As I said trust me - I am a professional automotive r and d engineer with 30 years experience and hold patents in fuel injection. If the system is mapped correctly on a dyno and everything is kept in adjustment (no likage wear etc) you see no difference in ignition advance between TPS and MAP. A number of production EFI motorcycles use just a TPS and no Map sensor.
The TPS does reflect exactly what load is on the engine. For a given throttle position and the a given load the only variable is the speed (rpm). So the power being produced is a function of TPS and RPM. If you change the load the speed changes, if you change the throttle load changes and speed changes.
The only benefit of MAP is handling transient condition and a well mapped TPS with correct enrichment settings will handle that. Spark is not really an issue.
I have ITB's so TPS in much better. If you run a single TB then go with MAP.
My TB's have individual air bypass needle valves (idle valves) so at idle the throttles are shut so linkage movement is not an issue. The other (and more complicated way) is to set up an idle control valve.
Why do you keep comparing motocycle engines with a VW motor. Any faults in the system caused by poor tunabilty can be overcome due to the extremely light weight.
But anyway, what is the sensor No. 7 ??
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
56astro wrote:The other issue with ITB on a VW engine is the linkage. When the engine is cold and the TBs are all shut, how far will they open when the engine warms up?
The ITB's are not shut when the engine is cold.....they are open to a pre determined gap so the engine will run.The linkage is adjusted while the engine is hot.The linkage is "longer" than required when the engine is cold as the intake manifolds are not spread as far apart until the engine heats up. I had no problems with mine at all. It ran a TPS and MAP.Air flow meters suck.
Yes Mick, as I said, modern ECUs are able to compensate (to a certain extent) for poorly designed systems.
On your particular system, is 0% throttle recognised by the ECU when the engine is cold, hot, or never ?
As Ken said, the proper way to overcome cold running is an Idle Air Control Valve.
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
56astro wrote:Yes Mick, as I said, modern ECUs are able to compensate (to a certain extent) for poorly designed systems.
On your particular system, is 0% throttle recognised by the ECU when the engine is cold, hot, or never ?
As Ken said, the proper way to overcome cold running is an Idle Air Control Valve.
Yes...why wouldn't 0% be recognised???? That's like asking would WOT be recognised. Isn't this getting a bit offtrack anyway from the original post?? It's turning into a "mine is bigger than yours" discussion.👎😘
56astro wrote:Why do you keep comparing motocycle engines with a VW motor. Any faults in the system caused by poor tunabilty can be overcome due to the extremely light weight.
But anyway, what is the sensor No. 7 ??
Astro - I am afraid your out of your depth mate, for an EFI scooter to meet Euro 4 emissions its control needs to be better than any aircooled VW on the streets today. The small displacement means pulse width precision needs to extremely good as does transient control.
I was waiting for yr question on sensor 7. If you look carefully at the diagram you will see that the pressure sensor is upstream of the throttle blade and therefore is not measuring manifold vacuum but just atmospheric pressure. To measure manifold pressure the sensor must actually measure pressure in the intake between the throttle and the intake valve,
If you want use your MAP sensor go right ahead but other readers of this forum hopefully will accept that based on common EFI practice 100% TPS is a viable tuning method particularly with multiple throttle bodies and all good aftermarket ECU's MOTEC, Haltec, Wolf, Gotech have the option of this mode.
What inputs are needed, by that I mean the minimum to run an EFI engine. And I found another picture of an R1 throttle body that shows the fuel rail. I'm sure you could make, modify or get one to fit when the two halves are split
56astro wrote:Yes Mick, as I said, modern ECUs are able to compensate (to a certain extent) for poorly designed systems.
On your particular system, is 0% throttle recognised by the ECU when the engine is cold, hot, or never ?
As Ken said, the proper way to overcome cold running is an Idle Air Control Valve.
Yes...why wouldn't 0% be recognised???? That's like asking would WOT be recognised. Isn't this getting a bit offtrack anyway from the original post?? It's turning into a "mine is bigger than yours" discussion.👎😘
Mick, you said in your post that the linkage is adjusted while the engine is hot.
Is that when the ECU recognises 0% throttle? Or more? Or less?
Or is it when the engine is cold when the linkage iis "longer" than required.
If the engine and linkage does grow, at what point does the TB read 0%
VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
56astro wrote:The other issue with ITB on a VW engine is the linkage. When the engine is cold and the TBs are all shut, how far will they open when the engine warms up?
This problem only occurs with the Kadron style linkage, not weber/dellorto linkages which are the type you use with ITB setups. Heat, or the 'growing' of the engine does not affect the carb sync on weber setups, so carby sync is maintained hot or cold.
56astro wrote:So we'll be seeing that type of system on all the european cars as well then??
Geez Astro - you just don't get it do you. This thread is about the merits of twin or quad throttle bodies. Clearly TPS is a viable solution on engines with an unreliable or fluctuating vacuum signal. That is - quad throttles or single cylinder m/cycle engines. Yes more modern multi cylinder engines use a MAP sensor - but the use of MAP sensors on modern cars as the primary input sensor went out 10 years ago at least. These systems are called speed density and no modern car uses speed density systems in production. It is viable as cheap aftermarket conversion for carbis - just as a TPS system is. Today ALL modern cars use a MAF - (mass air flow sensor). So the little knowledge that you are trying to demonstrate on this thread is getting in the way of sound advice to keen VW tuners wanting have a cost effective and reliable EFI system.
Out of interest Ken what are your thoughts on megasquirt?
Also what manifolds have you used with your k100 throttle bodies?
thanks
kkk
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Out of interest Ken what are your thoughts on megasquirt?
Also what manifolds have you used with your k100 throttle bodies?
thanks
kkk
A quick read of the manual indicate the megasquirt looks very difficult to set up. If you immerse yourself in it and understand all the various terms you not only learn a lot about engines and engine tuning but also end up with a good system.
On the other hand most of the latest series of aftermarket ecu's Motec, wolf, etc have much easier to set up windows based interfaces. For example after setting up the basic parameters in the Gotech you just adjust the height of a bar on a bar chart to vary the fuelling rate or ignition advance.
I used stock type 4 EFI manifolds with a cast iron base, cut the 4 runners tubes off and machined them to accept the base of the 4 K100 TB's. Just by chance the spacing of the K100 TB was exactly the same as the spacing of the manifold ends so the BMW linkages also were useable.
Hey Judsons4eva, that set-up looks REALLY good!!!
After reading you posts, I might switch my MegaSquirt II over to TPS based, and compare the two modes.
I think the MSII is easier than it looks, though you DO need to read the manual, and do your research! But it has a lot of features that we probably don't need. Also, the software is windows based, and apparently will even run on Vista, if that's your thing.
Rick
1970 914
Fed & Fired by MSII/EDIS/GSXR TB's/LC-1
1956 VW Beetle Looks like a dog, purrs like a kitten!
I've decided that the R1 throttle bodies are too complex and I'm now looking at CBR 954 RR instead. The new problem I have thought of is what's the best material to make the inlet manifold out of. Aluminium seems the popular choice from an OEM so is it the best or could one be made of SS. Would the thermal expansion rate difference cause any problems.
The expansion rate of the manifold material shouldn't make any real difference. In theory stainless would give some advantage as it would not retain much heat to transfer to the intake aire. However the most important thing is to get a smooth air flow from the throttle body down the the cylinder head/manifold interface with well matched ports.
