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Johnilicte: I'm doing a little bit of Noob tuning at moment following course from HPA. Would you be able to share some experiences in tuning Nissan VTC system in areas of ignition, fuel and dis/engagement? I'm using adaptronic ecu. Thanks.

Johnilicte: I'm doing a little bit of Noob tuning at moment following course from HPA. Would you be able to share some experiences in tuning Nissan VTC system in areas of ignition, fuel and dis/engagement? I'm using adaptronic ecu. Thanks.

of course, e-mail me all your questions and I shall answer ..

Long story short with VTC enabled you produce more torque due to higher cylinder pressure thus the motor can only take less timing, as soon as it disengages torque will drop off - reducing cylinder pressure allowing you to ramp up timing again. From my limited tuning experience, motors with a shorter stroke will prefer a mild ignition ramp after peak torque, where as a longer stroke motor i.e. SR OR 4G likes loads of timing hammered into it after peak torque.

Best way to determine where to disengage VTC... setup a mild timing map with VTC on a few thousand RPM past peak torque ~6500rpm (of course monitoring knock) do a dyno run, then set the VTC point around 4500rpm do another run..

Overlay the two torque curves and you will see your optimum VTC disengagement point.

Of course after you do that, you can start ramping more timing after VTC disengagement and tune for power up top.

That's a quick run down of it.

Just a note, I've never worked with variable cam timing and variable lift.. RBs and SRs use a fixed on and off point which makes tuning easy for an amateur like me.

In terms of injection, VE is closely related to torque.. more torque higher VE so it's natural you see your VE decline as your torque drops off.. this is the beauty of VE tuning.. makes tuning easier

Thought i would post up my results of Stao's fantastic handywork. My car has sat in my garage for 1.5 years, and finally got round to fixing it.

Unopened RB25

Pretty much the usual stuff.
740cc injectors

PFC

Greddy rad and cooler.
Scotty Intake

Just a typical hiflow which i bought 15 months ago. I was told it would see 230kw on 98 and roughly 260 on e85.
Anyway today i picked my car up and got this:post-75784-0-29419900-1405668770_thumb.jpg

All on BP98. Might be interesting if i put it on the juice.
Highest run was 265.

Thought i would post up my results of Stao's fantastic handywork. My car has sat in my garage for 1.5 years, and finally got round to fixing it.

Unopened RB25

Pretty much the usual stuff.

740cc injectors

PFC

Greddy rad and cooler.

Scotty Intake

Just a typical hiflow which i bought 15 months ago. I was told it would see 230kw on 98 and roughly 260 on e85.

Anyway today i picked my car up and got this:attachicon.gifIMG_0171.JPG

All on BP98. Might be interesting if i put it on the juice.

Highest run was 265.

is it an R33 highflow? the new ones can make around 270 rwkw around 20-22psi on 98 so your result is very good for around the 17psi mark. Personally I wouldn't push it to 20psi on a stock motor on 98 but it's possible.

The old highflows maxed out around 230 I think.

on e85 the new highflow makes around 320rwkw around 22psi

Personally I wouldn't push it to 20psi on a stock motor on 98 but it's possible.

Been running 20psi on a hypergear turbo as a daily for 2 years now :)

Boost doesn't kill engines it's detonation that kills engines.

  • Like 1

is it an R33 highflow? the new ones can make around 270 rwkw around 20-22psi on 98 so your result is very good for around the 17psi mark. Personally I wouldn't push it to 20psi on a stock motor on 98 but it's possible.

The old highflows maxed out around 230 I think.

on e85 the new highflow makes around 320rwkw around 22psi

is it an R33 highflow? the new ones can make around 270 rwkw around 20-22psi on 98 so your result is very good for around the 17psi mark. Personally I wouldn't push it to 20psi on a stock motor on 98 but it's possible.

The old highflows maxed out around 230 I think.

on e85 the new highflow makes around 320rwkw around 22psi

Dont mean to interupt but what do you mean new hi flows?

@Johnilicite: Thanks for the info. Using the adaptronic ECU in the VVT tab. This is for the Kia sportage. would you know what those sittings are corresponding for? Thanks.

kiavct.jpg

And Grimsy. Thanks for submitting the dyno result. This is using the current profile, the very distinct difference between the two, is the current model has no issues holding boost and much happier taking on timing. Great work.

My brother got his s13 road tuned today with atr28ss2 and s15 VCt motor only on 20psi due to running pump 98

Goes good but definately doesn't feel as fast as my 180sx but power feels very linear and comes on instantly

Not like mine as it hit 3500-4000rpm there's a big surge in power and throws you back or tyres fry

We will soon see the difference as were going to the drags soon

^^

Thanks for the feed back.

Everyone getting in on those HPA courses atm!

cheers

darren

I do highly recommend people go on the HPA site and at least acknowledge the content in EFI fundamentals and road tuning before even think of modifying any cars.

It would contain a good entry level information for a brief understanding of what the tuner does, what a good tune is, and how power and torque is generated in relation with supporting mods installed.

#@hypergear - with constant variable timing this is where it gets really fun/confusing as the cam timing varies over RPM & LOAD, i.e. MAP

Ignoring the duty cycle settings (determines how much duty is required to shift the cam actuator) & and the controller gains (closed loop calculations P = proportion gain at present correction, I = Integral gain past correction, D = derivative gain future correction)

VVT1 = Intake Cam

VVT2 = Exhaust Cam

VVT1 = uses Fuel 2 table to set the angle, which is depending on RPM & MAP - this makes it 3 dimensional, that being (RPM, MAP and angle of advance/retard).. so as MAP increases and/or RPM increases the timing changes. If you click Target Angles it will take you directly to Fuel 2 table.. please note the values showing in there are not fuel correction values.

VVT2 = uses just a standard RPM table, there's only 2 dimensions in there.. that being the RPM and the angle of advance/retard of the cam

Unfortunately I've never tuned cars with varying cam timing so I can't input too much here.. I've always worked with Nissan's dinosaur on/off timing (which makes tuning much easier too) :)

But I can imagine as RPM increases you would want the advance on the intake to decay i.e. retard, however at the same time you want to advance the exhaust cam as RPM increases to promote more air being "pumped".

http://www.learntotune.com/

for anyone interested..

cheers

darren

Yep, did that! :D Going for a 1 on 1 course at Unigroup Engineering once i register my 300ZX :D

Anyone used Siemens Deka V injectors? they come in "short" length, i.e. 48mm end to end OR 35mm O-ring to O-ring?

They seem to be pretty good based on these tests:

http://racetronix.com/product/Injectors/FI114700_Brochure.pdf

I've been trying to redo my injector needs by finding a cheaper alternative (yes I'm being cheap, but I can't envisage spending $1.2k+ on stuff when the motor cost the same price)

Posting some updates:

Been dummying some direct bolt for Holden VL Turbos. This particular one is made based on our ATR43G3 turbocharger. Factory 2.5 inches cast dump is not replaced with a full 3 inches dump including a much larger 38mm internal gate. Expected to support 260~280rwkws on a RB30ET with supporting mods on P98 fuel. Bigger profiled turbochargers can also be be built based on the same turbine housing configuration. That includes our ATR43SS2 (500HP), SS3(530HP), SS4(550HP) and G4(600HP) models.

comp.jpgrear.jpg

side.jpg

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