Evo IX w/ 3” turboback, 100 cell cat, ETS intercooler w/ LICP, ETS intake, stock IX BOV, reflash.

Car runs really strong & well. Has some compressor surge at part throttle in the lower rpm range. Not huge but ideally I’d like to deal w/ it.

Not concerned about ultimate power but rather drivability ….

What are the options?

Some thoughts thus far:

1. Speed density mapping – concerned about possible slow rev drop.
   
2. Install cams to make engine more efficient and thus reduce surge – considering GSC1.
   
3. Aftermarket BOV – play with spring pressures but this doesn’t really address the issue.
   
4. Install FP anti surge cover for stock turbo.
   
5. Porting work. What kind?
   
6. Remapping. What specifically?

Anything else? Any experience? Any thoughts on the best initial step?

 

Bump I'd like to see some options

 

I'd do this first, because I think you're most likely mistaking dv flutter for compressor surge.....like I did.

 

GG06MR, did the APS BOV in your mod list solve your issues? Synapse is one of the other ones I have considered.

 

Almost everyone makes the same mistake, so dont feel bad. Even aftermarket valves often flutter, Ive had several that did on several different cars.

A bit of off-throttle surge is really not a big deal, and when it occurs its really nothing to worry about. Surge while on the throttle is the real enemy, and fortunately its not that common even on heavily modified powerplants.

 

Yes. The APS BOV is no longer available new, but I've heard good things about the smaller Synapse unit as an alternative.