Team is right on the money. I get some pics of the collector in the next few days.

 

I like the design, do you think you may decide to fab up some more and offer them to the group?

 

No 0-60 or 0-100 times. Don't do that stuff.

I do recall running 146 mph in the draft at Daytona pingin' on the rev limiter (which we set for 6th gear of 8,900 rpm. That was behind one of those damn orange Honda's. Those things are F A S T!

 

That type of design is similar to what Hymee used to good effect a few years back . Having a long length of pipe before the collector seems to be the key . Is that how you saw it Eric ?

Also - do you think the extra pipe on the ports closest to the collector makes any difference . IE if all the ports had identical exit radii like the furthest port would the gains be as good ?

 

Correct. The 5.12 is so spinny that you never use 1st. Its good for pulling out of the parking lot before you hit the rev limtr (joke). You only use second at a few tracks with very slow corners AND someone checks up in front of you. 3, 4, 5 and sometimes 6th.

 

i'm confused. what exactly is set at .98 lambda?

 

Balancing! Solved our problem. Without going into a long story, I sent Daryl Drummond two of our engines for assesment. 1 blown motor, 1 good (running) motor. He pulled them apart and checked the balancing. Short answer: out of balance enough to wear the rotor tips were hitting the irons at higher rpm (remember we don't run this thing above 8,700 if we can help it). One of sources of this problem was prior engine failures that had me buying new rotors. Buy a rotor from Mazda, put it in the motor. Guess what---out of balance. We were not balancing these things because one well known entity in the rotary community balanced one for us, installed in and it blew the thing up and bowed out the bottom of the oil pan. There is no need to tell you who this vendor is because I'm sure it was a fluke. A $4K fluke that I ate. Needless to say I am never buying anything from them again. I digress. So then I talked to a very well known 3 rotor race team that runs this really fast black car. They offered that there was no need to balance the Renesis and it was fine out of the box (a new crate engine). So we didn't balance them. Cut to a few months ago and 14 engines later---sent the two engines to Daryl and viola! Issue found, issue addressed and the engines are singing like birds (actually I have two of them for sale right now---one with 12 hours, the other with 2).

The balancing was done by Mr. Daryl Drummond. Daryl has been around Mazda's since the 70's and was referred to me by Paul Yaw when we first started our Koni RX8 program in early 2008. Unfortunately Daryl was under contract with another team at the time and couldn't play ball with us. I have learned more from Daryl about rotaries and racing in the past few months then I've experienced in the past 12. I really think he is the best. Keep in mind that he does not market to or work with the street crowd much. Most of his stuff is Pro Mazda, RX7 PP and StreetP, 3 rotor jazz. Mostly all custom, no turbos and guys with a budget. He can actually tell you the hp loss you are likely to get after X thousand miles on several of his engines if you tune it the way he wants----crazy.

Daryl is the man and did/does our balancing work. His methods are proprietary and I'm not at liberty to discuss nor do I fully understand them. He is expensive and well worth it. Lots of rotary engine build knowledge gained over the past 30 years. I just spoke with him and he is writing up a bit of info that I can share with you at a later time.

 

Are you asking because you are tuning and you want to know or....

It depends on rpm. Anywhere from 0 to 26.

 

Great Ceaser's Ghost! Did I say .98??? I thought I said .92. Lambda is another way of referring to Air Fuel ratio. For some reason Paul Yaw, Bosch, Motec and Daryl all take in terms of Lambda. Ask them what A/F and they will tell you they have no clue. .92 equates to about 13.5 A/F

13.0 is approx .88
13.1 ~ .89
13.2 ~ .9
13.3 ~ .905
13.4 ~ .91
13.5 ~ .92
13.6 ~ .925
13.7 ~ .93
13.8 ~ .94
13.9 ~ .945
14.0 ~ .95

All numbers approximate.

 

Damn good info.

 

Long length before the collector---yes. Actually the more gradual the collector the better power we found WHICH IS WHY IT IS SO HARD (IMO) TO MAKE A STREET HEADER WORK. Because of packaging issues, you need to transition from your primary length runners to mate to the stock exhaust and this forces you to make this tiny little stubby collector. In otherwords, the cars packaging and the location of the "exhaust AFT of the stock exhaust manifold" require a tiny collector.

Extra pipe on the ports closest to the collector???????

I think you are asking about tight(er) radius on a few of the pipes---yes? If so, the designs we came up with HAD TO FIT INTO THE ENGINE BAY. THIS was the primary design constraint. Had we had a huge engine bay I'm sure we would've tried a bunch of crazy and expensive stuff. What is not pictured is the motormount which the headers intertwine with. Not the easiest thing for a 1st time to install. Also, I couldn't tell you what an stock airpump looks like if you hit me over the head with it. We remove this dude long ago and I don't recall if its stock location interferes with any of our designs we've tested.

 

I always thought a good long tube header would make power. Thats what I had on my racing RX7.

 

Interesting concept. Never thought about it. What would the ideal solution/solutions look like?

Keep in mind that we run a very different exhaust that is costly and loud. I don't think our current setup is the hot ticket for everyone. It would require about 99% of the purchasers to go find a custom welder to either make the system work, build it, install it, make custom brackets, etc., etc., blah blah.

Now that I think about it I have a few questions for you guys on this forum:

1. What location on the car does the stock Cat Conv terminate?
2. Do you HAVE to run a Cat and what happens if you don't?
3. Can you run the car on a closed loop with just one 02 sensor located upstream (Team, I'm thinking this is right up your alley).
4. Let's pretend a header could be made (a) that installs easily, fits well, (b) allows you to plug in your 02 sensor/your car runs well without a bunch of headaches), (c) makes signfiicant power, (d) is at a reasonable price point, (e) not too loud and/or you could use your own muffler choices to control this somewhat------------where does the header and collector end and what does it attach to?

I have totally forgotten what a stock exhaust looks like.

Perhaps there is an interesting product out there that the market values. Dunno.

Team---call me

 

Wow. Funky design. Looks like the leg muscles Arnold had in Terminator 1.

I'm not sure how this all mates together---two long exhaust pipes under the car and the longer exhaust/muffler at the rear of the car??

The only way to confirm it works well is to test it. I'm not qualified to comment on this.

 

Shaun---I apologize. I've mispoken. The header Diameter is not 1 7/8" on this particular motor and this dyno sheet. It is 2". The 1 7/8 was on an earlier test and not the ones in the photo. We also tested 1 3/4" which allowed more packaging/fitment options. We never tried to step anything nor did we try anything smaller than 1 3/4". I never go around to coating any of these items either (probably because we were building and testing them so much that it didn't make sense).

Side note on this exhaust thing: Many of the designs were initailly built in Steel as it is easy to work with and cheap. We would test them and decide to build them in S.S. or move on to another design. We did this with the rest of the exhaust as well (from the collector to the back of the car). Our current new header design for the RX8 (un tested as of yet) is a side exhaust. More on that later.

 

For these two questions the guys running AutoX in STX class this year have to run a cat. converter to be legal but they can move it further down the mid-pipe. I believe the Inlet for the cat. has to be within 6" of the stock Outlet. To me that means you can move the stock cat. down the length of the car. the length of the cat. plus 6". I think that's a good 18" to 24" further away from the exhaust manifold stock location. Team can correct me on that. I think there is also the school of thought that the mid-pipe is considered part of the Cat. which would allow us to put it wherever we want along the length of the midpipe.

 

I actually wasn't sure if you were talking about length of header pipes or diameter originally. I had visions of stubby little header pipes all going in to a big plenum manifold. Thanks for clearing that up.

 

S,

Approx. how long is the stock cat assembly?

 

Hey Eric. Thanks for the response on my post there Just wanted your thoughts on the exhaust is all. Do you at least have any thoughts on the 4 runner header idea as opposed to the 3 that you guys use and most other people use as a header?

 

Great info.

I have an ECM question. Ive read before (sorry did not find the post(s) from Rotary God that for max power the stock ECM would have to be disgarded and something else used, Bosch 4.3 in you case.

Why is that? How does changing over to a Bosch ECM help with power? Does it allow the Lambda and/or timing to be tuned better?

 

Good question. I thought the COBB would be good enough for things like that, no?

 

Stock ECU has it's shortcomings...especially in fuel delivery......

 

Thanks for posting this Eric. This answers my question from the other day when we were e-mailing.

-Chike

 

eric-- good to hear from you--hope we can cross paths again-- our guys will be at Rd ATlanta in Oct with the PCA............if you EVER want a ride. We are lucky to have you share knowledge with us.
?
Did you take the jet air nozzles out of the lower intake?
The balance work on the rotors was concentrated around the center part and not the faces--wasnt it?
Olddragger

 

right, so you've set 4th gear max load fuel map at .92. Got ya. so that's the sweet spot? richer and leaner mixtures saw losses?

I need to lean back out, i think.

what were the actual afrs on this pull?

great info, btw. thanks.