Thread: TD5 overboost box questions.

The problem that you have is that the turbo boost box only solves the issues with the MAP sensor readings.
You haven't accommodated the needs of the MAF sensor - three options for this: 1. install a bypass pipe around the MAF using 19mm hose, 2. get a modified MAF from Alive Tuning or 3. get a dual stage turbo booster box from IRB Developments.
If you do some searching you'll find my threads on this.

Hello,
You must confirm that it is over boosting with a Nanocom or similar before buying anything else or any other mods. Setting the boost at a certain PSI doesn't really give you any information as to what is happening inside the engine.
I have sent you a PM.
Ian

Originally Posted by robbotd5

G'day all.

I have fitted on my Disco a BAS over boost box. Some questions if I may.

I have my waste gate set to produce 20-21 psi on my turbo boost gauge that is teed into the EGR blank post inter cooler. On long steep climbs in 4th gear foot to the floor, it will go into over boost. The needle on the gauge flickers between 20-22 psi. Should the thing go into over boost with an over boost box in place?

Is there any way to confirm the overboost box is working as it should?

Or do I just have the waste gate wound up too far?

Thanks in advance.
Regards
Robbo

Over boost is 240kpa so about 20-21 psi with out boost box..

the idea of the boost box is to remove this... There is no over boost once box is fitted.


I doubt the MAF will trip with a standard turbo. 21 psi is about the max the std turbo will be efficiencent at anyway.

Check your MAF readings on a nanocom MAF will trip at 650 CFM

Originally Posted by Benny_IIA

I doubt the MAF will trip with a standard turbo. 21 psi is about the max the std turbo will be efficiencent at anyway.

Check your MAF readings on a nanocom MAF will trip at 650 CFM

Funny, that's the same response everyone gave me with this problem. I had a standard turbo running 18psi and it was too much for the MAF - tried three MAFs - two genuine (one brand new) and an aftermarket knock off, all the same result.

If I disconnected the MAF so that it ran default settings then the vehicle was fine. And once the modified MAF from Alive Tuning was fitted it ran perfectly.

I needed the MAF upgrade also, mine was all good with std boost, just not with wick turned up.

Your boost numbers are as expected.
As already mentioned confirm over boost cut or MAF fault before spending

Cheers

Originally Posted by twr7cx

Funny, that's the same response everyone gave me with this problem. I had a standard turbo running 18psi and it was too much for the MAF - tried three MAFs - two genuine (one brand new) and an aftermarket knock off, all the same result.

If I disconnected the MAF so that it ran default settings then the vehicle was fine. And once the modified MAF from Alive Tuning was fitted it ran perfectly.

so at 18 psi on the stock turbo you where using more the 650 cfm?

std pressure on d2 is around 18 psi with the modulator ?

Originally Posted by Benny_IIA

so at 18 psi on the stock turbo you where using more the 650 cfm?

std pressure on d2 is around 18 psi with the modulator ?

Stock on the D2 is around 15psi afaik.

Originally Posted by OffTrack

Stock on the D2 is around 15psi afaik.

I always thought the defender ran 15psi and the modulator allowed high boost pessure of around 18psi on d2's?