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      11-16-2010, 01:00 AM   #1
HP Autosport

Drives: F80 M3
Join Date: Mar 2007
Location: Santa Barbara, AP, Brembo, GIAC, Koni, Ohlins, Performance Friction,

iTrader: (34)

iCarbon N55 Downpipe Review

When iCarbon contacted us about trying their new N55 downpipe we were excited to see just what they had cooked up. Our N54 powered 335i responded so well to a free flowing downpipe that we have been itching to see what kind of performance could be gained on our new 135i. The results were shocking to say the least.

We gained power EVERYWHERE! A quick look at the dyno results will confirm this. There were literally no sacrifices, no shifting of the power curve left or right, this downpipe just took the stock dyno lines and increased power everywhere along them.

This mod is definitely noticeable by the seat of the pants. After we installed the pipe we drove to the dyno and the whole way there car just felt way better. It was hard to believe that the downpipe alone was responsible for the significant increase in power plus it added a nice growl to the exhaust note. Nothing outrageous or look at me loud, just that nice sporty exhaust note that all BMW’s should come with and it sounded even better with the quick shifting DCT.

Keep in mind that we completely reverted our car back to stock. We gained at least 17 hp and 16 ft/lb at the largest separation of the graph.

In conjunction with our N55 High Flow Filter, a Berk Technology exhaust and a tune, there is some serious gains to be made. These engines love to breathe freely as is evident by iCarbon’s well thought out downpipe and our comparisons with our filters and Berk’s systems. The HP to dollar ratio is great with this modification and is an integral part of creating a great performing car.

*** This DP Fits both 135 and 335i with the N55 egine

Here are some pictures from our install. You can tell just by looking at the side by side comparison how much more the iCarbon downpipe is set up to free flow.

Here is the result when Berk Technology exhaust(with rear muffler) is added.

Green - Stock
Red - iCarbon Performance catless DP
Blue - The above with Berk Technology Exhaust added

Again, we picked up power everywhere. Max tq is 273.5 and hp is 269.7. In comparison without the Berk exhaust, max tq was 267.8 and hp is 260.7

In stock trim the 135i N55 made 254 tq and 251 hp

Remember this is on a SuperFlow dyno. Dynojet numbers will be higher.
Attached Images

Last edited by HP Autosport; 11-22-2010 at 10:10 PM.