Lock & Load

Is there anyone else other than Hymee working on a twin screw supercharger for the rx8 that you guys are aware off ??, if not why NOT????.

As rotarygod stated........ "Hymee has probably the best and most realistic power upgrade for the real everyday , emmission passing , street driven crowd ".

So why hasnt anybody else approached the rx8 power upgrade with the same method being the twin screw type supercharger ???

Even from my limited knowlegde of rotaries it seemed obvious that the twin screw type supercharger was imho one of the most suitable method for getting extra power into the rx8.


Are others tuners engineers looking for the easier option of turbocharging, nitrious etc .???

CHEERS
MICHAEL

rotarygod

You need to realize that the rotary community as a whole is pretty close minded when it comes to supercharging. The big rotary tuners will always tell you to use turbos and that is all they know how to do. They'll tell you how a supercharger robs power off of the engine yet they'll use small turbo exhaust wheels and terrible exhaust manifolds that choke more power away from the engine than a good supercharger will. The twin screw supercharger is a wonderful platform. The new infusion of rotary interest with the RX-8 will start to see different approaches to rotary building. Alot of the rotary crowd still insists that the Renesis is weak even though it produces far and away more power and revs higher than previous rotaries. This is kind of like the LT1 crowd insulting the LS1. Something seems backwards about that. Personally I am not going to be surprised when (not if!!!) Hymee hits 400 rwhp with this setup. He'll do it with a super wide powerband and the same low emissions too. I only wish I were down under to see it.

Hymee

iTrader: (1)

Thanks guys for getting my thread back on track.

I guess I used the word "initially" in case one day I do increase the RPM, and someone says "but you said....". My current project does not plan on increasing the RPM.

Thanks also for the confidence in my work, and choice of technology.

If I increase torque at one RPM, then I increase HP at the same RPM. The two are inseperable. It is just a weird phenonemom, Huhsler, that people relate low down power with torque, and high-speed torque with power If an engine makes constant torque, then the power will be a linear slope line, as the RPM is then the only variable.

The use of a positive displacement supercharger is increase the airflow ( = torque) by a roughly constant amount over a wide RPM band. If you increase torque by "x"% at every RPM point, you increase power by the exact same amount (%) at each RPM.

It is essentially increasing the displacement of the engine, which is what super/turbo charging is anyway. With the use of the bypass valve, it is very similar to having displacement on demand



Cheers,
Hymee.

shelleys_man_06

As an afficianado of all things forced, whether engines or food, I am always willing to prove everyone else wrong. I don't find anything wrong with twin-screw compressors either. The power-robbing concept is widely exaggerated.

Keep up the good work Hymee.

BTW, what's with all the smilies? :D

Hymee

iTrader: (1)

Mate,

It excites me to read a post like that, and to see people understand my motives. I know a turbo is smaller, lighter and can make more peak HP. I'll never agrue that, and I aknowledge they are perhaps the best for the racetrack, in a narrow RPM band. But I want instant boost

BTW - My last car was LS1 powered. And they love a good screw as well!

You will be able to see it - with the wonders of modern digital video and the expanse of "cyserspace" you will all be able to see it first hand. And with the wonders of international shipping, you can experience it first hand!

As a "teaser" here is a nice little video of the boost gauge of an LS1 with a twin-screw

http://www.hymee.com/rx8/videos/twin_screw_ls1.avi (non-streaming, so right-click "save-as")

Watch the boost gauge go from great manifold vacuum at idle/closed throttle, almost straight to about 10 PSI when it is the throttle is cracked open.

Cheers,
Hymee.

Hymee

iTrader: (1)

I used 4 of my favourites in that post, and save one of my other favs to my next post (above)... just for you

Cheers,
Hymee.

Lock & Load

Rotarygod

" I only wish i were down under to see it ."

As i believe there will be tremendous interest from fellow American rx8 owners as to the Australian HYMEE twin screw supercharger (whatever the cost will be you guys will get a substaintial saving due to the exchange rate )

Possible the forum members would be interested in paying/ subsidising a trip Downunder for someone such as Rotarygod to view the work first hand (when its completed ) and be able to act as an ambassador /agent for hymees supercharger in America .?????

With the number of members online the cost would be minimal if shared between us .

cheers
michael

zoom44

i humbly submit myself as a volunteer for this. the finances needing to be collected would be much easier to meet for sending me since i am already a great deal closer than RG. also since i know next to half of nothing that RG knows about these things i will be much easier to impress i wouldn't mind tho bringing the wife along and perhaps there would be time for a side trip to bussleton to see the jetty there and then maybe a trip to the forest near there. i am very fond of the jarrah wood. what time of the year is best? :D

Racer X-8

No, no, no. It is I who, if I were to be there in person, would volunteer my services in taking Hymee to higher heights. To see if there really is life past 9000. :D Just gimme that throttle cable. I will show you how it's done. (Where's that friggin' rev limiter anyway?)

Hey! I sense Omicron lurking...

Synergy RX-8

I just read through this thread today ( I have been gone ) and WOW!!!!

May the god of the wankel rotary engine be with you

Hymee we all love you!!!!

rotarygod

If I travel in the tourism off season, I can get there standby for $75 round trip! My sister works for Continental and my Dad worked for Delta. Flying isn't the problem. Time is.

shelleys_man_06

Hymee, if you can hire me for the summer (intern :o), I would totally go.

IKnowNot'ing

And from European owners too! We're closely following this thread.

zyran

I'm in Malaysia.. not too far from australia ehh?
My only concern's about this setup is maintainance and reliability issues. Can someone enlighten me on this.

shelleys_man_06

Hymee, have you figured out how to mount the supercharger? I'm having a hard time visualizing what it would look like.

boarder

> BTW - My last car was LS1 powered. And they love a good screw as well!

Not to hijack the thread, but that sounds like the makings of a new tagline for the Hymee supercharged system...

"Everyone loves a good screw" .... Hymee Enhanced

"Guaranteed twin screw with your purchase" ... Hymee Enhanced

I'm sure you could find a ton more like that.

Good luck with the system. I'm hoping for the best.

Richard Paul

iTrader: (5)

Hymee, That is a very interesting boost gauge. It acts like you have a screwdriver in the back turning the needle. In fact the oil gauge is also of interest. It acts like the engine is off.

One of them is broken Hymee, which one is it?? Or is it just the vac/press gauge hooked to some sort of hand pump?
Want me to guess??

Richard

Hymee

iTrader: (1)

Richard, the oil gauge does look like it is not connected. I must admit I never looked at that. The engine oil pressure was not on my radar of interest.

Interesting comment about the hand pump... I guess a hand pump is indeed a positive displacement pump! That pressure gauge shows exactly the sort of boost characteristics that the twin screw is intended for. And only a PD S/C can deliver that immediate boost.

So yes - the pressure (boost) gauge is hooked up directly to a positive displacement pump and it is driven directly of the crank.

Cheers,
"I dont want no lag!" Hymee

Hymee

iTrader: (1)

One of the LS1 guy's tag was (is) "I love to be stroked and blown"

Cheers,
Hymee.

Richard Paul

iTrader: (5)

Hymee, I don't want this to become a streaming thread, but.
But it doesnt work that way. Now if you tell me that you personaly took that video on a car that was running then I will let it go at that.
However, if that is not your video then you better check your sorce.
It just doesn't work that way, you can't get boost in the garage, not in gear. You can't open the throtle till the point of boost before the engine goes to the moon.

There has to be a load first. If your cruising down the road there is vacuume, no matter how big the blower is. Same at idle. Because the load is the same, the engine requirments are the same. There will be the same manifold pressure blown or not. So if the engine is not conected to anything you cannot get any boost because there is no requirment.

Plus, you do not get a gauge to peg like it is hitting a pin. It has a soft effect.
I mean not to dis you Hymee, I just don't think you really made that tape. Prove me wrong and I'll buy lunch. with brew.


BTW my e mail is not back up

robertdot

Clash of the Titans!!! Woot! We've got front-row seats.

Hey, if this lunch with brew ever happens, let me know. I'd like to sit in. I'll even buy a round (as long as it happens in the US... if it happens in .au, I'll need advanced notice! I think Hymee said he gets to the US every-so-often, though).

Hymee

iTrader: (1)

Richard,

It is cool. No steam coming from my ears. I never said that video was mine! If that is the way it came across, I'm sorry; but I'm sure I didn't try to make it look like mine!!! The video is of a 5.7L LS1 - just like your GTO

I can understand how a positive displacement blower generates instant boost. It is basically because it is a "bigger" air pump than the motor. (I'll say 1.5 times bigger for the simple example below). At idle, the throttle is holding it all back - yes - there is vacuum as shown on the gauge. When you crack the throttle, the blower draws in all it's "displacement" and forces it into the intake manifold. The engine displaces less, so there is pressure staight away.

It doesn't need to be revving high - it pumps an mass of air pretty much in proportion to the RPM - just the same as the engine. As you know, boost is a pressure ratio, not an absolute volume of air flow. Therefore, at low RPM (lets say 1000 RPM) the engine is capable of taking "x" air, and the blower is pumping say for example, "1.5x". The pressure ratio is then 1.5, or ~7 PSI

Then lets go up to 6000 RPM. Our positive displacement engine is capable of taking "6x" air. Our pump, being linear in its mass flow, like the twin screw is, is then pumping 6 * 1.5x = "9x" of air. So what is the pressure ratio? 9/6 = 1.5. Still 1.5, so the boost is still ~7PSI in that example.

If we go up to 9000 RPM we get "9x" air required by the engine, and "9 * 1.5x" air pumped by the blower = 13.5x. The ratio then is 13.5/9 = 1.5 still. Still ~7PSI.

That is how PD blowers work, in theory. In practice, it is a little different, but the general principle is the same.

I can't comment of the reactivity / sensitivity of that gauge needle.

I thought you were getting the lunch on the 12th anyway? As long as I make my next flight

Cheers,
Hymee.

RX-Dreamer

9x1.5 is 13.5 ....

Hymee

iTrader: (1)

Oopsies - sorry. Fixed. End result is the same Thanks!

Richard Paul

iTrader: (5)

Nice try, but you are still gonna wind up buying. Because somehow I'm going to get through to you.

The best way I can prove it is for you to go get that car and try it.
Let's say you started at 1000 rpm and zinged it to 3500. All with 10psi along the way. So at 3500 rpm with wot and full boost what is the power? let's say 275 hp. Now what is that power going to do except overcome the internal drag. What does it do with the excess power? After it gets to the crank it just continues to increase the speed. So in order to counter act that power the engine goes to whatever rpm it self disructs at.

You can't put full mass into an uncoupled engine. By the time manifold pressure went into boost you would have oil on the floor. Here again I know what I mean but if I were good at explaining it I would be on campus somewhere.

Think about it though. Go out and try it with an NA engine see if you can get to zero man. before you hit the rev limiter.

I have had guys do this to me lots of times. They buy a SC from me and as soon as they get it on they start it up and rev it up in the garage. Then they call and say they get no boost. I tell them to try it on the road and I never hear from them again.

What would happen if you were to try that with your P 51 Mustang. Is the Merlin going to show you man press with no prop load?? Think not.

What would happen if you were at full war emegency boost and backed the prop off? Well, it wouldn't let you do that but just think it would.


As far as making your flight, that depends on how many brews you have. Anyway we can battle this out then.