I know, but I got the external one too so I figure I just as well use it.

 

Steve said It works best. I don't know for sure. It might be that on a N/A set up the map has a smaller range, than a turbo setup. I have a MAP Map that works good, I just don't use it. Maby I should

-Paul

 

If you've ever seen MAP sensor readings on an NA engine, the MAP sensor will read "0" (i.e max) with any liberal throttle inputs.  The Haltech doesn't know the different between 75% throttle and 100% throttle, as both will easily trigger a big jump from vacuum to "0".  Selecting TPS as load sensor will allow for better engine response for NA applications because of this - now the Haltech knows the difference between 75% throttle and 100% throttle.  With that said, the maps are significantly different, although the bars on the right side (i.e. close to 0 MAP and 100% TPS) will be pretty close.

If you're running custom individual throttle bodies, it's next to impossible to get a stable MAP signal from them.


-Ted

 

VERY well said RETed

 

I have, and do often... anything close to WOT on my individual throttles approaches atmospheric, yes. Haltech provides the full throttle map for this if you are having problems with proper WOT tuning with map based load sensing. They also provide the zero throttle map for idle tuning with map based load sensing, for radically cammed piston motors or heavily ported rotaries that have a poor vacuum signal @ idle.

Under the rest of the operating conditions, is it not true that MAP based load sensing is a more accurate representation of load?

I suspect this is more of an issue of simpler/easier to tune than better performance, no?

 

Ah, the full throttle and zero throttle maps - you are correct.  Haltech had designed them to work as you have described, and it does work very well.


In general, yes, but for NA applications tuning there is a performance gain by going TPS-depedent.  You're able to fine tune some area which would normally be very difficult to tune via MAP-dependent load only - this would be be approximately the 1/3rd throttle and higher TPS loads.  Yes, extensive tuning will get you very good running MAP-dependent fuel and ignition maps, but for those looking to extract every ounce of performance from their NA, TPS-dependent tuning is the way to go.


That is relative to each owner, but that's basically the point.


-Ted

 

Well, I don't claim to be an expert on tuning these things yet. I'm always interested in hearing peoples thoughts on what they think works better on our engines, and after my last post I emailed hitman (http://hitman.hm) asking him about the MAP vs TPS on NA rotaries issue. His response is:
I use TPS for bridgeport or PP motors, otherwise MAP. MAP is preferred, but TPS works better on teh heavily ported motors because of the intake pulsing and lack of vacuum at idle.

I'm asking him why MAP is preferred, I personally believe MAP gives you an increase in precision and as a result potentially better performance than TPS (obviously depends on if the tuning takes advantage of it). But I would like to see what Matt (hitman) has to say.

Does Steve come on the forums ever? If not maybe Paul could ask Steve to elaborate on why he chose to use TPS based load sensing, I suspect it was primarily based on simpler tuning rather than a performance based decision... and post his response in here.

I'm sure judge ito would be happy to give some input on the subject also, he's generally pretty helpful whenever I ask him questions about tuning.

 

Just got the response from Matt (hitman):

MAP is more accurate and it better reflects true engine load in a single sensor. TPS on the other hand also requires baro (altitude) correction, and air temp correction is a little more critical.


I would love to have more exerienced tuners chime in on this.

 

I've found that interesting.


-Ted

 

But the E6K can be set up to use Baro correction while in TPS mode.

 

Maybe for WOT but you still need load sensing through the map for driveability.

 

ill trade your injectors for mine 4x550 cc

 

If you're asking me to trade the 1680cc injectors for yours, I don't have the 1680s anymore, I sold them.