Thread: BAS VNT - ECU tune not required

Originally Posted by Mikey

Benefit is better flow

Got any details on this? Flow tests etc? Looks very similair in design to the original one (as opposed to being tuned length - e.g. when each cylinders pipe is equal length), just a bit less sharp on the bends, but pipes look similair sizes and still mergers the 1 and 2 cylinders and 4 and 5 together first, then merges everything in the center. So I'm not sure how much effect it would have on the flow.

Originally Posted by Mikey

are a proven product, well in the UK at least, I am led to believe.

Details on being a proven product?

I'm not trying to be a *****. I'm genuinely interested in them, but would expect to see some reasoning on the benefits before purchasing.

Originally Posted by Mikey

Pedro, the only picture I have seen of the stainless manifold is the one I posted. You could always send Allisport an email. From memory I think they said the stainless one was cheaper than the cast one.

I went the cast route because they have them on the shelf and are a proven product, well in the UK at least, I am led to believe.

Mikey

Given that the OEM manifold has a flexing problem, would a stainless steel, welded manifold flex less? I'm trying to work out what advantages the SS version would bring to the table?

Cheers,

Franz

Nope, no real firm details such as recorded flow tests using professional measuring devices/machines etc.

As i said, on it being a proven product as "I am led to believe", verbally, from them saying they have not had any problems or returns as yet on any units sold and I mainly refer to the warping issue here.

I am just an end user. I have never seen or spoken to anyone in person who has personal experience as another end user about any of the new gear I will be fitting to my Disco 2. I only know what I have been told (not much) by the suppliers of the gear I am purchasing and information I have gotten from the internet (again, not much of any substance).

Call me naive or what ever you like but I'm going give it a go. As in most things I do I usually have to go it alone to try new/different products or such. Some work as claimed and some not so much, so be it. I generally try to gather as much information as i can, substantiated or not and make decisions based on that.

Will post here with my own laymans experience once items are fitted and taken for a drive if you wish.

Cheers,
Mikey

Originally Posted by Franz

Given that the OEM manifold has a flexing problem

Does the OEM manifold have a warping problem after the webs have been removed? From what I understood it was only occurring on the standard manifolds, but once butchered a bit to remove the webbing between each pipe they were fine?

Twr7cx, my manifold warped initially sometime after I had a Bruce Davis ecu upgrade done.

The first I noticed was when I was towing my Camper back from a trip and was driving through a prolonged hilly section and it was struggling to hold any sort of momentum up the hills with the throttle close to being nailed to the floor.

I also had fuel cutout issues at the same time which I thought was the "real" issue. Turns out this issue was caused by the boost modulator failing but it did get me under the bonnet where I noticed the exhaust manifold was leaking and was found to be warped.

Anyway the manifold was stripped off, machined and the webbing ground out to relieve the stresses at a local Land Rover specialist. The snapped manifold bolts were replaced with standard ones.

Recently while trying to track down an unusual noise, I yet again found the manifold to be leaking and three manifold nuts missing entirely. All located around cylinder five. Two on top and one on the bottom. Of course its going to leak with no nuts securing the manifold to the head but I was surprised to find the exhaust leaking from around cylinders 1-3 as well and these nuts were all tight.

When I myself took the manifold off this time and checked it for straightness I was disappointed but not surprised to find it had warped again. This led me to seek out an alternative because I do not want to have this issue repeatedly. I am no exhaust expert but from the little I do know about this issue and the causes I believe that the new cast manifold will be beneficial in solving this problem.

I have been informed by BAS that fitment of the vnt will also go some way to relieving the exhaust heat issue although I do not understand how this is achieved. Anyone care to enlighten me how fitting a vnt helps to lower the exhaust manifold temperature?

Cheers,
Mikey

PS. Twr7cx, it sounds like your disco is quite a rig. Any thoughts on a different torque convertor for the auto such as the heavy duty units being offered by Ashcroft in the UK?

Originally Posted by Mikey

Twr7cx, my manifold warped initially sometime after I had a Bruce Davis ecu upgrade done.

The first I noticed was when I was towing my Camper back from a trip and was driving through a prolonged hilly section and it was struggling to hold any sort of momentum up the hills with the throttle close to being nailed to the floor.

I also had fuel cutout issues at the same time which I thought was the "real" issue. Turns out this issue was caused by the boost modulator failing but it did get me under the bonnet where I noticed the exhaust manifold was leaking and was found to be warped.

Anyway the manifold was stripped off, machined and the webbing ground out to relieve the stresses at a local Land Rover specialist. The snapped manifold bolts were replaced with standard ones.

Recently while trying to track down an unusual noise, I yet again found the manifold to be leaking and three manifold nuts missing entirely. All located around cylinder five. Two on top and one on the bottom. Of course its going to leak with no nuts securing the manifold to the head but I was surprised to find the exhaust leaking from around cylinders 1-3 as well and these nuts were all tight.

When I myself took the manifold off this time and checked it for straightness I was disappointed but not surprised to find it had warped again. This led me to seek out an alternative because I do not want to have this issue repeatedly. I am no exhaust expert but from the little I do know about this issue and the causes I believe that the new cast manifold will be beneficial in solving this problem.

I have been informed by BAS that fitment of the vnt will also go some way to relieving the exhaust heat issue although I do not understand how this is achieved. Anyone care to enlighten me how fitting a vnt helps to lower the exhaust manifold temperature?

Cheers,
Mikey

PS. Twr7cx, it sounds like your disco is quite a rig. Any thoughts on a different torque convertor for the auto such as the heavy duty units being offered by Ashcroft in the UK?

I think that by pushing extra air through the combustion chamber you should get a drop in EGT.

Originally Posted by Mikey

PS. Twr7cx, it sounds like your disco is quite a rig. Any thoughts on a different torque convertor for the auto such as the heavy duty units being offered by Ashcroft in the UK?

I have one sitting in a box on the floor of my garage waiting to be fitted! Just waiting for time to drop the gearbox - I have some leave in 6 weeks...

Originally Posted by slug_burner

I think that by pushing extra air through the combustion chamber you should get a drop in EGT.

Pretty much. More air should lead to a leaner combustion. The VNT is pushing more air into the combusion chamber at lower RPM's than the standard turbo would. Your accelerator pedal controls the fuel being put in, not the air (unlike a petrol motor). So essentially you should have at the same accelerator level, the same amount of fuel going in, but more air going in, resulting in a leaner running condition. This is a fairly simple view and doesn't take into account any changes that the ECU and it's sensors may do when they detect more air in. From what I have been told diesels are the opposite of petrol motors in that leaner is cooler (unlike petrol where it is hotter).