New computer (EMS Stinger) and lap times

Post Fri Mar 18, 2005 9:02 am

I posted a while ago about the new computer I got put on my car and dyno tuned. It is an EMS Stinger (fully programable, replaces factory ECU). At the time I said I couldn't notice much (or any) difference but now I have been back to a race track I use to go to where they have a good timing system.

Before I got the computer I did a 1:06.23 as my best time after the computer I did a 1:06.74. So it is about the same, the 0.5sec difference is probably due to the fact that I haven't been to the track in a while (it is different to the other tracks I go to), and I only did 2 runs when I normally do 4 (and my times on the 2nd run were still dropping so I probably could have gone a fraction quicker. It was also a fairly hot day, but probably not much hotter than last time I was there.

So what do you think? Should I have been any quicker with the new computer? The mechanic told me that the computer gave it a lot more low down torque than it had before which should have been helpfull on this track because there are a 3 corners that are too quick for 2nd (I have to change to 3rd while I am still in the corner) but also too slow for 3rd, so I just use 3rd to save a difficult change. Because I use 3rd I thought the extra torque would have improved my times?

Let me know what you think?

Aston

Post Sat Mar 19, 2005 1:10 am

Nobody knows? Surely someone here has put in a new chip and then gone back to a circuit and got some times? Or if not then what would you expect to happen?

Aston

Post Sat Mar 19, 2005 1:50 pm

seems like there are too many variables to be able to make a good comparison - still would have thought you might go a bit faster though

Post Sat Mar 19, 2005 5:54 pm

As you said in your earlier post, there didn't seem to be a lot of difference. I would normally expect to 'feel' or sense the difference if I make a mod, particularly something like a new ECU, to my car. Your experience on track seems to be confirming that there is little difference. I don't think that a couple of laps is a good test tho unless you are a Formula 1 driver who can drive at the limit from lap 1. My times can change quite dramatically over a day or an afternoon on track. The car doesn't change other than the fuel load but I do, in other words I'm the variable. It might be better to compare over a longer period so that you can get more used to the new characteristics of the chip. It might also be that is the fastest that you can currently drive round the track rather than how fast the car can go round it. This is not meant to be a criticism of your driving just a different way of looking at it.

Post Sat Mar 19, 2005 11:46 pm

Yeah I see what you mean but surely it doesn't take much of a driver to use more power and straight line speed. All I have to do is push the accelerator pedal to the floor

. I don't get any wheel spin, even at full throttle out of corners, so I don't have to wory about that.

I did a total of 10 laps on that circuit (then we went to a different layout). Usually all my laps are within 0.5 sec of each other, except the first couple when I am getting up to speed. You could be right though, too many variables. I will see if I can get back there again and have another go.

Aston

Post Sun Mar 20, 2005 12:21 pm

The 323 in the UK has the LJetronic management system and the only adjustment is to fuelling. It doesn't have all the sensors and tuneability of the Motronic. I'm not familiar with the brand, what is the Stinger actually managing? What other mods have you got?
I used to have a 323 and had a 2.7 conversion done. I then swapped the lump into my current Sport and was able to develop it because it then had the Motronic. I subsequently changed to MAF/Unichip and noticed big changes on track. Much quicker throttle response and power delivery out of the corners and more power overall.

Post Sun Mar 20, 2005 10:44 pm

The EMS Stinger completely replaces the factory ECU (not like a chip or piggyback ECU). It has it's own sensors and replaced the AFM with a MAP (air pressure in manifold or something?) sensor. I now have just a straight metal pipe between the air box and throttle body. The Stinger can control timing and fuel, it is supposed to be a level down from a MOTEC.

Aston

Post Sun Mar 20, 2005 11:14 pm

Hi Aston. Thanks for explaining the Stinger, sounds similar to an MBE or Emerald system. I would have thought you would notice a difference with that mod it should be infinitely tuneable. You've taken the restrictive mechanical AFM away so the air should be getting in quicker and throttle response should be a lot sharper. Don't know what other mods you've got but a bigger throttle body (or bodies) and a six branch and then a further re-map should certainly see a noticeable improvement to torque and bhp. I had an MBE on my car for a couple of hours and it was brilliant but we couldn't get it to work with my quirky autobox so hence I ended up with the MAF set-up.

Post Mon Mar 21, 2005 11:21 am

I have a full 2 1/2" mandrel bent exhaust with a 6 branch (that is headers/extractors right?) and straight through mufflers and it was on the car when the new computer was tuned. That is about all engine wise. I am thinking about a throttle body but since the computer hasn't made any difference I don't want to spend more money and still not be any faster. The computer cost me $2400 AUD (about 1000 GBP) which I think is quite a bit of money to get minimal/no results so I have gone off the idea of modifying for now.

Aston

Post Mon Mar 21, 2005 11:33 am

Sounds like you're getting the air in and out quickly so any meaningful mods will probably be in the middle i.e headwork and cam and or a capacity hike, all of which are a major investment.
What were the torque and bhp figures off the dyno when it was tuned?
Am attaching my printout post MAF fitting and mapping. Might whet your appetite for a 2.7!

Post Mon Mar 21, 2005 12:19 pm

That's looking good! I can't read it properly (late at night here and my eyes are tired) but I see about 237BHP!

Is that at the wheels or the flywheel?

I don't know if a 2.7 is for me though. I really like the power and torque your's is making but I also like smaller high reving engines. Just a personal thing. A 2.7 isn't big but I think maybe my 2.3 or a 2.5 is more what I would like.

I never got a dyno sheet after I got the computer fitted but the mechanic said it was making about 160BHP at the flywheel (the dyno place had corrected it from the WHP to at flywheel power). I think that is about 10BHP more than a standard 323i. The mechanic said it made a lot more torque down low compared to before the computer but he never gave me a figure.

So now you know more about my car and the computer would you expect my lap times to be any quicker?

Aston

Post Mon Mar 21, 2005 1:03 pm

Power is into the 240s now and yes it is at the flywheel.
I remember my old 323 was 150bhp when standard, so 160 is good. I have to say that I would have expected to see a more tangiable improvement with the Stinger. It sounds a good system but if you have a good dyno mapper you're probably getting the best you can.
A stand alone engine management system can get the best of what's on offer from the engine. To get anymore from the same capacity and keep it revvy, you're probably talking a hotter cam but the power will be at the top end of the rev range but that is where the engine is most of the time on track.
I have virtually stopped modding mine now. I still really enjoy track time but I spend it trying to get more out of me rather than the car if you know I mean. Had some tuition and had the greatest performance hike I've ever had!!

Post Mon Mar 21, 2005 11:58 pm

Yeah I know what you mean about the driver training. The problem is with my car like it is (handles very well and underpowered) there isn't a lot involved in driving it fast. I have had a bit of instruction before and I recently I have been on the track with a couple of performance driver trainers, including a freind of mine, as passengers and they didn't really have any advice for me. They said my lines and driving style were all ok and there didn't seem to be much left in the car. So that is why I am looking to upgrade the car a bit, then I can go back to improving my driving.

I also go dirt circuit racing and that is one place I can definately improve my driving. It requires a lot more car control than the bitumen.

Aston