Interesting, mappable, K-Jet system

Yes that is the MAP sensor for the K-Star.

 

Cheers, i did wonder myself.

 

I assume i have plate flutter problems with my schrik 276's, light part throttle and coasting result in a very ..... "Shunting" kangarooing ... effect that can only be solved with a wider throttle angle or more often dipping the clutch. Gets quite tiresome in stop start or slow moving traffic. defo a car that likes......

"The Thrill of Driving"!

 

Thats exactly whats happening with mine barny.
kangarooing a low speed, and revs up and down when idle. Pain in the frickin ****.

 

On the rare occasions I`ve run my kjet 9A on 290`s I`ve not had ^ problem ... what idle settings do you have ?

 

I haven't a clue James. It was "set up" by a Bosch place in Leeds about 5-6 months ago, but its never been right.
I'm going to use this guide: http://www.race.nangreaves.com/golf/FU01/index.htm that RJ provided,and see if i can make it any better.
I've got a full K jet system spare so, i suppose i could set it all to standard off the car and take it from there?

 

Mine idles ok, around 1100rpm but sounds lumpy partly due to the lightened flywheel i guess. as for idle settings im not sure ....

 

Is your ISV working OK ?

 

My conversion does not use an ISV, throttle position switch, auxillary air valve or overrun cutoff valve - needs to start on the throttle and then kept running `high` until it warms a little ... settles down OK after that.

Also have a lightened flywheel.

............

sean ... good luck setting it up, let us know what you find ?

 

I asked Unwiredtools if they had any RR data to share wrt showing the AFR control ... the disappointing reply being:

Personally, it would have to be half the advertised price for me to be tempted.

 

Thanks for taking time to investigate and get a reply from the "horses mouth".

 

I've only flicked though this thread thinking it would be something I've not heard off yet!!

I have fitted to my GTI but never tested it's effects, the Audi WUR that has a vacumm line to the inlet manifold to alter the fuel pressure depending on MAP - I think I need to get it set up and running sweet this year

 

Audi WURs are similar to 16v K-Kjet units. When the vac approaches 100kPa, the WUR reduces control pressure leading to fuel enrichment.

 

WRT this plot of my ex 2.0l kjet with modified WUR I was hoping to see how the UTCIS-V could improve things ... hence the disappointment with the reply [:^(]



Next item to try will be another modified but externally adjustable WUR albeit on a different but still kejt engine.

 

I have tested K-Jets vehicles on the dyno that actually had very consistent tail pipe lambda.
Some other do the same thing as in the picture except your rich point is more of an OK AFR and the Okish part at 7000rpm would be where it would run lean. So the lambda profile in the picture is more of a typical lambda shape offset richer.

However in that example I could see how a correction in fuel targets between 4-5K rev/min would have helped mid range torque/power, but not by a lot. Most of the sting is missing because you cannot target spark timing per load/rpm. You can globally shift the dizzy to wards the advance end stops and the engine may reach its det limit or 'ping' at 2.5-4K rpm at higher loads, causing you to back off the dizzy in the current compromised position.

That AFR plot can be fixed mechanically though.
Or as you said try another WUR you maybe lucky.

 

Thank you ...

 

In the spirit of the new year and all that, here is a little illustration that "tuners" do not tell you.

Here is the same plot only looking at AFR/ engine speed



The dark blue line is what is was happening in the plot and the ligher blue is what could happen with an aged and unmodifed WUR. This is what I was describing in the previous post and why folk automatically think they have to modify the WUR.
In the illustration your car would need to operate within the brown lines for given spark timing, octane and CR. Somewhere between those lines is the leanest best torque. You need targeted dyno testing for the engine to determine where this occurs. Depending on engine design/spec/rate of burn/etc the torque between the brown lines could vary +/- 5lbft of the LBT point. Outside this greater than +/-10lbft towards pre ignition (Green) or bore wash (red).

On average this engine was running and exhaust AFR between the brown lines so fuel control optimisation would only add a small change to WOT torque performance, depending where LBT was. Targeted spark timing would be the next most significant step.
This is why, K Jet in this sense is limited.

HTH.

 

Sure does ... thank you again.