Hey guys, I did a quick search but it didnt bring up any relevant results, so I'm just gonna ask this here. I recently purchased my second zed, similar modifications to the previous one, only real differences is that the new one is a two seater, has a malpassi fuel reg, and has been flogged it's entire life. It has a turbosmart duel stage boost controller I THOUGHT was set to 9psi low /14psi high. I've been driving it for the last few days and havent had an issue, pulls like a freaking train, no detonation/ overheating, and sounds awesome under acceleration:br:. I noticed today, that instead of 14psi, It was hitting 20 on the boost guage. The guage only goes to 20, so god knows what it was actually reaching. But no issues. pulls, revs out, and continues in the next gear. My other zed, with a healthy motor and similar mods ( apart from the fuel reg ) occasionally pings on hot days running 14psi. As far as i knew, with the basic bolt on mods my zeds have, 14 to 15 psi was the absolute limit. Can anyone shed some light on how the car hasn't thrown a leg out of bed yet!? Or am I wrong about the max boost limit??
its all in the tune and IT temps. i plan on running 23-24psi on stock turbo's with nitrous and water methanol to cool/fight detonation. you might wanna pull it back until you find out what exactly has been done to it. turbos are pretty much a heat pump past 18psi.
someone please correct me if im wrong. but doing some maths, does the T22/T25 hybrid that the zed has stock, not reach max flow (i.e cant flow any more air without becoming inefficient) at around 17psi?? i dont see how you can push 22-23psi from stock turbos.
Well depends if you got the means to cool The compressed air. Nitrous and water/methanol are good. Wet compression is good also. Fact is it been done numerous times
I believe this is the turbo map for the stock Z. I'm no expert, fairly much a novice at this, so correct me if I'm wrong but I think at 20 psi your pressure ratio is approx going to be (20+14.7)/14.7= 2.4, and so looking at the map your stock turbos will be 70% efficient for CAF between 20 and 26 lb/min (that flow equating to horsepower between about 400 and 520 assuming 10 hp per 1 lb/min). But your turbos will surge at 20 psi at a CAF below 15 lb/min (15 lb/min per turbo equating to 300hp). So it could work provided the 20 psi doesn't come on too soon (can your ECU control this?). (This only refers to the turbos and not what your engine can handle detonation wise of course)
20 Psi on stock turbo's without a tune to match will "seem" to run ok, but more then likely is going to cause damage in the long run. But how ever 20 PSI on stock internal's with upgraded turbo's and a tune would be fine.
I winder if the injectors are stock???? if so I wonder if the boost gauge is reading accurate, I would suggest maybe throwing another in if possible to compare, or better yet if you have access to the facilities pressurise it to a known point and confirm its accuracy, I would imagine the internals would handle it but if you have a stock tune and injectors I also thought that detonation would be your worst nightmare.
Doesn't actually. The T22/25 compressor housing won't flow any more than around 18-20psi (depending on head modifications, better the head flows, the less boost you will see, less restriction, etc) on a VGDETT. Oh you might see a bit more on the guage as the charge temps are so hot, it's expanded an extra pound or 2. Water inj won't actually change this, it will allow you to not explode, but really, the charge entering your chamber will be no different to a 17psi charge. The only way to change this would be to cool your charge temps at the compressor blade, allowing a denser charge in the compressor housing, allowing for more air, but this has it's own problems.
