philodox

hehe.. I wouldn't exceed 25mph right now if I were to go out in this weather. If someone is driving 45mph in 6inches of snow, I don't care if they are magic Mario.. they are out of control.

dmp

Good info John, thanks -

Question: Were your numbers 'corrected' or 'measured'? If they were SAE, can you find the correction value?

Let's think for a second...

40-65 more HP at 66% of the available powerband...That sounds great. While I am growing more frustrated at Mazda's refusal to 're-update' their claimed power levels, that GReddy turbo system may just be the ticket, eh? As long as it wouldn't lead to too many tickets. :-D

-darin

Kooldino

higher gear = higher load = more stress on the engine.

JeRKy 8 Owner

Unfortunately that ticket is sans warranty. But like they say no pain no gain - right?

Im_DANomite

iTrader: (1)

just out of curiousity. how would water injection be on a turbocharged rotary?? i'm coming from the MR2 community where WI was very popular. it allows you to run more boost and tune more aggressively, at the same time, being safer. although adding water injection isn't going to give you power itself, it allows you to turn up the heat, which in return gives you those wanted ponies.

Jason

Water injection has become popular on the RX-7 and works very well. It is something that would work on the RX-8 and allow you to run more boost on pump gas.

Jason
www.rx8store.com

Im_DANomite

iTrader: (1)

Do It Philodox

bureau13

If you're running a WI setup for added safety margin, great. If you're running it so you can tune for it, i.e. turn up the boost beyond what you would otherwise do, you'd better be damned sure you don't run out of water or something doesn't fail in the system.

jds

globi

If the system would measure the temperature it could reduce boost as soon as the temperature exceeds a certain limit (for instance when the water injection system fails or if its very hot (ambient temperature) and humid (less water can evaporate.))
Water injection is cheaper than an intercooler and reduces the length of intake pipes and doesn't restrict the airflow. I wonder why it's not more common it shouldn't be that difficult to control it and make it save. I heard rumors about potential corrosion but don't see how that could indeed be an issue as long as it always evaporates before reaching the engine and distilled water is being used.
Of course there's the inconvenience of having to fill a water reservoir occasionally.

bureau13

It has a much greater chance of failure than an intercooler and even without any failures you have to keep filling it...plus I doubt its much cheaper than an IC if you do it right.

jds

Richard Paul

iTrader: (5)

We've been through this before. WI can be usfull but as someone just said to use it as an intrical part of your tuneing system is nnot good. It is a band aid. What is it doing? Putting out the fire that's what.
If it saves you from burning a piston then it did it's job, but if that is your MO then you designed the package wrong.

We used water/alcohol in the race Merlins but were running 50psi at times. Notice that we used the alcohol to make up for the lost heat. Methanol burns cool has great latent heat of evaporation. Don't use ethanol.
If you must use it use 50/50 alki/h2o. Distilled water of course.

Don't mistake pure water for distilled.

ctupton

My brother had an Srt-4 that he installed a WI kit on, and it made his car absolutly sick.... with it, he was able to crank up the stock turbo with out any detonation....

Kenco

Philodox

You don't have a Gtech do you?

It would be good to see some numbers/graphs with the intercooler & intake getting their full quota of cool air!

When the snow stops!!!!!!!!

philodox

Sorry, no Gtech.. I've always heard they are pretty unreliable. So I never went out to buy one.

MazdaManiac

iTrader: (3)

I have a G-Tech Pro and a ton of before-turbo runs.
As soon as the roads clear (probably several weeks) I will get some new post-turbo runs.

Kenco

Nice one MazdaManiac!

Kooldino

I haven an Auterra (for the Palm OS) that hooks up through OBD-II. It can give you all sorts of info from your ECU, and on top of it, it can time 0-60 / 1/4 mile runs, etc. It's pretty spot on. You can even give it a bunch of info like the frontal area of your car, the weight, gear ratios, conditions, etc, and it can give you a dyno chart if you do a pull in the gear of your choice.

Believe it or not, it's reasonably accurate too.

Nemesis8

iTrader: (3)

Now that is an interesting product - Hymee you have a competitor...

http://www.auterraweb.com/index.html

philodox

Wow.. that's a nifty tool.. Something I may look into. Does it take AFR too? Would be useful for tuning.

dmp

I believe if one were to take measurements under the same conditions, roads, etc, the GTech is a fine tool to chart progress; Id est, while GTech's aren't comparible to dynos or actual track racing, they are a great tool to compare with other gtech runs in the same car.

MazdaManiac

iTrader: (3)

They are a lot like the dyno - they are for comparison, not absolute measurement.

Considering the Apollo missions were guided by inertial accelerometers that were far less accurate, I think the G-Tech is amazingly veracious.
The trick is knowing how to use it, knowing the accurate specs for your testing situation and, most importantly, knowing what it does and does not do.

Too many people just slap one on their dash and go out blasting down the highway.

r0tor

iTrader: (1)

umm no... you can only reach 100% load

philodox

Do you know what gears dp? I don't mean to be condescending. But gears take stress and load off of the engine. That's why it's easier to move in 1st gear vs 6th gear. It's just the way the physics work out. Gears provide mechanical advantage.

r0tor

iTrader: (1)

In order for the dyno to work, it has to put enough stress on the engine to reach 100% load no matter what gear your in and the engine can only produce xxx hp no matter what gear your in. A dyno is not going to load the car to the point where it stops the wheels and spins them backwards - which would happen if you hit much much more then 100% load.

The only result in the end of using a higher gear is the wheels spin at a much faster speed and will accelerate at a much slower pace then using a taller gear - which is what you want because the slower acceleration means less inertial losses in the drivetrain (plus if your in 5th the power gets transmitted directly through the tranny rather then going through a secondary shaft). The old 15% drivetrain loss rule implies you are in the 1:1 gear ratio or else it is going to be much greater. FWIW, before reading this board the only time i've ever heard of people dynoing a car in anything other then the 1:1 drive gear is when they are doing quick a/f tuning runs and just using the results to compare against other runs done that way.

Think of how much hp "increase" is observed from a flywheel in 1st gear compared to 4th gear... its the same laws of physics working


When i use to test engines in an engine lab we would actually hold the throttle wide open and then adjust the dyno resistance so that the rpms would remain constant for a good 30 sec at steady state and basically work our way up throughout the rev band that way to get the most repeatable results.

RotorManiac

Where did you get it from??