Guest Evo TME Posted May 7, 2012 Share Posted May 7, 2012 hi guys, im having a hard time understanding the twin turbo system on my supra and need some help. I just bought a twin turbo recently and came to know that the previous owner had converted the sequential twin turbo set up to the TTC (true twin conversion). The thing is the car keeps hitting the fuel cut at 16 psi and i want to make sure the cars TTC setup is correct, anyway i will be trying to explain the current setup using the below pic Actuator 1: no vacuum lines connected and not wired open Actuator 2: no vacuum lines connected but wired fully open Actuator 3: has been completely removed (cant tell is the gate is open or closed as its welded) Actuator 4:top vacuum connection is connected to turbo 1 and other vacuum connection is blocked is the above setup correct for TTC as it looks to me that something is incorrect as im always hitting over boost and fuel cuts??? Quote Link to comment Share on other sites More sharing options...
James Posted May 7, 2012 Share Posted May 7, 2012 Have you got a full double decat and catback exhaust with no restrictor ring/1.0-1.2 bar ring? If so, you'll boost high. Stock fuel cut is at 1 bar I believe (14.5psi) so that would come in unless you have a fuel cut defender installed. In conjunction with this, I'd advise also installing (if not there already) colder grade - NGK grade 7 are ideal - spark plugs, a bigger fuel pump than stock such as a Walbro 255 and also check that the SMIC/FMIC is in good condition. This is a must regardless of mode of operation, be it sequential or TTC. If the car is decatted as I am presuming, the above is probably what is causing the levels you are seeing and the fuel cut initiating. All the supporting mods will give you full BPU power levels, which you could then have delivered in whatever configuration you desired Quote Link to comment Share on other sites More sharing options...
Guest Evo TME Posted May 7, 2012 Share Posted May 7, 2012 the car does have a full decat and catback exhaust and i don't believe it has any restrictor ring on it, as for the fuel cut defender im not sure if there is one already installed, being a U.S spec supra i think the fuel cut kicks in at 16 psi. Anyway in regards to my original question, is the TTC set up correct or do i actually need to hook up Actuator number 1 in the pic? i will check the fuel pump, FMIC and spark plugs as well Quote Link to comment Share on other sites More sharing options...
Nic Posted May 8, 2012 Share Posted May 8, 2012 (edited) If it's a US Supra it won't need a restrictor ring, it's only the J-spec Supras that do. Does the car have a FCD (Fuel Cut Defender) fitted? The standard fuel cut is around 1bar if you want to run above this you will need an FCD, you will also need a boost controller - electronic or manual - to raise the boost level (1.2bar is regarded as the safe maximum boost pressure). The standard fuel pump should be okay, you will need cooler grade plugs to run higher boost levels. If the car has the standard ECU fitted I'd put the turbos back to work sequentially as the standard ECU is mapped to suit the sequential turbo operation, running TTC with the stock ECU can cause overfueling/underfueling. See these threads. http://www.mkivsupra.net/vbb/showthread.php?35924-Sequential-turbo-hoses&highlight=sequential http://www.mkivsupra.net/vbb/showthread.php?35926-The-sequential-system&highlight=sequential Edited May 8, 2012 by Nic (see edit history) Quote Link to comment Share on other sites More sharing options...
James Posted May 8, 2012 Share Posted May 8, 2012 Ah sorry I didn't realise it was a U.S. spec! Quote Link to comment Share on other sites More sharing options...
Guest Evo TME Posted May 8, 2012 Share Posted May 8, 2012 i have no FCD on the car, no boost controller and im running on the stock ECU my actual issue is trying to control the boost that it does not reach the fuel cut which is at 16 PSI, i do not want to raise the boost but control it...i am not sure if the actuator setup i currently have (details in my first post) is correct....i think the boost is going too high due to the actuators not being connected or cancelled out or could it be due to the decat exhaust and cold air intake???? Quote Link to comment Share on other sites More sharing options...
Nic Posted May 8, 2012 Share Posted May 8, 2012 i have no FCD on the car, no boost controller and im running on the stock ECU my actual issue is trying to control the boost that it does not reach the fuel cut which is at 16 PSI, i do not want to raise the boost but control it...i am not sure if the actuator setup i currently have (details in my first post) is correct....i think the boost is going too high due to the actuators not being connected or cancelled out or could it be due to the decat exhaust and cold air intake???? If I was you I would put all the vacuum hoses back to stock sequential using the links I posted earlier, as I said before it's not a good idea to run the turbos in parallel with the stock ECU. Quote Link to comment Share on other sites More sharing options...
Guest Evo TME Posted May 8, 2012 Share Posted May 8, 2012 i want to put them back to stock sequential but the idiot that owner the car before decided to cancel out actuator number 3 (refer to my 1st post) thus going back to sequential is not an option plus all the sensors have been removed. I just need to manage the boost on the current setup but i don't know how....should i connect vacuum lines to actuator 1, would that help??? Quote Link to comment Share on other sites More sharing options...
Guest Evo TME Posted May 15, 2012 Share Posted May 15, 2012 can somebody please tell me whats the function of actuator 1? Quote Link to comment Share on other sites More sharing options...
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