I just finished my Greddy SC install and I love it! It’s a great kick in the pants and sounds so cool.

This being my first experience with forced induction on any car I’ve ever owned, I have a few questions that someone here may be able to help me with.

1. I have a very loud whistle at around 2600-2700 RPM. If I push the gas pedal in 1/8” further or let off 1/8”, changing the RPM ±100, it goes away. It doesn’t sound like belt squeal at all, more like when brake pads are wearing out and the little metal tab screeches on the disc to warn you about it. I am running the SC with an Injen short ram intake and a lightened crank pulley. All mating surfaces were coated with silicone during assembly and all hose were checked for leaks. All vacuum hose are clamped. Any idea what this is? Is it normal?

2. I do have a boost gauge installed. It reads negative (vacuum) during idle and when the engine is not under load (like coasting down a big hill). When I step on the gas it does read 5-6 PSI of boost. Is this normal too? What should the gauge read during idle? I am getting around 15 PSI of vacuum. The gauge was tapped off of the vacuum line on top of the SC.

I appreciate any help you guys can give this “noob”!

Thanks,
Mike

 

Could you record a clip of the sound you are describing? I am no expert on this but if it sounds like metal rubbing on metal the pulleys are probably the most obvious places to look. You might want to start at the lightened crank and see if sheered off the pin. Just my uneducated thoughts

Are you planning on running any other gauges? I was considering getting the perrin 2 pod setup that mounts on the steering column but I am unsure of what the best second gauge to get would be with an s/c.

Either way I am watching the post as I am getting my s/c next week.

 

my guess just intake whistle thats all.... I wouldnt be worried cuz it only does it with the throttle at a certain amount open and only between certain rpm's.... I know this is not the same but my old neon used to do this exact thing and it was a whistle from the intake on that..... but maybe I'm wrong. Double check everything and if nothing is wrong I wouldn't let it bother me. As for the vacuum I would say its fine since the supercharger isnt going to be working at all and the motor has to work for is air. Also going to make boost alot faster then a turbo since its run off the belts so more rpm = more boost. Even turbo cars make boost reving the car only a couple pound but still do.

 

I cant answer your question but your ride is looking awesome...I want to see more pics of it, including interior and such...Nice going!

 

I'm pretty sure it's not metal to metal. I have checked everything out and if there was rubbing I think I would see some wear or at least some metal shavings somewhere. Unfortunately I don't have a way of making a sound clip of it. I know it's not the pin at the pulley because it has been on the car for quite a while and the whistle started immediately after the SC install, before I even road tested it. I could hear it right away when lightly revving the engine when I first started it.

Gauges? I have a boost gauge in the dash next to the speedo and I have oil pressure, water temp, and volts in a pod on the A pillar. Plan on an A/F later but I don't see too much need for it now as I don't plan on tuning the e-manage and don't really plan on "gettin' on it" on the road. It's not really for speed - it's more for show.

I suspected it might be normal but because I don't really have any experience with it, and I've never really seen another one installed, and I happen to be the first one in my car club that has one, I just wanted to make sure there was nothing wrong. If possible I would like to try and get rid of the whistle, or at least minimize it.

Thanks for the boost/vacuum info. I kind of figured that was the way it worked but thanks for confirming it.



Thanks, brother. It's finally coming together. I don't have any new pictures of it yet but a friend took some at the show we did last weekend and I will put them up when they send them to me.

I will be out of town for work for the rest of the week and I won't have internet access until friday night so please understand if I don't reply to anyone elses posts until then.

Thanks for all the help, guys (or girls as the case may be!)!
Mike

 

Thanks for the gauge info -- Maybe I should get an oil pressure for the 2nd gauge in that steering column mount. Correct me if I am wrong but thats probably the other most important thing I will need to monitor with the s/c.

 

He man at idddle you should be at 20 vac. Driveing no more than 6 ponds at max.On top off your sc theres a yellow wire you need to tee your gage off that.You have it on the wrong part.

 

O my bad i just saw another picture.You have it right

 

if your still wondering, that sound is most likely the boost bypass valve closing. the GReddy SC is an Eaton blower, they use a bypass valve to recirculate the boost. that valve closes as you open the throttle, it is proportional to the amount of throttle you give it, so you are only boosting when you need it, saving your gas mileage. the bypass on our kits dumps directly into the intake right before the sc, so what you are hearing is the whistle of the air as the valve is partially open. it surprised me the first time i heard it too, but after i figured out what it was i learned to enjoy it, if you hear it from the outside it actually sounds kinda cool...

 

mystery solved! thanks for th heads up easysbox.

 

no prob, just have to "relearn" how to drive the box to keep it from a prolonged "whistle", and just a short one ;)