Torinate
Well-Known Member
Tell me more about this restrictor in the bypass valve! How do you mean it freed up 2lbs of boost? You’re making 2 pounds more than before they did this modification?
Thanks!!
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Thanks!!
Burkey
Well-Known Member
Wait…so you’ve got a restrictor installed on the bypass valve supply line, to slow the opening/closing of the valve.
Wouldn‘t that partially explain the slow opening of the bypass valve?
Not sure how the restrictor could possibly influence the boost pressure.
illtal
Well-Known Member
I still have the stock restrictor in the bypass line. The nitrous pill is there to slow the notoriously fast opening and closing light switch bypass valve. I have driven with it off and it is so jerky for me I went back to the stock restrictor. I know guys put larger ones in it to speed up the response but just simple putting the car in drag mode give me the throttle response I want.
Semp1
Well-Known Member
When a bypass valve doesn’t open or close when it’s supposed to you can lose boost. If it’s not closing all the way at WOT for example you can lose boost which is common. By controlling the vacuum, it frees up boost that would’ve been there if the bypass valve had been working properly from the beginning. The valve still is opening and closing in a delayed manner on start up but it seems to be functioning better overall now. But this isn’t something I just did. My shop did it and revised the tune based on the airflow change.
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Semp1
Well-Known Member
honestly I’m not the shop, tech or tuner. I don’t try any of this. They do. I trust them fully with the car. The shop is JDM Engineering and are well known engine builders and tuners. Anything they do in my eyes is the way it needs to be done So if it’s a possibility they have already tested it. From what I gather and understand there’s no air restrictor in the “integrated” Edelbrock bypass valve as is. They modified it to have one So it would function more appropriately.
illtal
Well-Known Member
That would explain why there in a restrictor in the line. Going to the bypass valve. It also explains why it opens and shuts immediately like a light switch without it in the line. This allows you to tame the way it responds with just changing out the restrictor inside the bypass line.
Semp1
Well-Known Member
the Bypass valve is opening and closing delayed. It’s functioning better because of an added air restrictor. It did not have this prior to them installing one. I am in the process of getting the bypass valve replaced by edelbrock because it is to be assumed based on the visual and actual evidence that this is the reason this blower has this issue. There’s also the still a chance it TB connected and a slight chance that this is unfortunately as good as it‘s gonna get in regards to their design and my shop is just going to have to keep tinkering away and eventually will perfect it.
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illtal
Well-Known Member
Did you leave the restrictor in the bypass line too?
Just squeeze it and see if it is still in there. I have the exact opposite experience than you. With it out it closes and opens too fast making in and out of boost like a light switch. Hopefully someone can chime in on this. I have an early kit too, stage 1. But I have since upgraded all that I don't have regarding a stage two setup is the 8 rib.
Burkey
Well-Known Member
My point is that slowing the rate of opening/closing won‘t alter the actual open/close maximum points.
I‘m going to suggest that they may have played with the cam timing which will most certainly produce more or less boost if you so desire.
Vacuum should be very low at WOT, ergo the spring holds the valve closed, vacuum pulls it open.
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illtal
Well-Known Member
The cam phasing can give more or less cylinder pressure as well via controlling the valve overlap.
I find it strange that he's having a slow bypass problem when most people have a fast bypass problem.
It shouldn't matter if the shop is going to be that hands on. I'm a tinkerer so I like to know what goes on with the ride because I don't have a trustworthy shop near me.
The Lund tune was done in 4 revisions. It runs about 95% of perfect, with the other being going from WOT to something less than WOT but still deep in the throttle there is a hiccup. It likely has something to do with the ignition advance, seeing as I run meth, it's probable this is the issue.
Stang 19
Well-Known Member
FWIW: when Edelbrock installed the stage two kit on my 19 Mustang GT I had the same start up and die problem or it felt like it was about to die half the time upon start up. Then one day I went to do a warm restart and I got the wrench on the dashboard come on and it went into limp mode. Edelbrock sent me a brand new throttlebody and said that I needed to reflash the stock tune. After that no more problems no more start up problems no more idle problems.
Torinate
Well-Known Member
Ok.
So this is the nitrous pill in the line that goes from the passenger side of the unit to the bypass valve itself.
Mind you, mine is a 16 and I don’t know if the 18+ are different. When the kit comes, there’s already a pill in it. It comes with a 15 jet. I’ve played with mine several times and tried 20 25 32 35 jets and no jet. The best compromise I have come up with is 32. No jet was very jerky for sure. On / off and just not smooth. I found the 32 to restrict and get rid of the jerkiness but still off immediate type boost. No question the 15 was the smoothest and tamest. The 32 in my application offered a happy medium in the smooth to rowdy meter.
I’m not running the 103 TB though (I’m pre modular inlet) but I am running the 90mm Ford Racing TB which came with the prior stage 2s. No hiccups as you describe or starting woes. A little jerky when going from lots of boost to closed throttle. Maybe not jerky but more abrupt than the 15, which was silky smooth.
In all this, regardless of which pill was in the line, I didn’t see any change to boost.
I found the easiest way to change the pills was to just buy more vacuum line and switch out the whole piece rather than fight with the pill itself that’s a tight fit in the line. I just labeled the line with whatever jet was in it. 2 clamps and the switch was done.
Interesting about the comments about more boost needing a different tune.
I’m tuned by Lund and they expressly told me that if I wanted to change boost a few pounds up or down that the tune would be completely fine and no changes would be required. Again, I’m a 16 and only have one set of injectors so I can’t say for 18+ If that makes a difference.
My car has been completely great! My kids and wife have driven the car and it runs smoother that it did stock. The exact way it sits for “daily driving” Is the exact way I run it when I go to the track on rentals. Tech won’t pass the rag top on test and tune nights due to knowing how fast I run and the regulations. Rentals they turn a blind eye...
So this is the nitrous pill in the line that goes from the passenger side of the unit to the bypass valve itself.
Mind you, mine is a 16 and I don’t know if the 18+ are different. When the kit comes, there’s already a pill in it. It comes with a 15 jet. I’ve played with mine several times and tried 20 25 32 35 jets and no jet. The best compromise I have come up with is 32. No jet was very jerky for sure. On / off and just not smooth. I found the 32 to restrict and get rid of the jerkiness but still off immediate type boost. No question the 15 was the smoothest and tamest. The 32 in my application offered a happy medium in the smooth to rowdy meter.
I’m not running the 103 TB though (I’m pre modular inlet) but I am running the 90mm Ford Racing TB which came with the prior stage 2s. No hiccups as you describe or starting woes. A little jerky when going from lots of boost to closed throttle. Maybe not jerky but more abrupt than the 15, which was silky smooth.
In all this, regardless of which pill was in the line, I didn’t see any change to boost.
I found the easiest way to change the pills was to just buy more vacuum line and switch out the whole piece rather than fight with the pill itself that’s a tight fit in the line. I just labeled the line with whatever jet was in it. 2 clamps and the switch was done.
Interesting about the comments about more boost needing a different tune.
I’m tuned by Lund and they expressly told me that if I wanted to change boost a few pounds up or down that the tune would be completely fine and no changes would be required. Again, I’m a 16 and only have one set of injectors so I can’t say for 18+ If that makes a difference.
My car has been completely great! My kids and wife have driven the car and it runs smoother that it did stock. The exact way it sits for “daily driving” Is the exact way I run it when I go to the track on rentals. Tech won’t pass the rag top on test and tune nights due to knowing how fast I run and the regulations. Rentals they turn a blind eye...
illtal
Well-Known Member
I'm running an 18. Basically no more boost on 93 pump. With a 3.25". There is headroom with a 3.15" there is none which is what I'm running now.
I might tinker with the pills because on normal mode it takes about 70% throttle to get into boost. In track/drag mode it's about 45%. The transition is very smooth as you have stated. I do miss the animal getting loose off idle though. Does make it silly to drive.
Torinate
Well-Known Member
Yes it does. When I took the pill out it was literally an on off switch depending on pedal position. With the pill in it’s more gradual and easier to control. Takes more of a deliberate stab on the pedal to nail the boost. Makes for a more pleasant street car (although I miss the rowdy nature at times) and easier for the uninitiated to manage. The stock pill is just too smooth for me. Zero jerkiness and transition from vacuum to boost is very predictable. But with the 32 it does seem to hit harder but has some jerk to it in transition. Happy medium lol.
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