[Khughes]

Guys,

Just searching through the settings on the Apexi AVC-R that i got with my car, i must say that i have tried reading the manual and it is a little over my head so far!, but saying that i love gadgets so it shouldn't take too long to crack!

Also as far as i know the car is running 0.72 bar of boost (and the AVC-R confirms that), how would i increase that (97 GTR).

In the AVC-R you need to set boost and Duty which in the manual equals solenoid valve duration divided by total solenoid valve operation duration times by 100.

How do i work out the durations? obviously i cant count to 16ms

(i am more interested in knowing that i can do it rather than doing it for a performance point of view, i have just got the car so i am as happy as a pig in mud with the current performance!)

Can anyone help?
Thanks

 

[AlexD]

Hi.... from memory, 0.7Bar equated to about a 32% duty cycle, and 1bar was about 41% (on my 98 GTR with standard turbos).

To set them you just go into the A or B settings from the main page and select duty cycle and then set it to whatever you want, then when you have mode A (or B) selected, that is the duty cycle that the controller will be operating at.

Not sure if that made sense!? When I got mine it was a bit confusing at first, email me if you want a more detailed description.

Cheers
Alex

 

[Khughes]

Thanks, i will try them out and see.

So how does the Duty Cycle effect boost? What is Duty cycle?

Thanks!

 

[SteveC]

duty cycle

Duty cycle or injector duty cycle is the amount of use the injectors are running at.

so in a standard R33 with 440cc injectors (per cylinder) running 50 % duty means you are running at 220 cc/min on each injector. At full throttle

Tuners seem to try to keep below 80 % duty.

As for relationship to boost, more pressure from the turbo means higher fuel demand to keep the mixture nice and rich.

more fuel + more air = more power

This is why the big power skylines have huge turbos and 550 cc and up injectors.

(by the way there is a lot of other work required on the engine before you can run silly boost levels safely)

Hope this helps.
If I am talking crap please let me know..

Steve

 

[Peter]

Steve,

Err, you're talking crap (you did ask).

The duty cycle referred to will be the boost solenoid duty cycle, nothing to do with injectors. Also, this is not expressed as a percentage. For example my PFC duty cycle is set at 28 for 1.0 bar boost.

Peter.

 

[SteveC]

Glad I asked !!

I though that I may be wrong on the cycle part but the content should be ok.

I just answered the wrong question

I am now intrigued.. could you explain what it does so I can answer correctly next time

cheers
Steve

 

[Peter]

Steve,

Not wishing to invite the same response and please correct me somebody if I too am talking crap but as I understand it, the boost control solenoid cycle is the number of times per second that it operates, i.e. vents the boost from the wastegate line allowing control of when the wastegate opens and therefore controlling boost level. The higher the duty cycle, the more times it operates per second, the more it vents, the longer the wastegate stays closed for on boost, the higher the boost, I think.....

I'd hate to think I was talking a load of bull**it.

Peter.

PS. You may be right about the duty cycle being expressed as a percentage having looked at an English PFC instruction book.

 

[Khughes]

I have found the website with the manual from the AVC-R on it.

http://www.apexi-usa.com/productdocumentation/electronics_savcr_ins.pdf

If you look at page 24 of the document, it has a diagram of what the duty is, i am not sure what this exactly means though..

Page 26 shows the boost control menu.

From what i can gather 1bar = 14.5psi = 1.02kg/cm^2

From the instructions at the bottom of page 26 it seems to be the way you work out duty is by taking a guess, surely this cannot be good? what happens if you compltely stuff it and blow your turbo or motor?

AAAUUUGHHH! this is driving me crazy! shouldn't you jsut be able to type in the boost pressure you want and it works out the rest?

 

[SteveC]

try this link for some background..

Just found this on a site in the US..

http://www.supras.com/sogi/techtips/1_engine/1006_MKIII_AVCR_impressions_after_install/index.html

may give a bit of interesing reading..

/Steve