05 TST Power Surge

[TexasCat.]

I am wondering if anyone else is have the same results that I am with the TST.



With power on 2x2 the performance is good. It pulls hard and smokes very little.



With power or torque any higher, there is really no obvious difference in power, but when the when the boost pressure peeks at about 42psi, it then backs off and then comes on again. The power constantly surges up and down.



I was told that the power above 5x5 would be to much for my clutch. Yesterday just for grins I put it on 9x9. The power would come and go but was no stronger than on 2x2, but so much smoke that I could not see the road behind me. The EGT's would go out of site.

I can watch the RPM tach and it never jumps up so I don't think that the clutch is slipping.



Why is it surging? The power comes strong but it does not last. If fuel pressure was low wouldn't the engine cut out? Could it be the rail pressure relief valve? Or possibly the map sensor?



Has anyone else seen this? Is there a cure?



Thanks for the help.

 

[Scrappy]

sounds to my like the TST is messed up give them a call and see what they say.

 

[JStieger]

With power or torque any higher, there is really no obvious difference in power, but when the when the boost pressure peeks at about 42psi, it then backs off and then comes on again. The power constantly surges up and down.



I was told that the power above 5x5 would be to much for my clutch. Yesterday just for grins I put it on 9x9. The power would come and go but was no stronger than on 2x2, but so much smoke that I could not see the road behind me. The EGT's would go out of site.

The "surging" you are feeling is probably the wastegate opening and closing. The turbo develops the wastegate setting pressure before it registers on the boost gauge thereby opening the wastegate. Then the pressures (boost gauge and wastegate setting) equalize or perhaps drop thereby closing the wastegate - the turbo then develops more boost and the cycle repeats itself.



When I first got a TST I noticed what you noticed. When it came on it kind of freaked me out from how fast everything was moving and hearing thw whhhhooooosh as the wastegate opened so I in turn backed out of the throttle a bit and... so on and so forth causing this phenomena. Now I just roll into the throttle more and keep it steady - all is good!



Unless you have a modified CP3 pump the upper TST settings are useless due to rail pressure falling off. The rail pressure falls off due to the extreme injector open duration requested by the TST and the CP3 cannot keep up. Therefore you get poor fuel atomization, high EGT, and tons of smoke.