`sl!mXP

I recently installed a bonez midpipe to complete my exhaust system (Bonez DP, midpipe, and exhaust) and it went smoothly, however two days after the install I was doing some spirited driving and I believe I stuck my blow off valve.

The car idles and drives perfectly fine until i hit boost. When I get on full throttle and boost the sound of venting air is louder then the exhaust. It literaly sounds like someone spraying a can of compressed air or something.

A cursury look shows all my hoses still intact around the area that the sound is coming from (Sounds like top passenger corner of the hood) and Im pretty confident the exhaust is not leaking. My dad also noticed the bov opening somewhat when revving it at idle - even though my boost gauge was reading vacuum.

It sure sounds like the BOV is the problem but I just want to be hear from some of the more experienced rotory owners before I throw down $200 on a HKS or something. The bov I have appears to be the standard twisting top ebay special installed by the previous owner.

Thanks for reading guys - any input would be appreciated

(Car = 2/3 streetport, recent [<10k] rebuild by rotorsports, bonez dp, mp, exhaust, apexi pfc tuned by rx7store, and m2 ic)

FDNewbie

iTrader: (10)

Sounds like you have a boost leak to me. First things first, make sure the motor is warm, and w/ the car in neutral and the hood popped open, pull on the throttle cable/bracket to rev the motor (ie rev the motor from the engine bay while you're standing at the engine bay). Turn it HARD, hard enough to generate boost. You'll be able to hear the hissing noise of the air escaping from wherever it's escaping from. If you're lucky, you'll see/feel the burst of air off the bat. If not, do it a few times until you can localize where it's coming from. You should be able to then tell if it's coming from a hose/coupler, or shooting out of a blown BOV.

~Ramy

cohbra

iTrader: (13)

Can the problem he described also occur if he has too light of a spring in it causing the boost pressure to overcome the spring before the vacuum line actuates it?

RaPtOr-T

Thats how I found my leak, although IMO it would be easiar if you just had your dad hit the pedal so you can concentrate on the leak. I doubt you would see a leaking hose just by looking, my y pipe coupler had 2 rips, one going almost completly around the coupler and I didnt know it was leaking until then. Even once I knew it was the part it was hard to see the damage before taking the entire airbox out. I doubt the BOV would be the problem, probably opening up all that exhaust increased boost a little and finally pushed something that was barely holding over the edge.

FDNewbie

iTrader: (10)

While that's possible, that wouldn't account for the sudden appearance of the problem (which I think it is).

d1rx7

if the bov can be adjusted try that, as they do come lose after time, and then it doesnt take much pressure.

`sl!mXP

would a hole in a hose make a noise this loud though? It seriously almost drowns out my exhaust which is a bonez dp, mp, and just the bonez muffler for sound reduction.

FDNewbie

iTrader: (10)

Yes. Plus, it's not just about which is louder. It has to do w/ the pitch and proximity too.

Don't guess and wonder...go try and find out

~Ramy

DaleClark

iTrader: (55)

Yeah, check your Y-pipe coupler first. You have to take it off the car and inspect - a visual inspection won't cut it.

Ebay blowoff valve? Throw it in the trash. If nothing else, get a good used stock blowoff valve - flows great, awesome response, very reliable, and you can get a used one cheap. Not to mention it makes tons of keen wooshing noises.

I just wouldn't trust a cheapie BOV for long-term use. Sticking open is one thing - sticking closed can cause turbo damage. FD's deserve better parts than that.

Dale