47 replies to this topic

[Duncan VXR]

Is that from AET Duncan?? had a brief chat with them today re: my concerns with the OE Vx kit seems a very helpful bunch!

Are you having yours modded to Hybrid or just getting one off their shelf?

What benefits is the hybrid supposedly meant to give over the OE LEH unit?

As stated earlier in the thread the main differences are below;

'Main differences are the high flow 35Lb/min compressor wheel, motorsport 360 degree thrust bearing for high boost pressure, flowed and ported manifold and wastegate, CNC re-profiled compressor cover and uprated actuator.

I was getting my vxr turbo rebuilt by them but when I took it off the manifold had warped, AET said that they may have a spare LEH manifold spare to use for rebuild but in the end let me take one off the shelf and leave my broken one with them for the same cost as rebuild (including discount )

For me the main improvement was decent bearings which are the common problem for failing and end up causing oil leakage - Although John Faukner sent me a message this morning about a thread on vxronline taking about reducing the oil pressure to the turbo to help stop the seals leaking.

I would want to know more about that before trying as the turbo may be designed for high oil pressure???

Duncan

[Lps]

I was getting my vxr turbo rebuilt by them but when I took it off the manifold had warped,

Thats the first time i've seen that particular problem mentioned?? So whilst the std vxr manifold is stronger, it may just distort rather than crack like the Let one? wow...

For me the main improvement was decent bearings which are the common problem for failing and end up causing oil leakage - Although John Faukner sent me a message this morning about a thread on vxronline taking about reducing the oil pressure to the turbo to help stop the seals leaking.

I would want to know more about that before trying as the turbo may be designed for high oil pressure???

Duncan

hmmm i'm really not sure what the minimum oil pressure would need to be either tbh, low oil pressure to the lovely hybrid turbo would be very, very bad eh! What is it they say, something like no oil in a turbo for 2 seconds is like having no oil in the engine for 2 minutes

might have to look into that a bit further, agreed!

[Duncan VXR]

Thats the first time i've seen that particular problem mentioned?? So whilst the std vxr manifold is stronger, it may just distort rather than crack like the Let one? wow...

Well I had a snapped exhaust manifold bolt so it is not clear if the warped manifold caused it to break or if the snapped bolt then caused the manifold to warp???

It does get some abuse and done quite a few track days in hot temps (not england lol) not sure if this had made any difference though.

It is the 1st warped LEH manifold I know of

[Lps]

the snapped bolt then caused the manifold to warp???

I would have thought this was more the case. Have read a bit over on the Astra forums Re: Manifold bolts going. Oh the joy of having the engine in the back where you can easily get a right angled drill in there to clean it out

[markiii]

Is that from AET Duncan?? had a brief chat with them today re: my concerns with the OE Vx kit seems a very helpful bunch!

Are you having yours modded to Hybrid or just getting one off their shelf?

What benefits is the hybrid supposedly meant to give over the OE LEH unit?

As stated earlier in the thread the main differences are below;

'Main differences are the high flow 35Lb/min compressor wheel, motorsport 360 degree thrust bearing for high boost pressure, flowed and ported manifold and wastegate, CNC re-profiled compressor cover and uprated actuator.

I was getting my vxr turbo rebuilt by them but when I took it off the manifold had warped, AET said that they may have a spare LEH manifold spare to use for rebuild but in the end let me take one off the shelf and leave my broken one with them for the same cost as rebuild (including discount )

For me the main improvement was decent bearings which are the common problem for failing and end up causing oil leakage - Although John Faukner sent me a message this morning about a thread on vxronline taking about reducing the oil pressure to the turbo to help stop the seals leaking.

I would want to know more about that before trying as the turbo may be designed for high oil pressure???

Duncan

is it a ball bearing turbo?

they like high oil pressure, but dislike high flow, hence with teh garret GT series you should use a restrictor in the oil feed, otherwise seals blow.

On a non ball bearing turbo the oil pressure is the only thing keeping the bearings apart so a restrictor is a bad idea

[jay_vxt22]

I have gone with a hybrid VXR unit which can be rebuilt from your std poor vxr unit. Info from the turbo company below;

'Main differences are the high flow 35Lb/min compressor wheel, motorsport 360 degree thrust bearing for high boost pressure, flowed and ported manifold and wastegate, CNC re-profiled compressor cover and uprated actuator.

The actuator is set to 1 bar (14 psi) and we are seeing so far 340HP from this unit.'

I am also getting my manifold ceramic coated to help with engine bay heat and also should help with when the rain gets on my previous glowing manifold

Cheapest option to step up from a std vxr unit which WILL fail at stage 4 as everyone knows (how long depends how you drive but will fail)

A rebuil of std vxr turbo is about £270 all in so if your manifold is ok this is a cheaper option. Brand new vxr turbo is more like £475

GT2871 would be a nice setup and did think about going down this route but think 315bhp lag free will be enough for now and of course reliability which the std turbos do not give.

Also once above 350bhp you really are going to have to start thinking about rods and in my view if your changing the rods you might as well have a play with the crank (l/B) and then change the cams and all a sudden you have sold you 2nd kidney to pay for it all lol

LEH engine internals will be fine at sub 340bhp so cheap option for me - cams only getting done as the head is off to get a snapped bolt out. May do the bolts while the oil is out but again if I am going to do this I would be tempted to baffle the sump lol - cant help myself

Hope that helps a bit - need to stop working on other cars and finish my own

would this aet hybrid be ok to run on a cs4 map or would it need a custom mapping?

[Nev]

IMO the CS4 map MAY well be ok in principle, but you run the risk of running lean, as you will be flowing approx 5 to 7% more air. You could uprate your 3.3 bar fuel pressure regulator approriately (you will have to look it up) to increase fuel by approx 5 to 7%. The best way would be to put it on the RR sessions with fuel/air meterering and check for stoemetric compliance. I doubt that you'd be out by too far at worst. OR, just dont take my word for it, ring Mark at Courtenays ! Let us know what he says ;o)

[Duncan VXR]

Well turns out in this months total vauxhall mag there is a big write up on kkk turbo's and garratt options. With a full picture driven step by step of the hybrid vxr turbo I got from them and the differences between them. Almost purchased it to copy and upload the feature lol Still think the power claimed is off the mark though

[Lps]

Will have a look at total poxhall duncan, cheers for the heads up

[jay_vxt22]

ive just rang courtenays regarding this turbo, he said its not somthing theyve done yet but they can map it although it may be done on dyno time rather than fixed price, soo i think i will go for this after the ring in july

[FLD]

If it helps you guys out a friend of mine makes cast turbo manifolds (in SG nodular iron) and could make up one for a suitable turbo if theres sufficient demand. If your serious about a swap give mike at boost performance a ring and tell him Matt sent you.

[Duncan VXR]

ive just rang courtenays regarding this turbo, he said its not somthing theyve done yet but they can map it although it may be done on dyno time rather than fixed price, soo i think i will go for this after the ring in july

They will have a map after next wednesday as mine will have been done

DG

[cheeky_chops]

this lot? http://www.boostperformance.co.uk/

I have read that log manifolds are cheaper, far harder wearing and when properly designed offer 90% of the benefits of tubular

cast mani for £250. Nice:

[jay_vxt22]

ive just rang courtenays regarding this turbo, he said its not somthing theyve done yet but they can map it although it may be done on dyno time rather than fixed price, soo i think i will go for this after the ring in july

They will have a map after next wednesday as mine will have been done

DG

looking forward to the outcome

[FLD]

this lot? http://www.boostperformance.co.uk/

I have read that log manifolds are cheaper, far harder wearing and when properly designed offer 90% of the benefits of tubular

cast mani for £250. Nice:

Yeah, thats him.

[cnrandall]

this lot? http://www.boostperformance.co.uk/

I have read that log manifolds are cheaper, far harder wearing and when properly designed offer 90% of the benefits of tubular

cast mani for £250. Nice:

Yuck... Just think of the thermal distortion that thing is going to suffer.

The stock manifold is one of the best design 'log' types I've seen and look how many of those crack...

[slindborg]

this lot? http://www.boostperformance.co.uk/

I have read that log manifolds are cheaper, far harder wearing and when properly designed offer 90% of the benefits of tubular

cast mani for £250. Nice:

Yuck... Just think of the thermal distortion that thing is going to suffer.

The stock manifold is one of the best design 'log' types I've seen and look how many of those crack...

and how many (under proper hard use, not fcuking about in a vx220) get too hot in cylinder 3 and fcuk the valves etc

[FLD]

When cast in SG nodular iron rather than the filth GM use the thermal properties are different. It doesn't deform or crack. Used it myself on manifolds I have made and it holds up well. That zetec one is still going and is at least 10 years old. Anyway, if you dont want one dont have one. I also seem to remember something about VNT's?? You can use them on a petrol engine you just need to run an external wastegate too as the vanes cant cope with the range in volume. You also need to ensure it doesn't EVER go lean as you can melt the vanes. I used a K-type thermocouple in the exhaust. The sleeve type ones are better than the vane ones but the vane ones are more common. You get boost at tickover with these but they are a real ballache to map.

[slindborg]

When cast in SG nodular iron rather than the filth GM use the thermal properties are different. It doesn't deform or crack. Used it myself on manifolds I have made and it holds up well. That zetec one is still going and is at least 10 years old. Anyway, if you dont want one dont have one.

I also seem to remember something about VNT's?? You can use them on a petrol engine you just need to run an external wastegate too as the vanes cant cope with the range in volume. You also need to ensure it doesn't EVER go lean as you can melt the vanes. I used a K-type thermocouple in the exhaust. The sleeve type ones are better than the vane ones but the vane ones are more common. You get boost at tickover with these but they are a real ballache to map.

VNT's are fun to calibrate..well atleast interesting lol

most are only specced/capable of Diesel EGT's. I think the only in use VNT on gasoline is in the porka cayenne

[cnrandall]

When cast in SG nodular iron rather than the filth GM use the thermal properties are different. It doesn't deform or crack. Used it myself on manifolds I have made and it holds up well. That zetec one is still going and is at least 10 years old. Anyway, if you dont want one dont have one.

I also seem to remember something about VNT's?? You can use them on a petrol engine you just need to run an external wastegate too as the vanes cant cope with the range in volume. You also need to ensure it doesn't EVER go lean as you can melt the vanes. I used a K-type thermocouple in the exhaust. The sleeve type ones are better than the vane ones but the vane ones are more common. You get boost at tickover with these but they are a real ballache to map.

I'll stick to my design thanks :-)

Edited by cnrandall, 27 March 2009 - 08:23 PM.