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      01-08-2013, 06:46 PM   #54

Drives: N54
Join Date: Aug 2012
Location: USA

iTrader: (0)

Originally Posted by Dave W.
Originally Posted by jdbretz View Post
Well if you actually read my post, you would realize I never stated a single should flow more air than equivalent twins. The natural of twins though is they are generally smaller, but obviously there are 2 of them. They will still run out of air in high RPMs but will spool quicker. A large single will spool slower, but will continue to push more air in higher RPMs due to its larger size. I don't see what is difficult to understand about that. Of course you could put large enough twins and match the potential of a single, by that point the single will cost half as much and perform similarly. This is also assuming you had the extra RPMs to take advantage of. This platform is not revving high enough for it to matter right now.
not yet Higher rev limits are just becoming necessary thanks to the flow of the big singles. It's one aspect of performance that hasn't been needed until recently. I'm not sure what we'll see in the near future but I'd love to see a 64mm or 67mm turbo with a 7500-7800 rev limit.

There's no reason someone can't put a smaller single turbo on the car to get quick spool and nice top end. So far all of the 6MT guys have opted for the 62mm turbo. I have a feeling the 58mm turbo would be a killer on road courses.
You're talking 4mm difference on compressor wheel only, everything else stays the same. Spool difference between the two, negligible. You want to trade off good spool for less top end you start dumping A/R or going smaller turbine housings / wheels. People have a misconception of compressor size having a huge effect on spool. It does not, everyone just thinks it does because compressor size is the most publicized number on a turbocharger. In turn people automatically think smaller number equals faster spool