Rev2 9K

What causes a turbo to surge. People have been telling me that a 14b is to big for a D16 sohc, that the motor cant flow as muuch air as a DSM could. What can I do to fix this?

88crxSi

when a turbo flows too much air and when it gets to max psi u have it set to, it dumps exhaust out the wastegate.

compressor surge is commonly caused by the lack of a bov.

alwaystootall

that the motor cant flow as muuch air as a DSM could... a dsm i s a 2.0 and u have a 1.6 the 1.6 can make as much exhaust gases as th dsm so it would take the 1.6 longer to spool up the same turbo

Rev2 9K

So, how cn I fix this? Or do I need a different turbo.

ZexRex

i would not worry about it, i have a t3/t04e on a d16a6 @10psi/zdyne/450cc's sure it will only last a few months on stock internals but who cares, i will do a bseries swap.

that turbo will be fine, it would be a little small for me.

Kevin325isBMW

Typically surge is caused by using a too-small turbo (and / or) not having a blow-off-valve (BOV). The too-small turbo surge is where you get too much boost at too low an RPM. This plots on a turbo compressor map high up on the left (the leftmost line that angles up and to the right on a compressor map is the surge line).

I suspect however that in your case it is the lack of a BOV (or one that is not adjusted to open soon enough). This causes surge (which is really just compressed air at the compressor discharge trying to recirculate (back-flow) because it has no where to go when you close the throttle plate to shift.

Mild surge (like you would have with 5-psi boost) should not hurt the turbo, but at 8-psi or over it could get damaging. Further surge, degrades boost production during up-shifts and performance will suffer. I recommend a BOV.

Kevin

Rev2 9K

I do have BOV. It reachesmax boost about 4500 rpm, then it starts surging. The BOV works perfect. So i sounds like I need a bigger turbo. Would it be better to buy a bigger turbo, or convert the 14b to a 16g. After all, Greddy kits use the TDO4-15G turbos. PLease help.

JD

yeah surge happens when you have a turbo too small for your engine. I have a accord with a 2.2 liter and I had a td04 on it and it would start bosting at 1500-2000. I ruined that turbo in 3 weeks.

ZexRex

dude thats not compressor surge thats just your wastegate opening or something like that

Rev2 9K

I removed th line to the actuator an it stills does it, so it cant be the wastegate opening.