Nerd ^^^

LOL, sorry; I just throw them together - I am the data guy; no the presentation guy....

But glad it helps - twinks got right in on the heat transfer stuff - thanks bro; I had to sleep.

Interesting to hear if the meth injectors can run in positive pressure; this is going to be a good test.

 

you're welcome

 

Good thing your back...I'm completely indisposed at the moment...you'll have to take over as my higher brain processes seem to have stopped...

Nap time...

 

Water is basically a detonation supressor.

Meth is another fuel and charge cooler.

Rotary drag cars can run meth only for fuel w/ no intercooler. After a run you cannot touch the manifold upper or lower as it will freeze your fingers. The Colon car in PR just ran a 6.97 at 197 in the 1/4 on meth. He's making a mere 1100 rwhp out of a 13B. Side port + a semi PP. Video:
http://www.agracingvideo.com/videos/...sporty6.97.wmv

On the FD we will be adding a Meth kit to will be for High boost 22psi + on pump (91 in OK) and meth. We will be tuning for the meth.

There are a couple guys running street cars w/ a 50/50 water/meth mix and no intercooler w/ 13B's.

I have not researched it yet, but why can't we switch the MAF for a MAP sensor w/ the new after market ECU's

I have to start looking into my 8 more instead of Dailying it.

 

because there is no reason to switch to a map

 

what? i should repost my posts from the last 2 days again?

 

how does one become a boost atheist? if one does not believe in boost?

 

Bad News - work got out of control and I forgot to get the info I wanted - does anyone still want to see the math proof of the thermo dynamics or has that ship sailed?

If so - I can get it after dinner.

 

Ahh! Those speed crazy Puertorricans and their world speed record breaking rotary engine cars.

http://grs-motorsports.com/noticias/...s/15dic/25.wmv

http://grs-motorsports.com/noticias/...s/15dic/27.wmv

http://grs-motorsports.com/noticias/...s/15dic/26.wmv

 

We can switch to a MAP sensor. The Interceptor-X EMS is an example. However, the RX8's PCM will throw a CEL because it expects to have control over the Primary and Secondary injectors. The Int-X takes complete control of the Fuel and Ignition and removes the PCM from the equation.

In addition, some people have experienced idle issues and a general lack of tuning granularity with the MAP based systems.

Even when switching to a MAP based system the MAF sensor still needs to be mounted pre-compressor because the PCM needs to see a somewhat accurate airflow reading from the MAF sensor in order for the TCS and ABS to work properly.

 

Please God NO!

 

Zoom and I agree to disagree on this subject. I feel that there are great advantages to a MAF based system in a Street scenario. However, I feel that switching to a MAP based system has advantages in a Performance Scenario.

A MAF based system will have more advantages up to a point. This point can be moved around some by changing the tubing size where the MAF is mounted but, this modification like all others comes at a cost. When increasing the tube size you loose granularity in low load/idle situations and by decreasing the tube size you loose the ability to tune for the high airflow situations because you max out the MAF voltage range quicker. We do agree that there is NO reason to decrease the MAF tube size below the 3-3/8" OEM size.

A MAP based system is basically the opposite. You loose tuning granularity in low load/idle situations but gain it at the top end.

 

For boosted applications looking for good power a MAF is a waste IMO. From what I have read the MAF reads to 5 volts and then is limited. If memory serves correctly some want to use a larger diameter intake tube to compensate. Which is just another band aid IMO.

Take for example my track car. Its a 88 Turbo2. Came w/ a factory MAF. There is only so much you can do w/ it. I am currently running a Haltech and a 3 bar map sensor and 16 PSI on pump 91. The MAF could not keep up w/ the turbo I currently have. Its a restriction in the performance area. I have a feeling its the same here. I just need to tear into my 8 but other cars are in the way.

There is no reason you cannot tune the MAP for idle cruise the same as the MAF. Mazda never intended for the 8 to be boosted therefore used the MAF set up as it works good for N/A motors, but is a headache in boosted applications.


Charles, Sorry to get off topic. If we need to create another thread would a mod move this? I would like discuss it in more depth.

Thank you,
Brad

 

That was also 20 years ago. The OEM computers between a T2 and an RX8 are so drastically different.

MAF tuning for boost seems to be working fine for the scoobie and evo guys.

 

Keep in mind the air flow meter on your car was a flapper door style and only had 5 sq. inches of area when fully open. The RX-8 maf is not a flapper and has more flow capability than the rest of the intake system does so it isn't a restriction to anything.

I'm not getting into what is easier to tune but my RX-7 does run a map based system too.

 

How many renny guys are making 400+ on the MAF system?

I have 2 cars I can get in today w/ 400+ to the wheels on a MAP based system both rotary.

You cann't compare setups on evos and scoobies and compare that to an 13b.

I am not running the stock T2 computer. I have a Haltech E8 and a 3 bar MAP good for 29.4 PSI. Can the MAF handle that? Look at all high hp rotaries and tell me if you find a MAF.

 

The principles are the same there are just some different components to figure out.

Thats what we are here to do. If we wait for someone else we will just be well waiting.

 

RI - actually if you look at Kane's graph, there is plenty of resolution down low. Even if we compress it significantly by expanding the range, I would not expect to have any problems with idle operation using a larger ID sensor.

Actually, I would be more concerned about losing resolution at the top end. This might be a drawback of adjusting the MAF sensor in this way...

 

Exactly. The principles are the same. Don't dismiss what works for subaru / evo cos at the end of the day all we're trying to figure out is how much air made it into the engine.

 

That's irrelevant. It's not the MAF that is holding anyone back from doing that. It's compression and strength of other components. The MAF flows MORE than ANY other part of the Renesis intake so I don't see how it could EVER be a flow restriction. You'd run out of resolution before flow ever became an issue.

 

Since we are FI guys - I will start with pressure gradients - thinking in terms of the General Gas Law / Ideal Gas Law we know that for a specific period of time a larger pressure gradient will create faster airflow than a smaller one.

The same is true for temperature - like pressure temperature will always equalize given enough time - but since our time frame is short - we want to find the largest temperature differential to hit with our specific energy (meth shot). For X period of time - Y specific energy will have a larger impact when the temperature differential is say 50 degrees versus 10. This is why coffee sems to chill faster than room temp water would given the same ambient temperature (say 10 degrees below room temp).

Liquid (I will use water as an example) is better than gas because it conducts heat 10 times better (10 or more - looking for reference). But regardless of the efficiency of the liquid - the fact remains that the change in temperature can be optimized be introduction at the highest temp gradient.

 

I understand the quest for raw power , but lets not forget the majority on 8 owners that just want a good increase, streetability and a pretty good road track car. IMHO on the drag strip this car does not belong. Not that you cant drag with it--you can ---BUT this is a road race car.
If you tune for the best result from an injection kit then a flash will not work? You need more control to take full advantage of the cooler charge and the increase in octane?
If you get an injection kit just for charge cooling then you can run the flash Pettit has and run the injection kit when you want it? No additional tuning required?

So if you are using the injection kit all the time(tuned for it) how long does a the adverage bottle of mixture last? On the strip I now it doesnt last long---maybe 15 runs or so. Course that is wot
adverage Joe questions.
oscd

 

There are a couple things standing in the way of that right now. The MAF is not one of them. When the 8 is 20 years old there is no doubt in my mind there will be as many or more 400whp+ 8's as there are 7's. And they will do it on MAF systems.




Why not? I'm not so much comparing the motors as the computer/sensor setups. The computer doesn't care where the air ends up. It's metering the air to determine the fueling (and timing) needs. It doesn't care about reciporicating or wankling.

The OE MAFS? Nope, probably not. But there are MAFS' that can. And since we are talking about aftermarket air metering parts I only think its fair to take into account what could be used.


The great thing about MAF tuning and flash capabilities are not having to go to an auxiliary engine management. The OE computer can be retained, which is very nice considering all the functionality that is built in and how the dash lights up like a Christmas tree (Happy holidays!) when you try to take away its control.

Just because the tuning solutions have not existed in the past to properly setup a high horsepower MAF based system - or it was just more familiar to the tuner - to do a MAP system doesn't mean it can't be done or even that MAP is optimal.

 

I was talking about the various 13B's. I have a good buddy w/ a STI and it is in no way like modding a rotary.

Anyhow you guys keep up the good work I have a few meetings to attend and I'll catch ya later.

 

In bold