MazdaManiac

iTrader: (3)

I've already done that for my setup. That, I didn't think was the point.
We were talking about high-boost applications.
On my setup, the IATs end up being nearly at ambient.
You can go back and look at those logs in my other threads.

My only experience with boost levels that high have been with piston motors.
The first was a Grand National swap into a Fiero.
We ran 27 PSI through that motor with an a/a intercooler and IATs barely went to 10 over ambient.
The other was an SRT where we, at one point, took the manifold pressures up to 40 PSI through a giant intercooler.
IATs were about 20 over ambient.

BDC

In other words, "Sorry, Fred. I have no data to give."

B

joff

To be fair, my original beef was *only* with this incorrect assertion by MM:

Now, about the 40psi on the SRT with only +20degF temp rise...

Fact: A 20 degF rise on a 75% efficient turbo boosting 40psi corresponds to about a 95% efficient intercooler.

That, at least, violates no laws of thermodynamics by itself.

What seems to be left of the argument here now that we know the above quotation by MazdaManiac is completely and utterly wrong and that no-one will be attempting to defend it, is how common and realistic 90-95% efficient intercooler setups are. I do believe that a giant intercooler is able to do that. FYI, Bell intercoolers has this to say about typical A/A efficiency: http://www.bellintercoolers.com/page...AQ.html#FAQ_14

Also, as a side fact: Do you know how much difference a 75% adiabatic efficiency(typical turbo) vs. 55%(typical twin-screw) is at 9 psi on a 95% intercooler? about 1.9degF in IAT (5degF rise vs. 6.9degF rise)

zoom44

not true typical twin screw adiabatic efficiency is75% and can be as high as 85%. 55% is more like a roots.

Red Devil

Definitely not hitting 85% on a twin screw. More like low to mid 70s, and most of the range in the 60s.

zoom44

of course i cant find the 85% cites now except this one

http://books.google.com/books?id=QrQ...um=3&ct=result

most are in the 70-80 range and 75% is quite normal. 60s is not

http://www.whipplesuperchargers.com/...sp?ProdID=1162

http://www.bahnbrenner.com/about/8/BBM_Superchargers

http://74.125.113.132/search?q=cache...nk&cd=19&gl=us

zoom44

hmm there was a kenne bell link there somehow i lost it

Red Devil

See attached for actual maps from Opcon.

Rote8

Uh, we also have "people" running LARGE amounts of nitromethane.
I have experimented with as much as a 60% nitromethane mix of RC airplane and boat fuels.
The 40% "White Lightning Competition Fuel" is awesome. Pulling up to a red light with the windows down makes your eyes water after you have been on it hard.
(You get the strangest looks from the other drivers who do recognise the smell, and sour faces from the ones who don't)
I have also been told I throw 4 feet of bright blue flames out the back when on it very hard. (by someone behind me on a Harley)

The downside is nitromethane eats Snow Methanol pump seals, but you can buy the seals themselves for about 10 dollars.

zoom44

yes but autorotors as used by kennebell are not built he same as those lysholm blowers even tho opcon owns them both.

and Whipple produces its own blowers now which are also better than those lysholm blowers.

and there are commercial use twin screws that regularly are over 80 and i had read up to 85 but of course i cant provide those links now

joff

You're right. 55% is a slightly exaggerated down number. This makes the adiabatic difference between turbo/twin-screw even less consequential than 1.9 degF on a good and common (according to MazdaManiac, but debateable) intercooler.

I have seen the bias's of the forum members who typically spout off the adiabatic efficiency nonsense. When trying to illustrate a point mathematically, I found its best to round numbers against your position as a countermeasure against internal biases. The point I was "hinting" at was that the adiabatic efficiency range of our FI options at 9psi is just a number that seems mostly inconsequential with proper intercooling (whether it be chemical or A/A intercooling) at typical RX8 boost levels.

I personally am sold on the benefits of W/M injection -- there is another good thread about it on rx7club.com: http://www.rx7club.com/showthread.php?t=806104 and on that thread there is a link to another automotive forum with lots more good commentary on W/M injection (turbobuick.com)

Red Devil

If I could find my autorotor maps to post, you'd think differently. The Autorotor's are slightly more efficient, but not by much. Your engine will again spend the majority of time in the 60s.

But Joff's point is a great one...at our boost levels all this is just academic and inconsequential for the kits being sold. They all can operate safely and as intended.

MazdaManiac

iTrader: (3)

No, in other words: "Sorry Fred: I don't have time to search the forum for you."

BDC

Uhhuh. Right, but you've got time to post in this thread multiple times.

Can't question the forum expert! He's always right.

MazdaManiac

iTrader: (3)

Uh, OK.

Once again, I don't get your problem with me, but, whatever.

I've posted all of my temp delta data (and pretty much everything else about my system) all over the place.
I don't remember where it all is any better than Fred does.

If he wants that data, he can go get it.

Its not like it was relevant to the discussion at hand.

neit_jnf

I just ordered this kit for my FD:

http://www.coolingmist.com/detailmai...ricooltrunk120

the $350 price special will only last until they're all gone or this Friday, whatever comes first so better hurry!

I'm not affiliated with them, but we emailed back and forth and I got great support and technical questions answered quickly so I placed an order

halimsteven

i have a question here again, i am just wondering.
as i started the thread and i have turbo in my car, my AFR is 10.5 - 11.0 when it's in boost. just say that i wanna install W/M 50/50, do you guys think my AFR gets richer?
i just wanna have it as safety factor.......can anybody find this thing ? because my friend told me that if i just wanna cool it down or not tuning it, i should run only water??? i hope someone can give me an advice
steven

chickenwafer

iTrader: (9)

Just for increased detonation resistance I would just run windshield washer fluid. It's cheap, premixed to a low level of methanol, and readily available.

If you do a 50/50 mix of distilled H2O/Methanol, it will fatten up the AFR but it all depends on how much you spray.

dannobre

iTrader: (3)

You really don't need the soap and crap that's in the WWF....distilled/Meth is a lot cleaner

chickenwafer

iTrader: (9)

Just get the straight WWF, none of the Bug Wash stuff and it's pretty damn close to straight water and meth.

I've also tried finding Methanol for premixing but it's difficult. I've been using denatured alcohol.

Rote8

Try the wiper fluid (it's mainly water), then try my favourite; go down to your local hobby shop and get some 30-40% nitromethane/methanol RC car/airplane fuel.
Get one of the ones with mostly synthetic oil, and lower amounts of oil.... (RC airplane fuel has the lowest oil content)
Expect to spend $30.00 on a gallon.
These are the two extremes, the Snow Performance "Boost Juice" is the middle ground.

Then tell us what "feels" best......

I suspect you will become a CH3NO2 fan.
If you use the higher nitromethane blends for more than 6 months,(40% Nitromethane and higher) you will need to buy new pump top seals eventually, they are available at "The Devils Own" methanol injection for about 15 dollars.

Also, remember this stuff IS flammable, make triple sure you have no leaks before using this.

halimsteven

because i am planning to buy AEM, and they will have 3 nozzles, small (150cc for 150-250 HP), medium (315cc for 250-400 HP) and large (630cc for 400 HP and up).basically, my AFR will be richer if i go for 50/50. i heard about the "boostjuicer " from snowperformance, and it's $30 for 4 gallons. it contains 40% methanol and 60% water, do you think this set up is good?
if i decide to use 40% Meth and 60% water with the small nozzle (1500cc for 150-250 HP), do you think it will be richer on my AFR?
steven

BDC

+1. Go to a speedshop, buy one of their 5gal fuel jugs, and fill it up with methanol. I use VP Racing M1 Methanol. Avoid any methanol products that contain petroleum lubricity additives. They'll destroy the pump's valving.

B

BDC

Depends strictly on the amount added. It's not a static thing. Both water and alcohol introduce oxygen into the picture and will add to the Lambda on the wideband, "throwing" it off.

If you want to use it as an knock deterrant whilst not changing your boost level, then that's fine. There's not much you'd have to fuss with. You could probably just get away with using water in this case and not dork with any of the air/fuel blah blah tuning stuff.

B

halimsteven

BDC, my friend show me the thread that you make in RX7 club, i don't know if it's u. which is about AI (auxilary injection)...
so, just say i run 9 psi now, and i am planning to run 12 once a while for my high boost, but i wanna use it as safety factor only, do you think that water only will be good, or i should have 40/60 W/M for my applications........????