jims13 6 Posted February 19, 2009 Report Share Posted February 19, 2009 right, i have one of these on my vr turboat the mo, ive put some redtops in, 4 " maf , in prep for a c2 chip (injectors are to be changed to greens)the problem is this.. im getting boost spike in 3rd gear onwards.the unit itself is a adjustable external unit, from i think 6 - 20 psi.it has a top port and side port, at the mo ive got it hooked upto the side port.. or should i have it hooked to the top port ??i thought the top port was only to be used if your using a mbc/boost controller.secondly, if i want to run a set spring i.e non adjustable, can i just wind the adjustment nut off, and fit dor instance a 8 psi spring??? i no it sounds silly but ive no desire at the mo to adjust it , once i have it runnig right..it'll make 12 psi in 1st and second gear , but goes off my 15psi gauge in 3rd , 4th and 5thplease help.. as im kinda stuck, and am meant to be running the car at the pod this sunday and then the ring in a just over a month..any suggestions welcome.. Link to post Share on other sites
jims13 6 Posted February 19, 2009 Author Report Share Posted February 19, 2009 some specs on it ripped from the spa turbo usa webby.• Compact wastegate, good up to 400 HP• 36 mm valve• Teflon ring around membrane• Fully adjustable spring rate; from 6 psi to 22 psi• Also available 14.5 psi springs• Billet aluminum body• Comes in “S†or “L†style fitting for SPA Turbo manifolds.• Available in silver, blue, red and blackit has worked ok before, so ive no idea why its playing up now.. Link to post Share on other sites
FishWick 21 Posted February 19, 2009 Report Share Posted February 19, 2009 You don't want to use the top port with an MBC!That is used in conjuction with an IBC. You plumb in the solenoid between the top and side ports and it juggles the air between the two. It's how you get 25psi from an 8psi spring, but imo, it's not a nice way to control boost.So yeah, you're using the right port (side) but 36mm is a tad on the small side. 44mm is ideal for a mid size turbo on a VR, but no smaller than 38mm.I suspect you have a combination of MBC spiking and wastegate flow problems. The MBC in your case is built into the wastegate, or are you using another MBC aswell? Link to post Share on other sites
jims13 6 Posted February 19, 2009 Author Report Share Posted February 19, 2009 nah , just the adjustnent n the wastegate.. ive wound the adjustment back in half way, as there was no tension on the spring.. so ill run it into work tonight, and have another look..its someting ive done, as it wa holding boost fine, when it was rr .. it made 327bhp, at a rock solid 12psi.. Link to post Share on other sites
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