RX7LINK

iTrader: (3)

I tried all types of keyword in the search but couldn't find much... so if anyone have a link or any info please help me out..

I was on my 1 hr drive to my parents house over the weekend and on the freeway my primary turbo started fluttering when i'm on boost... more noticeable at low/light boost and less but still noticeable at WOT before secondary turbo kicks in. 2nd turbo sounds normal with smooth spooling sound.

at first i thought it was boost leaking, and sure enough my stock y pipe cupling was loose and worn, so i replaced it with a new 3ply one and new clamps. i checked and tightened all the clamps on the IC pipings... but on my way back i still noticed the fluttering while the turbo is spooling... less noticeable.. but i can still hear it from inside the car.

my boost patterns are still the same, set at 12 on the EBS3 (.82 bar) boost creeps to .86bar but pretty consistent overall on primary and secondary..

does that mean i still have a leak somewhere? or is my primary turbo going out (need new bearings..etc..)? am i going to need a replacement ? anyone had similar problem/symptom that can help me out w/ some info please?? thanks in advance

adam c

iTrader: (2)

If boost holds at 12, you probably don't have a leak.

RX7LINK

iTrader: (3)

any chance of the boost leaking and the ECU raising the boost to compensate to correct Map sensor reading??

so if it's not leaking boost, does that mean my prim turbo's going out soon or is there other possible problem from this symptom?

when turbos "goes out" what exactly does happen??

Fritz Flynn

iTrader: (263)

Boost will get slower and slower and more and more irregular as the compressor wheel becomes increasing loose and out of balance it will damage the oil seals and you'll start smoking under boost. Finally it will get so loose it starts hitting the sides of the housing and make lots of noise and that's about the end.

Sounds like a bad primary turbo to me.

Usually when it's making the whistling dental drill sound it's the just a nick in the compressor wheel itself and you could drive for a long time depending on the damage but when it's fluttering it's usually a result of lots of play in the wheel which leads to poor performance smoke etc...

RX7LINK

iTrader: (3)

damn... i love my stock sequentials.... looks like i need to decide on seq BNR or 99 efini ...

thanks so much for info

DaleClark

iTrader: (55)

I'd also make sure the factory BOV is hooked up right. If it's not, you'd get compressor surge, which makes all kinds of weird noises.

No reason to freak out - good stock twins are relatively inexpensive (about $150-300) and aren't too hard to swap out. If you love your stock twins, just get some more . But, rule everything out before you get too excited.

Dale

mad_7tist

make sure the crv is venting. especially if the sound goes away after 4500 rpms (switch over point)

that said when the turbos do go bad they will sound like your description also, just hoping for the best

NAN777

i got that problem before.... it ended up to be the BOV's triggering vacuum hose is folded and blocked clampped in between other parts. causing my BOV to be opening and closing simultaneously.... the boost pattern is still the same.. but the sound is very different... sometimes it gives me a little jerk depending on how big the BOV opens.

RX7LINK

iTrader: (3)

its definitly not the bov or vaccume line... i swaped out my blitz sus intake for the HKS RS intakes this weekend, switched out all the vacume hoses to hard silicone ones and all other hoses connected to the air filters. none of the vaccume lines are cramped or touching...

yeah, i understand when turbo surge, that sound comes from releasing the gas and the flutter sounds more like a turkey gobble... my BOV/CRV holds the boost pretty well until i release the gas.. and i get a loud and crisp ppssssshhhhh

just when i hold down gas and the turbo's spooling i get this flutter that sounds like turbos are stuttering..

but i think Fritz is right... if i gradually engage the gas and intentionally try to let it spool smoothly, it does kinda sound like a dentist drill a little bit.. different than how turbo whistles normally sound.... just it gradually turned that way i didn't pay much attention cuz it pulls pretty well and boost reads ok...

i just love the sequential part of the stockk turbo... not the size or the HP output... =P i'm leaning more towards seq BNR atm.. i just hope these turbos will hold on till january after this freelance job is over....

CantGoStraight

You still running your air pump ?

RX7LINK

iTrader: (3)

nope, air pump removed with block off plate. running greddy pullies... why do u ask?

NAN777

in that case....maybe your primary is fucked..... the fins are grind off by the sands or metal dust. or even apex seal chipped off a little and gone into your turbo fins grinding them to fine metal dust.

magic dust ala apex seal

RX7LINK

iTrader: (3)

magnetic drain bolt and oil filter magnet FTW !