Chip tuning - hype or the real thing?

Is it true that it is possible to gain more power from your engine, simply by replacing the main engine management chip? Most of us have heard both sides of this story, but if this is the real deal, then it's a very cheap way to gain more horse power. I decided to give it a go...

I am not sure yet about the use of K&N filters (going to check that next), but if you are installing one of these anyway, I believe a tuning chip will make a great addition. One of the larger K&N suppliers in Europe are YB Filters. Visit their site or eBay store for a great price.

First of all, let me start by thanking James and Jayson for supplying the chips. They made this review possible.

Secondly, please note that my car is the European version, not the US. Even though they appear to be the same, they aren't. Part of the Motronic engine management apparently differs, so if you drive a US version, you can not expect the below result with the Euro chips. The US chips which are not performing well on my car, should run perfectly good on US spec cars, whereas the European chips most likely will trigger a 'Check Engine' fault and performance should be down, compared to my results. Always go for the chip designed for your specific market if you want maximum performance.

There was a time, when doing a go-fast chip was for the major tuning companies only. But now quite a few hardcore BMW fanatics, with access to the right equipment, are making their own chips. AND making them available to the public too at a much lower price, of course. But just how big is the difference between the chips currently available?

As always, I must remind you that the info supplied here is as unofficial as it gets. I am not a BMW tech and I don't have any testing equipment. Instead I have a passion for BMW and the will to make it go faster! So when I test these chips, the result is strictly my own opinion...

All tests are done on my stock 525iA, 1989, M20. For the technically inclined, the DME is a 0 261 200 173 and the original chip is a 1 267 355 794...

It's a good idea to plan ahead for this, since your new chip will only run on premium gas. The standard chip on my M20 is designed for RON 91, but the new chips all require at least RON 95 or higher. Why? Because the tuning chips advance the ignition timing and that calls for a higher octane, or self detonation will be the result. On newer engines with knock sensors, the DME will readjust the timing to save the engine, but this will also take away most benefits of the new chip. Older engines may be subject to unreasonable wear, so take your precautions: with the old chip still in place, you should run the car until the tank is almost empty and the fill up with premium gas. Or maybe just fill it 50%, to save weight on your first test run :-)

A few words about octane... 91 octane is not just 91 octane, because Europe and the US uses different standards. Don't know about the rest of the world... In Europe, the Research Octane Number (RON) standard is used, whereas the US uses an average of MON and RON, the Anti-Knock Index (AKI). In comparison, AKI 91 octane in the US is the equivalent of RON 95 octane in Europe.

In other words: chip tuning requires you to use higher quality gasoline. If you are in the US, you should go no lower than 91. Europeans need 95 or higher...

Now we need to find the E-box (electronics box), where the DME holding the chip is located. On the E32 and E34's, the E-box is located in the engine bay. Other BMW's may have the DME inside the dashboard, above the glove compartment.

Remove the lid and locate the DME module. Unplug the main connector, remove the nuts and pull the box. I have been told that there is no need to unhook the battery first, so I don't. I have yet to experience any problems with this approach...

Next ->