Series II turbo. 220rwkw and beyond?

[sprint32]

I'm also in townsville The reason I asked (well actually stated) that is because I understand every dyno reads slightly different, But not 30 odd kw. At least nowhere I'd take MY car. I got narky cause I was attacked before even being heard.

If we make the combustion process more efficent with the same amount of air we've made a step ahead. The reason I was thinking of using water injection is because of not only it's cooling properties, but it's characteristics in the combustion process as well, enabelling better use of even pump fuel. Those sort of things. No-one is doubting my methods, only outputs. I dont belive anyone has come forward with 'my setup' (to be) to say it wont work have they? Maybe it won't, I dont know yet, But I wont be detered by people who won't try a different method. At the same time there was apparently a Le mans prototype that ran a refrigerant to cool their intercoolers a while back, maybe it didnt work, maybe it did, but it had to have SOME merit to it for someone at that level to try it.

Series II turbo. 220rwkw and beyond? That wasn't a statement, it was a question, and now I finally got a chance to say what I was thinking. This was about a different idea, not about dyno wars. (perhaps my title was a bit misleading as this is all anyone seems to be concerned with.) I'm after response before power, but if I can have a little bit more of both, I'm all for it.

[Cubes]

Some questions for u.

Are you going to run a 50% mix of alcohol?

Are you going to use an Intercooler?

If you are chasing the most efficient combustion process have you considered optimising the quench clearance and area?

Are you considering any head work? Oversized valves? Port matching? You should as this is the down side of the RB20T. Small valves. Have you seen a Rb20 head next to a Rb25 head? The RB20 valves look like little toys.

[Sydneykid]

Right Sprint, let's get into numbers as Joel suggested.

"2 litres less piping to have to compress which would be wasted turbo shaft speed"

At 6,000 rpm a 2.5 litre engine at 1 bar uses 250 litres per second, so 2 litres extra = 0.008 of a second of "extra shaft speed". What the hell is that? It's not lag either. That's response ie; how much longer it takes for the engine to recover from a throttle on throttle off. Got absolutely NOTHING to do with shaft speed.

"And dont give me any more of this crap about larger pipe systems not making any more lag,"

Well it's true, so why shouldn't I give it to you? Sure it affects throttle response but it does nothing to increase the rpm at which the turbo makes boost, so no extra LAG.

"sapping power if they are too big"

I could put a 400 litre intercooler on my car and it won't loose 1 rwkw. It will take longer to get there after I put my foot down, but it will still make the same power.

"but imagine if it had water injection"

If you have truly researched this, you would know that it would have to carry around 20 litres of water for a 1 hour drive. That's 20 kgs extra weight to carry, just in the water itself. Add on the plumbing, pipework, tank, air water heat exchanger and a recirculation pump and you're up to 40 kgs. That really stuffs up your power to weight ratio and pretty much negates any advantage you get from reduced pipework. ie; the extra weight to accelerate dampens the extra response. Want to discus the additional alternator load (power loss) from making the electricity to power the pump?

"Too many sheep believing we’ve discovered everything there is to know, not enough people with inspiration to develop technology to a higher level"

Give me a break! If it's good enough for the best, it's good enough for me. So take a look around and tell me how many people go faster than Keir or John or Andre? I have no intention of trying to reinvent the wheel and I certainly have no problems with learning from other people. I can do it by reading Corky Bell’s books or looking at what other people have done, it’s all valid research.

[Cubes]

Sprint,

Here's little clip of Keirs R32 when he was running in the lowish 9's on street tyres.

http://www.japanesemotorsport.com.au/46rot...tor2003Kier.mpg

He has since run a best of 8.8 at 160mph still on street tyres. Just good ol' Forced induction.

[Guest INASNT]

Sprint32 y are you trying to reinvent the wheel?

From your comments on here it sounds like you dont even understand how the wheel works let alone trying to reinvent it!!!

[sprint32]

Good way to put it, but no I'm not. I just notice there's not too many people trying different things. How do you think trust, hks, etc develop things? But they also sell according to trends as any company would.

Anyway, I'm only doing lap sprint's lasting three laps so no problem there, although a valid point sydreykid. (waer injection)

Answers for Joel:

I'm not sure about mixing in methanol yet. I know its advantages, I just want to play and see how far I can push just water first, ther go methanol mixtures.

Yes, I am going to use a water to air intercooler. Try a few different methods of cooling the water too.

HA! yeah, I've got the head off now actually. Water pump seal spat it and I did the head gasket! I was thinking of using a thicker headgasket but decided to keep the standard size for exactly that reason. (quench area) Lucky for me I tested the head for warping at work and was ok. ( I left it on the block for two days after it blew just incase.) This is something I've watched with great interest since back when I was running a xflow 250 in a cortina on methanol. (archerfield). Great gains to be had.

I looked in the ports and at the valves and have decided to just clean up the ports and match them (to the manifold). I'm not really chasing too much power as the track i'm running on is very tight and unlikely to be in third for very long, so I think the standard valves will do 'me' just fine. Not much room to play with those anyway.

Truthfully 180rwkw's will be plenty for my purpose, but we always want more dont we? I dont want to waste any potential.

The big part of my car on this track will be the suspension and brakes. But I wouldn't mind the extra power for the drags on the other side of road from this track, as this is what most of my friends are in to. That way I can join in with them.

Thanks for the link. Cool.

[Sydneykid]

Yo Sprint, a circuit racing post....

If you are truly contemplating running a water to air intercooler, I strongly suggest you check out the weight issues. Not just the total amount of weight added, but where you have to locate it in the car. It may change your mind on air to air intercoolers.

As for ports and valves, you are on the right track. The standard RB20 valves, with appropriate porting, are quite capable of flowing 190 cfm which is more than enough for 400 bhp at 1 bar.

As for circuit suitable suspension and brakes, there are a few good threads on the forum's "Suspension, Braking and Tyres" with alignment specs, spring and stabiliser bar rates.

If you check around the forum you will finds lots of valuable information, much of it posted by people with solid theoretical knowledge and plenty of practical experience.

[sprint32]

Cool. thanks, I'll do that. Would it be just as easy to go buy a fullhouse whiteline kit?

For brakes I was thinking just DBA 'sloted' discs all round with aftermarket pads.

For the sort of Airflow I'll be running I dont think the system will be 'too' much heavier than the air to air type, but could be offset by a surge tank system and the resivior for the water injection? Weight distribution is something I have considered. Does this seem feasible?

[Sydneykid]

Cool. thanks, I'll do that. Would it be just as easy to go buy a fullhouse whiteline kit?  

For brakes I was thinking just DBA 'sloted' discs all round with aftermarket pads.

For the sort of Airflow I'll be running I dont think the system will be 'too' much heavier than the air to air type, but could be offset by a surge tank system and the resivior for the water injection? Weight distribution is something I have considered. Does this seem feasible?

Whiteline kit is good.

We use DBA slotted disks (never drilled) with Hawke Carbotics (Blue Compound).

I assume you have a M Spec 4 piston callipers on the front and 2 piston on the rear. If not, then you need to upgrade to them.

I still think you are underestimating the weight and complexity of a water to air system. The lightest one I have seen used an air conditioning radiator, a 12 volt bilge pump (as in boat), a 5 litre water tank, a 2 litre heat exchanger, 3 metres of 63 mm pipe, clamps, silicone joiners and 2 metres of water hose. Add it up and you will find not much change from 45 kgs, with all of it in front of the front wheels. Very poor from a weight distribution point of view.

Other than the odd MR2 (mid engine packaging), I can't say as I have ever seen a water to air intercooler on a circuit race car. Why do you think that is the case?

[rev210]

Alcohol injection is worth a shot (pun) if you'd like to run quite high boost in drag racing applications. The alcohol of choice is isopropyl, the same stuff used as a video head cleaner and general electronics cleaner. The kits are availible if you do a search.

Tolunene injection can also be setup, using something like a cold start injector, hooked up to a pressure switch. A small fuel cell 2-4L and appropiate fuel pump located in the boot would do the trick.

Something I'd like to have a go at is installing something like the flexalite fuel cooler, looks a little like an auto trans cooler it is rated at 4,500 GVW I assume once you have air flow happening and the advantage over products like the moroso 'cool can' is that it doesn't weigh very much.The much cooler fuel spray would help drop the intake temps as well. The price is around $80. the dimensions are 12inches by 3 1/2 ,about 3/4 inch thick.

Sydneykid, ever looked at doing this for your track cars?

[rev210]

I might start another thread about the fuel cooler as it's a bit 'off topic'.

[sprint32]

Ok. Iwas thinking along the lines of a std rx7 series v cooler (flows well) converted to water to air with a small waterjacket around it so it can be placed in the same location as the std airbox, but more importantly the small water jacket would hopefully prevent heatsoak into the water already in it due to a high rate of exchange of warm water for cool water. Place the pump under the inner gaurd pumping through a aircon condensor core to a resivior on the other side (below battery) where you might want to try ice slurry's etc. Then another pump to the cooler again. The critical point being that the water remains in the condensor core longer than it does in the intercooler. The resivior wouldn't need to be any bigger than 1.5 litre's I would think. I dont think this is too much weight to be added, I'll just have to tune the rear end a little better. I know thats not the be all and end all but its only three laps on a low speed circuit so I think I should be able to keep the tyres (front) under control for that period. (obviously not ordinary street tyres)

[Sydneykid]

Alcohol injection is worth a shot (pun) if you'd like to run quite high boost in drag racing applications.  The alcohol of choice is isopropyl, the same stuff used as a video head cleaner and general electronics cleaner. The kits are availible if you do a search.

Tolunene injection can also be setup, using something like a cold start injector, hooked up to a pressure switch. A small fuel cell 2-4L and appropiate fuel pump located in the boot would do the trick.  

Something I'd like to have a go at is installing something like the flexalite fuel cooler, looks a little like an auto trans cooler it is rated at 4,500 GVW I assume once you have air flow happening and the advantage over products like the moroso 'cool can' is that it doesn't weigh very much.The much cooler fuel spray would help drop the intake temps as well. The price is around $80. the dimensions are 12inches by 3 1/2 ,about 3/4 inch thick.

Sydneykid, ever looked at doing this for your track cars?

Yep, quite a few times, I have never measured any race car with fuel temperature much higher than the ambient air temperature. So a fuel radiator would be pretty much a waste of time. Cool cans are the go, they are relatively light and mounted in the boot, they don't disrupt the weight distribution much.

I use these ones, cheap and light...

[rev210]

sydneykid,

that the moroso cool can. I thought they didn't work with efi?

[Sydneykid]

sydneykid,

that the moroso cool can. I thought they didn't work with efi?

Hi rev, you're right they aren't rated for pressure, but if you run the system this way they are OK.

Lift pump --> Cooler --> Surge tank --> Pressure pump/s --> engine

That works fine, the only trick is you run the engine (fuel rail) return directly back into the fuel tank. Not back into the top of the surge tank, as you would normally. This means all the fuel in the surge tank is cool, not mixed with some hot fuel returned from the engine bay. You will need a slightly stronger (higher flowing) lift pump to keep the surge tank full though.

Hope that helps

[sprint32]

Also about shaft speed....

A 1.5 litre tank full of air at 0 psi. If you add 1 more litre of air, the pressure of the tank will increse substantialy. If you take a full 3 litre tank and add 1 litre, the increase in pressure will not be as great. You will need to increase the amount of air you pump into the tank to get the same pressure. 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.) for the same critical point of shaft speed in regards to turbine failure. Remember, it's shaft speed that kills the turbine, not boost, and the reason I said 18-19 psi is because the rb25 turbo is rated at a higher flowrate at its critical shaft speed than the rb20 turbo, but is being placed on the smaller engine. I provide the air support systems I have discussed previously to try to provide the densest air I can, thereby increasing the amount of airflow through the engine without increasing the boost further. (Thereby increasing the efficiency of the whole system and therefore the turbo as well, denser air at same pressure increasing efficiency)

I realize also that there are compressor inlet problems as well. BOOSTD has decreased the thresh-hold of surge by machining out the inlet slightly wider than the highest part of the wheel, and slightly lower than it. Does anyone know of any other methods of increasing the eficiency of the compressor inlet?

OK. Time for you guys to poke holes in my theories again, But it still wont stop me at least trying. (I'm a fitter and turner so the labour I'm talking about is REALLY CHEAP! so are these turbo's, so I dont mind loosing one or two.) The only real reason I want to push the standard turbo's is because of thier lower inertia and therefore higher responce.

[Cubes]

BUT... always a but.

I see it as the turbo's shaft speed spinning at a higher rate for a longer period of time to fill/pressurise that void. Hence lag.

If you were to slap a .10 a/r exhaust housing on a 3ltr then plant your foot I could see how it may be possible if you had a really large FMIC and lots of piping that the turbo wouldn't be able to generate any boost or pressure before the shaft speed limit was reached.. hence turbo breaks.

Once the void is filled and the desired pressure obtained the shaft speed will be the same for both the 2m length of piping compared to say 50cm's of piping.

I do see your theory behind it however I personally think its a little incorrect.

Maybe correct if you are trying to fill a room with a little arsed turbo as the wastegate actuator is never going to see any boost hence shaft speed is going to spike and the turbo rip its self to pieces. Have huge amounts of air flow but no pressure.

The issue you are talking about does come in to consideration unless the turbo was very badly matched as my example of a .10a/r exhaust housing suggested.

Hope that makes sense. My explaniation was only an example. A far fetched example.

You think too much!

[sprint32]

What else have I got to do! My cars off the road and its easter friday!! lol

A Compressor map is provided under a fixed test condition. Every engine wont be the same as those test conditions though. If your engine is more volumetricaly efficient than this then the compressor efficiency moves towards the higher part of the flow rate axis on the map.

Remember too that the to* range of compressors are very old. With the advent of ball bearing centre's they were able to reach new levels of compressor efficiency, enabeling them to reach higher flow rates with the same size wheel, or the same airflow for a smaller wheel. So we need to take that into consideration too.

[Cubes]

I feel for you.

I really felt like a few drinks today.. Went every where but absolutely NO ONE was open

[Sydneykid]

What else have I got to do! My cars off the road and its easter friday!! lol

A Compressor map is provided under a fixed test condition. Every engine wont be the same as those test conditions though. If your engine is more volumetricaly efficient than this then the compressor efficiency moves towards the higher part of the flow rate axis on the map.  

       Remember too that the to* range of compressors are very old. With the advent of ball bearing centre's they were able to reach new levels of compressor efficiency, enabeling them to reach higher flow rates with the same size wheel, or the same airflow for a smaller wheel. So we need to take that into consideration too.

"A Compressor map is provided under a fixed test condition. Every engine wont be the same as those test conditions though. If your engine is more volumetricaly efficient than this then the compressor efficiency moves towards the higher part of the flow rate axis on the map. "

Wrong, wrong, wrong and totally incorrect as well. Who cares what engine is connected to the compressor? If the turbo shaft speed is 100,000 rpm, the turbo will produce 60 lbs of airflow per mintue at a pressure ratio of 2.8 bar. I don't care what engine you stick on the end of the compressor, at 100,000 rpm, the turbo will produce 60 lbs of airflow per mintue at a pressure ratio of 2.8 bar. Atmospheric conditions not withstanding.

Engine efficiency come into play when the 60 lbs of airflow is converted into horsepower. An efficient engine might get 600 bhp out the 60 lbs, an inefficient one, 500 bhp.

"Remember too that the to* range of compressors are very old. With the advent of ball bearing centre's they were able to reach new levels of compressor efficiency"

Equally wrong, wrong, wrong and totally incorrect. It doesn't matter what core the compressor is connected to at 100,000 rpm, the turbo will still produce 60 lbs of airflow per minute at a pressure ratio of 2.8 bar. It might get there faster due to lower roller resistance and it might change (up or down) the shaft rpm quicker. But it doesn't change the "compressor efficiency" one tiny little bit.

As Joel posted, you are looking at the compressor stage in isolation, a turbocharged engine is a closed loop system. If the air flow doesn't go into the engine (because it is fluffing around in the pipework) then it doesn't make exhaust. If it doesn't make exhaust, it doesn't spin the turbine. If it doesn't spin the turbine it can't accelerate the shaft, so overspeeding is impossible.

I strongly suggest you re read this from my previous post; "At 6,000 rpm a 2.5 litre engine at 1 bar uses 250 litres per second". What you are talking about is a 1 cc engine with a lounge room sized intercooler. Even then it is wrong, because in order for the exhaust to spin the turbine it has to get into the engine first. There would simply not be enough exhaust to spin the turbine, unless you had the most grossly mismatched turbine and compressor stages in history.

Next time you have nothing to do, I strongly suggest you put the keyboard away and read Corky Bell's books on turbochargers. It would be most beneficial for your knowledge and stop us having to read such obviously wrong, wrong, wrong and totally incorrect postings.

I hope that wasn't too harsh.