Thanks again...just checking some assumptions...

That's what she said...heh

 

Originally Posted by MazdaManiac
Just think how well it would work if you had it plumbed into the right part of the intake!

???

Please elaborate.

 

The meth injection should go after the blower, not before it.
The temp delta is greater if you use it after you have added heat to the charge.
Plus, you won't be introducing a non-compressible liquid into your blower, reducing its efficiency (and life expectancy).

 

there is no idle issue. the idle wont be affected because the MAFS is non linear. velocity matters not either. turbulence as we know can be a factor hence the screens before the MAFS to straighten out the air.

Our current MAF is 85mm. if needed we can move to 90mm. 90mm when scaled properly is enough MAF to cover more power than the renesis is capable of handling.

 

for sake of redundancy and clarity i have copied my post in another thread to here as well


i asked him to post that question while on my way to work. things have away of running in the background while im doing other things- like trimming my Christmas tree and then driving to work.

GTAW posted in this thread:


and

thats what i remebered on my way to work SOOOOO - how are you getting maf readings past 5v when it is a 0-5v sensor?



as jeff said you re scale your airflow map and then add injector pulse width to match.


Actually there isnt. idle doesnt suffer because MAFs are nonlinear. and that screen of yours can take care of any turbulence. it might even be a little over kill

thats true people have done it http://www.autospeed.com/cms/article.html?&A=2424

but that really is IMHO a really wrongheaded, bandaid approach and really unnecessary given the EMS solutions we have available to use today. but then id be arguing with Julian Edgar (here and here )so...

 

i want to make a comment at this point that im sure will ruffle some feathers.

i wasn't cognizant until the last couple of days of some of the particulars of the Petit SC kit. I hadnt paid attention to some of the details. For instance i did not know about the smaller than stock MAF tube and the IAB hose set up.

allowing unmetered air in an engine and then correcting for it afterwards is simply the wrong way to do things. downsizing the MAF tube as part of the correction is wrong. Shipping a FI kit for this car that does these things is simply irresponsible and i can not fathom how Cam Petit let these things ship in that condition.

Im glad they are now getting fixed and done correctly. But shipping them before this was just wrong. Its exactly on the same level as Greddy's Turbo kit when it came out and had so many problems. The only difference here is that Cam is lucky this system with his name on it didnt break a bunch of engines.

 

Correct - based on Jeff's engine info it is somewhat exponential.



This is the only information I can prove - the questions becomes with a loss of granularity with a larger tube - will it matter? I don't think so - thinks look pretty tight down low at least within reason.

 

every ford guy who has moved from a stock tube to the SCT tube of the Lightening 90mm tube is proof


actually just looking around i found a post that might be relevant to GTAWs issue.

this is in response to a question about using the Lightening MAF in blow thru

i was wondering about that earlier when looking at GTAWs pics.







there is not much same(and no stock) size pipe before and after his maf (in fact looking again none at all after the MAF) and what is there is changing size and direction quite quickly. that combined with the blow thru could be all of the problem.

the decrease in size and that turn directly after the maf in his blow thru is causing turbulence/killing the laminar flow. he needs to straighten that out and run the same diameter further out.

i bet if he runs the same diameter tube out to the same length he currently has the tapers before and after that would bring it to just about the same length as the stock or RB maf tubes and would solve his peg issue

 

Thanks, I see your point.

Here's what Snow Performance had to say about the subject.

"I don't know where you read that mounting the nozzle in front of the throttle body causes problems, because we recommend that location typically. We don't recommend injecting pre-compressor on turbos or centrifugal blowers - the high speed of the very fine impeller blades can be damaged by water droplets. On your twin screw it is perfectly fine, and keeps the rotors and housing much cooler as well (which prevents them from heating the intake air, etc).

We even have rubber nozzle mounting adapters available to make your install easier and cleaner!"

 

ok, im sorry to ask this, but what is a blow-through and a pull through system?

 

Nice!

That simplifies things tremendously.

 

blow-through means the MAF is mounted after the compressor.
draw-through/pull-through mean the MAF is mounted before the compressor.

 

ok, got it, thanks

 

What effect does oil pressure have on a turbo's bearings. Is it the pressure or the volume of oil that causes the bearings to go bad?

 

hmm, i would say volume. at work here, we have these new cam assemblies that dont use any bearings. they have small oil holes and very exact tolerances, so when the oil pump starts flowing, the cams are allowed to move virtually frictionless. i would say that the pressure helps them move easier cause more clean cool oil gets pumped to them. but if there was too much volume going to them, it could offset the toleances, and cease. it has happened a couple times. thats my contribution

 

This is absolutely wrong.
Alcohol will damage the lobes in a variety of ways. The alcohol is corrosive. The liquid is not compressible.
But, more importantly, you are getting a fraction of the potential benefit. Cooling the inside of the blower is silly.

It only simplifies things in that you don't want to change them.
Functionally, if you have meth injected before the blower, its like eating toilet paper along with your food and expecting the usual performance.

Journal and ball bearings have different oiling requirements.

A journal bearing turbo is depending on the oil to perform two functions. One is to create a cushion of oil that acts as the actual bearing surface inside the turbo. It takes very little oil to do this. The other function is to cool the bearing surfaces. It takes substantially more oil to accomplish this goal.
That is why restricting the oil to the GReddy turbo was such a touchy subject.
Reducing the flow kept the volume lower so that the drain wouldn't overload and the turbo wouldn't start smoking.
However, on shut down and idle heat soak, the bearings are cooking, which is ultimately what leads to the failure of the turbo.

Because ball-bearing turbos are water-cooled, the cooling benefit (especially at idle and on shut down) of the oil is minimized.
All medium and small framed ball-bearing turbos need an oil restrictor in normal usage.

This is true as well.

 

So what size oil restrictor would you suggest if I was running a ball-bearning T3/T4 turbo and a modified oil pressure regulator to increase oil pressure?

 

You don't need to increase pressure if you are using a restrictor?
Or do you mean inside the motor?

In any event, an .035" will do the trick.

 

K.I.S.S.?

 

why?

 

So, Is the purpose of the restrictor to decrease the amount of oil that is entering the turbo or is it to increase the pressure at which the oil is pushed into the turbo.

Ray is correct. Basically, I MAY be using a modified oil pressure regulator that will increase my oil pressure above what it is from the factory. What effect will this have on the turbo and should steps be taken (.035" restrictor) to prevent premature failures?

 

because you are only getting a small percentage of the possible cooling effect and therefor only a small benefit. your wasting meth and more than likely damaging the blower. shoot it after and you get the full cooling benefit

 

Wouldn't doing it before make the blower more efficient, and increase the likelihood of proper atomization (lower pressure pre-blower).

Anyone have some math to back this up? I'm not contesting anything here, I'm just very curious.

 

I do - but not here in the barracks...

Basically; the cooling charge will have a greater % change the hotter the air is; so to "pre-cool" the air is not as effective as the air may go from 80 to 75 degrees - then go right back up to 150 post blower vs. 170 and down to 90... all numbers are made up btw.

Think how much easier you can cool coffee vs cooling ice-water. Energy input versus change.

 

I think he was referring to how much energy is required to effect a change...

His example is a classic example used in thermodynamics...

It takes LESS time to chill a steaming hot cup of coffee than it does a "cool" glass of water...with the SAME amount of energy...

The "discussion" here is what location is best I think for the "overall" application of meth injection. In that regard POST compression is "better" because it gives you the benefits of meth, but with a better cooling effect...

PRE compression and you get some of the cooling effect, and the remainder of the meth effect...


EDIT
SEEK: Mpemba Effect...

http://en.wikipedia.org/wiki/Mpemba_effect


BUT...

POST compression...you get the meth effect AND much better cooling as a bonus...

It will work either way...but its more efficient POST in regards to effect...

Kinda like a recent discussion regarding cool-air for turbo/stupidcharged systems...cooler air going into the filter is not really required...but it does help...