It's still up in the air if i'm going to keep my car or not, but i've had a question on my mind for a very long time and can't seem to peice the little bits together.

Exacly "keep it simple" how does the sequential turbo system work

The car I bought was converted to non sequential using the poor mans tehnique, but he took some of the seq. stuff off and left other parts.

Can anyone give a detailed list of the Sequential setup parts?

Does anyone know if the parts can still be bought new? I have the rats nest and stuff, but do the solenoids tend to go out? is there any way to check them, How much is the going rate if I were to purchase the stuff used?


Thanks in advance for the insight, I just really need sombody to explain it with its countelss vacumelines and 20 somthing solenoid valves and 1 way valves.... and actuators.... and

well you get the point.

 

[/QUOTE]If you wish to keep it simple, this discussion probably won't work. I can try to explain what I know, but it would take patience on both sides.

Look in the parts list. Or, look up the nonsequential conversion details and figure out what was removed and/or changed. Also check the vacuum hose diagram, that's a pretty good list. If you have the parts in the vacuum hose diagram functioning correctly and connected per the diagram, you have most of it.

I've never considered doing the nonsequential conversion, but I believe it involves making cuts/changes to the turbo or exhaust manifold. Therefore, you'll need to find replacements to some of the parts. The 'poor mans' nonsequential I think is reversible.

Yes. New turbos are $2k-3k depending on if you get a good deal. Mazdaformance had them recently on their clearance list. Lightly used turbos are $300-800 depending on condition and mileage.

Yes, they will go out on occasion. About $55/ea. from Malloy. It's pricey to replace them all at once, but that idea does have merit if you have the cash and want to ensure operation. There are about 6 solenoids that are critical to turbo performance (the rest are emissions controls)
Used solenoids are cheap, $free-25ea depending on if they are low mileage.

If you choose to test them, do a search on how, and make sure you use an oven to warm them up and test them hot. The FSM tests are not stringent enough to ensure proper operation. You'll need a Mityvac (I recommend the Silverline test kit).

I can try to explain what I know, but it will be very detailed. I spent a long time studying diagrams to learn. If you're interested, I can sit down tonight at home and provide a proper explanation.

Dave

 

The exact method of operation is pretty complicated. I'll try and give a real simple answer.

Low RPM, the first turbo is the only one working. A flapper door in the exhaust sends all the exhaust energy to the first turbo for fast spoolup. As the RPM's rise, the flapper opens and lets exhaust energy to the second turbo to get it up to speed.

At 4500 RPM, the second turbo is brought online to provide boost, and both turbos work up until redline.

Most of the control system is to make the transition from the first turbo to the second relatively smooth.

Get a copy of the colored vacuum diagram and read through the turbo troubleshooting guides and non-sequential guides. Hopefully the "poor man's" non-sequential mod was done, which is relatively easy to reverse.

Almost all the various sequential system parts are available used, and should be easy and cheap to acquire.

If you're new to the car, getting everything figured out is going to require some dedication. It's never easy to reverse someone's work. But, I'm a big fan of the sequential system, so IMHO it's worth the effort .

Dale

 

That would be awesome if you'd give a detailed analisis. I'm doing a chemistry lab right now so I probibly wont be able to get back on tonight. I don't exactly know what I do and don't have, I do Know that the solinoids connected to the intake mani. have the nipples broken off ... uggh...


My engine has some messed up apex seals currently im trying to sell the car, but the more and more i look at it and tinker with it, the more attached I become. If I keep the car I will more than likely pick up a new engine and all my other performance parts from rx7store, as they're in ohio and i'm in KY. When it all goes back together I plan on removing all the emission stuff, as we do not have emissions where I live. Everything will be removed and put back together, I just hope for the simplest opperation possible.


I know this is kinda getting away from the original question but I was looking at going to the bnr stage 3's but was wondering if the power im looking for warrents them. I am only looking for ~375whp but I dont want to max anything out. Can the stock turbos sufficiently supply 375whp or would I be better off getting the stg 3's and keeping them at lower boost?


As said before I appreciate all the help. I want to do this thing right and get all the knowledge before i rush into anything.

 

Only 375hp, ha. You would need a BNR 3 to get there and not fry it. It will take some mods to get you there, but 375 on sequential is a beautiful thing. (Barry Jaminet's car - 'kwikrx7' here on this board)

I'm working on a powerpoint that illustrates both the basic actuator operation as well as solenoid control of the actuators. It will talke a little while, but hopefully be worth it.

Interestingly, I was supposed to be in Louisville tonight, but the Ohio Falls powerplant couldn't get the unit drained of water for our inspection. So I will probably be going down in the near future.

Dave

 

OK, here it is:

http://web.newsguy.com/geesaman/TwinTurbo.PDF

Dale, if you're listening, please check over and comment.

That was basically sequential turbos 101.

Next, I'll try to add the solenoids in another presentation.

 

Very nice Dave. This should be a sticky .

Jeremy

 

Nice job! Did a quick read - my only problem I found was the first picture of the "real" turbo - you have the inlets and outlets of the turbo backward. IE, primary turbo inlet is actually the outlet, and vice versa.

Dale

 

Oh, yeah. As I was driving somewhere last night the thought occurred I may have switched them, and I checked the diagram ones. I'll fix that tonight, and also draw in some little arrows to indicate the air flow.

I think doing the same thing now with the solenoids would be very illustrative. That will take longer to put together.

I was thinking of doing this before using Flash so I could animate the movement of the flapper doors, turbines, and valves, but I haven't learned Flash yet. Maybe I could do the animations in Powerpoint.

Dave

 

http://www.swishzone.com/ -- Swish is basically a click and point to Flash. It's really easy (not as powerful) to use (similar to PowerPoint). If you need help registering it, lmk.

 

Good job. My only problem is with the verbage.
On the second page, I would substitute the word volume or something similar for "boost." Mainly because the secondary turbo doesn't supply extra boost per say. Don't mind me, I'm just picky.

 

I made some revisions, including the 'verbage'.

Dave

 

If I see an non-seq rx7 with no rats nest, does that imply it wasnt a poor mans conversion?
likewise: rats nest with non seq implies a poor mans conversion to nonseq?

 

If there is still a rats nest, to me a half-assed job. Not nessicarily a poor man conversion.
I removed everything that was unneeded for fmy non-sequential conversion. The reason I chose non-sequential over sequential, because on the track, I won't really have to worry about the lag area. Plus if there is a vaccuum leak somewhere, less hoses to search through I have been in cars with non-sequential and don't mind it at all.
Dgeesaman thats a good write up you did

 

so what does distinguish a poor mans conv. to a full conv???