4722 replies to this topic

[Ormes]

Nevs jumper

[Nev]

Nevs jumper

I will need to remember to wear my more fashionable garage clothes next time I take a video

[leevx2.2]

Nev great figures I need a go in this beast or a drive on track. ;-)

[Nev]

Nev great figures I need a go in this beast or a drive on track. ;-)

Thanks Lee, though I do think the numbers are over the top by a long margin. Sure thing about a ride, let me know if you are ever passing Bristol way, I will take you out for a nice and torquey ride

I have now received the spare boost control solonoid (kindly sent by DaveE) and installed it in the car, I just need to wait until it stops raining and the roads dry out. Hopefully this will solve the over boost problem and 'surges' of power that I get when I allow the EBC/ECU (rather than my MBC) to control the wastegate.

I have also added a precise needle valve to act as a configurable 'bleed' valve off the side of the MBC. This should allow me greater precission in smoothness of the wastegate actuation, according to my understanding/theory the less I let it bleed the more agressive the boost will switch on and off. If this works this means I will have good control of how the car behaves for different situations. We shall see if it works that way in RL though.

Edited by Nev, 10 November 2012 - 12:47 PM.

[Nev]

A rather small update but rather large step for me at the bottom of here (possibly pertinent to anyone with a tuned/non standard VX220 Turbo).

Edited by Nev, 11 November 2012 - 11:56 AM.

[mbes2]

Wow Nev... 300Bhp more than mine is crazy, as mine scares me now... You are one crazy man for sure... well done on ya.!! like the comment "They do not road map the car, it was simply done on the rollers which does not test for real world characteristics. As a result my car used to come away from them with bugs." MMG also believes this...

[Nev]

I expect that it's not the power that scares you Mark, it's the torque and the speed of it's onset - unfortunately this is the problem with that titchy little k04 turbo being maxed out to overcome all the restrictions in the system. Have you tried fitting some wide wheels and tyres on and run them at lowish PSI - that will help give some confidence. By fitting a middling sized turbo on mine and a tiny 3 PSI spring on the wastegate, I'd probably get 300 BHP with just 230 ft/lb of torque (approx 125 ft/lb less than you I'd imagine), so it feels like a high reving NA with less propensity to spin up the wheels as a result. Moving to a bigger turbo has this nice benefit as a welcome wide effect, providing the engine is built to rev quite high and take advantage of the turbo puffing all the way to 8000 RPM.

Edited by Nev, 11 November 2012 - 12:27 PM.

[Nev]

I've added an interesting before and after graph (scroll down) to show how my mods have smoothed power delivery since it's original mapping. Even if you forget the actual probable discrepencies of like for like BHP figures (from using different dynos), you can see how different the shapes of the 2 graph lines are. This difference in shapes is noticable when driving.

You can see why I say it's more like driving an NA car now.

Edited by Nev, 14 November 2012 - 04:04 PM.

[Nev]

Ohhh Shiite, I have my first electrical gremlin I've been taking the MAF plug on and off to test which of the 4 wires coming from it was the 0-5v signal wire. Successfully detected it with my volt-meter (and noted that it read approx 1.53 volts), cut into the sheath of that wire and soldered in a take-off wire from it to lead into the cabin so I can read the voltage off it as I drive. However, on starting the car up I have clearly disturbed something or the MAF isn't working as it was, because my lambda at idle has dropped from 14.5 to around 18.0 ! Also the volt-meter is now reading approx 1.40 volts (where as it was reading 1.53) - hence the under fueling presumably. Things I have tried are: 1. I have disconnected the multi-meter from the new signal extension wire incase it was affecting things. 2. Check Ohmage down the new signal wire - it is 1 ohm which is correct/minimal. 3. I have cleaned the plug and socket electrodes with a file and brake fluid. What more can I try? Very strange, as I went out for a run at lunch time and all was fine. Thus whatever I have done tonight has buggered it up

Edited by Nev, 14 November 2012 - 06:12 PM.

[siztenboots]

i'm not sure you can look at voltage , as I believe the ecu is measuring the current flow through the heated wire. /edit inside the sensor it is current ( ie. the hot wire is kept at a constant temperature ), but this is then converted to a voltage as the ecu sees it.

[Nev]

i'm not sure you can look at voltage , as I believe the ecu is measuring the current flow through the heated wire.

/edit inside the sensor it is current ( ie. the hot wire is kept at a constant temperature ), but this is then converted to a voltage as the ecu sees it.

I thought I was 100% sure that the end pin (pin #5) sent a 0 to 5 volt signal indicating air flow to the ECU. However, after this cock up I'm no longer 100% sure

Thankfully DuncanVXR is kindly sending me a spare sensor and loom plug to eliminate those being faulty. If I'm lucky replacing those 2 will fix things. If not I have to wonder WTF is wrong... maybe a loom issue *cry*

Edited by Nev, 15 November 2012 - 11:19 AM.

[siztenboots]

afaik the ecu is protected from short circuit on those pins

[Nev]

But all I have done is T-into (carefully soldered) the end wire that leads from pin #5, this hasn't short cicruited anything (I think). According to Bosch: Pin #1: Unused Pin #2: +12v Pin #3: Gnd Pin #4: +5v reference Pin #5: 0-5v output signal Once I finish work this evening, I will check that the +5v reference it is receiving is really +5v or if it has dropped a bit.

Edited by Nev, 15 November 2012 - 11:24 AM.

[siztenboots]

could you have mounted the sensor reversed to the air flow

[Nev]

could you have mounted the sensor reversed to the air flow

I briefly thought that, but the top of it is asymetrical, so impossible to screw it down backwards.

I have taken it out and sprayed with brake cleaner, reinstalled it, but no improvement. I have also heated it lightly on the stove so see if it is some sort of cold problem as the air temps are low here ATM.

[hairy]

Never mind that, you're famous:

http://forums.seloc.....php?tid=350899

[mbes2]

Its good to see the comments from lotus owners... Good on ya Nev.

[Nev]

Haha, thanks for the link Hairy, I didn't know they had started a thread to discuss Nipper's asthetics. I can understand the criticisms of the wing, it was the most reluctant decission I made about the car's development. However, what those armchair chaps don't understand is that the car is way more stable now than it used to be. Before instaling the wing, I used to get propper scared about front end stability at 130+ leptons, but with the wing and splitter it just gets more and more stable all the way and beyond. In fact slowing down to < 70 leptons is when you notice it most IMO as it isn't offering any help from that point and below. Well, the reason I'm posting on here is that I've just got back from work this evening and "magically" fixed the issue with the AFR lamda going out of tollerance. Once quick spurt of WD40 on the contacts fixed everything - DOH !! Beginners oversight. Am off to my Karate grading tonight and then if I'm not to knackered will take it was a cautious drive later on (roads are super greasy over here). Also my new manual boost controller has turned up and is loads better at controlling the boost signal to the wastegate, so I've installed that instead of the old crap one. So, I am all set for metric gathering on Sunday with my mapping friend. We are logging some basic params from the ODB2 and MAF to start programming Nippers new map into the OEM ECU. A whole new step for me and the last substancial part of the car that I want to understand for my own satisfaction.

Edited by Nev, 16 November 2012 - 05:08 PM.

[Nev]

God it's greasy out there. I went for a little test run to check everything is ready for tomorrow and I think the back wheels slipped just turning out of my T-juntion at the end of my road at 5 MPH. Crazy.

[Nev]

Just soldered in a GND wire off the MAF circuit as getting a constant earth off the chassis with a "spike probe" was intermittant/unreliable.

I'm getting very excited about this now. If we can correctly isolate the different areas of the map in the OEM ECU, we should be able to start mapping it fully (.i.e. the whole caboodle). As far as I'm aware there are only a couple of UK based people who really know how to do this.

Edited by Nev, 17 November 2012 - 06:02 PM.