Silent supercharger?

90tbirdsc

Registered User
Hello, after getting a new coated rotor pack installed with the rotors in the right spots and removing the epoxy in the silencer ports my supercharger is virtually silent, is this a good thing or a bad one? I have Lmaf, with a 4in tube feeding it from my filter with a 75mm tb and mp inlet on a ported late model at 10% OD and a Fmic and prototype mandrel bending solutions 2.5 down pipes into a resonator and then 3in single exit out of the resonator and dump for exhaust and it seems to run pretty good with the base tune from DD for right now with a rich afr at about 12.0-12.6 and I make about 13-14 psi around 3k and the stock gauge is pegged at about 4200. Is this boost normal or do I have more issues?
 
That's all normal, but AFR should be mid 11's to be considered rich. Mid 12's is danger Will Rogers. Noise sucks.
 
That's all normal, but AFR should be mid 11's to be considered rich. Mid 12's is danger Will Rogers. Noise sucks.

I'm going to spin it at 20% and then datalog it and send you the log so we can start improving the tune.

Why is 12's dangerous? Or is it kinda a broad question? long and complicated answer?
 
I'm going to spin it at 20% and then datalog it and send you the log so we can start improving the tune.

Why is 12's dangerous? Or is it kinda a broad question? long and complicated answer?

20% is too much for the blower unless you have a pretty serious motor under it. 12's is for NA. 11's for FI.
 
20% is too much for the blower unless you have a pretty serious motor under it. 12's is for NA. 11's for FI.

Ok. There should be a power difference with a decent tune from where im at now shouldn't there? I'm not extremely impressed in how it's running so far.
 
Last edited:
Ok. There should be a power difference with a decent tune from where im at now shouldn't there? I'm not extremely impressed in how it's running so far.

A tune is the difference between a car not being able to idle and a car that can run 12's. So yes, you will probably see a decent difference with a tune, even if not in the performance department, it'll be in the reliability and drivability department
 
A tune is the difference between a car not being able to idle and a car that can run 12's. So yes, you will probably see a decent difference with a tune, even if not in the performance department, it'll be in the reliability and drivability department

it drives and idles perfect now, im just worried I spent a lot of $$$ and time and research for a disapointment
 
it drives and idles perfect now, im just worried I spent a lot of $$$ and time and research for a disapointment

Not sure what you might have been expecting. My car currently has a similar setup and makes 280rwhp. It's not disappointing to me considering the stock engine, but it's no 450rhwp screamer either.
 
your intake is so large it doesn't make a whistle/sucking sound...think about it, suck air through ur lips smiling like a donut and then like your yawning...same concept.
 
Not sure what you might have been expecting. My car currently has a similar setup and makes 280rwhp. It's not disappointing to me considering the stock engine, but it's no 450rhwp screamer either.

I was expecting 260-270 rwhp. I feel that it could be more around the 220-240 mark right now. I won't know till I take it to the track and the dyno but If I can run any number in the 13's I'll be happy
 
I was expecting 260-270 rwhp. I feel that it could be more around the 220-240 mark right now. I won't know till I take it to the track and the dyno but If I can run any number in the 13's I'll be happy

I think you will have plenty of power to run 13s.

David
 
Does anyone know why my supercharger is silent though? :confused:

Silent isn't the right word. Quieter than you are used to, maybe. Some of the noise in some superchargers is literally the sound of the rotors hitting each other. Properly timed rotors will quiet the blower significantly. Opening up the sound ports also makes it quieter. Then since you have a front mount IC, it is possible that you have closed up some of the gaps between the solid tubes. Silicone couplers transmit a lot of noise if they are bridging significant gaps between the tubes. I believe that is one of the main reasons Ford didn't use flexible silicone connectors on the SC originally.

Seat of the pants dyno is a terrible reference for anything. The car has to be tuned on a dyno before any statements about power can be made.
 
Silent isn't the right word. Quieter than you are used to, maybe. Some of the noise in some superchargers is literally the sound of the rotors hitting each other. Properly timed rotors will quiet the blower significantly. Opening up the sound ports also makes it quieter. Then since you have a front mount IC, it is possible that you have closed up some of the gaps between the solid tubes. Silicone couplers transmit a lot of noise if they are bridging significant gaps between the tubes. I believe that is one of the main reasons Ford didn't use flexible silicone connectors on the SC originally.

Seat of the pants dyno is a terrible reference for anything. The car has to be tuned on a dyno before any statements about power can be made.

I can't hear it reving the motor, I can faintly hear it if the car is about 2500rpm and I mash it, and it's only for about a second that I can hear it. Otherwise I can't hear a thing, I wonder if the noise could be related to the amount of air it moves since in another post after looking at my log you said it isint moving any air. Could sound and cfm be related?
 
Last edited:
I can't hear it reving the motor, I can faintly hear it if the car is about 2500rpm and I mash it, and it's only for about a second that I can hear it. Otherwise I can't hear a thing, I wonder if the noise could be related to the amount of air it moves since in another post after looking at my log you said it isint moving any air. Could sound and cfm be related?

No, I said after looking more closely your tune is fubar and needs to be rebooted. See the other thread.
 
Back
Top