You may have noticed that I've not been participating too much here as of late. Well, I'm very busy with work, but finally dyno'd the car 2 weeks ago ...
About 15 pulls, tuning every step of the way with the last of the pulls registering 402whp and 392ftlbs at 16psi. Not bad so far, but here's what happened next:
On the next pull, the throttle got stuck open at full boost in 3rd gear and bounced off the JWT set rev-limiter for about 3 seconds. After about 2 seconds of panic, I quickly turned the car down via the key (at the time not knowing what was happening) in order to shut down.
We checked over a few things and noticed that the little tab on the throttle cable rail on the throttle body had got caught on the radiator hose strain relief. After resolving that, we made another pass and had a spike up to 30psi due to what I believe is a faulty wastegate.
Shrooomed! The head mushroomed and allowed coolant to pass into the cylinder chambers ... white smoke from the exhaust filled the shop. Oh well, at least the ARP's did their job
I am very pleased with how strong the car is pulling though. And the sound is absolutely gorgeous under boost ... kind of like a super-bike with a bus muffler; deep and scary!
I am resolving this problem by cryo treating the head and disassembling the wastegate to see if the valve or spring got stuck ... either rebuild or new, to be determined. I am also looking into a stand alone management system, probably DTA since I have experience tuning them; but that's much later.
During the interim, I'll be contacting JWT to see if they can remove the rev-limiter as in retrospec I believe the second to last run (boucing off the rev-limiter) may have shocked the head prior to mushrooming. I've seen this before in my race car and other friend's.
Anyway, I'm one step closer ... work, work, work ... never time to play.
