223 RWHP DynoJet NA 4th gear
 

Since we don't run Koni Challenge anymore, I'd thought I'd share what was under the hood of both of our cars. For these particular pulls:

-Fresh Daryl Drummond rebuild. 100% legit/stock/no trickery
-Bosch 4.3 Engine Mangement running .92 Lambda
-11 Plugs
-Custom Header by Pete w/1 7/8" long primarys, extry, extry long collector to 4", very low restriction dual mufflers after "Y" split behind diff.
-Premium gas
-Lots and lots and lots of dyno time. Lots. So much that the dyno operator gave me a key to his shop. True.
-ACT flywheel w/stock clutch
-Air pump removal and oil injection delete
-Hundreds of intake tests
-Star Mazda throttle body (same size as stock and needed to use an alternate TPSensor)
-I have dyno'd probably 15 different engine BUILDS and each one of those typically both before we run them at the track (break-in), after we return from an event (to see what she is making') and then after the next event (repeat). I would suggest to you that each of the 15 motors I've owned/had rebuilt/bought new from MazdaSpeed (3), have been dyno'd on average of 2 to 3 times---each one with more hours on it than the previous dyno trip measurements.
-I'll suggest to you that there is very little variation in power and/or power curve(s). This based on ceramic apex or steel, one builder vs. another, rebuild vs. new, swapping out upper and lower intakes and plugs, new housings vs. used, new rotors vs. used, new irons vs. used. Variations in power could be written up as dyno variations and within 1-2% on the dyno we tested on. I have come to believe based on talking with guys who have been around the block much longer than own and have owned both chassis and engine dynos that this 1-2% variation we see is a very low variation and greeted by these smart guys as a strong testament to our consistent and repetitive dyno process (talked about below). Any variations in these new builds (and measurements after racing) can be explained as too small to pinpoint and could be written off as the small variance (or large in some cases as seen on this forum) of the same exact chassis dyno we test on here in Indianpolis (Cozzolino Motorsports).
-Biggest power gains came from continous header development (not just one kids) and testing, testing, testing them. I think I've been through 11 different header/exhaust configs. In many cases we would individually tune the new exhaust to the motor to maximize power. Same for intake configs.
-For those of you jackf__ks that think there is no power in a header----below me. I say this because most of you that say this have no idea what your friggin' talking about. There is power there. It may not be as much as your willing to invest in but there are power gains in headers period. If you want to argue this then meet me on the playground at lunch time and bring friends and an icepack. I've been on these forums and lurk in the background to see HOW people are testing and I've yet to see anyone talk about a detailed dyno procedure. This suggests to me that the majority of the "I'm going to the dyno this weekend and paying $75 to see what my pretty waxed car with the 20" blah, blah is going to pull and I think my new coat of RainX is goning to make 20 horse. This isn't a slam on those of of you that do it right but rather a crushing blow to those of you that DON'T know and argue that you do.
-After the first few months of pulls (back in late 2007 when we had the white car -- RIP) we began formalizing a dyno procedure that we would end up using every single time we would use the dyno/capture data. This included:
---A good once over of the motor at the shop before we put her on the trailer to go to the dyno (belts, hoses, plug wires, oil level, water level, exhaust leaks, air filter condition, trans and diff fluid level, condition of plugs and coil packs documented).
---Top her off with premium pump gas and 1 oz / gall premix (Redline 2 stroke)
---Checking tire pressures before pulls---40 psi (the same as we would run on track)
---Strap down car, check straps, recheck straps, doublecheck/recheck straps after several pulls to put demand upon them).
---Testing methodology communicated to everyone (what do we want to accomplish today)
---Plug in laptop and monitor engine parameters during the warmup (usually about 20 minutes or so). This includes Oil P, water and oil temps, trans temp, diff temp, A/F, Trim correction level, EGT temps, IAT. We look for abnormalities and might find one every once and a while that we fix before moving on.
---We are ready when the engine has been up or above about 200F oil and the diff temp (VERY IMPORTANT) is 130F+ WE HAVE FOUND THAT THE DIFF TEMP IS THE SINGLE LARGEST VARIATION IN RECORDING POWER. Read that one again rotary fans--the variation in power due to cold vs. hot diff temps is the single biggest difference in recorded hp and trq. (for us). Pulls with a heated up motor and low intake air temps and a COLD diff are usually about 5 peak hp lower than when heated.
---4th gear pulls (5th gear reveals higher power). Don't ask we why we pulled in 4th gear. We started it this way and continued it to have an apples vs. apples comparison data.
---We would try to make all pulls with IAT below 100. Oddly enough we found about zero variation in a very cold intake vs. a warm one (about 100). When the IAT was above 120 or so we did see lower numbers and/or numbers that weren't as high as numbers performed on the same day but with lower IAT.
--Fire extinguishers manned (except for that one time when the car caught on fire and burnt to the ground---yes this is true). Don't ask.
--Strong monitoring of oil temps (which grew much faster than water temps for us). Note: I found 1 or 2 more hp when the oil ran 210. We race it at a target 190F and run the water as low as we can----normally 185 F with our C&R custom radiator (which I've built and tested 4 different custom radiator configs).

So we can usually be in and out in about an hour with a long warmup, 3 or 4 sets of pulls of 3 and printing out the dyno sheet/sheets to store in our dyno log book

For the attached dyno sheet you will see this:
-A custom airbox allowing for large amounts of air TO the filter and then a short 45 degree or so angle (12" in length +/- measured on the outside longer side) and our old tried and true MazdaSpeed Intake (the polished Alum one) with a 90 degree turned down elbow and paper air filter (not a metal K&N or equivalent).

A warning in advance, as always, I really try hard to share the knowledge that I've learned over my short, detailed and crazy RX8 experience. It is my wish that people who read this think it through before posing any questions. In fact, my preference would be (and this will sound like a shocker) that people do some forum surfing before posing what is usually seen as a dumb question. My hat is off to those of you who pose links to similar topics that have been discussed on this forum before. To me, this shows that you do your homework and research---I tip my Meyer Motorsports cap to you. Thanks for your understanding and may I suggest re-reading this long email before asking any questions---chances are you may of missed it and/or you could figure it out for yourself---which would indicate you are learning and becoming a better steward of this wonderful forum.

Happy Rotoring

Do you have any performance numbers and the weight of this car? Also, is the drivetrain stock?

Eric,

I have around 50 dyno pulls on my car.

Setup is as follows:

Exhaust: RB Catback. RP Supercat, Stock Manifold

Intake: Racing Beat Revi with Duct, MAF tube insulated from Heat

Drivetrain: ACT Prolite with Stock Clutch. 17.6 lb wheels

ECU: Stock with Racing Beat "Street" Tune, Knock Sensor Unbolted

Ignition: Okada Coils with Magnecor wires


I have wondered the following and hopefully you can shed some light.

1). Would removing the bottleneck between the catback and midpipe offer and improvement and if so how much?

2). No one on this forum has dyno tested the RB Header so what are your thoughts on it for a street/track (DE) car?

3). Would the Mazdaspeed intake make more power than the Racing Beat?

4). What weight oil did you dyno with?


Thanks for your help,

My chart is attached for your review

Amen.

About time someone else agreed with me that's actually tested some, all I ever get is grief over my headers that 'can't possibly do anything'...

Performance numbers?

Weight is 2725 dry with about 5 gallons

Stock RX8 trans (not 2009), 5.12 ring and pin rem'd

My notes below in BOLD

Eric, awesome post. Can I purchase the best of your 11 header designs or do you know who can make a replica of it, assuming it mates with catless midpipe? Thx

there is no power gain near 9,000 rpm so stay away from there. The speedsource guys set their hard limiter at 8,700. They do this for a reason. We set our soft at 8,500 and hard at 8,700. Why???

Why???

Because there is no power up there and the ends of the rotor tips can (can) start to contact the irons.

It is faster to shift on or around 8,700, watch the rpm drop, keep it floored and repeat process than to run it to 9,200 and do the same. Figure out where the power is and operate your engine in said range.

What did the ignition timing look like?

I hope you will forgive my ignorance because I'm not sure race teams do this but by performance numbers I mean 0-100 times, etc. I just wanna see how much this increase in WHP effects the numbers vs. a stock car.

great post Eric, thanks for sharing!

It can be advantageous to shift at a higher RPM on the 1 to 2 shift because of the large drop between the two gears. Shifting at 8,700 in 1st puts you at ~5250 RPM in 2nd, which isn't the most favorable RPM to be at. On the track you're only going to see this shift once, so it doesn't really matter all that much, but for those that are trying to do the whole drag racing thing it is something to keep in mind.

I love when Eric Meyer posts stuff on here.

5250 rpm in 2nd with a stock rear end remember, not a 5.12 ratio.

Eric's attention to detail is the main thing that people should take away from this thread. If you REALLY want to play big, you need to pay big and that includes paying attention.

Paul.

Not bad for a Dynojet :)

I have no doubt a different exhaust manifold can make more power, I simply questioned and then proved that it doesn't have to be a complicated traditional header type design ... if that makes me a jackf_ck then so be it ;)

https://www.rx8club.com/showpost.php...&postcount=414


.

I think Erics post actually reinforces your earlier claims .

Eric, you mentioned in another thread once that you were going to start getting your rotating assemblies futher balanced...did you find any good result in this? And if you don't mind, what ISO standard did you balance to, and did you continue to balance like Mazda at the flywheel/counterweights, or at the rotors instead?

Thanks, great information as always.

Hey Eric. Great information as always with your typical attention to detail and using the scientific method.

I am most impressed with the fact that you maintained a flat torque curve up to 8Krpm and a nice steady power climb.

I have two questions:

1)On the rear diff. did you see differences in warm up power loss with different differential fluid? EG: was the difference due to the fluid properties changing when warming up depending on the fluid or more due to the growth and tolerance changes of the gears themselves?

2)You mention there are gains to be had with a properly designed header and collector. Am I reading it right that your header tube LENGTHs are 1 7/8" long (very short similar to OEM manifold style) and when you say VERY LONG collector are you saying just a continuous pipe before you get to the cat or resonator? I'm don't know what is considered the termination of the collector vs. mid-pipe. I am thinking if you are using a standard L to D ratio for fully developed flow of 8:1 and a 4" diameter pipe, you'd want ~32"?

Let me know if I'm interpreting your information correctly.

Thanks again!

/\ perhaps Eric could post a picture of his header ....

I took it to mean the header was 1-7/8" diameter primary tubes of long length, so I suppose a clarification is needed

I know Eric has dumped a ton of money into his program and I understand that is what had to be done to be competitive...the 8 needs that kind of attention to be competitive in these classes, that's why most of the ST 8 teams bowed out. The Bosch conversion alone was what, almost $50k...and then add the rest of the development of the car, you're looking at atleast a $150K+ car. I applaud Eric for continuing race development on the 8, hopefully we will be able to use some of his applications to help further the average owners pursuit of speed.

I'm just curious also if his header is the standard 3 runner, or a 4 runner. I had this question many times and noticed only a select few tuner companies in Japan running a 4 runner header. Now that about a year or so has passed since then... That company is now running this on their rx8 as a proto type for this years RE wars.
http://rx-race.cocolog-nifty.com/pho...3/r09_b022.jpg

Just wanted your thoughts on that Eric. Thanks for the great post and information.

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.