Austrian Supra Posted December 30, 2007 Share Posted December 30, 2007 On my Supra I run a 72mm tubo on 26PSI. I use the HKS Racing type 2 BOV. When cruising around and letting off at low and mid boost, or even when going WOT and letting off, I think I get compressor surge. Here´s a video: http://www.myvideo.de/watch/1607673 Sorry, it´s a little boring, but you can hear what I mean....at the beginning you hear how it seems to surge on low boost let offs and at the end of the Video you see some short WOT´s to hear how the turbo seems to get compr. surge then, too. It is surge, right? I´m pretty sure it slows down the turbo between shifts... I will install a 76mm turboand run it at 32-35 PSI soon, but still will cruise around a lot, too. So, if it´s surge (and I think it is), should I eventually switch to 2 x SQV Bov´s??? I know my old design SSQV didn´t hold 30+ PSI. BUT... but how´s the new design doing?? What´s different? Still plastic parts inside? I would be willing to buy 2 new SQV´s, no problem, but they would need to hold the 32-35 PSI, I will run, without leaking or braking internal parts in the BOV (still plastic parts inside?). Or is there an other way to get rid of that compressor surge?? Mabye that BOV?: I hope anyone can help........ Link to comment Share on other sites More sharing options...
Wez Posted December 30, 2007 Share Posted December 30, 2007 Compressor stall not surge Surge is when the turbo is producing more air than the engine can ingest, generally not an issue on large turbos only mismatched smaller turbos as they spool up so fast. Stall is when air in the system is not expelled and has no where to go but back through the compressor, this could be caused by the BOV spring being to tight for small amounts of boost. Its a balancing act because if you loosen the spring it may leak at high boost. Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 30, 2007 Share Posted December 30, 2007 Running that sort of pressure, i don't think you BOV is coping with the amount of air, you may find fitting another will sort it but i would be inclined to change it for something like a Tial BOV, much bigger outlet 50mm i think. Link to comment Share on other sites More sharing options...
Austrian Supra Posted December 30, 2007 Author Share Posted December 30, 2007 Compressor stall not surge Surge is when the turbo is producing more air than the engine can ingest, generally not an issue on large turbos only mismatched smaller turbos as they spool up so fast. Stall is when air in the system is not expelled and has no where to go but back through the compressor, this could be caused by the BOV spring being to tight for small amounts of boost. Its a balancing act because if you loosen the spring it may leak at high boost. Ok, Stall 90% of us sure do KNOW what I mean, though There´s nothing that can be adjusted on the HKS racing type II that will ensure better (sooner) blow off (according to HKS). The screw is just to adjust that the BOV doens´t open at vacuum and should not be turned (according to HKS). So that´s not it...... Anyone else has any thoughts on that?? Link to comment Share on other sites More sharing options...
Austrian Supra Posted December 30, 2007 Author Share Posted December 30, 2007 Running that sort of pressure, i don't think you BOV is coping with the amount of air, you may find fitting another will sort it but i would be inclined to change it for something like a Tial BOV, much bigger outlet 50mm i think. The HKS racing type II is announced to hold 40 PSI........would be funny if it then is not able to blow off enough....... But you may be right....it seems to be that way So that would mean on race application HKS doesn´t care for proper blow off and accepts compressor stall......?? They just trade that in for the high boost holding capabillity. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 31, 2007 Share Posted December 31, 2007 Don't worry about, remove the POS and have no BOV at all, that's what I'd do. Link to comment Share on other sites More sharing options...
Austrian Supra Posted December 31, 2007 Author Share Posted December 31, 2007 Don't worry about, remove the POS and have no BOV at all, that's what I'd do. I loose too much spool during the shifts........I hate that Would be even worse without any BOV. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 31, 2007 Share Posted December 31, 2007 I think you'll find if you measure it accurately it'll make no difference at all Link to comment Share on other sites More sharing options...
Austrian Supra Posted December 31, 2007 Author Share Posted December 31, 2007 I think you'll find if you measure it accurately it'll make no difference at all In that case all BOV´s were pretty useless. And on the other hand...the cha-cha sound is priceless anyway......... Link to comment Share on other sites More sharing options...
miko_supra Posted December 31, 2007 Share Posted December 31, 2007 And on the other hand...the cha-cha sound is priceless anyway......... http://youtube.com/watch?v=3qhnQDbYZAU Link to comment Share on other sites More sharing options...
Austrian Supra Posted December 31, 2007 Author Share Posted December 31, 2007 http://youtube.com/watch?v=3qhnQDbYZAU hahahahahahaha Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now