Guys,
Several people have asked me, "when are you going to update your sorry web-site!"

Well, I have finally got off my lazy rump and did it. Nothing really to new, some updated pics of the turbo FB mostly taken at SevenStock and a little more detailed list of specs...

My turbo FB

Enjoy,
Berny H.
83GS turbo

PS Sorry if you saw this post on one of the RX-7 lists.. I wasn't sure who all ask me to do it!

 

Cool car!

Does the Electromotive TEC II give you dual Leading sparks? I've always wondered about that.

 

That manifold looks like a 2nd gen N/A 6 port manifold. How did you get it hooked up to the 4 port engine?

 

Congrats Berny! I really enjoyed the web site throughout the build up of the project and now it is a great testiment to all your hard work. How long did it take, from conception to completion? I am most impressed that you stuck it out to the very end. Most projects like this tend to change focus, loose the interest of the owner, or drains his bank account and gets sold off prematurely. Lots of people start, few people finish. Good job.

I was glad to have had the chance to see you and your car at Sevenstock IV. Great event. It was fun hanging out with Ari Yallon and Rob Golden, and getting the chance to meet Kobi-san. Oh yeah, there were some nice cars there too BTW, Kobi says he never got the poster I left for him. Any idea of what happened to it? No big deal; I'm just curious.

For those who haven't seen it, I have a Sevenstock IV photo gallery HERE
--
Blake Qualley
Rotary Engine Illustrated

 

Hey Blake,
How goes it? It was very nice meeting a lot of RX-7 enthusiast at SS-4. Hopefully next years event will be bigger and better. Hope to see a lot of forum guys in attendance. BTW I'll ask the guys at Mazda about the poster..

On what it took for me to finish the 7.....

Well, it was tough... trying to finish this thing. Like most guys here on the forum, I don't have or make lots of bucks and had to wait to get things done, my patience was definitely tested though. It took me over 4 years from start to almost finished, I'm still dealing with interior parts and issues. In all of this time, I think I only drove the car once or twice during the shakedowns and then it was back down for the paint and bodywork. It really helps to have a second car as a daily driver. Also, you really need to keep focused on your project goal. Sometimes thing don't go as planned but, you just have to keep at it. And like you said, it drained my bank account every step of the way. I actually prayed to God for patience and to help me finish it.... I thought I would never make it... I used to think, if I only had big money!!! Shoot, all of the So-Cal club guys would laugh at me, over the last few years, saying that I really didn't own a 7.... it was tough!

I finally saw light at the end of the tunnel about a year ago or so and, it inspired me to get it done before this years SevenStock event. I also credit the guys at Mariah for helping me out every step of the way and having as much patience with me as they did. So basically, to all you guys out there wanting to do a project like this, hang in there and keep focused.

TECH

Pele, it is a 2nd gen N/A manifold.. some grinding, some filling, some drilling and shaping and it fit on to the Racing Beat Dellorto bottom intake manifold. REASON: Well, when we started this, it was meant to be a full smog legal conversion so, we needed a way to be able to use the stock 2nd gen ACV. The N/A upper manifold was our best fit for this. To bad smog laws changed in Cali and the 7 won't pass the visual test.... oh well, at least I'm green... kind of. And NOPE the T-II manifold won't bolt directly to the old style 4-port motor. You see, I already had the motor built. T-II motor would definitely be a better starting point.


Jeff20B, I'm not exactly sure what you mean by dual leading sparks. The TEC does fire separate coils for each spark plug (4-coils) and it's triggered off of a crank trigger wheel configured to in my case with separate pick-ups for trailing and leading. Please let me know if this answers your question... it not, clarify and I'll do my best to answer.

Thanks all for the interest!

Bern
83GS turbo

 

The 2nd and 3rd gen cars have one single coil for the Leading plugs which fires them both at the same time, hence dual Leading sparks. Some people call them wasted sparks using an old boinger term (the spark is not wasted on the rotary at all due to the 270* stroke, or rather, "cycle" compared to a boinger's 180* power stroke). The so called wasted spark occurs at 180* after it originaly occured on any particular Leading plug.

A two rotor engine has both rotors phased at 180* from each other, so in order to save a few bucks, as Blake put it on his web page, Mazda only used 3 coils instead of 4. 1 coil for each Trailing plug, and a single, dual output coil (DIS) for both Leading plugs.

What you're saying about the TEC II needing to use 4 coils tells me that it probably uses single Leading sparks just like the old school '81-'85 RX-7 ignition systems. The only redeeming feature of the TEC II is the direct fire (it doesn't need to go through a cap or rotor).

But then again, maybe Electromotive wanted the best, most powereful direct fire ignition system for a two rotor engine, and decided to fire both Leading coils at the same time. If that's true, then it is better than using a dual output coil because it gets away from the problems common to DIS style coils (shared internal windings resulting in colder, lower amperage sparks, generaly weaker high RPM performance, etc).

I've learned enough about this stuff to know that dual Leading sparks are better than single Leading sparks. I've heard lots of good things about Electromotive, but I'm not sure how their rotary ignition systems run. Does it really give you 60* of spark? Is it really an inductive type circuit?

Some food for thought. Later!

 

Jeff20B,
I got you now... Here is my answer, from my feeble understanding of the subject.

The TEC-II can actually be configured for both... Dual or Single firing and it is a true inductive system.

On my car the, the set-up is dual firing. Both the leading coils firing at the same time but, with the advantage of their own individual coil packs and long duration spark. Another interesting thing on the TEC is that timing can be adjusted in 1/4* intervals... real heavy duty stuff.

This is a very interesting and kind of complicated subject... just some more interesting facts.

2-rotor engine - rotors phased at 180* (as you stated)
3-rotor engine - rotors phased at 120*
4-rotor engine - rotors phased at 90*

All of the motors have to go through a 1080* rotation to complete a full firing cycle relative to all of the faces of the rotors and e-shaft rotation. So, as you can see the 3 and 4 rotors motors go through same 1080* but, with a lot motor power strokes in the same 1080* rotation, which obviously equals a lot more power....

If you really want to get the true and probably a lot more technical and correct scoop on the TEC-II, you could contact some of the Rotary vendors out there who have a vast amount of experience with the system.

Mariah Motorsports - 805.965.5115 (which did my system)
Jim is a master of the TEC-II, both tuning and explaining it. I've never been able to absorb his attempts to try and explain all it to me though. Give him ring and mention my name... They also have a cool 20B TEC-I install with 6 coil packs!

Tri-Point Engineering - 818.348.5385
Mark and Craig have set-up a lot of TEC-II's on Rotaries.

Peter Farrell Supercars- XXXXXXX (sorry don't have the # handy)
I've also heard Peter has done several 3rd gen TEC installs and has set up quite few 20Bs also.

SR-Motorsports -
Ray also has quite a bit of knowledge on the TEC. He runs one on his drag car and sells set-ups.

Thanks and sorry for my lame explanation

Berny H.

 

Actually, your explainations were pretty good.

Speaking of power pulses per revolution, a 2 rotor has the same amount per 360* of eccentric shaft rotation as a 4 boinger does. However a rotary has 270* of a "power stroke" vs the boinger's 180*. I have an old automotive encyclopedia from '72 that includes the RX-2 engine! Ahem, anyway there is a section that shows the relative lengths of power pulses of a 4 cylinder, 6, and 8. The 4 actually has a few degrees of dead time between the pulses. That means the 4 does not have two true 180* power pulses per revolution of the crankshaft. They are more like 175* or something like that. The 6 has a little bit of overlap, with pulses occuring every 120*, and the 8 has plenty of overlap every 90*.

Compare this to what we know about the rotary.

If a 2 rotor engine has two pulses with 270* each, just imagine how much overlap there is! Then picture a 3 rotor and then a 4 rotor! Heh, no wonder a 20B is so smooth.

So your TEC II is running in dual Leading spark mode? Cool! Yes, I'm fully aware of the benefits of having a dedicated coil for each plug.