2012/05/06 04:33:53
MANDALAY
Very scholar answer with great use of words and theory which frankly sounds impressive.
 
But at the end of the day really i don't care for it much, because your first statement is correct but choose to ignore the latter part of the sentence.
 
"It is a known physical property of gases that an increase of pressure results in an increase of temperature in the absence of any other energy transfer "
 
Great thing about dyno logging and with a great shop is the ability to compare data
 
I couldn't care less that a Turbo , a small one or a bigger one has more power than the Rotrex. I enjoy the lower temps in my IAT's and engine bay ,the predictability and response of my boost relative to my foot like a N/A. It suits me the way i use my car , the Beams engine and the aesthetic installation to my eyes
 
Now back to the post ignoring the fact that you wish to tell me again that the Turbo is better, more efficient , has the ability to have bigger boost etc than the Rotrex which again i don't care, you rely on theory for your argument that  it all results in lower temps and the Rotrex will have higher temps.
 
Well , fantastic thank you for the physics class but in real life that's a load of baloney.
 
The Rotrex's low IAT's are a testament that's its devoid of any other transfer heat being on the cold side of the engine away from any hot exhaust temperatures and NOT connected to the hottest part in the engine bay the exhaust manifold.
 
As far as the intercooler effectiveness for low IAT's well i don't think much for PWR barrel. Its weak compared  to other designs.
 
And if you wish to take the " intercooler effectiveness " out of the equation we ran my car without the water pump running a whole day ( to set up up cooling failure, ECU control ) at ambient temps of 36 degrees , the highest IAT's that were logged were 56 degrees Celsius , ( remember i DON'T have twin 12 inch fans on my engine lid ) now ild like to see a Turbo to be that low with no intercooler, IT WONT.
2012/05/06 07:37:14
MRTurbo
cog's post wasn't a personal slight on your setup, MANDALAY, he was merely pointing out the fundamental differences between turbocharging and Rotrex.
2012/05/06 09:48:33
MANDALAY
So where is the first hand experience with the Rotrex that supports his claim ?
2012/05/06 11:08:51
cogs
MRTurbo is right Mandalay, I have the utmost of respect for your setup, your attention to detail, and your desire to do things a bit differently.  My post certainly was NOT a "turbo is better" bashing.
 
The heat transfer from the hot exhaust side of a turbo to intake air is negligible - the air is simply not in there long enough to take on any appreciable quantity of heat energy.  I don't have first hand experience with a Rotrex, but I do have an understanding of fluid dynamics.  So do the people who designed the Rotrex and they will tell you exactly the same thing.
 
My problem with your post Mandalay is that you made a claim, and have done so several times in the past, without ANY evidence to back it up.  Where is your dyno session evidence with a turbo car producing the SAME boost as your Rotrex, showing the compressor outlet temp higher?
 
It wouldn't matter if I was zoologist and had never laid eyes on a turbo in my life, the physics in my post above is well established FACT, and anything that proves it otherwise is falsified.  Again, this is not a Rotrex bashing, just simply pointing out an error in your assertions.  I apologise if it seemed that way.
2012/05/06 11:23:15
MANDALAY
Well i wont make that claim ever again as i dont have the logs of other cars in my hand but had the opportunity to see them.
 
Also I will think more carefully in the future to not make comments without proof
2012/05/06 12:02:31
cogs
Another aspect to consider is that measurement of intake air temperature is very difficult to do with precision.  Most IAT sensors only give an approximation - good enough for the OEM application.  Even supposed "fast-response" sensors suffer a multitude of problems leading to uncorrectable errors, including heatsoak/sink from the mounting and sensor external surface, thermal inertia of the sensing element, the "point sensing" nature of the sensor not averaging the temperature of the entire air volume passing it, etc.
 
The only way to make a valid comparison is with identical sensor setups on both cars, and under the same environmental conditions.
 
BTW, Rotrex proponents on the web are claiming an efficiency advantage over turbos - 65% for the turbo and 72% for the Rotrex.  Seems to me like they're comparing the average efficiency of a 30 year old T-04 with the peak of a brand new technology Rotrex - hardly a valid comparison.  Some of the new Borg Warner EFRs peak at 77%.
 
Edit:  Again, this post is NOT a Rotrex bashing, just my objection to advertising folk not comparing apples with apples.
2012/05/06 14:26:56
Reddtarga
Mandalay, I notice you have CRW shifter cable end rose joints.
 
In theory these seem like a good idea to reduce cable end flexing however: 
A few months ago I got a set of these from CRW but found they were very stiff and tended to jam when I tried to turn them.
Since I couldn't free them up, and didn't want to have a siezed steel bush centre tuning on a steel shift lever pin I didn't fit them.
Although my set may have been just a bad batch, perhaps the design of these might be flawed anyway, since they are unsealed  to the elements. 
Anyway I will be sticking with OEM ones from now on.
2012/05/06 14:44:22
MANDALAY
Thanks for the heads up.
 
I have checked them just now and they turn freely 360 degrees like a ball bearing.
 
Maybe a bad batch ? Let Josh know im sure he will replace them.
 
But i still am hesitant to use them as i have bought new cables
2012/05/06 15:50:47
Reddtarga
I just checked your pic again and I think you also have the needle bearing replacement for the square block.
 
Sorry about more bad news but I also got one of those from Josh lol,  but when I went to fit it I found there was far more play in the system (slop would be a better word)  than with my old worn block, and I wondered how the needle rollers would wear on the bellcrank pin, so I fitted a new OEM part instead.
 
Although the OEM block looks like steel, it is obviously of a compatible metal bearing wise with the selector shaft locating channel, because my old block was badly worn but the locating channel had no trace of wear, even on my high k car. No sign of wear on the bellcrank pin also.
Toyota seem to know their stuff, design wise lol.
 
2012/05/06 18:54:11
MANDALAY
Ditto noticed that also. Since my gear box and cables are new ill think ill leave them alone.
<< ..3738.. >> - Powered by APG vNext Trial
© 2025 APG vNext Trial Version 5.5

Use My Existing Forum Account

Use My Social Media Account