[Kadarin]

I'm new to the BMW world, as I've owned my new '08 335i for just one month (as of today). So far I've modded this car by lowering it with the H&R Sport spring kit, the Dinan Stage 2 flash, and the Dinan exhaust. I absolutely love this car!

My other car is an '05 Pontiac GTO with JBA 50-state legal headers and a Corsa Sport catback.

In comparing the aftermarket for my BMW with that for my GTO, some differences become apparent, and my question is whether this is primarily due to the relatively short time the N54 has been available, or if it's a characteristic of the aftermarket for turbocharged cars in general that mods only tend to take a certain direction.

In the case of the BMW, available performance mods tend to be restricted to exhaust (inc downpipes), CAIs, ECM tuning options, and intercoolers.

With regard to the LS1 and LS2 in the GTO, available performance mods will also include headers, intake manifolds (not just CAIs), camshafts, cylinder heads, underdrive pulley systems, fuel systems (i.e. larger injectors), modified engine blocks, aftermarket FI systems (including twin turbo kits, nitrous oxide, and several different supercharger designs).

Has anyone in the N54 world thought about putting the cylinder head on a flowbench and seeing if gains are possible through portwork or aftermarket castings? Can valve timing events be adjusted for larger gains?

It seems that paranoia with regard to warranty issues is rampant in the BMW world; is this the reason why people appear to be less willing to perform more radical modifications to their vehicles? Or is the reason simply cost? Or, is it that the mindset is completely different among BMW owners/tuners than it is among those who are used to owning and modding American muscle?

I'm a noob here, so please go easy on me! Thanks!

[StarrDlux]

no paranoia at all. bmw is not the same company as GM. Warranty void for good.

You've already voided your warranty with those coils and engine warranty with dinan parts. And dinan will probably deny any claim if there are any non-dinan parts (like H&R) lol.

BMW motors are extremely well tuned for boost. It is simpler to replace the turbo's with better ones for more power;bigger fmic.

Tuning all motor is a compromise. You put alot of flowing parts on there, big 112lsa cam, etc you have a monster that had 40% VE below 1500rpm and shakes the doors at idle spitting fuel out the exhaust.

Turbo cars just tend go faster with more bolt-ons and more boost.

But i guess if you want to try nitrous; let us know how much that N54 motor costs to rebuild when it throws a rod. Can't be more than 20K

[Kadarin]

Originally Posted by StarrDlux

BMW motors are extremely well tuned for boost. It is simpler to replace the turbo's with better ones for more power;bigger fmic.

So am I correct in assuming then that in the FI world it is just more beneficial to focus on increasing airflow and boost via turbo mods and software, and that is why the aftermarket has focused on these areas?

I'm just fascinated because in the GM and Ford worlds, people are perfectly willing to spend a few grand on aftermarket cylinder heads and so forth even on cars that are still under warranty. Is the reason that nobody makes aftermarket engine internals for the N54 due to the relative immaturity of the market, or are there simply no worthwhile gains to be found from, say, altering combustion chamber design and port shape/flow, or are there technical reasons that make aftermarket parts of this nature prohibitively expensive?

[roozie2001]

Originally Posted by Kadarin

So am I correct in assuming then that in the FI world it is just more beneficial to focus on increasing airflow and boost via turbo mods and software, and that is why the aftermarket has focused on these areas?

I'm just fascinated because in the GM and Ford worlds, people are perfectly willing to spend a few grand on aftermarket cylinder heads and so forth even on cars that are still under warranty. Is the reason that nobody makes aftermarket engine internals for the N54 due to the relative immaturity of the market, or are there simply no worthwhile gains to be found from, say, altering combustion chamber design and port shape/flow, or are there technical reasons that make aftermarket parts of this nature prohibitively expensive?

u gotta remember for bmw this is like what 2 yrs vs GM/ford 40+ years. besides that this car has a restricted Fuel and air flow. Everyone thinks the turbos will go capoot but i dont think its so, i think soon as someone learns how to jack up the air and put a fuel pump and fuel filter that gets it flowing this car can become an absolute monster. Then the question will be can the driveshaft and tranny handle it? or will it snap like a twig?