Mayolives Posted August 6, 2006 Share Posted August 6, 2006 I have a Tial WG38 waste gate with a 14.5 psi spring and a GReddy Profec B boost controller. The controller has a hi and a lo setting. I have the low setting at 14 psi and the hi set at 20 psi. When dyno tuning, I'm having problems holding boost on the high setting. If I install a 23 psi spring, will my boost controller still be able to open the waste gate on the low 14 psi setting or will the stronger 23 psi spring over ride the controller? Quote Link to comment Share on other sites More sharing options...
Clifton Posted August 6, 2006 Share Posted August 6, 2006 The spring setting is the lowest boost you can run. 23 psi shouldn't be a problem with a 14 psi spring. I did it ow ith an 8lb spring. Does your controller send pressure to the top of the WG or just control the signal line to the bottom? Quote Link to comment Share on other sites More sharing options...
Mayolives Posted August 6, 2006 Author Share Posted August 6, 2006 If I remember correctly, one side of the controller valve is connected to the top port of the waste gate and the other side is connected to the charge pipe between the inter-cooler and the turbo. On the dyno, the engine makes boost, then stumbles at or near 4500 rpm, and then again makes boost up to the desired rpm shift point. I'm running an Electromotive ignition system and we have tried to turn the stumble out, with little success. This whole process makes a lot of hp and torque, but the stumble would make it very tricky if not impossible to handle on a road course. This car is a dedicated race car and will not be street driven. Quote Link to comment Share on other sites More sharing options...
Clifton Posted August 6, 2006 Share Posted August 6, 2006 Is it a boost stumble or tunning that causes a stumble? Will it hold boost setady top redline? If the spring isn't stiff enough even with a controller the boost will drop off in the higher revs. It doesn't sound like a spring problem. Quote Link to comment Share on other sites More sharing options...
Mayolives Posted August 6, 2006 Author Share Posted August 6, 2006 My tuner is an Electromotive factory rep. who knows what he is doing. So I will rule out this as a tuning problem. After the stumble at 4500 rpm, the engine pulls hard and makes steady boost to the shift point. The engine is new, so we are doing most of the runs at 6000 rpm max. We have made a couple of 7000 rpm pulls and the reaction is the same. Quote Link to comment Share on other sites More sharing options...
jt1 Posted August 6, 2006 Share Posted August 6, 2006 Tom, sorry you're having problems, unfortunately I don't have a clue how to help. Are you still planning to come to the T1 event this month? John Quote Link to comment Share on other sites More sharing options...
Mayolives Posted August 6, 2006 Author Share Posted August 6, 2006 John, We will get it worked out and I do plan to be at this month's T1 event. Can't wait to hear your German stories. Quote Link to comment Share on other sites More sharing options...
jt1 Posted August 6, 2006 Share Posted August 6, 2006 I don't have any stories yet....there may be some after the event! This is gonna be a shakedown cruise for me. First time in a different car, first time with a turbo, street tires (some kind of falkens????), unknown chassis setup/characteristics, all point to a conservative weekend for me. I'm really looking forward to seeing Red Bird. John Quote Link to comment Share on other sites More sharing options...
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