Mac Turbo Valve

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
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Turbokart
Posts: 13
Joined: Thu Jul 25, 2019 12:42 am
ECU Model: S60 Pro

Mac Turbo Valve

Post by Turbokart »

Right this may have been answered many times but it seems complicated for what it is.

Im as it stands using a Tial External waste gate at 12 pounds of boost, Spring pressure.
Now i only drag race so I'm only interested in wot. I have a mac valve connected to the ecu but never used it, I only have turbo control on to enable a boost cut.
I will connect it up as the 3 port set up which i understand to enable the ecu to take over.

I want to start increasing my boost say 1/2 to 1 pound at a time how simple is this to do in the turbo control? The reason for little steps at a time is i do a lot of data logging instead of dyno work as i only do wide open racing.

Would someone be able to explain the best way for me to start nudging boost up so i can keep an eye on my fuelling and timing as i go?

Thanks in advance
Ollie
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Mac Turbo Valve

Post by Rob Stevens »

Use the turbo control in open loop. You will need to fill out the PWM base table, start with say 10 or 20% across the board and see what this does, the valve may not respond at this low level but you need to find out. Edge your boost cut up a bit to give yourself a little more head room.
Don't be tempted to use closed loop just yet.
Turbokart
Posts: 13
Joined: Thu Jul 25, 2019 12:42 am
ECU Model: S60 Pro

Re: Mac Turbo Valve

Post by Turbokart »

So would i maybe best fitting a 7 pound spring and keep upping the duty to reach my 12 pounds im running now to ensure the valve responds ok then move up with better control?

In the PWM table is it as simple as 0 To 100% to fill out each box?
Does anyone have a screen shot of an example of this please.
Thanks
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Mac Turbo Valve

Post by Rob Stevens »

Keep the spring and perhaps try something like this, very simple, this way the PWM is auto/servo, don't use my figures but gives you an idea to try. In my example your boost will sit between 200 and 210 kpa or at least try to if it can make the boost.
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Annotation 2020-08-26 170117.png
Turbokart
Posts: 13
Joined: Thu Jul 25, 2019 12:42 am
ECU Model: S60 Pro

Re: Mac Turbo Valve

Post by Turbokart »

Brill Thanks for the info Rob.
My ecu set up using psi not kpa so i have put my top row at 0-40 psi. Im right in saying that 27 psi on that row will equate to the 12 pounds my engine is seeing over atmespheric right?
If this is correct i should allow the solenoid to bleed off there as a start and slowly up the numbers to then say try and achieve 29 psi say 14 psi ish?
Cheers Ollie
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Mac Turbo Valve

Post by Rob Stevens »

yes try something like this, if the pressure gets to 29 psi the control will stop, therefore boost should hover 28-29
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Annotation 2020-08-26 170117.png
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