Trevor

Hey guys...this has been bugging me for a while. My car is essentially stock for now (just some cooling mods and gauges). I live at 3075' altitude. I just got the sequential twins operating correctly (or so I think) but I have a question about the boost reponse. I noticed that the car hangs at 0 manifold pressure when coming off vaccum then makes full boost almost instantly at 2800-3000 or so. This happens in every gear...even 1st. After being in boost it's able to spool much earlier. I did some testing today...with the A/C on, coming out of neutral/vaccum straight into a 4th gear roll starting at 2k I don't get 5 psi until 2800 rpm. If I do a 3rd gear roll...let the primary turbo hit 10 psi then do a quick shift to 5th I can get 5 psi at roughly 2150-2200 rpm.



Is that normal? I think it stinks. No shooting out of corners after a downshift...bah!



It definitely feels like something in the control system is keeping the primary turbo from spooling until it deems the rpm to be correct. After a WOT shift that item is taken out of the loop and the primary turbo is allowed to spool to its full ability. I don't think it's load based either as 4th and 5th aren't far enough apart to cause a 600-650 rpm extra lag. I'm thinking it could be the double throttle system but from the searches I've done most people say that removing it doesn't do much (if anything) for you.



If it is normal what's the cause? Is there a fix for it? I have a Power FC/Datalogit going on the car with an wideband/intake box/full catless exhaust/and a ASP medium IC that are going on the car. I'm just holding off installing the Power FC until the IC gets here and I'm ready to do a full tune on it.