Originally Posted by splinter
In a typical OE setup, the Johnson CM30 pump will lower IATs ~10 degrees Fahrenheit.
Reputable source…
http://www.mbworld.org/forums/showpost.php?p=2376178
When getting after ‘em on a road course, or especially before fitting an aftermarket pulley, upgrading one’s heat exchanger is imperative for best performance. The DME will retard spark timing significantly, and dump fuel, once the 140 degree threshold is breached and continue to do so as temperatures increase. Properly controlling heat soak, high IATs, and their attendant ‘dialing back’ from ideal spark timing and mixture strength parameters will measurably increase performance.
Congratulations on becoming a member of the 12 second club!
I honestly think I can beat that 12.89 now with just the changing of the pump. The car is so much more responsive and oddly it gets to the magic 3000 mark faster now. I know the SC doesn't come on till that rpm so why its faster to 3000 now is a mystery to me. It revs much better and more consistently. Like I said before to those who haven't done this upgrade "I
thought my pump was just fine before."
