HC post (05-12-11)

MK post (06-20-11)

Current Date (08-06-2011)

I guess I'm confused How much can go wrong with a 'virtually new' harness? What's the update now?

 

depends on how in depth his rewiring is. Just replacing the engine harness isn't too bad, but if he's doing more than that, it can turn into a HUGE project.

 

Wiring isn't easy. First you've got to understand what needs to be done. Doing this requires knowledge of electronics and familiarity with circuit diagrams. The ability to make a reliable splice that meets or exceeds OEM quality requires materials and tools that aren't inexpensive or easy to find. Just having good tools and materials isn't always a guarantee the work will turn out correct. Unfortunately, most people who understand electronics and circuit diagrams aren't very experienced with automotive wiring... and many people who are experienced at working on automotive wiring aren't very good at understanding electronics and circuit diagrams. The people who are skilled at both tend to be expensive and not often willing to share their tricks.

It doesn't help that Mazda's circuit diagrams tend to be cluttered and not the easiest to follow. In some cases, Mazda's wiring design is not an example of good practice... at least not according to today's standards and knowledge base.

 

Have you ever seen VW's wiring diagrams? Even the latest 2011 diagrams will make you want to cry. Compared to VW, the Mazda wiring diagrams are golden.

thewird

 

Wiring isn't really all that hard, I think it took me 3 hours to redo my harness and a buddy of mine did his just as fast. I must be one of those gifted individuals? Although I have no tricks or anything I'm keeping secret, it's all pretty straight forward. A cheap multimeter works wonders!


I'm anxious for an update

 

I agree VW circuit diagrams are the worst by far, and I'm very glad Mazda doesn't use that oddball convention.


It seems every time I spend more than 15 minutes looking through the Mazda schematics I want to find their engineers and ask them what they were thinking. Recently I noticed that the ignition shield drain connects to the same ECU sensor ground pin that is used for the MAP and TPS sensors. I haven't verified this in the harness, hopefully it's an error in the schematic. I was taught that a shield is by definition going to receive some noise, so it should be drained to chassis ground so it doesn't interfere with the signals or the sensor ground. Obviously Mazda's arrangement works anyway, but that's not to say it is the correct way to do it, and this is just one of the many head-scratchers I've come across.

 

Ignition shield as in Ne+/Ne- and Ge+/Ge- wires? That is the standard.

 

VW diagrams can't be any worse then their actual wiring.

 

There are two types of wiring schematics:
(1) functional - shows minimal wiring for circuit to work.
(2) actual - shows the exact wiring as it exists.

Unfortunately, most wiring schematics for cars are functional.
Mazda's is functional and even has the color codes wrong in many places.

 

3.5 hours later and I've read every single post on this thread. Perhaps I missed it but I didn't see any engine specifics: Year, model, compression ratio, etc. I do not want to make any assumptions.

Howard, could you direct me to this info. Thank you sir.

PS Love your attitude and desire to educate John Q Public on this forum.

PSS Do you happen to know anyone that knows anything about the 4 port Natural Gas 13B's? I have one from Daryl D.

 

just a brief update.

i received my car back from Beyond Redline july 8. it was a bit weird as i really don't farm my car out but having had a succession of a number of elec problems, wanting to get a way overdue project moving faster, and having a high degree of confidence in BR i thought... what the hell.

upon receipt of the car it was clear there were still a number of items to fix. one of the EGTs wasn't working etc etc. they had done alot of work but it wasn't a turnkey. i cleaned up the items (new EGTs, lots of other stuff) and was on the dyno w the BW Aug 4.

after a bit of tuning it became apparent that we weren't getting alcohol. lots of diagnostics narrowed the problem to the FJO module. (currently irreplaceable). back home i wasn't quite ready to give up on it and ended up spending a week w it before finally deciding to shift gears.

Luke and I came up w a very interesting plan B.

i now have swapped my 1600 Bosch secondaries for the newer Bosch EV14 (1000 CC) in the secondary holes and am fixturing two more EV14 (1000) in the Greddy elbow. the elbow injectors will run 100% methanol. i have a Honeywell boost switch that i set to trigger the meth pump at 1/2 psi boost.

the AI secondaries are wired in parallel and will be driven by my FJO Peak and Hold module which will take the strain off the Power FC.

i have set it up w a 200 psi pressure sensor in the alcohol system so i will be able to log when the pump comes on and the pressure. i will probably run around 60 psi static rail pressure to the AI injectors and 43.5 for the gas sec and pri.

the system will deliver enough BTUs for a comfortable 600 SAE.

here's the details:

https://www.rx7club.com/auxiliary-injection-173/my-third-ai-system-965487/

all of the above, except for the fixturing of the two AI injectors to the elbow, is complete.

prior to dynoing i did drive the car w the BW for a couple of weeks. i ran 22 psi in 4th and liked what i logged. my EGTs are within 30 degrees or less front and rear. little knock, 25 psi at 4000. this w coolish 1450 EGTs and only a rough tune. backpressure at or slightly below boost pressure.

i am really having fun w the new AI setup. assuming it works i will have the ability to tune my AI as accurately as my base fuel map. 400 cells.

the project has turned out to have generated lots of challenges... i thought it would be the turbos, and of course it might still be, but actually it has been an amazing series of module failures:

failed and replaced:

Kenne Bell Boost A Pump
Datalogit
Power FC
FJO AI system
engine (the JB Weld fiasco)

oh well.

i finally decided to get off the thread and just take care of business. my absence should not be interpreted as lack of interest in the project. as long as i have the power to get it done it will be done. there's lots to learn assuming we get the chance. i remain very excited.

the module failures remain unexplained... i have looked at my battery voltage thru the DL and it is constant and robust... (high output alternator). it isn't that i am a newbie at this. from 2004-2010 i dynoed my car often at BR as well as drove it a bunch and i had no elec issues.

so no promises as to when i am back on the rollers but it will be as soon as we finish the injector fixturing. i had hoped to do the Oct Texas Mile this year but the turbo project comes first and the Mile will have to wait til April.

"Do you happen to know anyone that knows anything about the 4 port Natural Gas 13B's? I have one from Daryl D."

no. Daryl built my race engines during the last two seasons and i do run into him here and there. no one builds them better.

howard

 

hey howard good to know you still at it, what adapter did you use to fit the bosch ev14 in the fuel rail?

 

just to be clear i am (still) running the 850s in primary and the newer injectors are in my aftermarket secondary rail replacing the 1600s.

i deal w John at Fuelinjectionconnection and he knows FDs. he asked me for my O ring diameters and sent me drop in EV14s. he did send an intermediate elec fitting so i didn't have to mess w the Bosch 1600 connectors.

the AI EV14s are really neat... they are only 33 mm from top O ring to bottom O ring. tiny! which works well as space near the greddy elbow is somewhat limited.

 

Might I suggest some of these guys across all your sensitive (aftermarket ) electronics

These things will clamp attempt to clamp an over-voltage situation at 22V. The over-voltage situation can be as simple as a harsh road bump causing a momentary battery disconnect on the alternator.

 

Good to see you milling around here Eric. Hope World Challenge is going well!

 

As Jobro said, aftermarket electronics tend to be less tolerant of 'bad stuff.' One thing that could have zapped those parts would be welding on the car without disconnecting them.

 

Howard if you're running 22+psi and doing 4th gear pulls why not just throw it on the dyno, even on a rough tune it'd give a fair idea of how these magical unseen ports are working out for you.

What exactly is going on with the "injector fixturing" that is allowing you to make 4th gear pulls at that level of boost, but not allowing you to throw it on a dyno?

Glad to hear it's up and running, that is quite big step!

 

"why not just throw it on the dyno"

the car was driveable after it returned from BR but not complete. i had to replace the EGT converter module as i was only getting one rotor reading. further, my alcohol pressure gauge was reading zero so i was dealing w the AI system. the odds are i ran the 25 psi road tests getting no alcohol. this is probably correct as my knock was around 40 and it normally, w alcohol, is under 10. i did, then, attempt to dyno it (Aug 4) but it became clear (warm to the touch UIM) that i wasn't getting alcohol.

i just finished my end of the rewiring for the additional injectors. in the process i moved a number of items so they are located to my liking. probably 100+ splices. additional heat shielding, uprated silicone hoses and i am scratching the surface.

the elbow must now be reworked/re-fixtured so as to accept the EV14s. that will be done at BR and the elbow will probably arrive in Green Bay monday.

the project will move forward on the dyno as soon as the car is 100% ready. i have absolutely no interest in just being on the dyno without my ducks being in a row. i am after alot of data w this project and have already been to a rodeo or two.

 

Howard I just want to say that after reading this thread, I would like to apologize on behalf of all the rude *** people around here. Any time you are willing to spend your resources to provide the community with FREE and useful data, you will get nothing but gratitude from me, no matter how long it takes.

Secondly, as someone who works in R&D, I understand the necessity for clean data with minimal noise from other variables in the system, and too often I see people trying to test or tune a setup when the rest of the system is half assed enough to ruin any data they get. It is nice that you are taking the time to eliminate as many variables as possible before taking your data.

One thing that I would be very interested to see, which you may have already investigated, is quantification of the effect of turbine housing size on a 13B. For example, I just bought a S200SX for my FD, which is a comparatively small turbo, but with a good turbine/compressor ratio. This turbo comes stock with a 1.22 A/R T4 housing, but I purchased an additional 1.00. I will likely dyno back to back with both of these to see which gives me the best curve, as I plan to run near the efficiency limit of the unit. I am fairly curious to see how different the boost curve will be, have you done a similar test already?

The thing I am unsure about is the tradeoff between wheel size and housing size. Is it better to have a slightly bigger wheel with smaller housing, or vice versa? On piston engines this has been examined a little bit, but the issue is more important and less clear on a rotary where most of the energy is in pulses vs flow. Can you shed any light on this?

Thanks and keep up the good work!

Pat

 

Good to see some progress

 

the BW S200SX:

cold is 2.2 X 3

hot is 2.24 X 2.74

cold area is 5.4 sq inches V GT35 at 6.386

hot is 5.24 sq inches V GT35 at 5.171 (P trim is 5.89)

S200sx has a nice hot to cold relationship and is a 54 trim to aid spool as if you need it.

at one bar 50 pounds air or approx 375 max rotary rwhp
at 38 psi (!) 56 pounds or 428.

the relationship between housing and wheel is interesting. i have no solid info ATM. i believe Sean favors larger wheel and smaller housing FWIW.

my elbow arrived at BR yesterday so hopefully things are moving ahead.

howard

 

The flow of a larger wheel usually keeps the back pressure down uptop allowing you to run a reasonable sized A/R which keeps the velocity high but not enought to create excesive back pressure.

This alot of times gives you better response/power down low due to increased velocity (smaller A/R) without die'n off up top (Larger wheel flowing more).

There was a thread a bit ago that talked about it (trq on wheel/surface area/etc).

Honestly it's like everything else and there is no silver bullet and you just have to choose what you want.

Usually people will pick a

Large wheel with small A/R
over a
Small wheel with Larger A/R

for that very reason on a street setup. Now if they don't offer it off the shelf it might not be worth the cost to swap out turbines.

This question comes up alot with the

GT35 1.06 vs a P trim .84 (turblown has a resonable priced P trim GT35).

Problem is most turbos are not designed with the high flow of a rotary in mind.

 

I could be wrong but I do not believe Howard is talking about A/R when he says Sean is favoring a large wheel in a small housing.

I believe he is talking about frame size of the exhaust housing, for example T3, T4, T6.

A large wheel in a large frame but tight A/R housing will still drop flow (thus torque) on the top end due to the restriction to flow caused by the angle of entry to the exhaust wheel.

What some have found is a large diameter exhaust wheel in a smaller framed exhaust housing with looser A/R (1:0 and up) will spool quickly and flow well on the top end.

I believe it is from the high exhaust velocity from manifold/turbo small volume and the "leverage" the larger exhaust wheel can exert to spin the compressor for spool coupled with less restrictive A/R and large turbine area for flow on the top end.

For example, my car basically has a T04B 60-1 "P trim" in a S5 TII exhaust housing (T25 sized 1.0 A/R). Peak torque 280ft/lbs torque @ 3,500rpm to 6,500rpm @12psi on mild streetport (stock intake/exhaust closing timing).

I would expect a T25 sized exhaust housing to kill torque before then on the porting. I guess the true test will be when I increase boost (and backpressure) how fast the added torque drops.

On something like GT30R or GT35R on high boost with T3 exhaust housing it typically drops fast due to the small exhaust wheel.

On a rotary we have a lot of external combustion to deal with as well as the usual internal combustion and with the overlap in port timing this really changes the turbo dynamics compared to a piston engine.

 

Could be

Your turbine housings are based off your turbine wheel (like a P trim vs a GT wheel etc).

Alot just have the flange changed so if you order a garrett 1.06 housing you can get a T3 or T4 foot print but they are all based off a T3 A/R even though you can get a T4 flange on it (Same with the Tial V-band). This makes it easy to compare across the board.

Not often do you get real choice between housings such as a true T3 and a true T4.

Now they do make different turbine housings for some turbines wheels and then you can get them. But you are no longer comparing apples to apples.

Like a .84 A/R T4 flows more than say a T3 1.05 A/R.

This is b/c a true T4 has a larger area.

Which is what you are talking about I believe.

That being said - I would argue it all depends on application again which is why we have so many damn choices to begin with.

Aspec sells both a T3 and T4 turbo and for good reasons. It's because better is merely a perspective.

 

a good day for me is when i learn something

as you may be aware, i am in the middle of re-tooling my AI system since my irreplaceable FJO system decided to check out.

it should be a win for me and for Power FC owners as it uses the Power FC to drive an additional pair of new generation Bosch EV14 injectors in the elbow to spray methanol. (you could use water or a mix too).

i premise many of my calculations on an empirically derived relationship between rotary rwhp and airflow. if you know the airflow and AFR you can calculate fuel and lots of other interesting numbers.

it appears i have omitted a key additional deduct going from gross fuel to net fuel:

that factor is injector Lag, often also referred to as Deadtime.

i have read about it many times and we all input lag numbers when we set up our Power FC Settings 5 page.

i guess the lightbulb never quite turned on for me until it was brought to my attention by a board member and after i did some calculations...

i referred back to a previous run for numbers. here's how it played out...

507 rw hp SAE
12.0 AFR
75.1 injector duty
20 PSI

injectors:
primary 888 (RC flowed)
secondary 1650 (RC flowed)
secondaries run by an FJO Peak and Hold converter
Supra pump run by Kenne Bell Boost A Pump at 20% Volt gain

AI
Net delivery of 1128 CC/Minute of 100% methanol at 20 psi



let's now try to quantify the amount of fuel loss from LAG/Deadtime

507 rw rotary hp X 1.92 = 973 CFM/14.471 = 67.24 pounds of air per minute

at 12.0 AFR.... 67.24/12 = 5.603 pounds of gasoline per minute

5.603/6.35 (weight per gallon gas) = .882 gallons per minute

.882 X 116,090 (BTUs in a gallon of gas) = 102,448 BTUs to make 507


BTUs from AI system

two M10 nozzles. Gross deliverability 1262 CC/Min. at 20 PSI boost X .89 (reduction due to manifold pressure) = 1128 CC/Minute Net

1128 CC/Min = .298 Gallons per minute X 57,250 (BTUs in a gallon of methanol) = 17,060 BTUs from AI

102,448 (BTUs to make 507 hp) - 17,060 BTUs from meth = 83,388 BTUs needed from gas to make 507.


BTUs from gasoline

According to my Gross Deliverability (5060) times my duty cycle (.751) i was nominally at (3800 CC) /116,438 BTUs.

116,438 - 85,388 = 31,050 the slippage from Lag/Deadtime

31,050/116,438 = 26.6% deduct


i will be off the board in the wilds of Wyoming this next week while Beyond Redline fixtures my elbow. i should have it the following Monday and hope to be on the dyno that week.

it will be very interesting to acquire some additional data as to Lag/Deadtime.

Lag/DT will vary w re to RPM, ontime, battery voltage, type of injector, fuel viscosity/temperature but from my calculations it may be a really important factor to crank into fuel system requirements as far as getting to NET Fuel Delivery.

injectors generally come w Lag settings to compensate so proper fuel is delivered throughout the range... so the settings portion is handled.

my concern is that when figuring fuel requirements perhaps another 20-25% needs to be added so as not to run short. if that number is in the ballpark it is an eyeopener.

comments welcome.