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Saabotage is coming along nicely…
This weekend I took the newly rebuilt ’86 SPG T5 on 2 small road trips to get the break-in mileage done. So far I’m at 650 miles (1050km) and all seems fine (fine is relative, still have teething issues – see below).
I ran the first 500 miles below 4000 rpms and easy-to-moderate throttle, keeping the boost at about 5psi. I varied the rpms, engine load, mixed city w/ highway driving, etc. At 500 miles I changed the oil (regular Castrol 10w-30) and filter, and unplugged the BPV to make sure I was at base boost – 6 psi.
Or so I thought.
I started pushing rpms higher with a few runs all the way to redline. In 2nd gear, this resulted in a steady pull to redline with a nice bump in power past 4000rpms due to the cams. It felt like a strong N/A motor would. In third, fourth, and fifth, it felt faster. In fact it felt TOO fast. After several 4th gear runs to redline (big, big smiles), I finally looked down at the instruments and noticed that by the end of the run, boost was at 10-11psi! Holy creeping boost! Apparently in the higher gears, the internal Garrett wastegate cannot relieve the exhaust enough to maintain base boost. I’m not complaining. EGT’s were steady at 1550-1600F, Fuel pressure ranges from 40 at idle to 55-60psi when driving as above.
My plan is to drive it this way until 1000 miles, then plug in the boost and see what happens! Will probably switch to Mobil 1 at that time also.
That additional break-in time should give me time to sort out the Trionic system, which has some issues. When I clear the memory (disconnect battery) it totally screws up the idle. Sometimes it dies, sometimes it idles at 2000rpms. Eventually, over a day or so, it adapts to a normal idle. But there is obviously something amiss. Also, there is a part-throttle/light load hesitation that is evident at most speeds and most gears. It feels like getting hit by a gust of wind – the car momentarily slows, then a second later, it’s back. I think that the T5 may be backing out the timing periodically. Both issues may be due to my base timing (crank pos sensor) being off slightly from spec. What I really need to do is get the connector for the ISAT/TECH2 wired up so we can read the ECM settings directly.
I have some new observations regarding the c900 and the newgen 900/9-3. Keep in mind my 2 cars are a highly-sorted c900 SPG and a lightly modded newgen 900. In general the c900 has more body flex, creaks, general noise (a lot of which my mods have caused) etc. The newgen is a swift and comfortable cruiser. But the c900 chassis works better in every performance aspect - point and shoot steering, very little roll, excellent feedback, less understeer. The gear ratios in the newgen are 'taller' and much more flexible to drive with, where the 5 speeds in the SPG are closer-ratio and lower geared. I don't get it. With such a flexible power band, you don't need ratios this close, and with plenty of power on hand, you don't need gearing sooo low. Example: 3rd gear redline 84mph in the SPG, and 102mph in the newgen. Oh well, might be good on the track I suppose.
posted by 63.207.93...
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