So I went to the tuner last month to see what my newly built Z still running stock turbos could do. We stopped around 420hp @ 14psi because of slipping clutch. Thankfully the Z community has well documented the need to adjust the clutch pedal when such issues arise. Now, with clutch fixed and car spinning tires in 3rd, I'm trying to decide if I should go back to the tuner. The only thing is, when I set boost to 21psi (w/ e85 and closed loop boost control on haltech platinum pro) my gauge shows the turbos peak at 21psi and then quickly drop to 15 or 16psi. My internet reading would suggest the stock actuators simply can't handle the higher boost levels, but is 15psi really the limit of what a stock turbo can actually hold? To tune or not to tune... for one, I would like to know her actual power numbers. But also, my tuner did mention he didnt even do a specific tune for e85 in the first session because the slipping clutch was barely maxing out 93 octane. I've been using my Haltech Platinum Pro to raise boost to 21psi using the closed loop function and I am definitely a noob when it comes to tuning. Can another tune help raise the boost pressure? I figure either: No, because the oem wastegates open too early and the stock turbos simply cant push more air past 15psi. Or Yes, because a custom e85 tune will push more fuel, allow for more timing, and effectively allow more air to be crammed into the cylinder prior to combustion; thus, providing more umph in the spooling of the turbos allowing boost to hold above 15psi. I'd love to hear this community's thoughts before I book another appointment. Fyi, if anyone is interested, my tuner is DBW Motorsports in Atlanta, Georgia. Sorry for the crappy quality, the printer ink was pretty light...
Oh, and just another quick fyi, I have pretty much all supporting mods EXCEPT for bigger turbos. I want to really see what the stockers can do, and if they blow up it will be A LOT easier to convince my wife to let me buy new turbos Quick list of main mods (this is not the entire build list, just the mods that would possibly support the stock turbos to push past 15psi): Haltech: Ecu (tune via VE) Boost control Dual wideband controllers IAT sensor 3bar MAP sensor FlexFuel sensor Walbro 485 fuel pump Nismo 740cc injectors Tomei type-L FPR Dual pop charger (cone) intake with velocity stacks AMS exhaust manifolds Z1 2.5" downpipes and test pipes HKS Hi-power 2.5" exhaust I think those are all the relevant mods...
15psi is going to be about it as the revs rise. I'm running highflows and mine drops to 17psi. Yes you need to complete the tune. Unless you want to risk replacing a set of melted pistons
I would agree with your assessment on the capabilities of the oem actuator. They were manufactured to run stock boost when they were new, and how old are your ones now ? HKS used to make good heavy duty actuators for the zed. Don't know if you can still get them any more, but it would be worth a look !
420hp @ 14psi with stock turbos and actuators is pretty dam good, if you want more hp upgrade the turbos, 2860s are a good choice.
Amazing figures. Shows a strong motor right there. Manual turbos? If indeed running factory actuators, stock springs are 7psi which even when combined with a boost controller, it can't work miracles and 15psi is about it before they start to push open. A set of 1bar actuators will allow for more but realistically there probably isn't a lot more left in the stock turbos as you are on their limits already. For the next set of turbos definitely start off with the 1bar actuators and that will give you all the headroom you'll need.
Hey man check out my build thread where i added external wastegates to my stock turbos. Car went from only being able to hold ~14psi up top to holding 24 without an issue. Not a bad result on a mustang dyno, reads a touch higher than our dyno dynamics/mainlines but much lower than dynojet
Z1 sell adjustable actuators that fit stock or high flowed stock actuators. Regardless of how you preset the actuators there comes a point at which the pressure in those little turbine housings overwhelms the wastegates\
Dang man, thanks for all the replies here! Shane001: I'm still on the fence regarding finishing the tune. After reading the replies here, it just doesnt seem like there will be much gain. Btw: I'm running wiseco pistons and eagle rods Beaver: Thanks for the 420hp props. Going into this build I really wanted to make a run at these 'stock turbo records' just over the 500hp mark. I did go back and check to see if they were running aftermarket actuators, they were . I looked hard at the 2860s but if I wasnt broke from the build I would love to get a set of these from conceptz: https://conceptzperformance.com/czp...t-nissan-300zx-z32-00-14411-g5-kt_p_37568.php MikeZ32: It is a 5speed with mt turbos. I may end up buying some aftermarket springs or actuators within the year. I'm impressed with what my engine threw down on the dyno (with a slipping clutch mind you) and I really want to see how hard those turbskies can be pushed. I just need to get/be prepared to replace them once they kick off from too much boosting. Rob260: I did actually look at the Z1 adjustable actuators. Just dont think I'm really ready to pull the trigger atm. Thanks for all the interest/responses here. If I do give back to the tuner it will be mostly for solid hp/to numbers. And when that time comes, the results will be posted on these forums with a full build log. Have a great day everyone!
