Thread: Bigger exhaust fix for VNT Td5 with high gets?

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..

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..

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