Disconnect this sensor and gain POWER!

[turbomad]

A mate took his R33 to Dyson Rotary to have a power run done on the Dyno, everything is stock except the exhaust and an EBC(11psi), as you can imagine the power curve was up and down all over the place, for the next run they disconnected a sensor and did another run and suddenly the power curve was alot better and a good 10kw above the previous one everywhere! When he asked what that sensor was all he said was "it's a trade secret". The sensor he unplugged was the one above and to the right of the temp sensor, that goes into the head. Does anyone know what this sensor does and is it safe to drive around with it unplugged?

[Jay95R33]

Which temp sensor ?

Do you mean the one up top on the inlet side of the motor??

J

[SIR33]

yeah? any ideas anyone???

[BHDave]

No idea what the sensor is but it'd be intersting to see if it'll start and drive when cold, also whether the car pings like a bitch when the temperature gets high. On the dyno you atleast have the confidence that they are monitoring for ping.

[Jay95R33]

I just had a quick look under the hood.

On the radiator hose mount there are two plugs (sensors), is it one of these? Or is it the plug that is righ next to the radiator hose housing that connects to a big (3 inches long) hexaginal nut thing that bolts into the head ?

J

[riceline]

grab a digi cam and take a snap of it or get a photo of a rb25 motor and draw a big arrow on where it is

[predator]

knock sensor maybe?

but that probably isn't a good idea.. as the ECU uses that to protect the engine if it senses detonation.

[hungry6]

Is it the one hard up against the cam belt cover with a single wire output?It is situated to the right of the temp sensor.

[gtstii]

I found a really good way to stop the factory ecu retarding timing and running really rich when upping your boost - I took it out and threw it in the bin!

[strutto]

The sensor he unplugged was the one above and to the right of the temp sensor, that goes into the head.

The only sensor that goes into the head is the NVCS. And its an actuator, not a sensor...

[MicK51]

sounds like the wire from the variable valve timing

[BHDave]

sounds like the wire from the variable valve timing

Now that makes sense. I have a mate who has done an s14 sr conversion into an s13 running s13 computer.

He installed a switch to control the vvt and it makes a massive difference. When he was tuning the car on the dyno there was an easy 20kw difference in the midrange but it tapered off at the top end. There was a definate difference at the top end when it was on/off though i cant remember the figure.

[EnricoPalazzo]

can someone pls take a pic of which sensor it is. I will check to see if this works on a dyno

[turbomad]

JAY95R33 that's it, the 3 inch long hex shape thing that goes into the head. I'm not sure if it controls the VVT as I thought that was the one on the end of the camshaft but maybe it's all related as BHDave said by switching it on and off it made a difference on the dyno, ask your mate whether he attached the switch to this or not? It's definately not the knock sensor because I believe that is on the block not the head.

[benm]

here ya go someone put an arrow on this "sensor"

[Cecam]

I have a friend who unplugged his VCT while on the dyno, I think the results were less lower end torque and higher top end. I can't find the scan of the printout, but they're quite a different power/torque curves.... As the VCT turns off at 5500rpm not sure why it would make more top end power thou. Perhaps revs more freely not sure. I've unplugged mine before and it was smoother the lower torque at low revs was fairly noticable.

[turbomad]

OK here's a pic, it's the one below the Fuel press reg and to the right of the temp sensor, can anyone confirm what it is and does?

[Cecam]

The one with the brown plug is the VCT.

[turbomad]

OK if it's the VCT, then by leaving it unplugged does it keep the timing advanced through the entire rev range, is that right?

[Cecam]

I don't think so no, it turns on at about 1500rpm and then turns back off at 5500rpm. So with it unplugged its off so cam should be in its most retarded position. I'm sure someone else can confirm or correct that.