Ask the Best and Brightest: BMW Engine Mods ASAP?

Robert Farago
by Robert Farago

TTAC commentator carguy can’t leave well enough alone as he prepares to boldly go where no factory warranty will go with him:

I have a question that I would like some feedback on from the TTAC best and brightest. I am about to take delivery of a BMW 335i and am contemplating some mods for the engine (after all, 300hp seems like a waste when you have a 3-liter six and two turbos). My question is two fold:

1. Should I run the engine in and then get the mod or should I run the engine in with the mod in place?

2. I was considering a Dinan stage 1 or 2. Any feedback from TTAC readers on this mod or any other would be much appreciated.

Robert Farago
Robert Farago

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4 of 48 comments
  • U mad scientist U mad scientist on Jun 22, 2009

    We can see that he's looking for validation, but that doesn't make the idea any better. - But car choices are never about what’s needed or what’s necessary. They’re about what the buyer wants. If the buyer wants more luxury and he can afford it, go ahead. A lot of people buy cars for the purposes of security eg. male enhancement. Not exactly unexpected commentary for the site's namesake.

  • Niky Niky on Jun 22, 2009

    Doesn't make it any worse. I'm intelligent enough to realize that the most practical solution to all transportation problems is living as close as possible to your workplace in a city with good public transportation. But I'm also honest enough to admit I'm a hypocrite, I don't exactly care about what's most practical, and I have a yen for speed. On the automotive disastrous decision-making scale, a mild modification of a quick car with no warranty ramifications isn't particularly high... and the only negative against it is the cost of the modification.

  • Ricky Spanish Ricky Spanish on Jun 22, 2009

    Dinan is a HUGE waste of money. People are making 400+ horsepower (to the WHEELS, not bhp) with reflashes from the likes of Vishnu etc - for half the price. We're talking 115+ mph traps here, 1/4 in 12.5 or less, from a 3600 lb tank.

  • AnalogKid AnalogKid on Jun 23, 2009

    I have an '08 335i coupe that I bought CPO with 13K. I thought about a Dinan Stage 2 but decided against it. The problem is that Dinan will only cover repairs to the engine during the first four years/50K miles of the manufacturer's warranty and not during the additional 2 years/100K miles of the CPO warranty, so I would lose a good portion of the warranty. I love my 335i but I will never again own a BMW that is not under warranty (ask me about the "tranny slam" on the X5 4.4i.) If you really want to mod then lease a 335i, add the Stage 2, cane it and walk away in three years. If you plan on keeping it longer (as I do mine) then the mod is not worth it. The 335i is a great car but it has a number of issues (fuel pump, wastegates, etc. that make is a real potential liability to own without a warranty. Check out and read about the guys with failed fuel pumps who had their warranty voided when BMW found their Vishnu and JB units. The manufacturer support that Dinan has makes a big difference in my view. Now to your other question. I doubt it makes much difference from an engineering perspective if you break in the engine first and wait to mod and you might get a better deal if you have the mod installed at the same time you buy the car. Bear in mind that either way you are reducing the life-expectancy of the engine.