Options For Getting Vct Working.

[rad100]

hey all.

since my tune and posting my results up i have found that i have a fair bit of lag with my gt3076 .82

i have been told that not running the vct is giving me poor (approx 60rwkw@4000rpm less) midrange power.

now i have searched about getting vct working and come across people using there eboost street or a window switch.

my question is, what are some ways of getting vct to switch on and off at say 1500rpm and 4500rpm?

i have herd of NOS window switch.

eboost street (not an option as i have an eboost)

jaycar one but apparently doesnt turn back on unless u drop below the 1500rpm again.

any ideas.

heres my dyno sheet so people can see.

mods:

built 25

gt3076r .82

stempipe manifold

50mm gate

plazmaman

tomei poncams

e85

[Lucy The Skyline]

Dont have an answer but very interest in this info as I also have a R32 with a S2 RB25DET between the towers, also want to go the 3076 option but the newer GTX version with a .63 rear instead.

Loving your power figure too

[Don Dada]

maybe you could try switching is manually to see how much difference it makes first??

[PM-R33]

No way would it be giving you 60rwkw. Did they tell you that?

As has been said, ground the solenoid manually and do a dyno run and compare the graphs. Will give you an exact comparison.

Window switch will be your best bet.

Awesome power figure with the E85 one day. So jeleous of you bastards down south for being able to get it.

[XRATED]

I used an msd window switch... you really need a window switch and not just a simple 'shift light' style rpm indicated switch. Well worth the money for the extra midrange...

Cheers

Justin

[KiwiRS4T]

What kind of ecu are you using? I presume its not stock with your GT3076. Link or Vipec would do the switching or if you have a nistune you need another ecu (Z32 I think) to fit the nistune to and it will do the switching. Or get an msd window switch. Ok looked up your post and see you have a Nistune.Have a look in the Nistune thread or email the Nistune people and they will tell you how to go about it (with a Z32 ecu).

[R31Nismoid]

No way would it be giving you 60rwkw. Did they tell you that?

As has been said, ground the solenoid manually and do a dyno run and compare the graphs. Will give you an exact comparison.

Window switch will be your best bet.

Awesome power figure with the E85 one day. So jeleous of you bastards down south for being able to get it.

It's @ the hub's dude, take off around 40-50kw and it's getting closer to being realistic

Taking that into account "60kw" maybe possible at the hub. 60rwkw however - not a chance.

I mean there is no way you will make a legit 370rwkw from a 3076 on E85 when everyone else in the country makes 320-330

VCT seems to give ~20rwkw at the most at certain RPM points only. Sometimes it can be a bit more.

Agree RE: do it manually for now and just see what happens.

Every car is different - it's a built motor too so no doubt some minor touch ups have been performed so the gains certainly are there, it's just a question of where and how much.

[rad100]

soooo much hate for hub dynos haha..

either way ANY gain in midrange ill take even if its 10rwkw or 50rwkw.

atleast i know my car has been tuned without having to deal with wheelspin

im looking at selling my eboost1 for an eboost street as they have aux inputs to be able to control vct.

[PM-R33]

It's @ the hub's dude, take off around 40-50kw and it's getting closer to being realistic

Taking that into account "60kw" maybe possible at the hub. 60rwkw however - not a chance.

I mean there is no way you will make a legit 370rwkw from a 3076 on E85 when everyone else in the country makes 320-330

VCT seems to give ~20rwkw at the most at certain RPM points only. Sometimes it can be a bit more.

Agree RE: do it manually for now and just see what happens.

Every car is different - it's a built motor too so no doubt some minor touch ups have been performed so the gains certainly are there, it's just a question of where and how much.

Ahh crap didn't realise it was a hub dyno. Ok that explains a lot.

[Lithium]

I found ROUGHLY 10% difference with NVCS on VS off on the same boost level, if you make a few more psi at 4000rpm then thats going to exaggerate that difference. 10% more power anywhere is pretty big..

[wasnt me]

soooo much hate for hub dynos haha..

either way ANY gain in midrange ill take even if its 10rwkw or 50rwkw.

atleast i know my car has been tuned without having to deal with wheelspin

im looking at selling my eboost1 for an eboost street as they have aux inputs to be able to control vct.

yeah Hubs tend to read very high. for example my car has made 411kw on that same dyno with the same turbo as you. 320-330kw would be more realistic for your set-up.

[R31Nismoid]

soooo much hate for hub dynos haha..

either way ANY gain in midrange ill take even if its 10rwkw or 50rwkw.

Not really hate – Just the fact that AMM, well Garage 7 to be more precise, have the option to use a reasonable correction factor to bring it almost identical to a roller. Yet they choose not too for whatever reason. Maybe people just like seeing bigger numbers, i dunno.

End result is people then claim results are “rwkw” which is just wrong and over inflated by a ridiculous margin

As a result I’m not sure if you mean 60kw or 60rwkw in terms of what you were told to expect

60rwkw I think is a weeee bit optimistic, however 20-30rwkw is certainly something to look forward to getting.

But yes, you should certainly see some gains mate and they will be noticeable. There is no doubt in my mind about that as everyone that has toyed with VCT over the years and posted results they’ve only ever gone one way, and that is VCT ON is the only way to go!

Especially as stated above with regards to an extra psi or two. Get everything happening even as little as 300rpm earlier and it’ll have massive benefits to the low/middle area of the graph which you’ll feel on the street massively as that’s the main section of torque too.

You also get the added benefit of E85 which does seem to bring things on a bit earlier again so it’s a win-win situation.

Get it on there with a manual switch and then just do a run or 3 and have a look at what it does.

[Lithium]

This dyno BS actually really puts me off this forum, seriously. Open your fkn eyes, its just a tuning tool - the number is the number it read, if there was a median point for how "all dynos" of all types would read for the same car.... Dyno Dynamics read well below it so are far and away from being the definition of realistic readings.

If 320-330kw was more realistic on that particular dyno used, it would have made it - Dynapacks are very consistant. Who gives a shxt if it would make 320-330kw (assuming certain tyres, wheels, tyre pressures, that traction is there, and what shoot out mode they are running) on some old rolling road thing.

A relative gain is still going to be a relative gain, so lets focus on helping this lad find it.

[R31Nismoid]

I think it's actually quite good.

It gives you a pretty good indication if your setup is performing inline with other similar setups, or you have issues. (once you take into account a little bit of varience as nothing is perfect).

See if you have no example to use as a baseline/benchmark then you are really none the wiser.

EG: Some have made only 300rwkw with a GT35 on 20psi only to come to SAU, find out people are making upwards of 340-350rwkw and then do some more R&D. Low and behold 3-4 weeks later they have another 40rwkw. That to me is a great ending to a resource of comparative information

Although your comment is somewhat contradictory when you spend a lot of your time in the EFR/GTX threads posting dyno results for varying turbo comparo's - as that's exactly what goes on here

[Lithium]

Much of the GTX/EFR stuff I've posted is comparing between different turbo setups on the same dyno and car to give relative gains or losses

[rad100]

i guess its going to be good to see hwat gains i can actually make once i get vct running.

i have purchased a msd digital window switch.

so ill run it up, see what it does, turn vct on and run it up and see what it does.

then try get boost holding.

but like i have said, ive been looking at hub V hubs when comparing.

[R31Nismoid]

Good to hear! most results have been with stock style setups.

be good to see it on a modded on dude

[KiwiRS4T]

Ideally you need to set it on a dyno. Do a run with vct on and one with vct off.

1. This will show you the significant mid range gains and

2 The points where the lines cross will be the on and off settings.

And regarding dynos it doesn't really matter whether it is considered a "high reading" or "low reading" dyno so long as you are using the same one for the before and after.

And for what its worth in my view hub dynos are better and more accurate. At our last dyno (on a 4wd roller dyno) day the big power (over 400kw) cars were having difficulty getting a reading even with multiple straps and people sitting in the boot - no such drama with a hub dyno.

[rad100]

ok so have the vct for the first run ON all the way through the rev range and work out where its crossing the line with vct off and use that rpm range?

[R31Nismoid]

Yep, that's pretty much how it goes!