rising boost is this possible ??? read on

[gotmeaT-5]

My T-5 has rising boost after changing the oil for Mobil 10-30 Semi Synthetic, 17 inch alloy with 225/45/17 Pirelli P6000 tyres and a new set of Turbo oil seals Nothing else has been touched or changed since installing the MBC and cone filter

The Boost has risen from 14psi to 16-20, it's hard to look at the speedo, road and boost gauge at the same time or from 3/4 of the stock boost needle to off of the end.

[T5frankie]

has your car been mapped?

[gmain1967]

My T-5 has rising boost after changing the oil for Mobil 10-30 Semi Synthetic, 17 inch alloy with 225/45/17 Pirelli P6000 tyres and a new set of Turbo oil seals Nothing else has been touched or changed since installing the MBC and cone filter

The Boost has risen from 14psi to 16-20, it's hard to look at the speedo, road and boost gauge at the same time or from 3/4 of the stock boost needle to off of the end.

Seeing as you've installed an MBC, I'd look at that. Is it possible that it has unlocked and is gradually allowing more boost?

[gotmeaT-5]

Yes my car has been remapped, how can the remapping suddenly alter the boost level unless the chip has become corrupt.

The adjuster on the MBC is very stiff too adjust so can't see how it can unlock/loosen

There does seem to be a link between changing from the 18T turbo back to the stock 15G as my 18T is leaking along with changing all the necessary seals and lowering the boost back to 14psi then taking the car for several runs to check. The other change is I went from 205/55/16 on the front 205/50/16 on the rears to 225/45/17 all round and finally the 10/30 oil change. It has been suggested as I had two different aspect tyres the automatic transmission could be adjusting to the new wheel diameter [brookside effect "Say Waaaah?" didn't make sense to me either]

[gmain1967]

Yes my car has been remapped, how can the remapping suddenly alter the boost level unless the chip has become corrupt.

The adjuster on the MBC is very stiff too adjust so can't see how it can unlock/loosen

There does seem to be a link between changing from the 18T turbo back to the stock 15G as my 18T is leaking along with changing all the necessary seals and lowering the boost back to 14psi then taking the car for several runs to check. The other change is I went from 205/55/16 on the front 205/50/16 on the rears to 225/45/17 all round and finally the 10/30 oil change. It has been suggested as I had two different aspect tyres the automatic transmission could be adjusting to the new wheel diameter [brookside effect "Say Waaaah?" didn't make sense to me either]

Is it possible that with the remap, the ECU is still wanting as much fuel and air, in the correct ratio, as it was running with the 18T? If that is the case, the 15T will be working harder accordingly, which may account for the higher boost, as it tries to meet the remap boost curve.

Just a thought...

[Flatout Phil]

If you ask me, you fitted a moose badge didn't you - or was it a VPCUK sticker?

[gotmeaT-5]

ahh shucks you got me I removed the T5-D5 sticker and polished the moose sticker along with the VPUK sticker.

Hadn't thought the difference in turbocharger was the issue I'll lower the boost today. Anyone know what a greedy Turbo is ? [other than it eats too many sweets] Been told it's not worth having my 18T rebuilt the casing is damaged and should have been picked up when it was rebalanced last time. so it's either a TD05-16 or some kind of Garrat to replace the stock 15G

[gmain1967]

ahh shucks you got me I removed the T5-D5 sticker and polished the moose sticker along with the VPUK sticker.

Hadn't thought the difference in turbocharger was the issue I'll lower the boost today. Anyone know what a greedy Turbo is ? [other than it eats too many sweets] Been told it's not worth having my 18T rebuilt the casing is damaged and should have been picked up when it was rebalanced last time. so it's either a TD05-16 or some kind of Garrat to replace the stock 15G

Do you mean GReddy, rather than Greedy?? Japanese automotive manufacturer who do turbos, amongst other things. www.greddy.com

[gotmeaT-5]

Thats the one found one listed as greedy on fleabay I'll take your better judgement