Hi every one,
I have a 33 gtr with the usual mods for about 300-350 rwkw.
* n1s
* z32s
* pond cams, gears
* pfc
* larger intake piping with twin pods
* full exhaust
* injectors (700cc), pump, rail, reg, etc.
"keep in mind I done all of this in one go from an stock engine"
My issue is a surge noise coming, (shuffling from pod top pod) from air filters).
Now when I made the new intake piping, I did not put the link tube in between the two turbos, didn't think it was necessary but boy was I wrong! the thing wouldn't even idle, let a lone drive properly. any way I made a piece to link the two, behind the afms obviously. and the surging was removed and the car became drivable, did tune got over 300kw, driving quite well, other than that shuffle between the turbos (compressor surge at cruise). just wanting to try and get rid of it apparently a lot of gtrs have this problem when the things are opened up i.e., 80mm afms etc.
Now I have heard a few things such as the original bovs actually recirculate slightly when a after market vent to atmosphere would normally be closed , if this is the case, I guess it would help as what I think is happening is the air is being forced against the closed, or almost closed throttle body at idle or cruise, and backing up through one turbo and then the other, so if the air at this point was vented to the intake side of the turbo instead of backing up to the outlet side I guess it would work. but then if the original bovs do recirculate all the time then how would it make boost?? I ask this as the car has those poxy supper sequential hks bovs on it, (not my doing they were on the car when I bought it.)
Also I have heard that linking the two signal wires from the afms to the ecm so they read the same voltage also can have some effect, this sounds a little dodgy but have hear that they do that when running two afms on a large single set up.
I do think it may be something to do with the afms double reading air as I know it was when I had no link pipe in the intake as you could see the afm voltages on the pfc. but now they are pretty close to the same.
any feed back, opinions, experiences etc. on this would be appreciated as it pissing me off, especially at idle.
Regards, Mark.