Since these big turbos don't come alive too soon on the RPM range I usually open the throttle as much as possible, target 32-35 degrees of VVT advance and 100% wastegate duty. As for load I target 1.15 at 1000rpm, 1.35 at 1500, 1.55 at 2000, 1.8 at 2250, and 2 at 2500 (these are the targets I set for forged 2.3DISI-T engines, for factory engines I go a bit lower). The turbos I have on my cars (gen2 GTX'es) will make boost very soon in the RPM range (1100-1300) but that boost is more of a choke boost, healthy boost comes on only around 1600-ish RPM and needs control from like 1800-2000rpm. So those load targets I mentioned above can't be hit up until like 2200-2300rpm (I can hit load 2 at 2200 if I go WOT in 5th and 6th from 1500, but that's unrealistic, unpractical and unhealthy, with 0 usability in real life and 0 chance of happening unless you're stuck in 6th or someone that just got their driver license is driving the car), the reason I set them like that (along with tuning the response from the APP req load tables) is to preload the turbos a bit and have them ready for what's coming from 2500rpm up. In road/traffic situations having a turbo that still does something in the 2xxx RPM range is very nice. You don't need a lot there, but you don't want to wait 2 full seconds after pressing the acceleration before you go anywhere either. With this approach the response is great, but of course the physical characteristics of the turbo need to help you as well, and the CST5 (at least the pre-ball-bearing release, especially if it's IWG) is already known for spooling next week anywhere below 3500rpm.
If you wanted to buy the most reliable stock Turbo - do you have any recommendations? Do you know if you can get original cartridge for the stock turbo? I'm thinking of upgrading or replacing the stock turbo - it works but its got 150KM on it...and with engine out of car, it's easy to replace now.
If u want to keep it stockish I know BNR and Corksport offer similar to stock sized turbos. With most of these turbos though, there is a chance that you'll have to drop oil pressure to the cartridge to prevent oil pushing past the turbine seal and burning up in the exhaust.
That AFR dip in the high 6000's was quite an event. Do you happen to know what is the fuel rail pressure on your AUX fuel system? I noticed that the fueling issue started after the boost stayed a while above 23PSI (which is not that much though). Another thing to check is your battery. During high PT or WOT the alternator clutch pulley is disconnected so you're left with nly what you have in your battery. If the battery is weak, discharged, or whatever prevents it from performing well you will have all kinds of weird issues (in extreme cases weak spark, misfires, weird sensor readings, or in this case assuming that the aux fuel system pump is wired well whatever needs higher current will start to starve first).
Awesome info brother! So I'm leaning towards the in tank fuel pump possibly having an issue, because when looking at the video, the low side fuel pressure gauge (center gauge in dash pod) drops to 20 psi or so right before the AFR goes lean and fuel rail pressure drops. I didn't know that about the alternator, that's pretty cool. In the datalog battery voltage seems to hold steady at 14 volts.
@@WannabeTuners A slight drop in current (intensity, not necessarily voltage) may still be among possible issues. However I have no idea how you could check that unless you add an amperemeter on that circuit and have someone look at it while you \basically endanger the engine with that pretty lean mixture for the airflow. If you can borrow an Antigravity battery just to make a test, see if anything changes.
So what causes these factory setups to blow up at near redline? Is it literally because of the turbo choking the engine? What factors (like timing chain rattle for example, or an exhaust and pod filter setup without a tune) would add up to lead to a blown engine? Ive seen too many of these cars listed as rolling bodies. In New Zealand, even cars with the same/similar engine (cx7, mpv turbo) suffer blown engines.
Well to start the factory pistons and connecting rods aren't the greatest. The pistons have super tight ring end gaps which commonly cause cracked ringlands from excessive heat and or detonation, and the connecting rods are also quite skinny and can only take so much abuse. The earlier gen 1 models suffered more from chain rattle due to the VVT actuator stoppers cracking and or breaking off causing excessive slack in the chain. Other than that, with an updated VVT actuator, forged rods, forged pistons, enough octane, good quality parts, and a good tune, these engines can last a long time :)
I went with the jbr piping too and I love it. I'm building a sleeper so I fabbed the stock crash bar so I could hide the intercooler and not have to cut my plastics. Came out strong and clean, no hack job. I haven't seen anyone else do it like this so I made a quick clip. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ih5paTA2DIk.html
Watch your fuel pressure Guage on that one pull... drops to the 20s if I am reading it correctly. @6min mark. also looks like your tank is low on fuel.
@Wannabe Tuners hopefully you get it sorted. Yank that old dw out and put a aem340 in and don't look back. It could have just stayed for fuel being low on fuel in the tank also. Top of 4th under load 🤷♂️
@@gimmethecarkeys Yeah I noticed that also in the video but it definitely makes sense if the fuel is getting stuck at the back of the tank during a pull
I haven't had a chance to go back to the dyno after the engine blew, but based on the boost and ignition timing I was running back then, the car is probably making right around 400 whp.
I think I know what happened. If we look at the low side fuel pressure (center gauge on the dash) we can see that low side fuel pressure holds at about 70 psi until just past 7k rpm, at which point it drops to 20 psi or so and we can see the AFR on the Accessport go lean. It must be the In tank fuel pump not being able to keep up. I've been running this Aeromotive Stealth 325 LPH for several years now so maybe it's getting worn out. Great catch though man, I appreciate that :)
@@WannabeTuners While watching the end portion of the video, I was looking at all the log columns. I was waiting for you to point out the low fuel pressure, but you never did. Figured I’d mention it just in case you missed it. As someone whose gone down the road of rebuilding a motor for a ms3, I’d hate to see you have to venture down that road again. Happy to help.
