Speedsteve

I have the Mazsport cooling mod installed, and the only negative side is (as with other members) that the idle speed drops when the fans turn on.

I had to do a pressure test this weekend to find a bursted Greddy pressure hose, and while doing this and some other stuff, I found out that one of the radiator fans is very hard to turn by hand.

It seems that the bearings are worn out. The other one turns perfect and stays spinning for a while.

I was just thinking : could it be that that fan draws a bigger current to go round putting a bigger load on the electric system resulting in the "idle issue" ?

I have to wait on some replacement hoses, if I can find them, to measure the current of both fans.

Maybe other members, who have the same issues, could check the state of their fans ?

I am sure the fans do have to be replaced on mine, the difference between the two is too big.

Another warranty replacement...

mysql101

both of mine spin freely.

if you create a vacuum leak, the idle issue is reduced by a large margin.

Speedsteve

Thanks Mysql.. will try that!

mysql101

if you hadn't seen it, here's what I did:

http://rotaryinsider.com/rx8-92.html

Speedsteve

That is great ! If you ever visit Europe ->

mysql101

actually I'm considering the Synapse Synchronic BOV as a better solution:

http://videos.streetfire.net/video/6...3f0150f005.htm

The BOV is open at all times unless boosting. You then recirculate the fitting to your intake tube. This means that when you're not in boost, the bov can suck in air directly from your intake, bypassing your turbo/intercooler, giving better throttle response. When in boost it closes up and functions normally.

mysql101

http://www.synapseengineering.com/ar...bov_manual.pdf

mysql101

i ordered the Synchronic BOV today

MazdaManiac

iTrader: (3)

Looks neat, though the narrator/writer of that video doesn't seem to understand how a BOV (or, in this case, the HKS SSQBOV) actually works since the vacuum signal is not what moves the valve.
BTW - the "flutter" you hear at the beginning of that video is not really "surge", per se.
Furthermore, I'd wonder about turbo sizing if I had a turbo that could surge at light throttle application at idle. That shouldn't be possible. They must be using a tiny turbine.

mysql101

I think having the bov open unless in boost is going to really help.. not just the idle, but getting the car moving too, since it can breath better.

We'll see when I get it...

Also a feature you'll like, MM ... overboost protection


Meanwhile... check out this rx8 clip at 3:30 mins in: http://www.youtube.com/watch?v=NnqsaDUBySA

MazdaManiac

iTrader: (3)

Breathe better? What does that mean? When you are off-boost, do you believe that the turbo is a restriction? I have a regular HKS SSQBOV on my car and I never stall or have serious idle problems. I just get the usual "dip" to 800 RPM with the A/C on full and all of the fans on full.

BTW - that is a "Synchronic" wastegate, not a BOV or recirculation valve featured in that video.

Also, I was looking at your evaporative purge bypass page, but I am having a real hard time telling what you have done by the pictures.
When you remove the purge line, where do the two sides go to? The nipple on the left comes from the purge solenoid and the one on the right goes into the intake manifold. What did you do with the "T" fitting?

The evaporative system expects a certain "volume" of vacuum at that port, based on the duty cycle of the solenoid, RPM and throttle position.

mysql101

when I'm off boost, I think the int-x would breath much better by having an OPEN bov that is recirculating to just after the MAF. This would allow the car to suck in air directly from the intake as needed, but the BOV closes up when it has boost.

When driving from a dead stop where the turbo isn't spinning much, while giving the car moderate throttle sometimes has a brief moment when the engine wants more air than it's getting, which is why the car sometimes feels sluggish. It doesn't happen on low throttle, and doesn't happen on WOT (likely because the turbo is spinning fast enough)

The link I posted takes one of the tubes that hook up to the intake pipe after the MAF (I used the jet air hose), and put in a Y splitter after a one-way-check valve. The other end then connects to the top of the intake manifold. It allows the intake manifold to suck in more air than it could normally - bypassing the turbo. It has completely stopped the issue of the car dying at idle (which happens only when the cooling fans are on high). When the fans are off, or even when I just have one fan plugged in, there are no issues at all. I had tried this test out prior with a smaller (standard sized) vacuum hose and it didn't stop the idle issues...

So right now the car can still idle rough (though it doesn't stall anymore). With a much larger source of air, I think it'll idle normally... I suppose I can test by just taking off my current BOV...


ps: I know it's their wastegate, I just though that car kicked ***.

MazdaManiac

iTrader: (3)

Interesting theory and it may work - but for the wrong reason.
If you are having a flow restriction at part throttle, it is because the piping is too small to begin with.

The bypass valve you referenced in the earlier post isn't designed to do that, anyway. It is designed to open when there is pressure in the charge pipe that is not being used by the engine, not provide bypassed air when the turbo isn't spinning fast enough to keep up with demand.

mysql101

hey, you know there are shorter ways to say "I agree with mysql101"

MazdaManiac

iTrader: (3)

Nice spin.
No, I was pointing out that you were killing the patient to cure the disease.