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Read the WELCOME ALL BMWFANATICS post.
Racing against Honda S2000
- Thread starter Olorin
- Start date
Olorin said:
Hi Olorin
These figures which get claimed and even "tested" very seldom are true indications. 0-100 figures of ST's, Golf 5 GTI's, 330i were all better than the A4 2.0T I owned before my BM and I promise you that A4 gave all of them a hiding:excited:. A car that I struggled against with the Audi was the Astra OPC, they are quick. But compared to the lovely 335i I currently drive the above are slow:clap:
As mentioned at the coast the 330i might be a different story. Don't rely on quoted figures.:thumbsup:
Olorin said:If your Audi gave the 330i a beat down then perhaps the BMW driver simply wasn't giving it his best effort ? Or his handbrake was applied.Specs have to count for something, surely ? Otherwise what's the point at looking at the specs of cars ?
Well the proof is in the pudding. It didn't just happen once and I had witnesses.
Skwinty
New member
The engine specs are measured on a test bench in ideal conditions.
The engine is also blue printed. Once the engine rolls off the production line, it is about 15% to 20% under spec for reliability purposes.
It is no big deal at the end of the day, unless you want a racing car.
That costs plenty more than you paid for your beemer.
The engine is also blue printed. Once the engine rolls off the production line, it is about 15% to 20% under spec for reliability purposes.
It is no big deal at the end of the day, unless you want a racing car.
That costs plenty more than you paid for your beemer.
WyKiD
Active member
Olorin said:If your Audi gave the 330i a beat down then perhaps the BMW driver simply wasn't giving it his best effort ? Or his handbrake was applied.
Mnfr. specs are conducted under ideal conditions and with professional drivers, very rare can these be achieved in real world conditions.
Olorin said:If your Audi gave the 330i a beat down then perhaps the BMW driver simply wasn't giving it his best effort ? Or his handbrake was applied.
He isn't at the coast, so the turbo cars lose half as much power as the NA engines. The 2.0 tfsi engine is known to push out more power than is specified, don't know if this is on purpose. At reef the 2.0tfsi should do the same 0-100 as the 330i...
Specs are a guideline... They work for most car comparisons, but unfortunatly the comparisson here isn't 100% valid because its not at the coast...
killua said:Olorin said:If your Audi gave the 330i a beat down then perhaps the BMW driver simply wasn't giving it his best effort ? Or his handbrake was applied.
He isn't at the coast, so the turbo cars lose half as much power as the NA engines. The 2.0 tfsi engine is known to push out more power than is specified, don't know if this is on purpose. At reef the 2.0tfsi should do the same 0-100 as the 330i...
Specs are a guideline... They work for most car comparisons, but unfortunatly the comparisson here isn't 100% valid because its not at the coast...
+1
WyKiD
Active member
Dusty said:Olorin said:If your Audi gave the 330i a beat down then perhaps the BMW driver simply wasn't giving it his best effort ? Or his handbrake was applied.
Well the proof is in the pudding. It didn't just happen once and I had witnesses.
At the reef, boosted 2ltr beats 330i...fact.
Olorin said:
They are technically in the same class, but remember, the astra OPC 177KW, which is almost the same as the 330i. And it is lighter. And if I am not mistaken, we are still talking about reef not coast. So the astra has about 165kw at the reef and the 330i (assuming brand spanking new 200kw version) has 170kw at the reef. The astra should in theory win by virtue of being lighter and having less drive train losses....
Olorin said:killua said:
Could you please explain why that is ? I'm not very clued up when it comes to these things.
Thinner air being pumped through the turbo housing and thinner air mixed with petrol...:dunno:
Experts help here...
the turbo can boost more to make up a little for the thinner air, but on an NA car it just has to deal with the thin air as is
Olorin said:killua said:
Could you please explain why that is ? I'm not very clued up when it comes to these things.
Ok. The main idea starts with the concept that fuel+air creates power. I will keep things limited to petrol engines. The fuel and air have to be supplied in a certain ratio (stoichiometric) for all the fuel to burn properly. So when you add more air, you can add more fuel, and thus have more HP. Its why modern cars have valve timing and more valves per cylinder than old cars, to let more air in.
Now, coming to the highveld, the air gets less dense. To be more exact, we have about 15% less air density up here than at the coast, depending where in Gauteng you are. So now with a naturally aspirated (NA) engine, the same volume of air sucked into the engine has less air molecules to burn. So the NA engine will make aproximately 15% less power at reef.
Turbo chargers, I will only describe free-floating and normal wastegated, boost a certain amount of air into the engine. Lets say that a turbo boosts 1 bar at the coast, which has about 1 bar ambient pressure, the engine will have about 2 bar of air to burn fuel in. And that is the maximum power specified by manufacturers. Now here at the reef the ambient pressure is 0.85 bar. And the turbo is still only boosting 1 bar, but working harder because the air is thinner. So the total pressure inside the engine is 1.85 bar. Which is 8% less than the 2 bar at coast. So the turbo engine will lose only 8% of power where the NA will lose 15%.
