wastegate spring

[xbmwguy]

hey guys just installed my new to me fabspeed headers from brian and a new tial 46 with 1 bar spring. i def need an 8 as the boost goes to 1.2 and thats not good. anybody got one? i figure an .8 should get me to 1 thanks

[pkracer21j]

Frank, take the wastegate apart, there should be a big spring and a little spring in the waste gate. just pull out the little spring and you should be at .7 or .8 bar

[pkracer21j]

and if you have the fuel, 1.2 is fantastic!

[RarlyL8]

If you have the correct grade of fuel the engine may not detonate. I doubt you wish to run racing gas.
Overboost is typically blamed on the elephant nose waste gate pipe design. The exhaust flow is disturbed by the sharp angle at the base of the turbo flange.
Lowering your boost pressure release threshold will help but the actual pressure seen by the engine continues to fluctuate with operating conditions. A boost controller may smooth the fluctuation but can do nothing to increase the pressure flow out of the waste gate pipe that will relieve the tendency for the engine to see boost greater than the spring setting. The spring setting on the stock waste gate is set to operate based on the pressure differential between the stock heat exchangers and the stock 3LDZ and stock muffler. You now have to find a spring setting that will best match the pressure differential between the aftermarket headers, turbo and muffler while dealing with the sub-optimal waste gate circuit.

[xbmwguy]

thanks pete and brian. Yep finally got my wur back from brian for the second time, it was nothing he did but just wanted to "be safe" and he set it to his settings for his 400 hp cis "silver" 930 and flowtech re-massaged my fuel head from 15% over stock to now 20% now i finally seeing 6500 @12 thanks Larry and thanks Brian leask and rarely late next is suspension comming from rebel and clint so drop her down an inch or two replace some obsolete rubber crap some helper coil overs on the back and let the mustang beatings begin!!!!for palooza in fall

[A930Rocket]

Brian, did you increase the size of the wastegate pipe over stock or other aftermarket headers? With stock headers, my Tial gave me 1 bar of boost. With the GHL's, I got 1.2 bar and had to back off the spring. With my replacement GHL's I had them upsize the wastegate pipe and had to increase the spring again to get 1 bar.

[RarlyL8]

No, I chose to use a better flow path from each bank of cylinders rather than to change the pipe ID. The reason for that is these engines may be modified to produce anywhere from 300WHP to 500WHP and the waste gate pipe ID will affect them differently. If I were designing a system for a specific HP rating then I would look at using a custom W/G pipe ID for that application.