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I am currently running a 48mm progate and since fitting the 6870 it will not hold boost at the track.

It held it on the dyno with slight creep after 6000rpm but at the track I'm hitting boost cut in first no matter how low I set the eboost.

Has anyone done the straight swap for a 50mm? Will it hold it ya reckon?

Or will I have to get a 60mm and do a cut and shut job on the exhaust manifold?

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Want it to hold 30psi for 700hp (on dyno we had it set at 28 and it crept late then ignition break down at 7200)but as stated at the track I had it set 20 points lower on the eboost and it still hit 32psi as soon as it could in first gear.

60ft in 1.34. Was like a boost line was off.

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Try a much stronger spring first - as near as possible to target boost is better. Set your boost cut a bit higher. Does it overboost in the other gears (apart from 1st)? If you can borrow a 50mm W/G that would be worth a try but if you have to buy one I would go straight to 60mm.

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If a boost line was off it may have hit over 60psi, mine did.

Not sure about the gate you have, but Turbosmart had to re-design their spring caps to hold that boost. They made a much taller cap with springs 3 times as long, so the stiffer springs wouldn't limit the travel of the gate.

If you hit the soft limit at the track, that would cause overboosting no matter what the controller was set to.

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Interesting Scotty that sounds promising for the 50.

Jet I would just get the 60 but it's a manifold off job, which I will do if I have to but I'm sure ive read plenty of people having success with the 50 so just chasing feedback. So easy to just bolt the 50 on and go racing. 60 is a major for me at the moment.

Thanks for the feedback.

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