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Celica GT-Four Sprint ST205 - Jonny Milner/Merlin Motorsport
http://www.gt4dc.co.uk/forum/viewtopic.php?f=13&t=5038
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Author:  bozo-merlin [ Thu Jul 07, 2011 7:27 pm ]
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Sirius wrote:
Nibbles wrote:
Re. another thread going on at the moment, interesting to see the use of Distributer ignition on an 800BHP engine.


I noticed that as well!

Given that this car is pretty much money no object it does bring the real life benefits of COP et al into question if they have decided to stick with a distributor.


andycaca wrote:
one tasty bit tho, is people are calling into question the power of 700bhp (without nitrous) at 5700rpm, saying its a typo and the journalist meant 7500rpm instead. nope, jonnys car doesnt rev, it really does make that much power at a low rev count. adrian doesnt know why, but he suspects its due to the engine build, possibly because it began life as a WRC engine.



This explain that, he have enough time to charge the coil as he did not rev his engine, everything is fine until 7000's come with 1.2+ boost.

Author:  cms-gt4 [ Thu Jul 07, 2011 8:28 pm ]
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Didn't the WrC cars make really high torque at lower RPMs than one might expect.

http://rallycars.com/Cars/Toyota_GT4/Corolla_WRC.html
Quote:
Output: 299 Bhp@5700 rev/min*, 510 NM@4000rev/min. Toyota oil lubricated , water cooled turbo type CT20 (2 bar max. pressure) and air/air intercooler. 2 OHC belt driven and solid tappets. 4 valves per cylinder. Oil cooler. DENSO EFI integral engine management (injection, ignition and turbo).

Author:  TrackToyFour [ Thu Jul 07, 2011 10:09 pm ]
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Quote:
700bhp at 5,700 rpm
Am I missing something here? According to the info plate (photo no 1) alongside Milners Celica the engine puts out 700bhp at 7,500rpm. I suppose its possible that the info plate had the numbers the wrong way round but the quoted 700bhp at 7,500rpm corresponds to the output of similar build 3S-GTE's I've seen.

The WRC variant of the 3S-GTE engine has a lower block deck height and special rods and pistons as well as having thicker cylinder walls. This, along with anti-lag, would probably at least partly explain the high torque figures at relatively low rpm.

Author:  Diceman [ Thu Jul 07, 2011 10:16 pm ]
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Image

The spec sheet indicates 7500rpm not 5700rpm.

Are you sure we are not all getting knickers in a twist?

That means 644 lb/ft at 5700rpm if it really is 5700rpm!

With nos = 737 lb/ft @ 5700rpm.

Sorry to *bleep* on peoples fire but I just don't see it being true.

Author:  Diceman [ Thu Jul 07, 2011 11:05 pm ]
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hmmmm.....

Image


Basically you put another throttle / restrictor down stream of the intercooler, the turbo runs at a higher boost pressure than you require in the plenum, and you drop this "excess" pressure across the restrictor. Now, that actually takes more exhaust energy to do (as the turbo is doing more work) so reduces engine performance. The key point is that you are boosting the effectiveness of the intercooler to over 100%, becuase your high pressure air exiting the compressor is V hot, you have a large delta T to ambient, so your aftercooling system is able to remove lots of heat. (you remove heat at the highest enthalpy point of the system) Then when you allow the air to expand post IC (at a lower enthalpy) it is cooled BELOW ambient temperature by that expansion. (assuming that you expand it fast enough and at a point of poor thermal conduction to the environment, so the energy required for the expansion (change of entropy) has to take heat from the gas itself)

If you have an engine that is heavily knock limited, where it's sensitivity to intake air temperature is very steep, you can find that the extra turbo work is more than offset by the combustion pressure gains from the cold aircharge / advanced ignition, so overall it's a win = more power.

Image

Author:  two_OH_five [ Fri Jul 08, 2011 12:38 pm ]
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Er run that by me again in English

I was with you up to
JP wrote:
Hmmm.....


then it all went a bit blah blah breaking the law of thermodynamics?

Author:  Diceman [ Fri Jul 08, 2011 3:02 pm ]
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It does sound a bit highbrow.
In reality I very much doubt Milners TB expansion will be sudden enough for the theory to be effective.

The pic posted of the subaru WRC however should work dandy. And I have been asking myself why they seemed to have a air to air and chargecooler type intercooler! DOH.

I'll get my (lab) coat.

Author:  TrackToyFour [ Fri Jul 08, 2011 8:46 pm ]
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Well I understood your post. The Subaru engine bay pic is the usual mess and IMO not a good example of how to do things.

The Milner setup does seem to make sense at high rpm. I don't think it would be very good at lower rpm particularly if there's no IACV.

Author:  andycaca [ Fri Jul 08, 2011 11:17 pm ]
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TrackToyFour wrote:
Quote:
700bhp at 5,700 rpm
Am I missing something here? According to the info plate (photo no 1) alongside Milners Celica the engine puts out 700bhp at 7,500rpm. I suppose its possible that the info plate had the numbers the wrong way round but the quoted 700bhp at 7,500rpm corresponds to the output of similar build 3S-GTE's I've seen.

The WRC variant of the 3S-GTE engine has a lower block deck height and special rods and pistons as well as having thicker cylinder walls. This, along with anti-lag, would probably at least partly explain the high torque figures at relatively low rpm.


i could be wrong actually, and mistook the tuners comments of "it doesnt rev" meaning it didnt go to 8300rpm ish like other high power 3gtes. sorry guys!

Author:  Diceman [ Sat Jul 09, 2011 10:27 am ]
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I am loving the twincharge setup he is using. We have spoken about it over a pint or five many a time but never seen a 3sgte running it. Top marks actually getting it to work and switching between centrif SC to turbo.

I bet that is the main source of torque low down. Now then what we would like next is the centrif SC running off an APU to provide boost at tickover please. :-)

Author:  TrackToyFour [ Sat Jul 09, 2011 9:47 pm ]
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Diceman wrote:
.... Now then what we would like next is the centrif SC running off an APU to provide boost at tickover please. :-)
Why not go one better and use an Aeristech HTT full electric hybrid turbo technology for zero lag and maximum boost on demand. Also eliminates the need for antiquated anti-lag :D I woudn't be surpised to see this in the new V6 F1 turbo engines in 2014 and/or Le Mans prototypes

Image

http://www.aeristech.co.uk

http://www.electronicsweekly.com/Articl ... etails.htm

http://www.electronicsweekly.com/Articl ... etails.htm

Author:  Wolf_Tm [ Tue Oct 18, 2011 3:18 pm ]
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Mmm... now it's a central feed stock plenum while previously it was the TTE short runners side feed...
Image

Author:  Meurz [ Tue Oct 18, 2011 8:10 pm ]
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No, it was a Caldina side feed, iirc.

Author:  Wolf_Tm [ Tue Oct 18, 2011 8:30 pm ]
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Meurz wrote:
No, it was a Caldina side feed, iirc.


Nope mate, I was wrong... just checked old photos, and it was always been the oem central feed...

Author:  Meurz [ Wed Oct 19, 2011 10:54 pm ]
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Ah, indeed. My bad.

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