Went to Island tonight with #139 tonight for Test&tune hoping to break into the 10's:
100# lighter, on racegas, with bigger springs in the tial wastegate. I did not get time to make that 4" intake pipe so I just ran it with open turbo & missing headlight.
Total weight was about 3060lb. Boost was still dropping off to 24psi. I must have some other issue, maybe a leak in the piping.
Anyway, here are the runs:
11.523 @ 122.00 1.721 had tires set to 30psi, I spun then hard and let off in first gear. boost was at street setting of 25psi
11.732 @ 120.81 1.763 Tires down to 17psi, dead hooked and bogged the launch.
11.329 @ 121.72 1.549 good launch, early 1-2 shift at 7000. Boost spiking to 26, setting down to 24psi.
11.104 @ 123.36 1.492 Awesome launch @ 6600rpm. not a hint of spin, the car just took off. all clean gear changes with the throttle down at about 7800rpm. Boost hit 28 for a little bit in 3rd then went right back down to 25. I'd guestimate that 75% of the run the boost was under 25psi.
Fifth run I got an even better launch, but broke the drivers rear axle inside the outer CV boot midway through first gear. The car came out even harder, Id bet a mid 1.4 60'. I left at 6750rpm with about 14psi on 2step. I had raised the boost controller, added 2* more timing, and leaned out the AF a bit more for this run too hoping to see a 10.xxx.
That 11.10 moved me up to #9 on the DSMtimes GVR4 list. Cool and all to break into the top 10, but I really wanted that 10.xxx. Damn
So, while I still think the car had a 10 in it for the night, there is still something wrong in the boost control setup. Seems increasing the duty cycle on the AEM controller gives me a bigger spike, but it always settles down to about 24psi at high rpm. I'll have to do a leak test asap. Increasing the spring pressure in the Tial external from 1.0 to 1.4bar seems to have changed nothing.
Air temps were also not very good, starting in the 60s at the line on most runs and getting past 115*F at the traps, about 55*F gain in temp! That's pretty bad, Im starting to suspect the fmic core is holding back quite a bit of power and am suspicious of it being part of the boost drop issue.
I think Im going to try and make some graphs of the boost and rpm logs, post, and see what others think.
ACT250R came out and made some videos for me, Ill try and get them uploaded to youtube tomorrow. He was a super help and good advise the whole night. Thanks.
Drove the car home from the track with the broken axle all contained in the cv boot. Made it home without issue. I love welded center diff