i have a 1987 sierra rs cosworth 3 door.

i keep being told that the level 8 ecu is better than the level 6 ecu due to these reasons:

1. data logging.
2. monitoring sensors.
3. running closed loop.
4. running launch control and anti-lag.
5. faster processor.

all the above reasons do not interest me due to the fact that i don't need or want any of them!

however, people have mentioned that a level 8 ecu will run much smoother and is the best ecu that you can get, pushing aside aftermarket units.

my plan is for a fully customised chip from stu at motorsport developments. he offers a 380bhp chip which you can then customise further to your desired spec. i have been told that the smoothness of power delivery will be down to the quality of mapping and not the ecu type whether it be a level 6 or level 8 - is this correct?

please remember that a will have to spend £80 extra a for 4x4 tps and rewire the connections. i just can't see any benefits for my car as surely the mapping will be exactly the same for both 380bhp chips whether they be for the level 6 or level 8.

any comments whatsoever will be welcomed!!!

 

hmm tough one!i am still on a L6 on my sapp you have upgraded already by going up to a L6 on a 3 door!the L8 is a better ecu and if u are thinking of future plans with anti lag etc ,you will need a L8!the L6 has that annoying characteristic,of when you back off then reapply the throttle you get that split second delay,with L8 you will not have this!but yes alot of it is down to the mapping!tbh for what u want i think the L6 will be fine!

 

i had l6 and then l8 now going T2. there is no real diffrence. all comes down to the car being mapped. IMO

 

please give me your experiences!

many thanks!!!

 

Why don't you ask Stu@MSD for his opinion, seeing as you intend for him to be your tuner?

 

the L8 ecu cannot do datalogging as such - it can output a datastream that can be datalogged externally on a laptop etc

 

If you go for another custom chip I do advise to get closed loop. Not in the first place for fuel economy but for the healt of your engine.

 

I'm sorry, but this 'engine health' rumour needs to stop as it's not accurate. A well-mapped open-loop chip will perform 99% as well as a closed-loop chip with regards to fuel economy and engine wear.

Comments have been made about poor quality calibrations running excessively rich which will damage engines, which is fair enough.. it's not the closed-loop aspect of a chip that fixes that, it's the quality of the calibration - adding closed-loop on top of that just very finely tunes things!

If you go unplug an oxygen sensor off of a car running closed-loop and check the fuelling, it'll barely change. Of course, this is on a well-mapped system. A badly mapped chip running closed-loop will 'damage' the engine just as much, because most likely it won't be able to do the closed-loop control as it's so far wrong!

I'm done.

 

Closed loop is better over time, as the VE of your engine changes.

That said, I agree with pa sjo, an open loop system can actually run MORE economically if mapped correctly, as you tend to get better economy at say 15.2 than you do at 14.7

 

Yes it does Chip and that is one of the main reasons of using it but man, i've checked cars with 150,000 miles on the clock (albeit domestic vehicles, not highly modified cars) without closed-loop and they've never been more than half a point out on the fuelling. Certainly not enough to bore-wash an engine!