maxim

This might be an obvious answer to some of you, but lately I have been looking for possible solutions to my boost building problem. Rarely do see anythng above 5-6 psi and i have all of my vac lines nto the right places.
Today it just dawned on me that i have those damn AEM underdrive pulleys on my car, which I always felt had no impact on my N/A performance, but now I feel they might be hindering my boost build up. I figure the reason for those thngs is to decrease load on the engine and free up hp(as they say) which may be the load am lacking to build up sufficient amounts of boost.

Could this be a hinderance for me or am I just crazy?

rjardy

i dont think the pulleys would have anything to do with your boost problem because your boost is being made by spent exhaust gasses, and as long as your engine RPMs come up allright, theoredically you should be boosting, and the pulleys would free up more power so that would in turn raise the amount of power you were making with or with out the turbo. so i think the pulleys arnt the problem. Any body else? HTH

D-SPEED

i can pretty much guarantee that your pulleys have no relation to your boost problem.

downpipe

if i remember correctly, the unorthodox racing pulley for the 300ZX tt netted around a 40HP increase

dbman96

I can't imagine the underdrives being the problem. Either your WG is opening early or you got yourself a boost leak. Is it possible your blowoff valve is venting boost pressure? I know on mine if it is adjusted too loose I can't build boost worth a damn. Also try (briefly) hooking the wastegate vac line up to a point after the throttle body and see if you can build more boost.

bigTom

the pulley's have nothing to do with ur problem

rtype11

well is you really want to blame the pulleys we could say that in some cases the alternator pulley causes probs with the charging system, if you have a standalone it is very importante to maintain voltage, but not being able to make peak psi is another problem, you have a boost leak and your car cant read manifold pressure right.

maxim

Well, my WG vac line goes to my fpr line, so I know there is no problem there. It also seems that I don't get on the pressure side of the guage until 3rd gear and in fourth I usually have the rpms all the way up to 5000-5500(I was under the impression it was 4500 when I hit max boost) before I see even 5-6psi. I will try to tighten the BOV screw a little more maybe that will help. Maybe my Greddy is bleeding off too much pressure when I shift. Thanks for the info guys.

dbman96

If you're not getting boost until 3rd or 4th gear I really suspect a boost leak somewhere - doublecheck EVERY hose connection from the turbo to the throttle body.