swoope

iTrader: (5)

yea i knew that. as to the problem, would be hard for us up over to run at high speeds for any length of time to see if we have a problem.

beers

Gomez

Has the RB Ram Air duct been around for a full American summer yet?? Just wondering if an effect on cooling would show up at more moderate (sub 160kph ) speeds.

Nemesis8

iTrader: (3)

We need to go to the Salt Flats I guess

swoope

iTrader: (5)

yep,
mine has been fla usa tested. upper 90s and 130kph ish cruizin for a couple of hours. the delta in abient temp between outside and intake air is about 8deg f. at 70mph. the delta decreases as the speed increases. tested with the hymee scanalizer.

i have seen it decress up till 125mph. cant think of the delta right now.

btw. it has been hurricane tested also.

beers

olddragger

iTrader: (3)

leaned her out and the pcm retarded timing. I bet he also has one screen out.
olddragger

rotarygod

I think this is interesting. I'm sure it'll give the Racing Beat haters some fuel to gripe with but this is only 1 instance when many others have been getting better results and mileage. This can potentially be explained. The same thing happens with fuel grades and ecu tuning. Some get good results, others don't. I don't think the duct is blocking an appreciable amount of air from getting to the radiator. If the engine was working harder to keep the same speed before, of course it'll make more heat. The total inlet area of the ram air duct also isn't an issue. It's total area is larger than the total area of any other part of the induction system including the throttlebody so it wouldn't pose any restriction itself.

There is the possibility that the flow through the ram air duct is too good for the stock airbox. There could be issues with the internal shape of the stock airbox which doesn't lend itself well to good flow and to the pressure changing inside of it from the ram air effect. If this were the case, the air inside the box would back up at some static amount of pressure and the rest that were trying to get in would simply go around the inlet duct. With the REVi box, the internal shape is very different and very open. It is also very smooth inside. This may lend itself towards the air more effectively filling up the airbox and pressurizing itself to some degree. This would lead towards less air going around the inlet duct and more actually getting into the engine. This is all very possible. I just don't see it as being an issue with the Ram air duct itself but more of a problem with the combination of the ram air duct and the stock airbox.

Although it is claimed that the ram air duct and the stock airbox can be used together, their shapes where they join aren't compatible unless you do some work to it. The inlet to the stock airbox is much smaller than the outlet from the ram air duct or the inlet to the REVi box. You can make them fix with some effort but they weren't intended to be used that way. The REVi and the ram air duct do match in size and shape as they were designed to be used together. This combination just isn't set up to work well together. It should really be used with the REVi box only. Many people with that setup are getting better results with mileage increases so it can't be a problem with any one part as it would show up for everyone. This is my guess as to what is going on.

Off topic: For all you guys who want to do temp conversions in your head really quickly but hate that whole 9/5 math equation crap from Chemistry, here's an easier way.

30*C X 2 = 60 Subtract 10% (6) = 54 Add 32 = 86* F

dannobre

iTrader: (3)

I'm always amazed at how people interpret data with a sample of one

This could mean anything............So until we do some more looking...all this tells us that there is a potential that needs to be checked out!

Gomez

I'm sure RB carried out extensive testing before this duct reached the market, but I wonder how much high speed/ high temp testing they carried out?

This duct is located smack bang in the middle of the frontal high pressure area as I mentioned earlier. Unimpeded airflow in this area may just be important to cooling at very high speeds.

It's not a big deal as we all know, the number of RX-8's doing these speeds on the road is very small.

Gomez

It doesn't even need to be checked out.......

Wildcard

Both MAF screens are in. The internal baffles have been removed from the airbox though.

At high speed the car runs pig rich (0.8 Lambda or worse). My theory is that the PCM does this to keep the exhaust temps under control for emmisions reasons.

The VDI valve was not the cause of the initial low top speed. My car topped out at 215km/h (6800rpm) in 6th. Even though the VDI valve was disconnected, at that RPM it was still functioning correctly (i.e. it was closed). Once I changed the intake I got 235km/h in 6th with the VDI still disconnected. Hooking the VDI back up yielded me 236 in 6th and 240 in 5th.

Valid point made I think about the compatability of the ram air intake with the stock air box versus the revi intake.

Hymee I want my blower back!

Nemesis8

iTrader: (3)

Did the ambient wind speed and direction change after your fix? Meaning head wind vs. tail wind?

You should also change your request to Hymee to say, "You can have my blower when you pry it from my cold dead fingers"

r0tor

iTrader: (1)

I just did a quick look at the choke flow equation and a few charts i have for sizing nozzles (yea those are round and the nothing is round here... hence a "quick look")...

but i wouldn't be surprised the flow at that speed/pressure would choke up in the diamond grill pattern at that speed

zoom44

it was shown at this past SEMA and it is to be on the market in just a month or less. So yes Mazdaspeed does indeed offer something int he induction area.

zoom44

I am amazed at your response. The posts prior to this of your's i am quoting are inquistive. not a one is shouting "BS" or any such thing. they are all simply asking for more information so they can have a clearer understanding of the events leading to this thread.

im amazed that you think we should all fall in line and start saying how horrible it was for RB to make a product that would cause such problems on the basis of one persons drive cross country. when there have been those of us who have had no issues. (driving in 90 defree F weather over 100mph with Revi and RAM) why should nobody ask for clarification? what if everyone when told by a person that glasspacks were forbidden on a rotary had just accepted that without question? should everyone have started talking about how bad you are to make them like that or should we ask for more information to make a more informed judgement?

rotarygod

I have a simple pitot tube/magnehelic gauge setup that I could install behind the grille of a car to test that theory.

nycgps

iTrader: (1)

Im not sure , my setup is a Ram Air Duct + K&N Typhoon Version 2.

I didnt reach 134 MPH yet. but I tried a little 120 MPH without any problems, RPM was around 6K that time. and I cant go anymore higher not cuz of the car, it was because of the roads (NYC !!! Too short !!!! )

So .... Maybe I should try to find some place for me to stress the car for longer.

zoom44

I'm bringing over some quotes from the other thread you mentioned.

Why don’t you ask the folks at RB to talk about the effects of ram air that they have seen during the development of that piece Hymee? They’ll tell you how much (or little) effect they found and where at in terms of RPM or speed. The stock intake also boasts of a RAM charging effect. Of course the Mazda folks lie about all sorts of things so why bother believe their engineers.

As far as the holes- what affect do those holes have you think? Lets not let others argue it- lets hear your insinuated opinion.

Now lets read this:

So he had heat problems as well in this same area. He has the stock intake. It appears to be from locusts trapped in the intake area by Hymee grills. . BTW someone tell him the coolant light only means LOW not hot.

I understand from a later comment he was not being specific. But as far as admitting that Mazda got a lot correct about this car in the first place- you will not find any legitimate source saying anything other than that. That’s one thing we all agree on is that Mazda did a lot of great engineering on this car that is hard to improve upon. No one finds that hard to admit at all.


So you are seriously trying to say that RB should have spent time going thru every single possible scenario for every car in every part of the world? Are actually suggesting to us that it was LAME of RB to not – install a Hymee supercharger then drive it around for awhile (with a Hymee exhaust) and what ever other things he has. Then removed it and put on the stock box minus the vfad plus the RAM duct (leaving off the vacuum hose) Then driven it at 9k RPMs in 5th gear across some part of California that mimics the exact temps and humidity of that part of Australia that wildcard met etc etc? Then what? If they found it raised temps or lowered mpg in that scenario should they have asked each person who was buying one if that was their intended purpose? Or should they have not sold it at all? Or maybe with a warning label?

How is that pretty easily assumed? I have never had an overheat problem while having the RAM on. I haven’t heard of any one actually until Wildcard. How much of a percentage of the whole frontal area responsible for airflow to the radiator is being used by the duct? What would cutting open the rest of that faux grill get you? Where would that air go? Certainly not at the radiator.

zoom44

Having said all that I want to make it clear (although some will find it difficult to believe) I am not here to defend RB products for them. They can do a fine job on their own.

Wildcard had issues and he reported them. Some folks asked for clarification on some points.
It seems a bit extreme to me to blame Loss of power, Bad Fuel Mileage, Over Heating and inability to rev over 6800(or7200) on just one plastic duct. It should not be so wrong of us to ask questions. If it turns out it was the duct then it was the duct. But until then I have some questions.

For instance what about this header back exhaust? Who made it had it been done before or was this a one off custom job?

Were all the bits of the SC removed? Every bit?

Does this car have a protection kit for the radiators and oil coolers (like the Hymee screens)?

Was there a locust (or other bug) problem as in the previous example above?

Was there ever a coolant level light? Was there any coolant added before, during or after the trip?

I will probably have more and some follow-ups to these as well.

Hymee

iTrader: (1)

Charlie,

Sorry if you took my comments as confrontational. My "amazed" comment was more a loud sigh than anything else.

The posts were never intended to be confrontational, and I thought I chose my words wisely.

Wildcard's o'heating problems were not locust related AFAIK. The temps went back down when he reduced speed.

The VDI is not at issue, since the car didn't (couldn't) make it to a speed / RPM where the VDI would open. Sure - in the lower gears it would have had an effect.

The S/C was off. The stock intake was in place. The car does have screens fitted (1st batch).

Cheers,
Hymee.

rotarenvy

most of these can be answered with some searching.

timbo

That's interesting news..
....and given this:
....what claimed and verified benefits from induction mods (excluding FI) have been achieved?

zoom44

really ? mind telling me which ones?

QBallz

Wooo hooo. Thanks for the slam.

See what happens when you read the first part of the post then come back later and read the bottom half. Would have been much clearer if you had put the screenshot at the bottom IMO.

I realize now that the VFAD gave 20km/h and fixing the VDI gave another 5km/h. BTW I don't have the Ram Air and wasn't trying to be an ***. Sorry I pushed you over the edge with my inability to read.

zoom44

Mark, it bothered me mostly because in the past people have made comments about your product and many of these same people have "stood up" in your defense. nobody even questioned the veracity of the story or the idea that the duct was behind it. they only were asking for clarification. i didnt se anyone "shooting the messenger"(well until me) You have a way of insinuating your opinion without actually saying it.

So most likely a blockage of some sort. what about the oil cooler. he only still has one or is a second fitted?

Why couldnt it tho is an issue. many people have been on the track with revi and duct and have had no issue getting it over the rpms mentioned in wildcards account. if i remember my scanalyser results correctly it did show an increase in air across the MAF when fitted with the RB parts. so it shouldnt have limited the rpm at all.

Every bit? nothing left in place at all for quicker replacement later?

we have here 2 rx-8s one with stock intake one, with stock intake and ram duct. both have hymee screens. both had overtemp problems in the same general area. one could draw the conclusion that they have the hymee screens in common and there fore that caused the temp problems.

of course that would be the WRONG conclusion and i wouldnt believe it for a moment. but that is the kind of conclusion we have been asked to draw concerning the revi duct without furthur information.

Hymee

iTrader: (1)

C'mon, I didn't say the ram air duct was preventing it revving. I know it is the VDI. I thought I made that clear. What Wildcard and I said was that because the car wasnt' able to make it to the speed/RPM where it opens, it was not a factor. It was a factor in the last few km/h, one that RPM point was reached.

NTRH made it clear the o'heating he had was because of the locusts. That would have happened if the screen was there or not, yeah?

Cheers,
Hymee.