Aoshi Shinomori

Didn't you post above about a 77 whp increase by using a big fan?
411-334 = 77?
This all confuses me, don't take this as an insult man, I'm just not understanding why an engine needs to be fed massive amounts of air to dyno correctly, moreso than while driving. What's the point of using fans? to sell more products? Any info is appreciated. Thanks.

Vrimmick

You cannot look at it in absolute values. 77 hp over 334 that is about 22% but 70 hp over 170-180 (what on average we're getting from dynoing rx8) equals roughly 41% - such a gain is unreal. But I am sure that 20% more can be squeezed from rx8 and that would equal 35hp bringing whp to 200-210. Why it needs air to release all the power? WTF knows? I wish I did .......I can only speculate. Perhaps if there is not enough air and the engine is put to stress (high revs) computer retards timing and changes a/f proportions to protect it. Dont worry you will never run out of air while driving it so all the ponies will be pulling on the road... they get lazy on a dyno though
I remember an article in Car and Driver about the effects of using different octane gas on power. Among tested cars was bmw m3 they could never get any real numbers from a dyno on this car because of the lack of blowing air... so they did not post any results for the bimmer.
BTW what do you mean sell more products? Fans you mean? Dont think mazda really cares about how the fans sell... but then who knows that might be a good point

BOOSTD 7

Fortunately it's usually other people's motors that I blow ... fortunately for me that is :D

Vrimmick

Are you gonna be driving any rx8s sent to wolf for ecu tuning... say for testing or something?

BaronVonBigmeat

Errr...to everyone above, the point about the fans wasn't "let's simulate how air would be rammed into the motor at highway speeds, maybe that's why power is missing".

The point was: apparently the BWM (our car too, maybe) can sense that the airflow is not matching up with the apparent MPH, so it cuts back on the fuel or timing or what have you. So maybe we won't see an honest, 100% bone stock RX-8 making ~ 200 rwhp until someone runs the car on a 4 wheel dyno with big fans. [/wishful thinking]

Either that, or we're actually only getting 215 or so at the crank, so 180 rwhp is actually accurate. If that's the case, then jumping to 242 rwhp is....absolutely unholy. (Or, we're making 238 even during dyno testing, but our transmissions are lubricated with wood glue and pencil shavings.)

PoLaK

iTrader: (1)

Ok its not so much how fast the air is moving its how much air is being moved. If you held a dustbuster can up to the intake you’re probably propelling air at some 40+mph at the tip of the Dustbuster straw, but you’re only moving a tiny amount of air. So the more important factor is that you move a large volume of air over the intake, the C&D article your referring too was pretty much a windtunnel moving 11,000 cubic feet (check my #'s) of air per second. And also the major different between our car and the cars in that article is all cars they tested had some from of Forced Induction which probably contributed to the rise large rise in HP (all had air intercoolers), more then a N/A would.

But I'm willing to admit that you right that sticking the 8 on that particular Dyno would yield a close to real world HP number, but it still won’t be exact. For me it’s enough that I know that a 3100-3200lbs car can run a 14.5@94MPH under a hp calculator that’s putting about 197-205 to the wheels which makes me happy. ITS JUST A DAMN #'!!!!

I also fail to see how and I fail too see how the windtunnel Dyno is pertinent to Mr.P&P's testing?.... He dyno'd his stock 8 before he did his porting and he got a 197 once and 184 another time. Then he worked his magic and he dyno’d again and got 242..... As a comparative tool especially if done on the same day nothing beats a Dyno......

Aoshi Shinomori

Ohh, ok that makes more sense, I was not understand the whole fan thing.

Aoshi Shinomori

I get it now. What I meant about selling more products, was that say a company is dynoing a product. They then use a fan to make the gains seem bigger, thus making their bogus product seem much better than it is. I made this assumption before I understood what you meant about the fans. I thought this was universal among cars which is why I was confused. Now that Baron explained that the ecu senses little to no airflow I understand it and most of my questions don't make much sense. Sorry for all of the confusion.

Vrimmick

Well that was just a joke... not funny?

zoom44

what if the air tunnel dyno was also in a big cooler like at a meat packing plant and we could also have a dehumidifier there too. cold, dry, 200mph wind blowing at the car on a 4wheel dyno. yeah and then we could...

Vrimmick

what if we dyno it in the outer space using rocket fuel not a bad idea ha?

PoLaK

iTrader: (1)

no... i just don't see how its part of the issue at hand...?

Or are you a non believer in the HP he made?

Why a 4wheel/roller? 4wheel doesn't meen there is a pully attached from the rear to the front rollers it just means that you can dyno 4WD cars on them, right?. And far as im concerned there in no "half limp mode" (when the abs light turns on, its normal, alot of cars do the EVO included and they don't have a problem dynoing with the light on) if limp mode engages on the dyno you loose 100hp not 5 or 10.

Icemastr

I haven't blown anyone elses motor yet but I am sure I would be equally skilled at that :D

zoom44

exactly my point polak- i was being silly because the dyno topic is silly. you can change a number of things about the conditions you dyno in and get a different number with each change. whats the point? dyno your car on the same dyno with as close to the same conditions as possible each time you dyno. the percentage increase or decrease is alot better to go by than just the number. also looking at the charts to see where in the band the power was made.

PoLaK

iTrader: (1)

sarcasam is lost on the young

smrx8

iTrader: (1)

Mr. Port & Polish were are you installing the n2o hose thats send the juice in to the car,i know charles hooks his up to the rubber piece thats attached to the air cleaner.would you reccomend any other place.

alex

sorry, the thread grew fast and I didn't want to read it -- sorry --

Is this a wet or dry NOS setup? I think its a dry setup, correct? and, are there any #'s yet?

smrx8

iTrader: (1)

iam pretty sure he will use a wet system.

Kari

350RWHP? I am sure he is adding additional fuel somewhere as a rotary needs about 4 850CC injectors to handle that much HP.

Ajax

if he's ported it, i see no reason why he wouldnt have already replaced the injectors.

Floyd

I think the whole point of his project was to keep as much stock as possible. Am I wrong? I was under the assumption that everything from the ECU to the Injectors is stock.

rotarygod

My God! Kari is that you talking? Both cute AND technical. That there is a woman!!!

rotarygod

To do it the easy way you could just use an additional injector controller that doesn't touch the stock fuel or ecu systems. An additional fuel line with it's own dedicated pump could be used for this system. The factory ecu would never see it.

Mr. Port & Polish

Yes sir...

Kari

Which with this type of setup would be the best way to go in my opinion. As long as the stock injectors are up to the task of handling the power the car would be making before the nitrous (which with 230-240 that shouldnt really be a problem) adding a secondary injector or two in the intake manifold and having it set to add the fuel when you are on the spray is the way to go. This is the type of setup Icemastr has with his Turbo Van using 4 additional fuel injectors in the intake manifold set with a hobbs pressure switch to activate when the car sees above 2psi and monitored with an EGT gauge and wideband for tuning. With this large of a shot of nitrous I am sure aditional fuel beyond what the stock system would be able to provide. So while I can't say Judge Ito is using a "wet" nitrous kit for sure, I think thats most likely what he is using. For anyone that doesnt know a "wet" nitrous system is one that adds an additional fuel supply rather than just using additional fuel from the stock fuel injectors. Installing larger fuel injectors would add complications to the install as well as possibly decrease fuel economy or make the car a little less driveable.