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Frequently Asked Questions


Which carburettors are supported?

WinSU currently supports the following carb sizes in single, twin, triple, and quad configurations...

·         1.25" HS2 (0.09" jet)

·         1.5" HS4/HIF38 (0.09" jet)        also suitable for HIF4

·         1.75" HS6/HIF44 (0.1" jet)        also suitable for HIF6 and HD6

·         2" HS8 (0.125" jet)                  also suitable for HD8


Which engines are supported?

WinSU currently supports the following engine types in standard and modified form...

·         Austin/BL/Rover/MG

·         A series : Mini/Metro/Midget/Minor, all common capacities 850cc-1430cc

·         B series : MGB/Marina, 1800cc plus standard overbore capacities

·         C series : MGC/Healey/Princess, 2639/2912cc

·         E series : Maxi/Allegro/Marina/Princess, 1485cc/1748cc 4-cyl, 2227cc/2622cc 6-cyl

·         K series : Metro/Rover200/MGF,1120cc/1396cc/1588cc/1795cc

·         O series : Princess/Marina/Maestro/Montego, 1700cc/2000cc

·         MG-T : TA/TB/TC/TD/TF/TF1500, 1292cc/1250cc/1466cc

·         Rover V8 : Range Rover/TR8/SD1, 3528cc/3948cc/4278cc/4554cc

·         Jaguar

·         6 cyl : XJ6 etc, 4.2L

·         V12 : E-type, XJS, XJ12 etc, 5.3/6.0L

·         Triumph

·         4 cyl : Spitfire Mk1/2/3/4/1500, TR2/3/4/7, 1147cc/1296cc/1493cc/1991cc/1998cc/2138cc

·         6 cyl : TR5/6, 2498cc

·         V8 : Stag, 2997cc

·         Other

·         A general purpose engine type for any other car which calculates the best needle based on estimated power, 500cc-6L, for standard and modified spec


What operating systems will it work under?

Microsoft Windows XP/7/8/10

This software was written using VB.NET and requires the Microsoft .NET framework v3.5

This software will not run under Windows 3.1/95/98, Linux, Unix, or Mac.


What PC spec do I need?

Recommended PC spec : Intel i3 dual-core processor 2GHz, 4GB ram, 100MB free hard disk space

Is there a free trial available for download?

Previously, it was possible to download WinSU on a free trial basis, allowing you to evaluate the software before deciding whether or not to buy an activation code. This method of purchasing the software is no longer available due to the way in which this website handles digital product purchases. If you wish to run any of the features within WinSU then you must buy a full copy of the software via this website. After payment is received, you will be sent a download link. The software will still need to be activated after installation, as before.

I'm already a registered user of an older version, am I entitled to a free upgrade?

Yes, although be aware that the only difference between v2.6 and 2.7 is the change of .NET frameworks (to allow easier use with win10). At present there are no functional changes or new features. These will

Please use this form to request a new activation code :

You will need to provide your previous activation code as proof of purchase. If you cannot supply your previous activation code then you will need to purchase a new copy.

I've upgraded my PC  /  My PC has crashed - Can I have a new activation code?

If your old installation of WinSU is no longer working due to a computer failure, or your need to move it to a new computer, then there is currently no charge for this.

Please use this form to request a new activation code :

You will need to provide your previous activation code as proof of purchase. If you cannot supply your previous activation code then you will need to purchase a new copy.

Will WinSU run on European Windows (eg: Netherlands/France)?

Yes, WinSU v2.1 onwards will work on European versions of Windows (eg: countries which use a comma for the decimal point).


Where can I buy SU carburettor needles?

Recommended needle suppliers...

The SU Carburettor Company :

Minisport :


What engine data do I need to enter into the software?

As a bare minimum you need to select the engine type, capacity, and size/number of carbs. You can then get a more accurate needle estimate by entering things like air filter type, cam choice, exhaust system, etc.


How do I connect it up to my engine?

WinSU does not physically connect to the engine. It isn't like modern diagnostics equipment for engine management. It simply runs on your PC and suggests needle codes based on your engine spec. You will then need to purchase the needle(s) and fit them into your carburettor.


Why is it only showing spring type needles?

What you need to do is go into Tools->Options and untick "Only suggest sprung/biased needle codes". This option makes WinSU only show the spring loaded needles which tend to be popular nowadays in the later SU carbs (eg: HIF38/44).


Will it suggest needles for turbocharged engines?

WinSU does not currently have the facility for turbochargers in the engine spec pages. This is something I hope to add in the future. You should still be able to work out roughly what needle to use though.


Does WinSU suggest the dashpot spring as well as the needle?
v2.5 onwards will suggest the dashpot spring for your engine specification.

Are the suggested needles chosen for maximum power or maximum economy?
WinSU will aim to suggest 'factory' needles which give a good balance of power and economy. For racing applications where power is more important then you should aim a little richer, and likewise, aim a little leaner for more economy. To find needles which are slightly richer or leaner you will need to use the 'Find similar needles' feature.

Any further questions? Please get in touch...

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