Here's a bit of a write up on the M90 generations.
http://rivperformance.editboard.com/t7823-faq-m90-supercharger-info
89-93 M90's had no coating on the rotors.
I mounted my boost/vac gauge. Pretty easy, really. I'll see how it works out.
Still no bearings for the M90. Stuck in customs.
I found a guy that will powdercoat the casing, but I have to wait till he has another job he can piggy back it with. Good guy, and the price is right. If I want it returned fast, it would cost a couple hundred bucks. I can wait.
I agree. Ive gone all over the city.
it seems no one wants to bother with a small item.
That's crazy. I usually go to the local powder coating guys who have small operations because they are more hungry for business and do a good job because they want you to keep coming back. For that much I would think about just buying my own PC equipment and doing it myself. Of course the garage might not like having even less room.
I agree. Ive gone all over the city.
it seems no one wants to bother with a small item.
I mounted my boost/vac gauge. Pretty easy, really. I'll see how it works out.
Still no bearings for the M90. Stuck in customs.
I found a guy that will powdercoat the casing, but I have to wait till he has another job he can piggy back it with. Good guy, and the price is right. If I want it returned fast, it would cost a couple hundred bucks. I can wait.
What gauge is that?
your hooking it up after blower right?witch leads me to the next question or point,how are you hooking up you fuel pressure regulator?i think it needs to be after the sc also.from what i understand when there is vac it lessens the pressure and when there is no vac it increases fuel pressure.so only place that happens is after the blower right?before the blower it should be creating vac ALL the time now
yea you lost mewe are using a stock fpr.i works by vac,high vac it opens and lowers fuel pressure,low vac or no vac it closes and increases fuel pressure.i didnt understand the pre blower or pre tb stuff either.after the charger where it mounts to the lower intake manifold should see vac and boost right?i would think everything on the other side(the intake side for the blades) would see nothing but vac.i would think at low rpm the air bypass would cause vac and when in high rpms the sc would be causing ALOT of vac.where does the boost gauge mount?i think this is where the stock fpr needs to mount,it needs vac and no vac(boost)On a roots type of supercharger setup when you place vac lines pre-blower and TB you will see neither vacuum or boost. Post TB and pre-blower you will only get vacuum but no boost. Post TB and blower and you will get vacuum and boost.
You have a few choices when it comes to hooking up an aftermarket fuel pressure regulator (FPR). You can either boost reference or not boost reference it. Doing the boost reference is all about keeping the same injector delta (pressure drop across the fuel injectors) at all times during idle and accel. The reason for this is because how the pressure or vacuum acts on the fuel trying to come out of the orifices in the fuel injectors. When in boost the extra pressure pushes back against fuel pressure in the fuel system and less fuel will come out. When sitting at idle with 20in/hg vacuum (roughly -10psi vacuum) then the vacuum in the intake manifold will tend to suck fuel from the injectors.
In a non-boost referenced FPR in a supercharged vehicle your overall fuel pressure read by a FP gauge will remain at a constant psi. But the actual psi making it out of the injectors in relation to the pressure/vacuum in the intake manifold will vary. So if I set my FP to 43 psi without the car running then when I crank it and it sits at idle my gauge is reading 43 while I am actually injecting in about 53 psi worth of fuel because of the -10psi vacuum in the intake. When I get into boost this situation reverses and I will get proportionally less fuel into the intake manifold because of the boost pressure pushing against the fuel in the rails.
A boost ref FPR will ensure that whether you are in boost or vac that your pressure drop measure across the injectors (aka inside the rail before the injectors and post injector inside the intake manifold) stays the same. Your read FP on the gauge will increase or decrease of course since FP in the system is raised or lowered to compensate in a 1:1 ratio for the boost or vac the FPR sees.
As long as you know your overall FP will not exceed any internal pressure bypasses that your fuel pump might have then I recommend to boost reference your FPR if it has the capability. That way it will prevent you from running out of fuel on the top end or just putting your fuel injectors under a duty cycle that may be too demanding for them.
Hope I made at least some sense here because I typed it pretty quickly.
ok understand this a little better.i would think pre tb would see a little vac at idle and full vac at acceleration?sounds like a stock fpr works like a boost ref fpr,just increases fp in the rail when under boost(no vac) or accelerationOn a roots type of supercharger setup when you place vac lines pre-blower and TB you will see neither vacuum or boost. Post TB and pre-blower you will only get vacuum but no boost. Post TB and blower and you will get vacuum and boost.
You have a few choices when it comes to hooking up an aftermarket fuel pressure regulator (FPR). You can either boost reference or not boost reference it. Doing the boost reference is all about keeping the same injector delta (pressure drop across the fuel injectors) at all times during idle and accel. The reason for this is because how the pressure or vacuum acts on the fuel trying to come out of the orifices in the fuel injectors. When in boost the extra pressure pushes back against fuel pressure in the fuel system and less fuel will come out. When sitting at idle with 20in/hg vacuum (roughly -10psi vacuum) then the vacuum in the intake manifold will tend to suck fuel from the injectors.
In a non-boost referenced FPR in a supercharged vehicle your overall fuel pressure read by a FP gauge will remain at a constant psi. But the actual psi making it out of the injectors in relation to the pressure/vacuum in the intake manifold will vary. So if I set my FP to 43 psi without the car running then when I crank it and it sits at idle my gauge is reading 43 while I am actually injecting in about 53 psi worth of fuel because of the -10psi vacuum in the intake. When I get into boost this situation reverses and I will get proportionally less fuel into the intake manifold because of the boost pressure pushing against the fuel in the rails.
A boost ref FPR will ensure that whether you are in boost or vac that your pressure drop measure across the injectors (aka inside the rail before the injectors and post injector inside the intake manifold) stays the same. Your read FP on the gauge will increase or decrease of course since FP in the system is raised or lowered to compensate in a 1:1 ratio for the boost or vac the FPR sees.
As long as you know your overall FP will not exceed any internal pressure bypasses that your fuel pump might have then I recommend to boost reference your FPR if it has the capability. That way it will prevent you from running out of fuel on the top end or just putting your fuel injectors under a duty cycle that may be too demanding for them.
Hope I made at least some sense here because I typed it pretty quickly.
Wow. Tons more info.
My boost/vag gauge is pulling from post SC. I have a nipple already installed. Ron at RPCaster had drilled and tapped a line for me.
Im not planning on running an external fuel pressure regulator. High volume fuel pump, and larger injectors. Factory fuel pressure regulator in the tank.
Yup, returnless. The fpr is in the gas tank, and on the rail there is some kind of pulse smoothing unit. I've read quite a bit about the returnless system. Lots of confusion around it.