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Old 5th December 2002, 08:52 AM   #61 (permalink)
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It is indeed an air pump as Mario, myself and now your good self have stated, it is a point that does need regular re-iteration as it is forgotten during in depth investigations.

I hope early in the New Year to have partially finished my work with David Vizard (Induction Guru) and Andy from the MLR (Evo register) and then the entire heat/torque, flow/torque, LCA and Turbo exhaust flow will get it's own thread to which any and all constructive comments will be greatly received.

Additionally there have been small snippets dotted around this forum regarding many of the things you mention, these will be scavenged up and dragged into that thread, so the whole thing will be given a fair wind from the outset.

So anything discovered or revealed here now on that subject will be in that thread.

Oh sorry, welcome matey.
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Old 5th December 2002, 09:34 AM   #62 (permalink)
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It sounds like a massive project, rather you than me Mycroft !

I will await the results with great anticipation.
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Old 5th December 2002, 10:23 AM   #63 (permalink)
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Quote:
Originally posted by Philip
"they were looking for a 2400bhp limit on the new GT-R engine"

Bit ambitious I'd say. Could your memory have been Photoshopped?

Phil
probably is ambitious, but remember its the point in which the block will start to crack, so maybe not
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Old 5th December 2002, 02:01 PM   #64 (permalink)
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Quote:
Originally posted by MarioGTR


There are infact two 2JZ-GTE powered cars that have run into the 6's at over 200mph. They are the Bullish racing Solara's.

HKS's RB26DETT powered 180SX tube frame car almost made it as well (a 7.1 @ 196mph I believe) but couldn't get the traction - it had the power - the chassis is what let it down.


Mario.

all I can say is, jesus christ that is impressive!


there is surely no question that at this point we are talking cars with only one purpose in mind!


Can these cars be driven home legally? or would that be foolish?
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Old 27th December 2002, 03:58 PM   #65 (permalink)
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On this matter I have been looking into the present 'state' of the VE/TE compromise and with the changes that have occurred to the fuel we now all run I believe that the goal posts have moved slightly.

To explain, in the Nineties and until quite recently the 'ideal' bore that ensured the most efficient burning was around 86mm±1.5mm, this was a good and fine compromise between VE and TE but now with these fuel changes we are having to face the fact that with a better flame control and head design the VE/TE boundary has moved up to 95mm±1mm, so many of the latest designs from around the World are adopting this dimension so it is becoming quite obvious that things have moved on.

This presents the car tuner with a number of problems, the most important of which is that the 'tuning edge' (which they work very close to) on the Next Gen of cars will be frought with even more difficulties, things have just got one step harder.

The head design for the NextGen is more critical than this Gen and will present real problems for all involved, add to this the work on Flame boundary layer thresholds and temps will mean even more expense for all involved and quite a high risk of failure during developement, in fact, for any real upgrading for these motors we have to accept that pistons will have to be made from MMC and that the bores may well require the gaseous form of Diamond to be substrated onto the bores of our cars.

As the VE is raised because of that larger bores and therefore the bigger valve and valve train we get closer to very high tech valve gear, pneumatics are a little unreliable for production cars at the moment but Toyota have already revealed and run steel sprung 2½litre motors that can run 16,000rpm without too much trouble these motors can outlast the Pneumatic F1 systems by a ratio of 6:1, so 13,000rpm on a barley modded valve train is a serious LONG TERM performer.

To put this in perspective this would mean that in 5-7 years time Mario/Gary/Mark (Abbey) will be sending cars out with a 16,000rpm rev limit and they will stay the course!

I have wanted to post some stuff on here for a while with regard to outputs and this eems the time to clarify a few things. Forgive me if you are all aware of this stuff, but it may give one or 2 of our members a better grasp on this 'efficiency' thing.

Output per Ltr.
Now we all hear about cars that put out 100hp per ltr it is an achievement and the Manufacturers have every right to 'crow' about it.
Go back 30 years to F1 in 1972/3 the cars ran 3ltr motors and kicked out 400hp on average jump back to today and we have 3ltr motors producing 800hp how can this be you ask?

Well would anyone care to explain this apparent 100%improvement in just 30 years, what happened?
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Old 27th December 2002, 04:38 PM   #66 (permalink)
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Mycroft,

In answer to your question in a word ‘computers’ (ECU’s) able to retune the engine 1,000’s of time a second, anyway, what’s happening with electronic valve trains? A few years ago I applied for a patent for an electronic cylinder head design that got rejected because (then) Mercedes Benz and BMW had similar designs submitted. A short while later the motoring press was full of stories of how new electric valve trains would change the world.

Paul.
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Old 27th December 2002, 05:17 PM   #67 (permalink)
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Interesting...almost every one I meet thinks that is the reason..it is wrong, any one else know?
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Old 27th December 2002, 06:36 PM   #68 (permalink)
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Less weight=less strain=moving the goalposts?
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Old 27th December 2002, 06:38 PM   #69 (permalink)
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No.
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Old 27th December 2002, 09:49 PM   #70 (permalink)
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I understand that:

- output per litre has increased as engine speeds have increased; and
- that engine speeds have increased as a consequence of "materials development", that is the improvement of engine components and their interaction such that they can collectively sustain engine speeds of ~17000rpm

thats as far as my knowledge goes...

Harry

ps keep pullin those strings...
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Old 28th December 2002, 12:46 AM   #71 (permalink)
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...and the winner of tonights Star Prize, a luxury holiday for 2 in Mablethorpe is...Harry (applause all round, Nicholas Parsons 'beams' congenially at Harry )

But seriously folks (Hughie Green) Harry is right, the old '72 3ltr V8 DFV hit its peak at 7900rpm and produced just 395hp.
The modern V10 Ford equivalent produces 770hp at 16500rpm.

Now look at it this way, this means the '72 car produced 16.7hp per 1000rpm per 1000cc, the latest car with better fuel and and all that tech produces 15.6hp per 1000rpm per 1000cc.

These are both 'peak' values.

Interesting eh!
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Old 28th December 2002, 01:33 PM   #72 (permalink)
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To put this into stark relief the 1989 Peugeot MI 16 put out 13.2hp// and the 2003 BMW M3 SMG puts out 13.0hp//

This parameter is now pretty much accepted as the true guide to the VE/TE efficiency quotient.

So...
Theoretical max BHP?

For a road car 14bhp// seems to be about the road limit at this moment.

7800rpm peak seems to be about as far as we would wish to go for a very fast road car with decent longevity.

2.5 litres seems the limit for a 6 cylinder.

So for an N/A 2½ltr this seems about right 14×7.8×2.5=273bhp

For a Turbo'd motor say running one bar of the same or similar capacity would have to have 28hp// @1bar, so to get that level of efficiency you need to get an RB26 to (28×7.8×2.6) =565hp

All of you can get your Dyno sheets and 'do some numbers' and see where you stand.

The 'base' number is a real indication of how good the 'headwork' is on your car.

I do recall Gary saying that he can with a 'dremel, some cutting paste and a couple of hours' he can make quite some gains in the power dept, well, if he can see efficiency gains in his 'minds eye' then what seems like 'magic' is not, it is just a honed skill and entirely plausible.
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Old 5th January 2003, 04:18 AM   #73 (permalink)
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Quote:
Originally posted by Mycroft


#Yes, but if you apply the same technology to the big displament engines, you'll get even better results!#

I was correcting you in that the 'same effort' with larger displacement you'll get worse results, just as David Vizard has pointed out, I only did the Maths afterwards to see if he was right.

Ok, so according to you, a larger displacemwnt is of hinderence.

Well lets say we have 2 engines, a 2.5ltr 6cyl one, bore 86mm and stroke 72mm.

And the other is a 5.0ltr 12cyl one, same bore and stroke of course.

Which one will make more power? The one with the larger displacement.
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Old 5th January 2003, 12:03 PM   #74 (permalink)
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Hello Syed.

I am having difficulty with expressing this to you, so forgive me my bluntness.

But I do believe that you are purposely posting in a vexatious manner, the subject title is 'shortened', to my eye the unwritten part of the title is '...in a Skyline at any given boost', it is not '...regardless of size' as that would be of little or no value.

Theoretical Max BHP is to an Engineer 'short-hand' for efficiency.

I have strived to make my explanations clear, my test is my 13yo son, he is quite smart, the OB thread foxed him slightly, but this Sunday morning he has read this thread and understands it perfectly.

I have been as patient with your inability to grasp what I write, as all can see you are just not 'cut out' for Tech. stuff.

Please feel free to put me on your ignore list..just as I am about to with regard to you. Thank-you.

PS. I won't ignore on the TIF site.
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Old 6th January 2003, 04:18 AM   #75 (permalink)
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Thanks for ignoring my point there Mycroft, you seem to do that a lot when you are wrong.
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Old 7th January 2003, 02:16 PM   #76 (permalink)
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syed,

I dont believe mycroft is wrong here.

It has been made clear that power is only dictated by how much air you can flow, regardless of stroke and bore.

displacement alone has no effect on the amount of power you can produce, only the rpm at which the power can be produced.

Obviously if you run two identical engines each individually having 200bhp, then the combination will produce 400bhp, but I think that if they share a crankshaft, it is not a simple case of doubling the output of one engine.

If you have more cylinders with the same gemoetry at the same rpm, then it will pump more air and produce more power, I suspect however that a larger rotating mass engine will not yield the same efficiency as the smaller engine. No doubt the drop off will be proportional to the square of angular velocity. come to think of it I dont recall many 5 litre plus (road car) engines which rev beyond 6.5k rpm

aside from this, when most talk about increased displacement of an engine such as a 2.8 or 3.0 skyline, this is not achieved by bolting on two more cylinders, it is normally by boring or stroking, since this will affect the magic efficiency of power per 1000 rpm per litre, I can completely how mycroft can say that increased dispalcement is not always the way forward. You have to qualify that by saying in similar conditions.
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Old 7th January 2003, 02:18 PM   #77 (permalink)
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On another note,

I am a patent agent in britain, and qualifying in europe as we speak.

Was just wondering on what grounds the patent that was applied for was objected to.

You say that it was flatly refused, but this is never the case, you have the option to argue, or amend based on the existing technology they show you.

Did you go through it with a fine tooth come to make sure the patent Examiner had the right end of the stick with regard to yours and the mercedes etc patents?
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Old 7th January 2003, 02:32 PM   #78 (permalink)
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In fact, whilst I am on here, I would appreciate some advice from those who would have looked into this.

In building my 2.5 impreza, my block has been wire ringed.

I was intending to use the standard uprated subaru 2.5 steel multilayer head gasket, but am told that they have replaced the previous three layer with a four layer whioch I have bought. The trouble being the three layer had an integreal fire ring, but the four layer does not.

Due to the incompressibility of the 4 layer gasket I am told I am likely to have sealing problems.

The heads will be held in place each by 6 14mm studs (boxer two heads remember).

The option I am currently being presented with is to have some copper head gaskets made. copper being softer and therefore more compressible. Was wondering if one of the high power engine builders or someone with a head well versed in engine theory (mycroft ) could explain the merits/downfalls of using a copper gasket over a steel.

I am not intending to rebuild the engine once it is running, which I am told is an advantage of copper, so is there anything else i need to consider?

sorry for the change of topic but it looks like the engine will be being finished in the next two weeks, and I need to order the gaskets with a weeks notice.
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Old 10th January 2003, 09:20 PM   #79 (permalink)
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Ahh,

but Mycroft said that displacement would yield worse results on drag cars etc. Not true.

We were not talking in the context of Skylines, simply displacement. Obviously if the stoke is increased, less power will be made due to the limited ability to rev.

Now a 4ltr car WILL ingest twice the amount of air from a 2ltr car at any given RPM (approx).

So, therefore, if it can rev as high, then it will make more power, and with the same stoke, it can do this.

Simple really.
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Old 10th January 2003, 09:42 PM   #80 (permalink)
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Quote:
Originally posted by Syed Shah


Simple really.
Which is why I think they were trying to look at the bigger picture, which applies in the real world.
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