NA tuning, sugested features and sensors

hey gang, i have a bmw M42B18

thought id ask/ start a discussion

i have a haltech elite 2500 and spare inputs and outputs

NA specific what are the best things to meter when it comes to engine control

Wideband, barometer, ethanol, engine pressure ratio, exhaust pressure, theres alot to sense but what is best for a NA if you are limited to 10 functions what would be at the top?

besides triggers and tps what do you think is the prioritys? theres alot to choose and not much guidance as to why.

last thing you want is to buy a dual channel wideband and dual knock and find out theres no way to bank them both on a 4cyl, and ethanol isnt a gain unless boosted after you bought ethanol equipment....

Hello the key inputs i would say are

water temp

air temp

lambda

map

tps

fuel pressure

oil pressure

Ethanol if used

Regards Ross

Hello the key inputs i would say are

water temp

air temp

lambda

map

tps

fuel pressure

oil pressure

Ethanol if used

Regards Ross

any others and a reason why?

Sensors are for answering questions, or allowing compensations. There is a minimum required go get a running engine, and if the purpose is specific enough (say drag racing), you can often get by with very little.

So you have to ask -- what questions will you have about the engine operating conditions, and what is the intended purpose for you car. A car to be driven at all seasons and altitudes, may need to have multiple temperature sensors (ambient temp, manifold air temp, perhaps fuel temperature) and a barometric pressure sensor.

I like an ECU to have access to all the engine health parameters, so I will generally want oil temp and oil pressure. I may want coolant pressure for racing, where coolant leak can ruin and engine, but it can be detected with a coolant pressure sensor. Porsche GT-3 Cup cars have a crankcase pressure sensor, and it is useful to determining when an engine needs rebuilding (leaking rings, or a bad dry sump pump)

Thanks Dave, my thoughts on sensors, were ones that alow better control or acuracy of the engine, and less dataloging type stuff, better info in is better efficiency over all.

i was told e85 makes no improvement with a NA engine (10:1) but its all internet hearsay untill i get factual data.

and theres info on what sensors do what

but when i want to know which is better i hit roadblocks

for example using < 1 knock sensors or < 1 wide bands, which is beter to see in stereo data fuel or ignition? for people who have to choose one or the other?

I recently tuned an LS3 V8 on 91 octane pump fuel and was able to make about 475-479 hp on my Dynapack. I then filled the tank with E85 (producing about E70 effective according to the ethanol sensor). I then made 495hp with adjustments to the ignition timing to suit E85. So there is some gain even for a normally aspirated engine.

Number of knock sensors and number of wideband inputs that is useful is really dictated by the engine. If the factory setup had two knock sensors, then it makes sense to duplicate that. But if the factory setup is just a single sensor, then it's likely you can use a single sensor effectively.

If the engine configuration has dual exhaust, then you really need to have two lambda sensors for insight into the engine mixture. Plus it's extremely handy for diagnostics -- got a misfire, generally this will show up on the lambda sensor for one bank, and you can concentrate your diagnostic efforts there. I find that the same with per-cylinder EGT. With a good intake, not really needed for tuning, but super helpful for diagnostics when the engine has a slight miss.

I'm not sure that more sensors is necessarily "better", particularly if you don't spend the time looking at what they are measuring. But if you have the need to know, there is no substitute for having the proper instrumentation.