Gt4 rc running problem

This isn't a solution so I won't post it as such.

The problem is down to there being an air leak somewhere.

Basically when you're not on high boost, the turbo is still compressing air a bit, and the proportion of air which escapes is enough for the air/fuel mixture to be too rich to ignite. Only so much air can escape from wherever the leak is. As the pressure increases, the air/fuel mixture starts to get closer to normal (because proportionally speaking, there's less air escaping) and reaches a level at which ignition is possible. Note, however, that the mixture is still rich. You'll be able to smell petrol, and you won't get very far on a gallon.

You need to find out where that leak is. Make sure you've properly plugged the hole where your dump valve used to be, using something solid, and check the jubilee clips on each end of the charge cooler as well as the piping from the air filter to the turbo intake.

When I first got my RC, it had a dump valve which wasn't plumbed in properly so it started opening more as I gave it more gas. Result was that if I put my foot down, the car would splutter to a halt!! Pulled it off and plugged the end of the pipe with a piece of wood held with a jubilee clip. That held for over a year, before it decided to make a sharp exit somewhere in Goole, some 60 miles from home. Temporary fix was made with a piece of lamb skin & some leather thonging, now it's got gaffertape over it too, but I really do recommend something more substantial. If you opt for wood in the rubber pipe, make a notch in it so the jubilee gets more purchase. This isn't a solution so I won't post it as such.

The problem is down to there being an air leak somewhere.

Basically when you're not on high boost, the turbo is still compressing air a bit, and the proportion of air which escapes is enough for the air/fuel mixture to be too rich to ignite. Only so much air can escape from wherever the leak is. As the pressure increases, the air/fuel mixture starts to get closer to normal (because proportionally speaking, there's less air escaping) and reaches a level at which ignition is possible. Note, however, that the mixture is still rich. You'll be able to smell petrol, and you won't get very far on a gallon.

You need to find out where that leak is. Make sure you've properly plugged the hole where your dump valve used to be, using something solid, and check the jubilee clips on each end of the charge cooler as well as the piping from the air filter to the turbo intake.

When I first got my RC, it had a dump valve which wasn't plumbed in properly so it started opening more as I gave it more gas. Result was that if I put my foot down, the car would splutter to a halt!! Pulled it off and plugged the end of the pipe with a piece of wood held with a jubilee clip. That held for over a year, before it decided to make a sharp exit somewhere in Goole, some 60 miles from home. Temporary fix was made with a piece of lamb skin & some leather thonging, now it's got gaffertape over it too, but I really do recommend something more substantial. If you opt for wood in the rubber pipe, make a notch in it so the jubilee gets more purchase.

If your dump valve has "exploded", what have you replaced it with? Can you explain your current plumbing configuration? (The stock setup for the GT4 RC does not include a dump valve)

If your dump valve has "exploded", what have you replaced it with? Can you explain your current plumbing configuration? (The stock setup for the GT4 RC does not include a dump valve)