In my post “Why is the E34 M5 So Unique?”, I highlight several aspects of the E34 M5 that are truly last in a generation. However, there is one “last in generation” characteristic that I left off the list–that is the fact that the E34 M5s were the last BMW 5 Series model to leave serious torque and horsepower change on the table with their factory ECU mappings. Thus the question any M5 owner SHOULD NOT ask “Do I chip my car?” but rather they SHOULD ASK “What result am I looking for and which of the available performance chips gets me closest to that result?”
There are three reputable BMW tuners who manufacturer performance chips for the E34 M5. These are Dinan, Confortti by Turner Motorsport, and D’Sylvia (EAT). Each one of these chips has a little different setup. Based on my own personal experience and feedback I’ve gathered from the both the chip manufacturer’s marketing materials and countless online forum discussions, I’ll do my best to recap the options. Before I get into each manufacturer’s offering, let’s quickly review what these chips do.
“Chipping an automobile” generally involves remapping or modifying the instructions on a car’s electronic control unit in order to achieve improved fuel efficiency, horsepower, and/or torque output. Increased performance is achieved by recalibrating the ignition timing and air/fuel parameters of an engine. Performance chips can also be used to increase RPM rev limits and remove top speed limits of a car. Though every automobile manufacturer’s end goal is to provide a high performing vehicle to its consumers, conservative settings are often used in ECU mappings to prolong engine life, compensate for varying fuel quality, or even to promote vehicle operation safety.
Dinan E34 M5 Performance Chip
The Dinan D900-3631E performance chip is marketed for 1991 through 1993 S38b36 powered M5s who have access to 91 octane gasoline or higher. In addition to increased horsepower and torque gains, the Dinan Performance Chip increases the rev limit and removes the top speed limiter natively programmed into the E34 M5’s electronics. According to the Dinan website, the following are expected gains and new peaks after installing their chip.
Max HP Gain 37@ 7000 rpm
Max Torque Gain 36 lb/ft @ 3500 rpm
Peak Horsepower 342 @ 6800 rpm
Peak Torque 294 lb/ft @ 4000 rpm
Though I do not own this chip for the M5, I did have a Dinan chip in my 525i donor car used in the project on this site. Based on that experience and online feedback about the M5 chip, it is safe to say this is a true performance chip goaled at upper RPM horspe power gains and amplification of torque in the car’s normal power bands. As with just about anything Dinan, customers satisfaction is great. More information can be found on Dinan’s website.
Turner / Conforti Performance Chip
Like the Dinan chip, Conforti’s performance chip (sold by Turner Motorsport) targets S38b36 platforms running 91 octane or higher fuel. Per Turner’s website, both the horsepower and torque gains are slightly higher than Dinan’s chip with their ECU mapping. Again, based on their published data and the online discussion, this chip is a direct competitor with the Dinan chip as it’s results really highlight gains in the M5’s natural power band range. Response #3 in this thread gives direct account of all three chips I highlight in this post. See Turner Motorsport’s website for more info.
Horsepower Gain: +39 @ 7,000 RPM
Torque Gain: +38 @ 3,500 RPM
New Rev Limit 7,500
EAT by Mark D’Sylva
Mark D’Sylva of Enhanced Automotive Technology features a series of E34 M5 chips that are quite popular based on online discussions. Where this chip differs from others is threefold. First, Mark doesn’t make a horsepower or torque claim. If you ask him, he will provide you the results of his his chip’s application on his personal E34 M5. Second, the EAT chip is designed to smooth out the M5’s torque curve by adding torque to lower RPM ranges. Three, EAT actually makes chips for both 91 and 93 octane levels allowing M5 owners to match their chip purchase to the fuel types available in their state.
As my E34 M5 is going on 23 years of age, I was really looking to take a balanced approach in realizing both the torque and horsepower left on the table by the Motorsport Division at BMW. I was also interested in a smoother curve as drive my M5 under a variety of city and highway conditions. My decision in picking the EAT chip exceeded my expectations by providing me smoother realization of unquantified torque and power. One of these days I’ll put my car on a dyno so that I can add quantifiable results to this post.
All three chips listed in this post are made by reputable and dedicated tuners. The purpose of this post is less about a “bake off” and more about providing both a strategy as well as a consolidated set of links to online information related to these performance chips. In the end, as long as your expectations are inline with your choice, I don’t think you can go wrong with any of these performance chips.
In researching for this post, I did come across several generic chips available on eBay. Though I can’t comment on the legitimacy of these chips, I think you’ll be hard pressed to come up with a reason to step outside the three options listed above.