compressor surge FTW?!?!

[clutch kick drifter]

http://videos.streetfire.net/search/...8250795ac2.htm Is this all compressor surge? Answer this question.... does he have a blow off valve or not?

[McRussellPants]

It sounds like it has a BOV but its sprung to tight.

The most baller sounding 240SX ever was the Falken S15. nothing but the beautiful sound of ass raping the bearings out of a 3071.

[Nachtmensch]

why was his motor smoking?

[clutch kick drifter]

Originally Posted by McRussellPants

It sounds like it has a BOV but its sprung to tight.

The most baller sounding 240SX ever was the Falken S15. nothing but the beautiful sound of ass raping the bearings out of a 3071.

HEll YEAH!

[clutch kick drifter]

Originally Posted by dc2_lsvtec

why was his motor smoking?

cuz SR's suck

[redsuns3838]

sounds like hes getting some blow off but its too tight. But some track cars dont run them because they dont care about turbo life that much, and would rather have preformance benefits instead. Just depends on how much $ you have to spend.

[derk]

the motor wasnt smoking.

it was the sprayer for the intercooler, i forgot wether it was water mist or nitrous that the used though.

but it isnt smoke thats for sure

[clutch kick drifter]

my question is though where in the hell do you benifit from surge? Pretty sure it dosnet make the turbo spool any faster does it?

[GSXRJJordan]

This is something that not many outside competitive drifting know about - very few cars use blow off valves.

That sound you heard is compressor surge ~ a BOV really only vents once, maybe twice if you've built up a lot of pressure. Whenever you hear the multiple 'pssht' sounds, that's compressor surge. The Formula D car I worked on was a lot like the Falken S15 mentioned above - RB25, GT3076, and no BOV. The newer GT30R series turbos have special vanes around the compressor intake to relieve a little bit of the surge and to make the compressor surge sound even louder, which is what everyone wants, cause it puts V8's to shame =D

Anyhow, from a performance standpoint, no BOV means your hotpipe/intercooler stay charged with pressurized air, so your throttle response is 'better'. I put 'better' in quotes because I never enjoyed the jerky feeling, I like to build power in a drift, let off, and have a second to build it back up again, but whatever. From a competitive DRIFTING perpective, it's all for the crowd - people love hearing turbos.

That's all. Put that SSQV back on, you dont have 3 spare turbos that Garrett bought you sitting on a shelf in your shop. Keep your bearings/seals in good shape.

[clutch kick drifter]

^^ thanks man

[spoolin_s14]

sounded like a revlimiter and a hks ssqv to me? my car does the same at lower bost

[HalveBlue]

^^Same here.

Although, I don't know about the rev limiter part, since I don't have one.

And since the newer SSQVs aren't adjustable, even if it is too tight you're SOL.

[McRussellPants]

I ran no BOV on a T25 for a year or so and it didn't shit its pants.

I'll be doing the same on a bb T28.

Compressor surge rules the day.

[hellion240sx]

not trying to promote this bov, but very useful info...

http://videos.streetfire.net/search/...3f0150f005.htm

+1 for me

[Team Rootbeer]

Originally Posted by McRussellPants

I ran no BOV on a T25 for a year or so and it didn't shit its pants.

I'll be doing the same on a bb T28.

Compressor surge rules the day.

welcome to the club.

mine shit out on me along time ago, and i just took it off and welded up the pipe. fuck that noise.

[chibo]

Originally Posted by hellion240sx

not trying to promote this bov, but very useful info...

http://videos.streetfire.net/search/...3f0150f005.htm

+1 for me

Hm, that seems kinda neat. Research time

[sbanzer123]

Originally Posted by JeffMilano

This is something that not many outside competitive drifting know about - very few cars use blow off valves.

That sound you heard is compressor surge ~ a BOV really only vents once, maybe twice if you've built up a lot of pressure. Whenever you hear the multiple 'pssht' sounds, that's compressor surge. The Formula D car I worked on was a lot like the Falken S15 mentioned above - RB25, GT3076, and no BOV. The newer GT30R series turbos have special vanes around the compressor intake to relieve a little bit of the surge and to make the compressor surge sound even louder, which is what everyone wants, cause it puts V8's to shame =D

Anyhow, from a performance standpoint, no BOV means your hotpipe/intercooler stay charged with pressurized air, so your throttle response is 'better'. I put 'better' in quotes because I never enjoyed the jerky feeling, I like to build power in a drift, let off, and have a second to build it back up again, but whatever. From a competitive DRIFTING perpective, it's all for the crowd - people love hearing turbos.

That's all. Put that SSQV back on, you dont have 3 spare turbos that Garrett bought you sitting on a shelf in your shop. Keep your bearings/seals in good shape.

i dont know if i agree with that. because when you run no bov, and your compressor surges. when you step on the throttle again your starting out with a turbine that isnt spinning or is spinning in the opposite direction. so that to me would seem like it would take more time to get spooled up again then having a spinning turbine and half empty intercooler piping, because not all the air in the piping is vented out. just my .02

[misfitsfreak81]

Originally Posted by sbanzer123

i dont know if i agree with that. because when you run no bov, and your compressor surges. when you step on the throttle again your starting out with a turbine that isnt spinning or is spinning in the opposite direction. so that to me would seem like it would take more time to get spooled up again then having a spinning turbine and half empty intercooler piping, because not all the air in the piping is vented out. just my .02

i absolutely agree. compressor surge is when the charged air in the piping comes back and "hits" the compressor momentarily stopping or even reversing the flow. this is not something that you typically want, and is arguable as to any performance gain or not. anyone that hears this and doesnt have a couple spare turbos should cringe with fear.

[chibo]

Originally Posted by misfitsfreak81

i absolutely agree. compressor surge is when the charged air in the piping comes back and "hits" the compressor momentarily stopping or even reversing the flow. this is not something that you typically want, and is arguable as to any performance gain or not. anyone that hears this and doesnt have a couple spare turbos should cringe with fear.

Compressor surge being a performance gain is the dumbest shit I've ever heard in my life; who ever said that should go read Corky Bell's book rather than listen to what 'professional drifters' have to say.

[annie4rb20]

Originally Posted by misfitsfreak81

i absolutely agree. compressor surge is when the charged air in the piping comes back and "hits" the compressor momentarily stopping or even reversing the flow. this is not something that you typically want, and is arguable as to any performance gain or not. anyone that hears this and doesnt have a couple spare turbos should cringe with fear.

+1

On the importance of BOV's..

"The pressure spike can also throw the compressor into surge, which can cause it to overspeed and damage the wheels by causing them to bend or even burst. Severe surge will fracture the compressors blades. Spinning at 120,000 rpm, even the slightest unsymmetrical weirdness in a wheel can cause it to burst explode. At best the pressure wave will drastically slow down the spinning turbo causing a loss of power, as the turbo must respool to re gain boost pressure after the shift."

From Mike Kojima himself... Nissan Performance Mag

[hellion240sx]

so how do you eliminate comp surge?or is that something that you have.

[McRussellPants]

Originally Posted by chibo

Compressor surge being a performance gain is the dumbest shit I've ever heard in my life; who ever said that should go read Corky Bell's book rather than listen to what 'professional drifters' have to say.

lol, Corky Bell.

Or I could go out and drive my car with no BOV and like it.

PS, thanks for bumping this shitty thread so you could play Mr. Engineer since you read some shitty 100 page picture book from the 1970s.

so how do you eliminate comp surge?or is that something that you have.

lol.

[upSLIDEdown]

A good friend of mine has run without a BOV on all of his SRs. Never had a turbo blow. Granted he has sold them all fairly quickly too. While compressor surge will shorten the life of the turbo, it will NOT do so in 5k miles. It does cut down on turbo life, but not by leaps and bounds. Plus, from what I've been told, it isn't that expensive/difficult to rebuild one; granted I've never had to do it, so I wouldn't know.


P.S. Surge still sounds FUCKING BADDASS!

[chibo]

Originally Posted by McRussellPants

lol, Corky Bell.

Or I could go out and drive my car with no BOV and like it.

PS, thanks for bumping this shitty thread so you could play Mr. Engineer since you read some shitty 100 page picture book from the 1970s.

I wish you luck, good sir.

[clutch kick drifter]

thanks for the responses.

[Ca_laurier]

wow that totally sounded like mad compression serge. i was running a gt28r and had a sard high boost bov that was to tight and it sounded exactly like that.

This year i am not running a bov for a bit but thats on a crappy ca t25 so i could give a rats ass what happens to it, just gives me a reason to upgrade and than i will consider a bov

[white97s14]

Originally Posted by hellion240sx

not trying to promote this bov, but very useful info...

http://videos.streetfire.net/search/...3f0150f005.htm

+1 for me

i like that bov but i will always love the hks

[codyace]

Originally Posted by McRussellPants

PS, thanks for bumping this shitty thread so you could play Mr. Engineer since you read some shitty 100 page picture book from the 1970s.
lol.

IIRC Maxium boost was published in the mid to late 90's...but who's checking?

Originally Posted by upSLIDEdown

A good friend of mine has run without a BOV on all of his SRs. Never had a turbo blow. Granted he has sold them all fairly quickly too.

Why bother making the point when you have no long term information. Megan Racing manifolds are good too for at least 100 miles...

Originally Posted by upSLIDEdown

While compressor surge will shorten the life of the turbo, it will NOT do so in 5k miles. It does cut down on turbo life, but not by leaps and bounds.

You bet your behind it could kill a turbo in 5k miles. If you actually abuse the shit out of your car, it could...undoubtedly.

Originally Posted by upSLIDEdown

Plus, from what I've been told, it isn't that expensive/difficult to rebuild one; granted I've never had to do it, so I wouldn't know.

If you don't know, then don't post it. This is how mis information gets spread. Rebuilding a ball bearing turbo is NOT cheap/impossible...if you chuck one, you're usually out the 600-800 a replcament CHRA costs you on a GT series b/b turbo.






I run a BOV because i'm a girl., and can't afford replacing turbos like they mean nothing. I've realized that being 'baller status' on a forum usually makes you look silly to 95 percent of the rest of car guys....

[clutch kick drifter]

^^^ !!!! YES , PUt them to shame. Baller status is the way to go ! lol

[upSLIDEdown]

Originally Posted by codyace

Why bother making the point when you have no long term information. Megan Racing manifolds are good too for at least 100 miles...

I wasn't making any particular point, just giving some input from my experiences.

Originally Posted by codyace

You bet your behind it could kill a turbo in 5k miles. If you actually abuse the shit out of your car, it could...undoubtedly.

Again, from my experiences, it hasn't. I've seen him go through at least 3 cars running them this way, all of them definitely longer than 5k miles. Saying it COULD is worthless, because it just as easily COULD NOT. That's like saying you could die in a fiery car crash tonite, you just as easily could not.

Originally Posted by codyace

If you don't know, then don't post it. This is how mis information gets spread. Rebuilding a ball bearing turbo is NOT cheap/impossible...if you chuck one, you're usually out the 600-800 a replcament CHRA costs you on a GT series b/b turbo.

Again, that's the reason I said I didn't know. I'm probably gonna run a BOV, but I haven't fully decided yet.

Originally Posted by codyace

i'm a girl.

At least you can admit it... Relax, I'm just kidding with you man. Like I said, my post was from my experiences. If I don't know something, I'm sure as shit not gonna tell you it's the truth. I was actually also told by another good friend of mine that had and EVO, that when he took his BOV off alltogether, the car's driveablility was a LOT better.