mattipuh

I checked few days ago, just for curiosity, what is the position of throttle valve when on full throttle. For my wonder, the throttle valve vas not in 90 angle compared to throttle body, but it was more or less 10-15 degrees from it.

My question is, that what should the throttle valve position be, when throttle is fully opened, and is there a good reason why valve is not 100% open?
I started wondering should I try and adjust the valve to open fully? Might be that A/F mixture would get too lean, but with custom software this would not be a problem.. or, is this just one thing that P-factory has done to detune our mighty front engined four-banger?

I remembered reading that adjusting valve in proper position would be a cheapo trick to free few ponies. if so, is there a DIY how to adjust the valve opening?

I had too little time on Saturday to investigate it more, and didn't figure it out how do to it then.

RajDatta

People typically adjust the linkage to reduce any slop that develops over time. I doubt you could get a full 90degree opening with the linkage. I have not tested it yet. As far as tuning, the engine uses the MAF to measure the amount of air and adjusts accordingly.
Raj

mattipuh

so, with tuned "linkage" it could be possible to add more air (i.e. valve would be more open. this should, of course, be taken into account in other variables aswell.

Jaap968

By adjusting the stop (bolt) under the gaspedal you can make the valve reach the 90 degree open position. First adjust the linkage to remove any slop.

Jaap

mattipuh

don't think that gas pedal adjustment would make any difference, because i was not able to move the throttle valve further manually with hand, from accelerator wire.

Jaap968

That's strange because on my car it car easily reach the 90 degree open position. I adjusted the bolt under the pedal so that it no is very close to this 90 degree position when on full throttle. I think there may also be some small adjustment screws on the throttle body itself (used to limit the range according to the Throttle Position Sensor)

Jaap

mattipuh

I've found one adjusting bolt in throttle body, and it seems to control how throttle closes. have to investigate this better when there's more time, latest during winter.