Series II turbo. 220rwkw and beyond?

[sprint32]

I'm pretty drunk right now so I'm not gonna put any big post up but go and talk to ray hall on the net Sydneykid. I'think you'll find i'm right. VERY right. Infact so right I should open up a right factory. (glug, glug...) Rather like using plasticine around the entry of a intake port on a manifold to stop the distruption of a right angle turn from the FACE of the sealing surface harming flow by as much as it does. Rather like ....Actually, I'm not sure the track i'm going down has any sense/relevance to my point at all right now so i'll talk tomorrow. Later tomorrow. (if im lucky.)

But please dont go flaming me in the mean time. (please.) I will back it all up tomorrow.

[sprint32]

By the way, I hope i'm not totally WRONG, WRONG, WRONG and INCORECT in saying that not even a 350 chev requires 250 litres per second. I'll even start dropping names and offer quotes too if you wana be smart and then coy. (sorry, that was uncalled for.)

[Sydneykid]

By the way, I hope i'm not totally WRONG, WRONG, WRONG and INCORECT in saying that not even a 350 chev requires 250 litres per second. I'll even start dropping names and offer quotes too if you wana be smart and then coy. (sorry, that was uncalled for.)

Do the numbers yourself sprint;

It's a 2.5 litre engine

multiplied by 6,000 revolutions per minute

equals 15,000 litres per minute

divide by 2 because it's a 4 stroke

equals 7,500 litres per minute

divide by 60 seconds in a minute

equals 125 litres per second

multiply by 2 as it is running 1 bar

equals 250 litres per second

Thank you!

I'll be here all week.

[sprint32]

Couldn't help yourself could you. Anyway, In your first (ahemm) 'correction, I was talking about increasing volumetric efficiency, not combustion efficiency, changing the efficiency of turbo. If you can flow more air into the engine before reaching the set pressure you alter the aerodynamics of the compressor. It will flow more air before starting to rech its stall range.

All airflow systems are tested under only one condition. Using what I've shown you above you can see it would be not only naieve but propostrous to think they can represent the restriction of all engines around the world. ALL airflow systems are different. We all agree you need to port the head on a turbo engine at some stage as the restriction wont let you flow enough air no-matter what pressure you run.

Also as I was meandering on about last night, this is the reason they use placticene to put around flanges of intake ports on manifolds (and thier exits aswell depending on which way your testing), to prevent the air stalling as it has to turn 90 degree's. We all know the advantage's of a bell mouth at the start of your inlet tract.

Your formula is a great one. IN FAIRYLAND!!! NO engine is 100% volumetrically efficient. none. You even said yourself that pressure is the restriction of flow, and correctly so. But unless your boost gauge is reading the pressure after the restriction (the valves) it wont be 100% volumetrically efficient. Then we take the inefficiency of the compressor into consideration as well and how much it heats the air, none of which i see in your working.

And let's not even get into the efficiency of old versus new compressors. That was a really silly thing to say sydneykid. I'm dissapointed in you. I hold you higher than that. Maybe you were drunk too.

Hey, if you stick around all week you'll watch the amazing man pull his foot out of his mouth seven times.

(I hope that wasnt too harsh,lol)

[Sydneykid]

I asked "Do the numbers yourself sprint?"

Well, show me how you would calculate how much air an RB25 needs at 6,000 rpm with 1 bar of boost?

Since you seem to think you are a flow bench guru....

If an RB25 cylinder head flows 190 cfm (inlet) at standard (max) lift, tell me why that doesn't support the previosuly posted calculation?

[sprint32]

how long is the valve open for in a real engine. how much pressure is still in the cylinder when the intake valve opens. How long does it take and how agressively does it reach fully open. it may be possible to get a little vacume (i hate spelling that word, it doesn't look right. what, me fail english? that's unpossible! lol.) but in a engine with a turbocharger, that's impossible. The flow bench is a good tool but doesn't show the effects of cylinder backpressure. But we can change the effective efficiency of the turbocharger on the system if we can improve the breathing of the engine. you can use a bigger intercooling system that uses more air to reach the same pressure if you want, but thats wasting the turbo's shaft sp....lets not go there again. In the end your not going to make any more power cause the engine isn't breathing any better (when stock like most people, cams port's etc...), but you'll create a lot of heat in the air for no reason cause your spinning the turbo faster to do the same job. Surge line comes closer, efficiency decreases...

You need to look at volumetric efficiency as well when testing how good a port flows.

Thats not isolating the compressor side, thats thinking of the entire system as a whole. Your turn.

[Sydneykid]

Dah, what's the calculation?

How much air does an RB25 need at 6,000 rpm with 1 bar of boost?

[sprint32]

No. your calculation was correct, just incomplete. I know it sounds like a cop out but...Hang on. I've already told you why it doesn't work, no sense TRYING to show you again. but even a 350 chev (no im not a v8 lover, far from it. just a good size to show as comparison.) at 80% volumetric efficiency uses 226 cfm. thats at AMBIENT air temperature. Enough said. Sorry man. Physics and gas laws are on my side, weather you like it or not. I don't know everything but your starting to really dissapoint me. Do you really understand this stuff or are we just continuing this arguement for the entertainment of others. What say we deflate our brain muscles for a bit and just cool down? ( cause I must admit, It's getting to the point where I'm starting to enjoy this intellectual argument too, which isn't a healthy mindset to be in on these forums. teh, he!)

[Cubes]

Sprint32,

Personally I think you are barking up the wrong tree with everything you have suggested. Its like you have been skim reading.

If you seriously think having less IC piping and No FMIC tank to fill is going to reduce the turbo's shaft speed to the point where you will increase the efficiency of the turbo where it will make a noticible difference; well.. I'm lost for words..

I think you fail to see the pressure drop through the fmic & ic piping is negligible.

I.e the Bar and plate FMIC I am running has an *apparent* pressure drop of 1.5psi when flowing 580hp worth of air.

You have to start thinking realistically. You are talking about the difference of your I mean a bee's dick. lol

[sprint32]

Yeah I cant really call it a shlong....It's more lite a shlort. (He, he.)

It's good you have a low pressure drop. But try blowing up a balloon and then try blowing up an airbed. Egsadurated (i know, it's not spelt right.) example,I know, or is it? us blowing up something is like a positive dissplacement pump. however, a centrfugal compressor has alot more pumping efficiency up till a point. If you modify your engine to flow more air, you increase the airflow before the turbos efficiency is effected to the same degree by pressure ratio, heating of the air, etc. I know it will take a while, but read over this thread again and then do a search on all these different methods. You will find that everyone agree's with all of them when considered alone (as they should as they are facts), but rarely tie them all together. But then we say it's all the little things combined that add up to quite a large difference!? Some even completely agree with me in other threads and then come here to try to tell me I'm wrong!!!!?? (yes, I have been laughing at this over the last week.) Seriously. You're either paying lip service to your friends and people who have done it before, or your just coming here to be argumentative. I know which I think, as the fact's are there, and everywhere else on these forums for that fact, as well as living proof.

Before you try flaming someone, check out the facts.

Those who do not learn from history are doomed to make the same mistakes.

[Cubes]

Sorry buddy you've lost me.

If you modify your engine to flow more air, you increase the airflow before the turbos efficiency is effected to the same degree by pressure ratio, heating of the air, etc. I know it will take a while, but read over this thread again and then do a search on all these different methods.

So we are no longer talking about the IC & piping volume?!? Instead talking about increasing the engine ability to flow air in to the pots easier?!? They are two different things.

Honestly sprint I find it hard to follow yours posts. They tend to jump around a little.

Logically, I also can't see how you can relate blowing up a baloon to pressurising the IC piping/fmic/more piping/plenum/inletmanifold.

I'm not being argumentative, only trying to understand.

Its called discussion.

[sprint32]

Obviously you dont read well. The whole point of this discusion was increasing the efficiency of the ENTIRE system. The reason I said to read all of the points that I've covered is because I'm spending too much time repeating myself for those who just jump on the last post without relating it to what I said formerly. (when they do all they look for is spelling mistakes, Like that means something on the road. Wasn't aware this was a spelling bee.). No-one seems interested in relating facts together to make a gain, There just looking to put someone down as if that makes them feel better about themselves. Very narrow minded. As I said, These concepts arn't new, and there all facts, and if you do a search on these (come on, at least try.), you will find everyone understumbles them alone, but put them all together at the same time and they're like a deer in headlights. I don't understand that.

sorry about the balloons and stuff. Wasn't explained well. we dont have any 'slip' of air, like a positive dissplacment supercharger. But centrifugal compressors are affected more readily by pressure ratio, and when they do start to 'slip' because there fighting against this pressure ratio, they create heat which makes matters even worse. The air is less dense at a higher temperature. Thats all sydneykid's example was missing.

[Cubes]

To make your posts a little easier to read/follow please use the return key.

The problem I had with your post/theory is when you stated

Therefore the pump (Turbo in this case) has work harder (spin faster) to provide more air to pressurize the tank to the same level.

For this reason I belive it is reasonable to assume that if you provide the engine with the same amount of pressure in such a smaller system the turbo would not spin as hard. Therefore being able to run at higher pressures (18-19psi, most bigger systems 14-15.)

One minute you are talking about pressurising the tank (which is the lag) & the turbo's shaft rpm then you are talking about the turbo not spinning as hard once the tank is pressurised in turn allowing you to run the turbo at higher pressures as for every rpm the turbo spins it is pushing more air (better efficiency)?!?!? How is a pressurised system turbo's shaft speed related to a system that is being pressurised. It isn't.

Once the pressure is there the turbo will spin at x speed. Unless there is a pressure drop over the system.

If the IC and/or IC piping you are using provides a restriction at that given airflow that is the only time the turbo will be spinning harder to provide say 1 bar at the plenum. Hence there may be a 7psi pressure drop from the compressor outlet to the plenum. Tim from RPM quite a while ago did a test on the R33 stock IC system when boost was upped he measured a 7psi pressure drop, fitted the FMIC and measured a power gain (cooler air which relates to the turbo sitting in the meat of its efficiency range). From memory he measured a 1 or 1.5psi pressure drop I can't remember exactly. Which is bugger all.

Do you agree with what I am saying?

Do you see a 1psi pressure drop enough to warrant ditching the fmic and applying the hassles of a water injection system?

Like I said before.. I know exactly where you are coming from but the difference of a 1psi gain is a bee's dick.

Honestly I am unsure if it is possible for a Rb20DET making ~350-380fwhp with a rb25turbo to run with no fmic and with only water injection, especially when you consider the turbo will be running at the edge of its peak efficency band, remember as stated previously over 1.2bar and the rb turbo's tend to superheat the air. hence its way out of its effiency band.

So is this what you are saying?

You combine:

1. water injection

2. As little IC piping and no IC = no pressure drop (hence lowering shaft speed for any given airflow in to the motor, only by a bee's dick though, remember you will have to match up the piping size that you use to meet the air flow requirements, from memory 2.5" will flow enough to only cause a restriction some where around 600hp maybe slightly less)

3. efficient combustion process by the use of good quality correctly selected spark plugs

4. RB20DET turbo motor

5. RB25DET turbo

Is there anything I have missed?

This you are stating? will provide a motor that will make more power with better response than a *conventional* RB20DET running the ol' FMIC with 2.5" piping, no water injection.

I can see it will make better response BUT it I can't see it making more power. Maybe if you were running stock boost??? Who knows that requires dyno testing and $$ for such a small result.

[Nizman]

just get a bigger Turbo!

[Cubes]

lol.. it is a pretty bad thread..

Please tell me any 1 if I am way off track?!?!

[Guest INASNT]

This guy is still spilling shit!!!!!!!!!!!!!!!

TIme to unsubcribe to this thread!!

[Cubes]

TIme to unsubcribe to this thread!!

Agreed, its starting to stress me out.. lol

[Sydneykid]

No. your calculation was correct, just incomplete. I know it sounds like a cop out but...Hang on. I've already told you why it doesn't work, no sense TRYING to show you again. but even a 350 chev (no im not a v8 lover, far from it. just a good size to show as comparison.) at 80% volumetric efficiency uses 226 cfm. thats at AMBIENT air temperature. Enough said. Sorry man. Physics and gas laws are on my side, weather you like it or not. I don't know everything but your starting to really dissapoint me. Do you really understand this stuff or are we just continuing this arguement for the entertainment of others. What say we deflate our brain muscles for a bit and just cool down? ( cause I must admit, It's getting to the point where I'm starting to enjoy this intellectual argument too, which isn't a healthy mindset to be in on these forums. teh, he!)

Sensational sprint, I got an answer, no formula but at least it's an answer. How about I do the formula for you.

It's a 5.7 litre engine

multiplied by 6,000 revolutions per minute

equals 34,200 litres per minute

divide by 2 because it's a 4 stroke

equals 17,100 litres per minute

divide by 60 seconds in a minute

equals 285 litres per second

no need to multiply as it is N/A

multiply by your volumetric efficiency of 80%

equals 228 litres per second

So if the volumetric efficiency of a 5.7 litre normally aspirated Chev with 2 valves per cylinder and pushrod valve operation is 80% what do you think a DOHC 4 valve per cylinder RB engine is? I reckon it's over 90%, plenty of evidence to support it, if you care to read around.

What you seem to have ignored is the 1 bar of boost in the RB25DET example, that effectively doubles its air consumption ability. Plus an RB is 90% efficient in its air consumption, so 250 litres per second X 90% = 225 litres per second. So the 0.008 of a second difference in airflow through your super duper inlet system makes SFA difference to the response. Which is what I said in the first place.

I think it is you that has no understanding of "this stuff", either that or your maths is as bad as your spelling and grammar.

[krzysiu]

stop bulshittin already. IF you can get that much power from stock, y da hell would u do it up, This thread is complete shit. 220+KW LMFAO from stock ha ha ha ha ha ha ha ha a

[Guest INASNT]

stop bulshittin already. IF you can get that much power from stock, y da hell would u do it up, This thread is complete shit. 220+KW LMFAO from stock ha ha ha ha ha ha ha ha a

It was shit from the first post!