Courtenay Sport - VXR Turbo Unit Upgrade

***MikeWarner*** · 29-10-2005, 11:42

There has been some discussion over the Astra VXR turbo charger unit and its benefits. Earlier this year, we were lucky to get hold of a unit and we have recently completed some tests with this fitted to a Z20LET Astra Coupe. The purpose of the test was to see how the VXR turbo compared to the Turbo Dynamics Stage 2 unit.

We have included the Power and Torque graphs along with an acceleration graph. This graph shows us what the power delivery does on the road in terms of acceleration from 40 mph to max speed of 127.5 mph (in 4th gear).

The production unit looks much the same as the standard Z20LET, ZLEL and ZLER turbo. On our unit the actuator was a prototype unit, however this was changed to a 1 bar actuator to directly compare it with actuator fitted to the TD unit.

Both cars were fitted with a complete Milltek exhaust along with the Milltek sports cat that has the rear flange at 62mm internal diameter, up over the standard 52mm ID. They both had uprated intercooling / boost cooling set ups so the air temps that were recorded were also consistent. Finally both cars used an identical version of our Stage 3 software.

The first thing that was evident was that the VXR unit produced its peak torque sooner, also the torque was flatter across the rev range, dissecting the Turbo Dynamics power curve that was sometimes higher or lower on power. These results suggest the TD unit has a larger “AR” ratio building its boost later it would also seem that the TD unit is capable of much more power but is hampered by the restrictive exhaust manifold casting, leading to this, albeit minor, power oscillation as the internal pulses change the restriction in the manifold.

To form some kind of conclusion it’s clear that they do things in a different way but overall there is very little between them. It's very much give and take with them trading punches all the way through the run. This is especially evident when you look at the acceleration times. On other cars with a similar spec fitted with the TD unit we have seen small variations in power and torque but the profile of the delivery is always much the same. In the same way, on the many runs we did with the VXR unit, they varied a little on power or torque but the general profile remained the same. The VXR unit did not hit the same peak torque as the TD turbo (although on one run we did see 290lbs ft), but VXR unit did hit peak torque earlier and went on the make a bit more power. In the VXR unit’s favour, the manifold section has been recast in a higher specification of material to prevent cracking. Good news if you have been on the wrong side of this failure.

The final and major plus is that the unit is rumoured to have a retail price of £585.12, whilst the standard ZLET, ZLEL & ZLER unit has a retail of £867.15! As long as Vauxhall don’t revise this, then it’s the performance bargain of the year. It’s just a pity that there is no stock available at the moment. But watch this space for more information as it becomes available.

And here are the graphs...........

Power Curve: Red=VXR 278.8 bhp Blue=TD 275.9 bhp

Torque Curve: Red=VXR 281.1 lb ft Blue=TD 292.5 lb ft

Acceleration: Red=VXR 127.5 MPH 15.6 seconds Blue= TD 127.5 MPH 15.9 seconds

Forward orders are now being taken by Courtenay Sport for this turbo unit. Ideal as an alternative to the existing hybrid turbo units for those wanting to run Stage 3 remap.

This turbo will require an uprated actuator and bracket to allow maximum overboost and peak boost to be acheived with the Stage 3 remap.

Turbocharger £499.00
Uprated actuator and stainless steel bracket £120.00

Address:
Courtenay Sport Limited
10c Folgate Road
North Walsham
Norfolk
NR28 0AJ

Telephone:+44 (0) 1692 404313
Fax:+44 (0) 1692 404069
Email: info@courtenaysport.co.uk

tomstickland · 29-10-2005, 20:20

127mph in 15.6s? Surely some mistake there?

***MikeWarner*** · 29-10-2005, 22:13

I think this was done on a rolling road and is quoted only for comparison.

tomstickland · 29-10-2005, 22:21

Ah right, just some sort of acceleration vs load thing.
Pity the VXR is knocking on the door of 1500KG.

S3 VXR · 30-10-2005, 08:21

Quote:

Originally Posted by tomstickland

Ah right, just some sort of acceleration vs load thing.
Pity the VXR is knocking on the door of 1500KG.

The thread is only in regards to the turbocharger of the VXR, not the car itself, the graphs show figures of the turbochrager unit fitted to a G coupe running a z20let. The astra VXR not with the old z20let may be 1393KG now but it doesnt have to be !

Power - 237bhp
Weight kg - 1393
BHP/Ton - 172.87
0-60 - 6.33 sec 0-60 6.2 sec ( With optional 19s )
0-100 - 15.59 sec
60-100 - 9.26 sec
1/4 mile - 14.69 sec
Term speed / mph - 97.07
1/4 mile [D] - 14.49
Term speed / MPH [D] - 98.76

mattcoupturbo · 30-10-2005, 18:02

Really is a bargin when you compare prices. I'll get a VXR turbo when my standard one goes pop.

***MikeWarner*** · 30-10-2005, 18:05

Oh - forgot to mention. The first one Courtenays get in has my name on it.

Turbo Dan · 30-10-2005, 18:27

The price is that cheap because the vehicle is not released yet, I bet that vxr turbo will double in price when the Astra hits the roads!!!

S3 VXR · 30-10-2005, 19:15

Quote:

Originally Posted by Turbo Dan

The price is that cheap because the vehicle is not released yet, I bet that vxr turbo will double in price when the Astra hits the roads!!!

You will be lucky to get one any time soon all of them are going to the factories right now. The price should not change, as courtenays have said, the unit is Much better quality than the predecessor and yet its cheaper !

Turbo Dan · 31-10-2005, 06:38

Quote:

Originally Posted by S3 VXR

You will be lucky to get one any time soon all of them are going to the factories right now. The price should not change, as courtenays have said, the unit is Much better quality than the predecessor and yet its cheaper !

The price will change, the complete Z20LEH (VXR) at the moment is over £1000 cheaper than a Z20LET, but that price will change when the vehicle hits the roads!!!

Stefan · 01-11-2005, 15:31

Quote:

Originally Posted by MikeWarner

These results suggest the TD unit has a larger “AR” ratio building its boost later it would also seem that the TD unit is capable of much more power but is hampered by the restrictive exhaust manifold casting, leading to this, albeit minor, power oscillation as the internal pulses change the restriction in the manifold.

Did Turbo Dynamics produce a new manifold/turbine housing casting? This would be the only way to change the A/R (Extrude Honing's a possibility but would weaken the stock casting).
There's possibly another reason for the boost fluctuating...

***MikeWarner*** · 01-11-2005, 15:42

The test was done on a standard Z20LET manifold. The VXR one is different, but only in respect to the actuator mount AFAIK.

mystery machine · 01-11-2005, 16:47

i cant wait for my back pay.... the bus is going for a lil holiday in norfolk

***MikeWarner*** · 07-11-2005, 10:27

I just spoke to Courtenay Sport and my VXR Turbo unit is in. I'm booked in for Wednesday next week for fitted and software upgrade. I'll post back first hand experience of the conversion next week once it is done!

K3FUS · 08-11-2005, 08:30

Quote:

Originally Posted by MikeWarner

Oh - forgot to mention. The first one Courtenays get in has my name on it.

"Cough cough" Mike, that's the second VXR unit they have had, you know who's got the first one!

Seriously it's a great conversion, the drivability is spot on and the car is very responsive even at partial throttle.

I have just had to change my spark plugs and if you have not yet done so then I suggest you do it as it makes a huge difference.

***MikeWarner*** · 08-11-2005, 08:32

Lol - the first one they had was a pre-production.

mystery machine · 08-11-2005, 09:26

well lets hope that its all got b4 i order mine then

***MikeWarner*** · 08-11-2005, 09:43

Quote:

Originally Posted by mystery machine

well lets hope that its all got b4 i order mine then

Eh?

Turbo Dan · 08-11-2005, 11:04

I heard its a vxr220 unit and not a Astra vxr

K3FUS · 08-11-2005, 12:04

Quote:

Originally Posted by Turbo Dan

I heard its a vxr220 unit and not a Astra vxr

Axctually it's my old Z-Let unit with a coat of paint on it, but don't tell Mike, well not at least until he's paid for it!
!

mystery machine · 08-11-2005, 14:37

Quote:

Originally Posted by MikeWarner

Eh?

oops forgot the 'sorted' word

well lets hope that its all got sorted b4 i order mine then

my bad

Aussie · 08-11-2005, 17:17

Quote:

Originally Posted by Turbo Dan

I heard its a vxr220 unit and not a Astra vxr

i asked the vxr guys and was informed they are hybrid based of the VXR turbo designed for the astra

"It'll be the hybrid. To all intents and purposes it'll look like an perform similar to the Astra VXR unit but that has been designed specifically for Astra

Stu"

Turbo Dan · 08-11-2005, 19:23

Does anyone know the internal sizes, fitted a k26 on my mates C20LET what a difference that made

***MikeWarner*** · 16-11-2005, 23:30

My new turbo is fitted - my god has it made a difference!!

mystery machine · 16-11-2005, 23:45

more gen needed mike!