This durable billet spool valve collector with included turbosmart gate effectively allows running two different A/R ratios on your twin scroll T4 turbine housing turbo!
Based on dyno and track test results, this gives you about 500-1000rpm wider boost range compared to using a traditional single fixed A/R turbine housing.
Compatible with all our Garrett 76.2mm vband collectors(must be purchased separately), allowing great flexibility and use in many different setups.
Tech overview video: ElmerRacing Youtube
For T4 twin scroll turbochargers without internal wastegate. Allows good spool up characteristics with half the nominal A/R ratio of the turbine housing with the gate closed, and good turbine efficiency with the full A/R once on boost with the gate open.
Recommended for turbocharger sizes up to approximately 1000hp. (the flow rate for the gate for the second scroll will start limiting flow to the second scroll at very high power ratings)
Operation setup should be done with electronic control or spring rates so that the spool valve gate is at least 50% open before the traditional wastegate starts to open. For easiest setup, we recommend using a Turbosmart sensor housing cap (not included), and datalogging the gate position, or using it for active control feedback.
The Garrett vband inlet on this spool valve is tilted to the side giving good priority for both the spool valve and wastegate.
Data sheet
- Inlet Pipe/Tube Size: Garrett 76mm V-Band
- Outlet Flange :T4 Dual-Scroll
- Wastegate Size: 1.25"Sch10 (42.2/36.6mm)
