(The most current infomation is at the bottom of this page)

• Dinan Engine Performance Software:  You have to have this done.  It's expensive but, to progress your car to other levels it's a must.  In my opinion it's worth every penny.  You will notice a slight increase in power but, the big difference is the governor that restricts your topend engine speed will be gone!
• Dinan Cold Air Intake System:  This is a very nice upgrade to your car I love it.  Yes, it gives you a very noticable performance increase in all RPM ranges especially above 3500rpm not to mention a nice growl when you step on the gas.   The car can breathe now and get the air it needs to get the additonal 16-20 HP.   You can hear the difference with the video above called Dinan.   This is in my opinion the best designed system for performance on the market.  It extends from you airflow meter down past the headlite and near the opening of the front spoiler vents.  This allows the cool air entering the vented area of the spoiler to pass straight to the air filter.
• Dinan Peformance Transmission Software:   I was dissappointed at first with this modification.  I didn't notice any difference at all (doh)!  I thought, this is a mistake it's not doing what Dinan claims it will do for automatic transmissions!  I watched my video's I had taken before and after the modification and could hear no difference with speed and timing of the the shift points.  I knew something was wrong!  I called the dealer that did the installs and explaind to them I didn't think the Transmission Software Download took!  They said bring it in and will check it!  I took them up on that the same day and they had the car for about half hour. I waited wondering is this going to make a difference?  After 30 minutes they said here you go and you were right the software didn't take the first time, but it did this time!  I was excited to here that and couldn't wait to get on the road!  I left the parking lot and tested the 1st to 2nd gear shift!  It only took a few seconds to realize the difference.  The shift seemed incredibly quick!  I came to a stop light put her in second and  waited for the green to test some more.  I got the green and gave her about 3/4 pedal!  I was thrusted into second gear from 1st!   Dinan claims about a 25percent increase in shift presure when you're getting on the gas.  I would contest to that being very close if not under rated.  It feels more like about 30-35 percent when you stomp on it.  I'm very happy with this upgrade.  If you have an automatic do yourself a favor and get this upgrade.  I added the Video above called Trans to see and hear the difference in the shift points.
• Dinan Free Flow Exhaust:  Ok,  there is a lot to choose from out their.   I don't get any reinbursments from Dinan!  I have heard and seen other exhausts, I wont mention names but, it comes down to two things.  What sound are you looking for and how is the quality?  I'm very happy with the sound from the Dinan exhaust.  They have a nice throaty sound to them.  When you step on the gas they ROAR.  The fitment could be better for the e39 as they do hang down and stick out a little to far.  Once again check out the vids above to get a idea of the sound and look.
• Dinan 3.15 Open Differential:  My car came with a 2.81 differential.  With the addition of this modification my car has taken on a new personality.  The car is much quicker off the line and feels much faster overall.  This was the modification I was missing and is worth every penny. Yes, you can buy the OEM 3.15 differential for about $500.00.  I purchased Dinan's.  Listed below are the 0-60 times with the 2.81 and 3.15 differential.

• Update: I haven't come close to 5.2 since I've installed the High Flow Air Flow meter.   The best I can get is 5.7 and that is consistent in 60 degree weather.  The mass air flow sensor in conjunction with my shiftpoints are not in sync.  The car loads up in 1st gear and hesitates a little before shifting to 2nd gear.  Very similar to the oem shifting.  The great shift presure is gone in this range.  Unfortunately, this is the range where you would feel it the most and get the best results.   I have spoken with Eric Forester (spelling) of Dinan Engineering and so has John Harte of Cunningham BMW about this issue.  It is believed to be a software issue and the Software Engineers of Dinan are working on  it.  I have not heard anything else about this since April 19, 2002.

• Update:  Wednesday evening May 1, 2002 - The installation of the manifold did not correct the issue with the transmission software.  It is as if the transmissioin software is not even installed.  The car loads up even more now in the 1st gear before shifting to 2nd.  I'm not a mechanic, but believe there are issues withn Dinan Stage IV and V software, or perhaps the mass air flow sensor.  The strange thing is it's the same version of software for the Dinan supercharger.  I would like to see Dinan make corrections to the Stage V engine software so it is better suited with the Manifold and High flow air flow meter.  I Just got back from a cruise on the freeway.  I found a nice section with nobody near me and let her rip.   Going up hill the car excellerated to high speeds in a very short time.  The topend   just keeps on excellerating faster and faster from about 45mph up.  The lowend side is TERRIBLE from 0-20mph.   The car does not even want to power brake burn offs.  The time lost in the quarter mile and 0-60 runs are brutal.

• Conclusion:  My HP  and Torque from Decembers Dynojet run was 312HP at 5700 rpm's and 332Torque at 4500 rpm's.  This was before the Throttlebody, High Flow Air Flow Meter and Intake Manifold installations.  In conjunction with the 3.15 Differential installation my 0-60mph times were 5.2 - 5.3 seconds pretty much constant with decent launch's.  After the installation of the  Throttle body I noticed no significant changes in performance.   After the High Flow Air Flow Meter installation I could tell I dropped power on the lowend. The best 0-60 times were 5.7 seconds and very consistant.  My 1/4 mile times were 13.9-14.1. Not to shabby! The Dinan Transmission software was not working like it was before the install.  It lost its punch from 1st to 2nd gear.  This is where it really made a difference, but the air flow meter was making up for that in the upper end.  After the Intake Manifold installation  I could tell right away my car lost more of the lower end side.   I had my car dynoed again at the same place and same dyno as the December run with just about the same temperature etc.  Here are the numbers 325HP at 5900 rpms and 364 Torque at 4400 rpms.  I should of had 320HP with just the Throttle body installation.  The air fuel ratio was 11.5 normally where you run for supercharged engines. My car is not supercharged (yet) and should be running more like 12.5-13.  I picked up only 13HP, but 32lbs more torque with 3 modifications.  I was happy with the torque readings and who wouldn't be.  That's the new M5 territory.  The 13HP was not adequate especially with the engine management software (Dinan Stage V Engine Software). I gained numbers and lost considerable quickness through the 1/4 mile. The amount of power lost on quickness at the lower end is far to great.   At this point of my modifications I'm dissappointed in the lower end.   My advise to anyone who is installing mods from Dinan to stop at the throttle body and Stage III engine software, or even at the air flow meter and stage IV engine software unless your going to install the Dinan supercharger right away.  My car was very quick at this stage of modifications even going with Stage IV and the Air flow meter. The car was quick and fast!  I'm thinking about  having  my old manifold reinstalled and possibly my air flow meter since the Transmission software does not work well with the air flow meter.  If Dinan got the Stage IV engine software  working  with the air meter or vice versa  the car would be a beast.   Stage V software is supposed to be a match for the intake manifold.  This may hold true on some cars, but not mine.  It should be reconfigured and setup for the manifold only. This could possibly bring out the HP needed for this installation. There is probably another 15 or more HP trying to get out.  I would like to see Dinan create a Stage VI software for the Supercharger installation.   I have to decide if I want to have my old manifold put back on.  I love the speeds from about 20mph up, but the takeoffs are terrible.   I'm surprised with all the R&D Dinan has done they wouldn't know this and have corrected it? One last comment! The car does move out from 20-30 up to the redline and seems to be much faster.  If you want quick 1/4 mile times or 0-60 times stop at either the throttle body for automatic transmissions and stop at the air flow meter for manual transmissions unless your installing the Supercharger:)

• Update:  May 30, 2002 - Spoke with Dinan Engineering.  They have released a new High flow air flow meter that is supposed to correct the lowend speeds. Mine is on the way to the dealer.  I will update the differences once it is installed.  If the performance is not what it should be I will have no choice but to place my origonal manifold back on.

• Update:  June 10, 2002 - I took my car to the dealer for a 4 wheel alignment that I was overdue for when I changed out the suspension.   They also did a balancing on my new wheels that should have been balanced to begin with. I wont get into this one right now and it wasn't the dealers mistake it was where I purchased the tires and wheels.   I also had a radiator hose that started to leak replaced no charge and an air meter replaced no charge that sounded like a turbin when the car was started cold.  The mapping thermostat was also replaced no charge.  Whatever that is?  I also had my Koni shocks in the back stiffened up a bit to eliminate tire rubbing when hitting dips on the freeway at high speeds.  The car is a little stiffer for sure, but handles great with the Dinan suspension and the new wheels and tires!

• Update:  June 11, 2002 - My replacement High Flow Air Flow Meter was installed.  This was a redesigned air flow meter that is a little smaller in diameter within the meter then the original.  This redesign was to fix the issue with the loss of lowend speeds and the impact it had on the transmission software for the automatic transmissions.  I have only driven the car a few miles, but I can tell that the transmission software is working again the way it should be.  I have very good shift presure from 1st to 2nd gear again.  The takeoffs are much better than before the swap, but not as quick as it was before the highflow meter and manifold insallations, but that is expected with the increased air flow.  Dinan backs their products and stands behind them 100 percent.  The correction in the air flow meter did make a significant change.  Overall,  I'm  very happy with the changes:)

• Update:  June 11, 2002 8:30 PM  - Just got back from a cruise down to La Jolla.  I tested the new high flow air flow meter thoroughly.  The power is back and the shift presure is back!  You press the gas and the car responds quickly an very efficently.  The Stage V Engine software, MAF and Manifold are working together now and not against each other.  What a difference!!!  The car feels quick and fast!