MazdaManiac

iTrader: (3)

Party-pooper!
However, this won't violate your warranty since it isn't a material modification of the drivetrain.
Furthermore - there should be no perceived difference between warranty work and cust-pay work from the perspective of the tech, so I don't quite understand what you are suggesting there.
Where are you a tech and what are you doing here?

Xyntax

What's the worst that could happen mazdaspeedtech? Don't flame the party-pooper guys, this is the reason why I'm posting my experiments. I'd like to get suggestions as well as warnings from the experts. I've been waiting for someone to study our 6-port intake feature, yet everyone's so stuck on trying to get gains off of bolt-ons. Buying expensive bolt-ons will only get you so far. Understanding what you're working with, will get you further.

MazdaManiac

iTrader: (3)

Whenever anyone says "voided warranty" a flag goes up.
It is a violation of the warranty contract to deny warranty coverage on unrelated issues.
If I want to pull my VDI, you can't void my warranty for my headlamps.
If someone at your dealership has told you this, you have been scammed.

Xyntax

Just an update for the curious. I took advantage of the open freeways during Thanksgiving night. I did an open VDI first, logged the run. Unwired the vdi to keep it closed, logged the run. And then I plugged back the VDI solenoid connection, logged the run.

Here's the chart:



...notice how the Open VDI (red) gives less airflow? Yep, like I guessed, it's a bad idea. I like the closed VDI better. No 7250 RPM dips like the stock setup.

ps. I still think my Aux ports aren't opening, because of the lack of jump around 6500 RPM.

rotarygod

I need to go think about this. Something isn't making sense to me.

rotarygod

The blue and black lines are close enough to basically be considered the same curve. I understand that the red VDI open full time line should be lower than the other 2 but it would only seem to make sense if this was below the 7250 rpm opening point only or at least near to that point. What doesn't make sense to me is the fact that at the spot when the VDI does open stock, the black airflow line doesn't change to basically mimic the red line above that rpm. It still stays with the blue line. That doesn't make alot of sense. Something is telling me that the mass airflow reading ability isn't telling you the whole story when it comes to power. Is there a way you can do any timed runs within a certain speed range and then compare numbers?

Xyntax

I went back to my logs and calculated the time it took from 6000 RPM to 8500 RPM. Sorry, I don't log MPH anymore since I've been logging STFT/LTFT at every run.

Here's what I found:
- VDI open = 5.318 seconds
- VDI close = 5.137 seconds
- VDI stock = 5.277 seconds

...hope this helps. These runs were done in 3rd gear at WOT from 3500 RPM to redline. Insomniac aren't we?

r0tor

iTrader: (1)

...but the VRIS system was very effective at screwing you when it got stuck closed

real resonance tuning sounds nice on paper, but usually fails to make big gains in reality because the air stream (especially in the intake) is not full of nice uniform and distinct pressure waves - but instead composed of a turbulent mess


slightly off subject rant... they got waaaay to cute designing the intake manifold. This is the only car i have ever seen that to replace a secondary valve requires removing the lower intake manifold which REQUIRES REMOVING THE ENGINE and TRANNY. I'd hate like hell to foot that bill if not covered under warranty

rotarygod

You don't have to remove the engine to remove the lower manifold. It's just not too fun to get to some of the bolts.

Xyntax

Update: I filled up a tank tonight and decided to unplug the VDI while waiting for the pump to finish. I had left it the way it was during my tests, in which the last test was with the VDI stock setup. Well, I reached in and found the plug to be lose. It wasn't even plugged in. Soooo, this may be why the black and blue lines were following the same pattern. They were both VDI-closed runs. I'm gonna have to do this all over again. Sorry...

rotarygod

That makes sense.

r0tor

iTrader: (1)

well, mazda says differently as well as 4 mechanics that tried getting it done without doing that.

The problem is not the bolts, the problem is the clearance between the manifold and chassis and taking an intake manifold out of the side which has 6" long tertiary ports that go into the engine.

dannobre

iTrader: (3)

The shop manual says to drop the engine, tranny, and front suspension, crossmember as one unit out the bottom of the car.......to remove the intake tract......

Sapphonica

I have a GReddy kit & boost controller and am working with a tuner to get the most out of my 8 without popping the engine again.

It's been ported, and is using a skunk works standalone ECU that will allow us to control the secondary & tertiary ports.

Theoretically, we should be able to get more power at mid rpms by increasing the mass flow rate via tweaking when the ports open.

Has anyone actually tried this yet and/or have any substantive information to share before I charge in as the 'crash test dummy'?

Thanks.

Xyntax

^ I guess you'll have to be the crash test dummy for this :D

Read up on the SAE tech paper about intake tuning for previous RX-7s or the 787B. That really helped me a lot about understanding how to approach intake port timing.

Sapphonica

Thanks, Xyntax.

Where can I find the SAE tech paper online?

Thanks again.

Xyntax

I can't find the link where I downloaded them. Possibly from nopistons or barotary. I have uploaded all the tech papers concerning RE on my site. Please abide by the Terms and Conditions before downloading.

http://www.deanq.com/stuff/rotary/

sburkett

VDI works exactly as described by Mazda (I happened to test this the other night). Dyno sheets here:

www.tuxedoparkracing.com/vdi

Hope that helps.

Steven

Xyntax

Awesome sburkett! Thanks for sharing! I guess this closes the experiment then :D