Jackson1320

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valve float is a very real possibility. the spring on the gen2 are not much better then gen1. i would install valve springs
 

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I think rule of thumb with a 3 port solenoid is don't exceed twice spring pressure so if your seeing 5.5 then 11 is maxing out its efficiency. If you want to to go higher boost without starting at a higher spring pressure then the 4 port should help. I have heard the 4 port solenoid isn't as precise as the 3 port though.
 

illtal

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3 Port has more "resolution" and 4 port has bigger jumps in psi.

do you have a twin port wastegate or a single port controlled by a 3 port solenoid.

you should probably run a 7 psi spring which should still be good on 93 and see if you get the same problem on 11 lbs, if you do it is likely valve float.
 
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1Slow5PointOh

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3 Port has more "resolution" and 4 port has bigger jumps in psi.

do you have a twin port wastegate or a single port controlled by a 3 port solenoid.

you should probably run a 7 psi spring which should still be good on 93 and see if you get the same problem on 11 lbs, if you do it is likely valve float.
Yeah after posting that's the general consensus I read about 4 ports, is that they're much more sensitive and you can't make as small adjustments.

It is a twin wastegate setup controlled by a single 3 port solenoid.

I went ahead and ordered 8 lb springs to try and find the least expensive solution. I'll keep you guys updated.
 


illtal

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Yeah after posting that's the general consensus I read about 4 ports, is that they're much more sensitive and you can't make as small adjustments.

It is a twin wastegate setup controlled by a single 3 port solenoid.

I went ahead and ordered 8 lb springs to try and find the least expensive solution. I'll keep you guys updated.
but does it have a top and a bottom port that can be controlled to raise boost more than x2 spring pressure or does it only have the one top port?
 
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1Slow5PointOh

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This is essentially how I have it setup, the only difference is instead of running a "t" to the compressor housing, I run it to the vacuum block.
1660052542604.png
 

illtal

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This is essentially how I have it setup, the only difference is instead of running a "t" to the compressor housing, I run it to the vacuum block.
1660052542604.png
So it is dual port ... I think it should go above 2x spring. But the easiest thing to do is what you're doing now
 
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1Slow5PointOh

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So it is dual port ... I think it should go above 2x spring. But the easiest thing to do is what you're doing now
Yeah I'm not entirely sure because I know people with the same on3 wastegates who also have problems with going 2x over pressure on a 3 port solenoid.

But yeah definitely going to swap out the springs and probably inspect my plugs to make sure they're gapped properly in case its a spark issue. Hoping between the two that it solves the issue and I don't have to worry about springs.

Last weekend I was able to dyno the car and it did semi-decent but I saw a dip in power between the 5-5.5k RPM range even below 11psi. Maybe I'll be able to post that video/graph when I get back home.
 

illtal

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Yeah I'm not entirely sure because I know people with the same on3 wastegates who also have problems with going 2x over pressure on a 3 port solenoid.

But yeah definitely going to swap out the springs and probably inspect my plugs to make sure they're gapped properly in case its a spark issue. Hoping between the two that it solves the issue and I don't have to worry about springs.

Last weekend I was able to dyno the car and it did semi-decent but I saw a dip in power between the 5-5.5k RPM range even below 11psi. Maybe I'll be able to post that video/graph when I get back home.
If it was a spark issue you would get it at lower boost levels too. Spark blow out would occur on high boost, but we are nowhere around "hi boost" at 11/12psi. You can have a .038 gap at that boost level and not get blow out.
 

illtal

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Yeah I'm not entirely sure because I know people with the same on3 wastegates who also have problems with going 2x over pressure on a 3 port solenoid.

But yeah definitely going to swap out the springs and probably inspect my plugs to make sure they're gapped properly in case its a spark issue. Hoping between the two that it solves the issue and I don't have to worry about springs.

Last weekend I was able to dyno the car and it did semi-decent but I saw a dip in power between the 5-5.5k RPM range even below 11psi. Maybe I'll be able to post that video/graph when I get back home.
good deal I hope it isn't valve float.
 
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1Slow5PointOh

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Here's a video of the 10+ psi pull with hesitation and a graph of the couple pulls.
Tuner said the Blue line looks like i ran into some misfiring or a little bit of spark blow out. He said the dip around the 5k rev range is pretty normal and likely tied to the VCT moving.



Dyno.jpg
 

illtal

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I have the same kind of dip around that RPM.
looking at a lot of sheets it seems to be common.
it does sound like it's missing a LOT.
 
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1Slow5PointOh

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I have the same kind of dip around that RPM.
looking at a lot of sheets it seems to be common.
it does sound like it's missing a LOT.
Well, got the wastegates taken out yesterday. Upgraded to an 8 lb spring from the previous 5(?)lb spring. Sadly, while taking apart the wastegate I noticed that one of the diaphragm's were pinched, so I'll be waiting for that to come in sometime this week. Planning on checking the plugs in the next day or so as well.
1660505351377.png

1660505386687.png
 
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1Slow5PointOh

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I have the same kind of dip around that RPM.
looking at a lot of sheets it seems to be common.
it does sound like it's missing a LOT.
Well, only pulled a couple plugs and finally got around to measuring them. They came in closer to 0.032", definitely going to tighten those back down and send it again to see how it acts.
 

 
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