That's a level of science well above my pay grade.
Your overthinking this. It should not matter. In a N/A application you may have a point. And the only time this is N/A is idle, cruise and deceleration. Move your base idle speed up a bit and any surge should go away. You can also fatten up the idle circuit as well. What you are getting is called compressor surge, which is typical in positive displacement S/C applications. A larger by-pass valve may help. If you can, bypass from the cold side to the inlet.Does anyone know what effect plenum volume has on an engine? I don't mean for power output I mean for wave reversion......
It seems from some reading that a larger plenum volume causes the air to "slow down" so to speak. So the pressure drop when a cylinder opens causes a back wave that aggregates the issue. Essentially I have created a massive plenum (11ft of 3" pipe + huge IC + cobra intake) I was wondering if some of you smarter than me guys can help here. Or if I can put in a short path bypass so the tb feeds the plenum almost directly when in idle conditions, otherwise I am gonna tear all this new **** out and put both tb back on...
I am certain it's not compressor surge, I put on a shorter belt so the SC is not spinning and have my bypass opened with a vacuum pump. The car won't idle down past 1300rpm afr of 13.6......Your overthinking this. It should not matter. In a N/A application you may have a point. And the only time this is N/A is idle, cruise and deceleration. Move your base idle speed up a bit and any surge should go away. You can also fatten up the idle circuit as well. What you are getting is called compressor surge, which is typical in positive displacement S/C applications. A larger by-pass valve may help. If you can, bypass from the cold side to the inlet.
I ask is brand new and idle just fine before I move the throttle body. This is also with the IAC unplugged setting idol with a FRPP idle control plateIf it still has an IAC valve, that could need some cleaning or replacement. Either that or your Mega whatever engine management system is not set up right.
Then you have an air leak or it is programmed wrongI ask is brand new and idle just fine before I move the throttle body. This is also with the IAC unplugged setting idol with a FRPP idle control plate
You're running it as speed density, right?Now I mean no offense but the tune is fine, will it need tweeking yes but the car should idle.
Now after looking at some pictures of cars with similar setups (supercoupe) they positioned the bypass so that air when in vacuum only has 1ft of travel or so to reach the plenum not 8ft +Ic. So my test today will be to put in a short path bypass.
I just removed the SC and bypass out of the equation all together to test this. Same issue, lots of frustration. Lol.Yup.
Oh and I think I found the problem too..... I forgot that the bypass was originally intended to blow off excess pressure (the up stream to was opened farther that the one at the plenum.)
Soooo guess which tubes are still flexible and crush under vaccum?
I do agree with you there! I am going to roll na for a bit and get those tune areas dialed in better.I tell you what, if the thing ran really well with two throttle bodies, so be it. Its home made, so it doesnt have to model anyone's kit. Whatever works and makes it run well so you can enjoy it is what I would roll with.
Thanks!Well, had you shelled out a bunch of cash to a shop to fab up a kit, then yeah it would be fair to worry about the overall look. But being you have made it out of scratch, for pennies on the dollar compared to supercharger kits, it works! On the flip side, some folks like @madmike1157 clearly get more enjoyment out of the build than the finished product, so maybe you enjoy sorting out the issues that come with refining your creation. Either way, its a really cool thing youve done with your car.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?