'90 Mazdaspeed Miata Rallycross Project

92CelicaHalfTrac wrote:

DaveEstey wrote: Recirculating BOV solves the noise problem.

Mayyyyybe. Depends on the valve. My MSM is set to recirculate, and it's still one of the loudest valves i've ever heard.

Maybe is right. The HKS SSQV on my Evo is terrible. It flutters like mad, and chugs the engine if you try to pass someone on the highway. It is recirc.

vooooooOOOOOOOOOOSSSSSSHHHHHHHH!!!!!!!! PPPPSSSSHHHH!!!! GOBBLE GOBble gobble gobbble....

Get a TIAL recirc, but make sure you get a legit one (use a spotter's guide), and you'll be quiet and happy.

J308 wrote:

92CelicaHalfTrac wrote:

DaveEstey wrote: Recirculating BOV solves the noise problem.

Mayyyyybe. Depends on the valve. My MSM is set to recirculate, and it's still one of the loudest valves i've ever heard.

Maybe is right. The HKS SSQV on my Evo is terrible. It flutters like mad, and chugs the engine if you try to pass someone on the highway. It is recirc. vooooooOOOOOOOOOOSSSSSSHHHHHHHH!!!!!!!! PPPPSSSSHHHH!!!! GOBBLE GOBble gobble gobbble.... Get a TIAL recirc, but make sure you get a legit one (use a spotter's guide), and you'll be quiet and happy.

Mine WORKS fine, but it sounds like i'm making eleventy billion horsepower at all times and it's releasing the pressure of a GT45R pushing 50psi.

Instead of a tiny IHI pushing a whopping 11-12psi making ~250hp.

I never had problems with an adjusted (with a hammer) recirc on my 330+hp Legacy GT.

DaveEstey wrote: Recirculating BOV solves the noise problem.

Throwing the device into the dumpster also solves the problem.

(Yes, I hate those devices. Why throw away all the boost you just spent all that time trying to make? Neither of my turbocars had these things on them, and the world somehow failed to end. Both had IHI turbos on them, too)

Wait. Evan is in my class. I mean, uh, you want the biggest and riciest sounding blowoff valve ever!

Biggest and most ricer sounding? I have that covered.

EvanB wrote: Biggest and most ricer sounding? I have that covered.

Shenanigans. I guarantee I have you beat!

Oh yea? I challenge you to a blow-off.

That didn't sound right...

BTW: I have a HKS SSQV.

Knurled wrote:

DaveEstey wrote: Recirculating BOV solves the noise problem.

Throwing the device into the dumpster also solves the problem. (Yes, I hate those devices. Why throw away all the boost you just spent all that time trying to make? Neither of my turbocars had these things on them, and the world somehow failed to end. Both had IHI turbos on them, too) Wait. Evan is in my class. I mean, uh, you want the biggest and riciest sounding blowoff valve ever!

It's somewhat common in japan to just let compressor surge do its thing as well. I'm thinking about trying it on the MX6 since the turbo is on its way out anyways.

Keep in mind that a bypass or a blowoff will help keep the turbo spinning. So instead of saying that you're "throwing away" boost, look at it as decreased spin-up time for the turbo when you get back on the gas after a shift. Better performance, not worse.

Clearly the answer is anti-lag setup.

yes, that's obviously a much better answer.

Keith wrote: Keep in mind that a bypass or a blowoff will help keep the turbo spinning. So instead of saying that you're "throwing away" boost, look at it as decreased spin-up time for the turbo when you get back on the gas after a shift. Better performance, not worse.

Call it a solid "it depends". I didn't notice that at all on my Subaru, nor on my Isuzu. No matter what, the turbo IS going to spin down when the engine is no longer providing exhaust gases, but a recirc valve just vents all the stored boost while not having one keeps it in the pipe for longer.

One thing people note is that the boost after a shift is instant if you eliminate the recirc valve. It's only there for noise reasons. My cars weren't that bad for noise, but my friend's XR4Ti has compressor surge that is loud and clear on my friend's cell phone.

(And if you wanna talk about a sloooow turbocar. 8psi boost just to gently merge with traffic? No thanks)

When the reflected boost spike hits the compressor going the other way, it slows the wheel considerably. More than just a coast down due to a lack of exhaust gas. And there still is quite a volume of exhaust gas coming out of the engine on a shift, the engine doesn't stop spinning.

Cleaned it up a bit today.

Pretty! Almost too pretty for a RallyX car...

Where'd you get the meatballs? I want a set!

Meatballs are easy. Tape and a spray bomb! Or, a piece of vinyl and a compass.

I agree, that's too pretty for RallyX.

I had a guy in Columbus make up the meatballs on his vinyl cutter.

It's not really that pretty in person, there are quite a few dents, the back end is tweaked a bit (maybe just the trunk lid) and evidence of areas resprayed. Although with some body work and a repaint it certainly would be too nice to rallyx.

Not many updates lately. I have done two events since I got the new engine in. There have been some overheating problems so I ordered a new aluminum radiator. Here is a picture from the first event.

And a teaser of what is coming up.

Here is some video from the morning runs on Saturday. I am on the left and Chris is on the right.

http://www.youtube.com/watch?v=QS5XLRuM0lc

"So, if this is the Answer to Everything, why isn't it number 42?"

Just wait till the next rallycross.

That looks like a caption contest.

"This thing sucks, why is it so much slower than a Rx-7?"

Needs more metal in the CD player region

Works for me, anyway.