New JRSC install, sounds normal?
 

Hi Guys,
I've finally bite the bullet and got the upgrade, but I was not expecting the obvious whining noise coming from the unit (is it from Rotrex or belt?), can some of you share your thoughts on my setup and let me know if it's "norm?"

cold start
https://youtube.com/shorts/iK5m8neBsEo?feature=share

warmed up
https://youtube.com/shorts/jISghmF6E6w?feature=share


i found another video on youtube when they had their Rotrex unit replaced:
https://www.youtube.com/watch?v=Ff5I...vMABpg&index=2

Since mine is a new install, i want to make sure it's done correctly early on.

Thanks all!

Not normal, imo. I drove a JRSC brz and it didn't have any strange high pitched whining at idle like that.

do you have a video of it start up/warm up like mine that you can share?

i want to have enough reference for comparison.

Is this new or used? You said new install, not new parts. This isn't normal

It was years ago, so no. But yeah it didn't make any obnoxious sounds like this.

Who did the install? Was it a new kit?

Brand new kit installed at a professional shop (they have done at least half dozen) - they also said it was louder than usual but JRSC said it's normal and that my video is hard to tell... I am not quite convinced so I thought I check in with the JRSC owners.

I have heard other JRSC owners at car meets and i don't recall this obvious whining.

Any JRSC owners if you coming out to the next group SJ meet let me know!

i would expect the noise to match the rpm increase as he is doing in the first video, but it s only at idle and then seems to disappear, so it seems more related just to some resonation within the bypass valve

At first it sounded fine inside the car but when you opened the hood it sounds like a failing refrigerator compressor. My re circulation valve hisses but it also doesn't sound like that.


Did you end up bleeding all the air out of the traction fluid tank? It took me a few tries to get it all out. Maybe you have air trapped in the lines?

yea they have pointed out could be bypass valve but said its normal to hiss like that.. i don't understand why it is loudest at idle (1krpm) when it disappears above 1.5k or below 800rpm

so far no one from JRSC or my shop offering solutions, they said wait til after 100miles, which it did and still sounds same.. (now said wait longer)..

what tweak we can do on the bypass valve?

I did nothing since the shop did the work. i don't think they need to touch the ref compressor during this install, and I am 1000% certain my car did not sound like that before it went in.

brand spanking new order from JRSC, directly to the shop that installed it.

If something happen, then shop is liable least. They said its normal lol

Sent from my SM-S918U using Tapatalk

Sorry I didn't mean to imply that it is the compressor making the sound, I mean that the sound you have sounds like that for some reason. Honestly I don't know what a rotrex sounds like that is low on traction fluid but that is the only thing I could think of.


I'm not sure how the shop installed it, but if they gave you back any traction fluid it probably wasn't bleed right. It took the whole bottle for me to get a good bleed out. What does your dipstick read?

let me check that today and see if its low.

It could be that I'm just some idiot following their instructions, but when I followed the install guide, I had probably 1/3rd of the bottle left. I did a lap around the block and was at the bottom of the dipstick, and topped it off exactly to the full line. Drove some more and it was a little below full so I let it cool, cracked the bolt open to bleed it just a tad and poured the last little bit from the bottle in. It has been fine ever since. I'm actually slightly above the line now, which I think might be from thermal expansion.


I figured they gave you exactly how much you needed + whatever they figure an idiot like myself would bleed. That stuff is expensive.

looks like they have a page of instructions how to check the oil level, i want to assume they did it as instructed, but i'll find out when i drive out today. i guess the question would be, is the excessing whining noise coming is usually the sign of low Rotrex fluid?

you have to have help checking the oil have to rev to 2500 and have someone check the fluid

so i followed the last page of the manual to check the fluid, revved for a min at 2k rpm, then jumped out to check it, it was pretty much at max. but as i continue to check it through out the next min, it drops rapidly down to minimum, but Not empty.

I presume that's the part about the oil will dissipate out of the reservoir quickly mentioned on the manual as to how to check it..

i don't think i need to keep the foot on the pedal at 2k RPM while someone else open the reservoir right? i feel like that would spill out as the oil is rushing into the can?

Lastly, is the assumption that the reservoir should not be "Empty" during idle? cuz i assume if its empty you will likely get air bubbles into the supply line as the oil coming in from the return..?

What shop in San Jose? Lived there 55 years, so curious.

Hate to say, Sounds like mine when it died. If so, it will get louder and louder in the next couple weeks.

i won't say the shop for now since its all speculation, they are willing to help but so far JRSC is not giving any helpful resolution other than let me send the Rotrex unit back to them and they can have Rotrex check it for a nice $350 if there's nothing wrong with it, replace if it's bad.

but so far what im getting at it may not be the Rotrex unit making the sound, could be from other things..

block the pressure source of the bypass valve so that inside remains closed (should be).. pinch it with your fingers
does it still whine?

also i d be curious for a video of engine bay while revving stationary

according to Jackson racing yes you have to keep the revs up to 2500 while someone is checking it i ask that question also because i was interested in how to check the level as well

also push in on the clutch see if it goes away

will try this and check, but looks like it is enough since even when i let off the gas within 10 seconds still shows at max.

clutch doesn't affect the noise.

Sample set of 2 cars with jr sc...both does not sound like that at all.

try to pinch the vacuum hose and see if it disappear when bypass valve is forced closed.. Attachment 219591

ok let me try that today, fingers crossed!

did that today, doesn't appear to make any difference. it feels like coming from the pulley/belt area.
i'll need to have someone rev it while i sniff around the engine bay.

Call me crazy but in a situation like this where something clearly isn't "right", and you are not satisfied, shouldn't the shop that did the install be doing all this legwork/testing/investigating until the source of the issue is identified and resolved?

It just feels somewhat frustrating to me, like the shop isn't standing behind their work. I'm sorry that you're going through all this hassle and headache.

i totally agree with you, but as i mentioned before, JRSC is claiming this is "normal" sound and IF i want to get it checked out, they can send my Rotrex unit to Rotrex for analysis, if no issues found they charge $350.

the shop is basically going with what JRSC is saying and said they can swap out the unit for me, but it sounds like the source of sound still not quite determined, and the shop is not really bothered to really do much since they said they installed as it was instructed. (also it's an hour drive so im trying to gather more information before I take the car up (since i am not sure why they can do for me)

If it were me I’d get some written confirmation by the shop that you should drive it some more and see if it goes away.

Otherwise it’ll be too easy for them to say « well you should have brought it back immediately so screw our liability ».

Try a DIY mechanics stethoscope (or a real one, if you want to splurge) - a long screwdriver or other long piece of metal that you can place against suspected sources of noise and press other end near your ear (for bone conducting the sound). Of course be extra careful around moving belts and pullies (even more so if you have long hair/beard/jewelry/loose clothing)!

good idea, will do thx!

Quick update,

today i took the air filter off while the car is idling and had my friend rev it above 2k rpm, i can clearly hear the sound coming from the Rotrex unit, so I believe the source is identified, I have emailed Rotrex (just realized they in Denmark) couple of days ago with the support comment from my shop and see how it goes. Fingers crossed.

but when you rev it it disappears? it s only present under 2k rpm?

800rpm to 1500rpm is most prominent, outside of that band the sound is minimal.

Alright ladies & gents, here's a quick update on my investigation on the loud whining noise on my JRSC system:
Thanks for couple of nice dedicated FT86 members who was nice enough to meet up with me to show me their JRSC systems and how they sound, i was able to figure out how they measure up compared to mine.
We had 3 BRZs with JRSCs, one C30 kit and 2 C38 kits.
I attached 2 videos of the idle (5-10 mins after cold start)

1. with sound meter:
https://youtube.com/shorts/TSE3zHZAv8o?feature=share

2. no sound meter
https://youtu.be/4-vjGp_ma3g

Right off the bat i noticed the C30 kit was much quieter (83dcb) than the C38 (idle 1kRPM), and the C38 on mine was about (93dcb), while the other C38 was the loudest (98dcb)

Both of my friends BRZs have modified headers just FYI, I don't believe it has much weight on the sound of the whining (all 3 cars idle same range), but the obvious part was that the C30 Rotrex looked smaller than C38, I wonder if that's the reason.

With the hood closed the C30 you can hardly notice the whining noise (it's what i recall as my previous encounter with JRSC owners), as for mine and the other C38, both of ours you can definitely notice the whining even with the hood closed.

So far neither one of my friends had any issues with their JRSC and seems to perform as expected...

My questions for the forum are:
1. C30 vs C38 differences, does anyone know? on JRSC website both kit description are verbatim except the part number of the Rotrex and Billet bracket.

2. C38 owners - is your whining noise most noticeable at idle 800-1500rpm?

3. Anyone can explain why it is loudest in that range? I emailed Rotrex still pending response.

Lastly, i also want to thank Stacyu18 for troubleshooting with me over the phone for hours trying to see if everything was installed correctly, you rock!

c38 is bigger but with a different internal ratio between its gears. it spins less with the same pulley compared to c30 but moves more air anyway... one of the advantage is cooler charge air

potentially if you put high pulley into the c38, it becomes a beast and will snap your rod pretty quickly)

it sounds like i should have gotten the C30 for the same hp gain/performance without having a bird living under the hood, not to mention i save $100!

i don't expect to make more hp gain upgrade that will further stress the engine.

just odd there's no difference between the kit performance wise? C38 has more potential for upgrades?

cooler air is good and all but if both can do the same, why have 2 kits?