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Apparently this T603 will be racing at Goodwood again, but after the last show the organisers told the team to make the car more powerful and a better sound (even an aircooled V8 can sound timid through big silencers) This is a replica of a car Tatra raced in the late 1960s, looks nice don't it?  And this is what they did to make more power and noise  It's not just a pair of Saxo exhausts, picked up from McDonalds car park. This was an experiment by Tatra in the 1950s for their racing engines: they realised that the cooling fans sapped a significant amount of power, but in a rear engined car you've got to have them. The Czech boffins suggested using the exhaust gases to draw cooling air through the tinware, basically if there's exhaust gas coming out at 100mph that creates low pressure at the back which can be used to draw cooling air right through. Those megaphones have exhausts coming through the middle, and cooling air through the big outside tube. Does it work? I'll have to dig out the book written by their technical director at the time, but I seem to remember 170bhp, which was up from the standard car's 100bhp but I don't recall what the racing engine made with normal cooling, probably around 150bhp. 10% extra power for free? Sounds (pun intended) good to me ;D |
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you could probably get away with an electric fan for hill climb these days, battery technology has come on a long way so getting enough run time may be possible from a fairly light battery?
you just need to gain more power for the few minutes going up the hill than the weight penalty costs you and be able to swop in charged up batteris for the next run.
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Volvo back as my main squeeze, more boost and some interior goodies on the way.
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The pressure drop you need to cool an aircooled engine is massive, it’s not just like the air through a watercooled radiator. You need to shove it through some pretty densely packed oil coolers, over cylinder fins and cylinder head fins, then out.
The cooling fan on my Tatra 613 took 20bhp, that’s 15kW of power plus whatever efficiency losses, let’s guess at 18kW? Even if the batteries were small, the motors themselves would be massive – 12V and 1500 amps
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Even if they could use electric fans, where is the WTF! factor in that ;D
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1993 Fiat Panda Selecta
2003 Vauxhall Combo 1.7DI van
2006 Mercedes Kompressor Evolution-S AMG SportCoupé
"You think you hate it now, wait til you drive it"
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Aug 23, 2010 10:47:39 GMT
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Awesome genius engineering that has the advantage of looking completely bonkers at the same time as being 100% functional!
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Sierra - here we go again! He has an illness, it's not his fault.
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Seth
South East
MorrisOxford TriumphMirald HillmanMinx BorgwardIsabellaCombi
Posts: 15,514
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Aug 23, 2010 10:55:17 GMT
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Would love to know what that sounds like now  Different front end or different car from '08?  It'll be competing with a Borgward this year....  |
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Follow your dreams or you might as well be a vegetable. |
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Aug 23, 2010 10:57:00 GMT
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This reminds me of the Norton Rotary motorcycles with the Wankel rotary engine. Apparently the race version had a special exhaust system which used a similar principle to suck clean air over the engine for cooling using the pressure of the exhaust pulses. I'm not sure whether this air was shared by the carb intakes or not, as the Nortons with these exhausts reputedly used to blow smoke-rings on idle!
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Aug 23, 2010 11:11:48 GMT
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I believe norton rotarys (the race ones anyway) used to suck the inlet to suck the cooling air over the fins, I only remember this because a Battle Of The Twins racer swapped the system to an electric fan to cool the block, gained huge power (as you wound with a drop in inlet temp) but couldn't make it go around corners or stay on the straights.
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Aug 23, 2010 12:08:31 GMT
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Would love to know what that sounds like now Different front end or different car from '08? It'll be competing with a Borgward this year.... It's the same car with a different front end, the bonnet with snout and 3-headlight panel is wrong for that car, it's just to make it look older. Genuine older cars have a lower windscreen, quarterlights in the front doors, different rear end... I'll be there on the Sunday, see you there! |
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Aug 23, 2010 16:43:37 GMT
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The pressure drop you need to cool an aircooled engine is massive, it’s not just like the air through a watercooled radiator. You need to shove it through some pretty densely packed oil coolers, over cylinder fins and cylinder head fins, then out. The cooling fan on my Tatra 613 took 20bhp, that’s 15kW of power plus whatever efficiency losses, let’s guess at 18kW? Even if the batteries were small, the motors themselves would be massive – 12V and 1500 amps if theres no rules outlawing multiple motors you could run the fan off a chainsaw engine? |
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Volvo back as my main squeeze, more boost and some interior goodies on the way.
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MrSpeedy
East Midlands
www.vintagediesels.co.uk
Posts: 4,786 
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Aug 23, 2010 18:00:14 GMT
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I actually built a similar system to ventilate a narrowboat engine room a few years ago.
Would probably be ok for the 50ish second dash up the hill, but i'd be wary of any extended racing with it !
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-Scott-
Part of things
I am easily satisfied with the very best.
Posts: 549
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Aug 23, 2010 18:24:12 GMT
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Would love to know what that sounds like now I'm thinking kinda like this but louder (sorry about the music) |
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Last Edit: Aug 23, 2010 18:28:18 GMT by -Scott-
Keep calm and carry on
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