VNT control

[cwspellowe]

Just had an idea regarding VNT control which may be of interest to some people.

Basically, as we know, there's two ways of controlling VNT. Mechanical or electrical. Now Ruan has gone for a complicated microprocessor setup but i've had a genius idea and I want to see if it'll work first. So yeh Ruan, pipe up!

Having thought about aftermarket rev counters etc, I'm thinking we could use the alternator W terminal to control the vanes on a VNT blower too. It's an output directly related to RPM's, all we'd need is something to invert the power output and feed that to a stepper motor like in a rev counter.

Hey ho, adjustable boost directly linked to RPM.

Can't believe noone else has thought of this yet

What I want to know is

a. feasible?
b. what can be used to invert the current?

Ruan.. i'm looking at you

[Ruan]

Yeah, feasible for sure, will probably work quite well...

Remember, Alternators are engine load sensing, so will output more amps the more the engine is loaded...

Win?

[Dum-Dum]

It is feesable but the vane position needs setting according to the position of the throttle and current boost so your idea wont work well. Imagine cruising at 100mph and putting your foot down, youd just have nothing.

[Ruan]

Yeah, btu alternators are engine load sensing...

[cwspellowe]

Yeah, feasible for sure, will probably work quite well...

Remember, Alternators are engine load sensing, so will output more amps the more the engine is loaded...

Win?

So it'd work?

YASS!

Right, should probably look into parts. Wish i'd spent the money on a VNT instead of the 56 now if this has credibility dammit!

But if the load is greater at higher RPM's, wouldn't the current need to get LOWER to decrease boost and open the vanes?

[Ruan]

Nah, just turn the can upside down

[cwspellowe]

Ahh switch the spring to the other side of the diaphragm?

[n0v0s]

Have any of the vagfag fukwits tried this?

[Dum-Dum]

Nah if your starting with electric operation finish with it and get a later VNT with the black box of tricks like the 2260 off the bmws

[cwspellowe]

Don't know, Tom's our resident fagcock isn't he? Might drop him a PM see if he knows any more.

---

Nah if your starting with electric operation finish with it and get a later VNT with the black box of tricks like the 2260 off the bmws

Would they take an input signal from the alternator ok? Or would I need capacitance in the line in to it?

[Ruan]

50uF Cap in the line should do it...

[Dum-Dum]

Nah if your starting with electric operation finish with it and get a later VNT with the black box of tricks like the 2260 off the bmws

Would they take an input signal from the alternator ok? Or would I need capacitance in the line in to it?

Pftt, f*ck knows Ruans the electrics expert.

[cwspellowe]

Something like this?

Sorry it's a crap circuit diagram but you get the idea.

[Dum-Dum]

^^^ seems fair Chris

[strictly_perv]

I'm still figuring ways out of controlling it mechanically, either some cable/linkage system to the throttle with a boost actuator in-line to push open the vanes when boost is reached. Orr just feed pure boost, and start to melt stuff...

[Dum-Dum]

Orr just feed pure boost, and start to melt stuff...

I thought we werent talking about full boost on here

[strictly_perv]

Orr just feed pure boost, and start to melt stuff...

I thought we werent talking about full boost on here

f*ck it, weld the arm so the vanes are shut! welded vanes could be the new forum fashion overtaking the TD04....

[sweeney1987]

Why is your capactor in the diagram grounded??

[cwspellowe]

To get a true reading, the signal from the alternator is noisy, we want a pure signal

[Toms306]

Don't know, Tom's our resident fagcock isn't he? Might drop him a PM see if he knows any more.

Aww, thanks.

But seriously, I put a lot of time into researching how vnts work and stuff BUT never came across attaching them to the alternator. Will be interested to see how succesful it is if anyone tries it.

[n0v0s]

It's probably more of a case of people jumping on ye olde bandwagon, as per most forums. And so neglecting other possible methods? From my research, the arduino board seems to have been used by a few select vag boffs who have written some source code, themselves gaining kudos and realising some Internet fanclub, allowing most of the bum boys to copy and follow. Giving advice, to further kudos/forum buming... Doesn't mean it is the only way though,

[sweeney1987]

To get a true reading, the signal from the alternator is noisy, we want a pure signal

yes and capacitors are used to smooth out noise/interference no?

never seen one grounded before, mind you when i did electronics the stuff we were learning was outdated.

[Ruan]

I'm AMAZED no one has noticed the free software some bloke has done yet...

[Eeyore]

I'm AMAZED no one has noticed the free software some bloke has done yet...

?? this?

[Dum-Dum]

Cos if it was good everyone would use it.

[Piggy]

those arduino ecus are a fortune too....nice work MrGTkiller...good thinking...

I am going for traditional gt1752 for my first 2.1 turbo...but was going to work on a VNT for next winters project...

good light bulb moment there chap

---

....so just to think on...
the vnts with a blackbox...can we take the W terminal signal from a alternator and clean it up with a cap and run it straight into the black box?!

[strictly_perv]

I've read somewhere they've done it in with the alt on VAG cars.

[cwspellowe]

Good enough for me! Shouldn't be that hard to knock it up, only a few quid for a capacitor and wiring. Wish id gone vnt to try it now

[zx_volcane]

I'm AMAZED no one has noticed the free software some bloke has done yet...

I'm also amazed, but there we go, not sure how many people on here are looking at programming for control or have any experience with it. Altering source code can prob be a bit daunting, as well as troubleshooting if you're not familiar.

There is probably still a divide between people who are happy plugging a computer into a car and those that prefer a hands on hammer approach.

those arduino ecus are a fortune too....nice work MrGTkiller...good thinking...

What decade do you live in? An Arduino board is pretty insanely farkin cheap. Every other post is you moaning about the price of something :/

Development boards were ridiculously expensive not too many years ago, and the ones I started using you had to program direct into memory by hand in hex - not exactly user friendly, but to be fair probably the most slimline and efficient code I've ever written

Given their age I would have thought that the majority of modern electronic servo controlled vnts will be on canbus, maybe some of the earlier ones aren't. So something to think about when choosing a vnt.

Or just replace with an RC Servo on the go and hope it doesn't melt every week!

[darrenjlobb]

those arduino ecus are a fortune too....nice work MrGTkiller...good thinking...

I am going for traditional gt1752 for my first 2.1 turbo...but was going to work on a VNT for next winters project...

good light bulb moment there chap

---

....so just to think on...
the vnts with a blackbox...can we take the W terminal signal from a alternator and clean it up with a cap and run it straight into the black box?!

WTF planet are you on, complete kit to get you going is like 20 quid....enclosure + small power reg another 20 quid, so 40 quid and your fully set, if your just running single VNT, then that free source code works perfectly and has a tonne of features, hes not made a twin turbo version yet tho, altho I wrote my own version which I was going to use on mine, but imo I for what they cost i dont see the point in trying any other way.

I know people dont like plugging computers into there cars incase they cock up etc, but remember at the end of the day, its only turbo control...worst case if it totally dies, you still have a car to drive, turbo is just a bit laggy!