Jump to content
SAU Community

Recommended Posts

Hi Guys

Im now tuning my PFC and trying to work out the Optimum VTC setting for R34GTT with a slightly laggy T04E turbo. To compensate the low rpm load before the turbo get spooling at fullboost around 4k rpm, can i set the VTC like 3500 rpm and will it do any damages if it were set that low? Still stock cams but with adjustable cam gears for exhaust side only (slightly retard settings).

Link to comment
https://www.sau.com.au/forums/topic/292181-optimum-vtc-setting-for-r34gtt-neo/
Share on other sites

Hi Guys

Im now tuning my PFC and trying to work out the Optimum VTC setting for R34GTT with a slightly laggy T04E turbo. To compensate the low rpm load before the turbo get spooling at fullboost around 4k rpm, can i set the VTC like 3500 rpm and will it do any damages if it were set that low? Still stock cams but with adjustable cam gears for exhaust side only (slightly retard settings).

Run the car up on the dyno with the VCT off then with it on, note the rpm at which the dyno graph cross over and set it at that - you could run full advance till the rev limiter and not cause damage.

Today i tried setting at 4000rpm for road tuning (since i hv wideband), car felt very lively and more spirited in town driving. Felt like VTEC effect especially when downshifting or upshifting the rpm will just drop on the sweetspot.

Just wondering whether VTC helps more on low or high load? Would consumption suffer at the setting im running now?

Not planning on doing any dyno runs atm, until i upgrade injectors and cams.

Edited by driftmeister
Run the car up on the dyno with the VCT off then with it on, note the rpm at which the dyno graph cross over and set it at that - you could run full advance till the rev limiter and not cause damage.

Make sure to do several dyno runs, one at 25,50,75 and 100% throttle and note the cross over points, put the change over at the mid point of all 4 cross overs.

Another option is to set up a 2 dimensional VCT activation mode, eg TPS (throttle position) and RPM to get he maximum effect. I do not know if PFCs allow you to create custom 2D maps from two inputs to control an output though.

Certainly be interesting to know your results if you do do this though.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I hadn't thought about the variable power steering assist. Presumably, it will always be the same level of assist as you get in an S14. The R32/3/4 are either helliishly heavy (at low speeds) if the solenoid is not powered at all, or hellishly too light (at high speed) if it is powered all the time. I presume that it is PWM controlled on those cars. I hadn't thought about the S cars not having variable assist. ugh. What crappy plebby cars they must be!  
    • Hmm yeah that is a good point. It looks like it'll just bolt in with no real issue besides maybe the bushings being different. My other concern was that 2 pin plug that I assume is used in some way to control the rack solenoid depending on the speed signal from the ecu. The DMAX rack doesn't even have that plug though so, don't think it'll matter. Might just order the rack and see how it goes. Will update this when I figure something out
    • I'd say it's a fair bet that the feed and return fluid lines will be in different enough spots that you would need to come up with a way to cut the originals short and adapt with new hard line adaption or braided teflon hoses or somesuch. But really, you have the car, you have the photos of the DMAX rack - you should be able to go out there and see for yourself whether they're in the same or different spots.
    • I've been doing some looking around and honestly was just considering throwing a new rack at it. I saw that the dmax silvia rack bolts up into the 33 with the silvia bushings but not sure if the high pressure lines will sit in the correct spot. I believe other version of the 33 rack are the same/similar to the racks that can be opened up without as much fuss so I assume the dmax rack would fit but any ideas?
    • I've never played with one, but I would expect that you are correct. That slot looks like it is intended to be used to unscrew the end, and the flats on the body would be better than grabbing it around the round bit with a pipe wrench. So, yeah, probably unscrews. You'll probably have to make a tool to drive in that slot.
×
×
  • Create New...