Sequential blues
 

This is more of a rant than a question, but I need to let it out.

Vaccum lines are your enemy. This Friday I went to the track (anyone been to Mo-Kan?) and embarassed myself. The source of my embarassment - a turbo control system that's reluctant to produce more than 5 psi on the track.

On the street I'll see a full 12psi of boost, sometimes less, and sometimes the secondary doesn't kick in, but I don't understand why I had these severe problems only on the track. The only difference I see is the drag-style launch and full throttle. On the return road, I can give it about 80% throttle and it'd boost right up.

I've decided I'm going to order hosetechniques.com's kit unless anyone knows of a better source for silicone vaccum lines.

go big single turbo and have 4 Vac lines

That's what the 90 is for, I ran out of vaccum caps when installing the engine. The FD is my daily driver that I plan to keep mostly stock.

That reminds me, I need to update my signature.

If you're really sick of having vacuum line problems, check out the 60 durometer Viton tubing from McMasters. The tubing is more expensive than silicone, but is resistant to oil and gas, and resists knicks and tears much better. The cost of tubing is about the same as the Hose Techniques kit, but you'll have to use your own cutters. You also will not need to use zip-ties except for a few hoses. Check out www.maxcooper.com for more info.

Just seems like Mazda was smoking something. They could and I say could have made a one part Vac housing with all the control in it. Like a auto trans control housing but with Vac not fluid. It could work and make the car soooo much more.

Don't get me wrong cause I'm no expert, but when I look in the engine bay I start thinking it looks like the inside of an old vacuum tube radio before transistors were invented. You would think that all those hoses that are used just to get the second turbo kicking in at the right time could be "transistorized" wouldn't ya? I mean would someone explain why there is so much hardware to make "decisions" (e.g. if this pressure hits this point then this solenoid opens this hose which then causes this pressure to drop, etc. etc.). Couldn't the decision trees be made with pressure sensors and leave it to some software to scamble through the decision tree? As it is now, this system has to be optimized for it to work at all. You cannot have a leak in a hose. Period. It would be nice to replace all those hoses with a chip. Am I making sense?

BTW, if someone came up with a "black box" idea that allowed everyone to both keep their twin turbo setup AND get rid of all the hoses, they could make a lot of money because Rex owners are fanatic and would buy it if it worked.

As much as I'm horrified when looking at the rat's nest, Mazda actually did some impressive engineering. Don't forget that the sequential system on the FD was the first in the world. They paved the way for cars like the Supra Turbo and 911 Turbo. Also, this car was designed in the late 80s and very early 90s. The computing power available for use in cars at that time was very primitive.

This post is funny as I've been thinking a lot myself lately of why they couldn't make it much more of an electrical process instead of a mechanical one. Just rembember that even though it seems ridiculous and Mazda made mistakes, some of the engineering is just damn impressive.

Hmmm...
 

finding the right parts is one thing, but installing them is another. Just remember that ONE KINK HOSE can throw the whole car in a loop, such as boost problems. Make sure that all your lines are secure and not kinked.



see ya,

car 53:cool:

GO with hose tech!!!! it is good stuff. also when the sytem is in good working order it is sick!!!take your time and be very easy on that old hose if you get into a jam or get stumped call me!i have done a billion ty-rap jobs 301-370 0567
ryan:cool:

OK, I grant you this, but it seems to me that the whole rats nest could be ripped out and a computer put in. Every single one of the "decisions" that are made by the mechanical hoses could be made by a chip. The ECU was advanced enough, what am I missing in the engineering process that this couldn't have been extended to the whole process of the sequential turbos?

I don't get it.

BTW, does the Supra or the 911 have a rat's nest? Or is it more refined?

It seems to me that, short of converting to single and its inherent 4 hose vacuum setup, someone could map out the system, deep six the rats nest completely, and interface with the ECU. Can you imagine walking out to your FD and ripping out all the hoses and bolting a box with 3 or 4 electrical connections and 4 vac hoses...and that's it!!!! Man....tell me where to sign up.

Well, actually, the computer does do all the decisions. But like a human, how effective is a head without a body. All the hoses and actuators are the lims of the ECU. The ECU controls when they move. Yes, the computer doesn't control boost by monitoring and acting, but it does control the process. Ideally, if you remove all the emissions crap hoses, you are left with just a few components. I do think that Mazda should have made the Turbo Control Actuator an electric motor instead of vacuum actuated. This would have saved them a bundle of money in warranty crap, not to mention made a pretty solid car. Same goes for the Charge control actuator.