Bigger exhaust fix for VNT Td5 with high gets?

I think your setup is pretty much similair to mine - BAS VNT, TD5 Alive/Alive Tuning intercooler and TD5 Inside ECU tune.

My exhaust system is the standard 2.5" pipe, but replaced all the cans with high flow Lukey Race Series straight through stainless steel mufflers. The previous owner also replaced the flexable joint on the down pipe with a proper 2.5" sized unit as the standard one is much smaller than the exhaust pipe causing a restriction.

Turbotecnics (the actual supplier of the VNT to BAS) only recommend a 2.5" for the BAS VNT.

Recently I got rid of my TD5 Alive/Alive Tuning Turbo Booster Box and Modified MAF and replaced them with a Dual Channel Turbo Booster Box from IRB Developments (took forever to organise and purchase). I now have no EGT issues, after installing it and manually tuning using my Nanocom, I can hit hills with the accelerator flat and my MadMan EMS alaram won't be beeping at my anymore due to the EGT.

In regards to my ECU tune Jose from TD5 Inside spent some time refining it for me based on the Nanocom reading I was sending back to him and it got better and better the more he worked on it.

Hello
I have the same VNT and had a 2.5 inch exhaust which went great. I now have a S/S straight through 3 inch and in performance wise it does go better, lost a little bottom end but HUGE around 1900 + rpms I tow my boat and when I first did the exhaust it seemed as no difference bit once the boat was on wow didn't know it was there. It does spool quicker (it seems) and gives a wicked sound. I will make a more taped section at the manifold end next week and fit my EGT probe at the same time when I get home trying to get a little low end back. The reason why they say only 2.5 inch is so the turbo doesn't over spool. I am not gentle on my TD5 and never had a problem. Looking at a different air box have done the mod as in taking out the hyclone thing. I did try the bypass but lost performance due to not enough air though the MAF took it off, since made my own boost box never had a over boost again. I found the boost box that you have never worked at all.
Ian

I have the 3" and found it great. Cant compare with 2-1/2 though as I went from stock to 3". I have my VNT but is off with the new manifold getting layered in good ceramic stuff.. I found it interesting that the outlet of the exhaust manifold was ~5mm smaller than the VNT inlet all the way around.. Is this normal??

I bought one of those "performance manifolds" from landrovertuning and spent 2 hrs on the die grinder smoothing out the very rough casting marks/daggs.

I am also installing a EGT gauge and was going to drill and tap into the EGR blank but will relocate. I assumed that there would be no difference from one end of the manifold to the other. Be an interesting experiment.

Here are some shots of the manifold (count the # H/T studs supplied)

The before and after smoothing out..

Quote:

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Originally Posted by granno

I have the 3" and found it great. Cant compare with 2-1/2 though as I went from stock to 3". I have my VNT but is off with the new manifold getting layered in good ceramic stuff.. I found it interesting that the outlet of the exhaust manifold was ~5mm smaller than the VNT inlet all the way around.. Is this normal??

I bought one of those "performance manifolds" from landrovertuning and spent 2 hrs on the die grinder smoothing out the very rough casting marks/daggs.

I am also installing a EGT gauge and was going to drill and tap into the EGR blank but will relocate. I assumed that there would be no difference from one end of the manifold to the other. Be an interesting experiment.

Here are some shots of the manifold (count the # H/T studs supplied)

The before and after smoothing out..

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My egt has been drilled and tapped right in the middle on the collector in front of the turbo. Best place imo.

On a completely mechanical engine it could help. But yours is EFI.

The ECU tune defines the air/fuel ratio under full load and yours is running too low (too much fuel, not enough air).
You need to go back to your tuner and get them to raise the smoke map to give it less fuel for the same air.

Then you can get your power back through more boost which will let you burn the same amount of fuel as before but with safer EGT.