H1C compressor surge and bov flutter

[Wecrash99]

My small h1c fully spoils at 4000 rpms but the boost gauge starts jumping incredibly fast at around 17 psi. Plus whenever I let off it blows off and the flutters. I have no clue how to fix any of this, can someone help?

 

[sirbow2]

have you ported the turbo?

 

[Wecrash99]

pretty sure the hot side is ported

 

[BoostforBreakfast]

boost leak and BOV issue probably. Dont need to port the exhaust side of the h1c..... sirbow2, have you seen an h1c? What kind of play do you have in the turbo? also what compressor wheel is in it? the h1c has many different compressor wheels and if you have a smaller inducer than is supposed to be in the compressor housing, it will completely fubar your compressor map. Please provide pics

 

[Dsmkauai]

What bov do you have?

 

[JusMX141]

The turbo is not surge-ported, so what is happening is the turbo's making more airflow at that specifc boost level than the engine is demanding. The only way to fix this is to free up the intake system a bit...usually with the addition of larger cams.

have you ported the turbo?

This fixes nothing.

 

[BoostforBreakfast]

yea i forgot a bunch of h1c's didnt have the anti surge groove. You're off your compressor map. its not your bov studdering

 

[Wecrash99]

I just got all my gaskets redone on my exhaust and turbo so it shouldn't be leaking any, It's a GReddy type RZ BOV. It has the stock 260 cams, do I have to change them or can I go with adjustable cam gears and adjust the exhaust cam just a bit to open everything up more?

 

[JusMX141]

The restriction is in the intake, not the exhaust. By making the exhaust flow freer you can potentially reduce spool even more and further-compound the issue of surge.

You'd need to increase the valve overlap a bit, changing the lobe separation to reduce intake restriction....HOWEVER, the stock cam duration being rather low may hurt power output more than it's going to help surge by tuning the stock cams.

 

[Wecrash99]

It has the stock 260 cams in it, if I was to buy the cams to fix the problem, I'd need a bigger intake cam and a smaller exhaust cam, correct? Or what would you recommend?

 

[JusMX141]

Buy cams in a matched pair, don't mix-and-match cam brands or profiles. Ideally you'd want something in the 272 range.

 

[pagosa dsm]

I had compressor surge. I tried everything and the funny fix was installing the Tornado in the intake pipe as close to the turbo as possible. Read the GN web sights. More information on them.
Rick