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"TSR" Switch Fuel System, save money, drive on pump gas!
Component Matching #2
Page 2
It’s easy to tell that I consider the fuel system to be of major importance. As stated in the 1st part of this article running lean should be avoided, at all costs. Now that we have addressed the fuel system we can continue with the progression of upgrades in the proper sequence.
If you are counting then last thing was # 6, that should get us past the fuel system
7, Boost Gauge. 30 PSI range. This is not only necessary to be able to read the boost level above gauges that only have a 20 psi range but also is easier to read at a glance and like any mechanical device will be more accurate in the mid range of it’s operation rather than the upper limit.
These are readily available from aftermarket suppliers and should be mounted in easy view. I like the a pillar gauge mounting pods.
When wiring gauges connect the light circuit through the (lps) fuse block cavity with a female spade connector. This will cause the gauge lights to work in conjunction with the stock dimmer switch. It’s easy to check this function with a continuity tester. The bulb should brighten and dim with the panel dimmer switch.
8, adjustable boost level control. The stock version of this consists of 2 components. The waste-gate canister control rod and the bleeder valve on the passenger side valve cover.
The stock canister control rod is the preload and is set at the minimum boost level. With this canister receiving boost pressure, it will control the boost by the baseline spring tension in the canister. Maximum boost achievable with the stock canister control rod is in the 13 to 15 psi range.
The bleeder on the valve cover will open and close in response to commands burnt into the ECM PROM chip. The bleeder’s function is to remain in the normally closed position, which allows boost pressure from the turbine housing to be contained in the line that runs to the control rod canister.
This bleeder is plumbed into the line between the turbine housing and the control canister. There is a grey plastic y connector, with a built in restrictor that limits the flow from the source.
This boost pressure that is supplied from the turbo acts on the canister to force open the waste-gate. When the boost level reaches a point that overcomes the pre set spring load, internal to the canister, it moves the rod to open the waste-gate.
When the bleeder is opened by the computer command it allows some of this pressure to escape. This is the pressure that is used to open the waste-gate and limit boost. When pressure is vented by the bleeder the boost level will increase.
This may seem like a very in depth explanation of these functions but it’s best to understand the exact operation of components, especially when attempting modification.
The modifications that follow are intended to allow for an increased boost level while utilizing the stock components to the greatest degree.
I like to eliminate the stock bleeder from the boost circuit and replace it with an in cockpit bleeder valve. The elimination of the stock bleeder must be from the boost circuit only, since if it is unplugged from the electrical wiring harness there will be a SES code set. There is no harm in leaving it plugged in.
The manual control in the cockpit will be the only control and override the stock bleeders function. I have seen and tried myself to use both in the boost circuit. This is not recommended since they will be both functioning at the same time making it difficult to set.
This bleeder function is only intended to temporarily increase the boost level over the baseline setting. This is the way it was designed by the factory engineers and we are only changing to a manual control as opposed to an automatic one with this cockpit bleeder.
The stock waste-gate canister rod assembly comes in two different versions. The difference is in the rod, which may be adjustable with a threaded portion as opposed to a non threaded non adjustable one. The ability to adjust the pre-load of the internal spring pressure by varying the length of the rod is the difference.
The spring pressure preload on the control can be modified by the addition of springs to the canister arm assembly as well as by varying the length of the rod. This is the initial pre-load adjustment and the base line setting for the minimum boost level.
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