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@ 10 psi on pump fuel you shouldn't be even coming close to knock unless they are running some crazy timing on your setup or your engine build is higher compression. I was running 16psi on greddy twin 20g's on pump 93 with no knock and I think 9-10° of timing and made 527whp and 554wtq on a mustang dyno. I stepped the boost up to 20lbs and upgraded turbos to the FP blacks which flow almost double what the 20g's flow and got a little knock. I dumped in 5 gallons of vp110 with every fill up and i have 0 knock @ 20-21lbs on the bigger turbos. Going to be back on the Dyno in a few weeks.
this would worry me...can you monitor your VTC solenoids to ensure they are getting a duty-cycle?
I had intermittent VTC activation issues and my torque was down 80ft*lbs when they were inactive. 477hp/446t @ 12psi also on 91 oct.
The Tuner said he started getting knock when trying to go higher. This shop normally only deals with Subarus though, so I'm not sure how experienced they are with Nissan. I haven't really messed with the Uprev Tuner software as far as data logging....I need to though. I very well could have a VTC issue....awhile back before being turbo I started to notice a slight.....kind of irregular resinonse out of the exhaust when cold merging onto the freeway at speed...but not stuttering...more of a sound like the exhaust sound was out of sync?.......best way I can describe it by words. I researched on here and only could come up with needing to replace both VTC covers and solenoids...$1000.00 for both...something like the oil ports get varneshed or somewhat plugged in the covers. Figured I was worrying to much and ignored it due to it going away once fully warm after driving it for 15min.
Last edited by knuckles899; 01-11-2018 at 09:44 PM.
Wow man, on 91 oct I was only pushing 397.. And the tuber dropped me down to 383 to be safe.
Also I second that tq number is rather odd. Even at my 380hp my tq was 360.. No way you should be getting 440hp and only 360tq. And I'm on a single turbo set up.
just curious why a ST would make less torque than a TT? is 10psi worth of airflow different on a ST than TT?
Is the thought that a ST wouldnt be at full 10psi boost at peak torque ~4500rpm?
Power isn't based off of psi, it's based off of air flow and volume.
If a turbo can push more volume at a lower pressure it will still have higher numbers than a small volume turbo running huge psi. Psi is just the pressure being forced into the intake. Volume is the amount of flow or substance in our cases air being supplied.
Which is why turbine and housing optimization is such a big factor in different turbos and why there is a space race for the "best" design.
Power isn't based off of psi, it's based off of air flow and volume.
If a turbo can push more volume at a lower pressure it will still have higher numbers than a small volume turbo running huge psi. Psi is just the pressure being forced into the intake. Volume is the amount of flow or substance in our cases air being supplied.
Which is why turbine and housing optimization is such a big factor in different turbos and why there is a space race for the "best" design.
absolutely agree (boost vs. airflow). Tcode said it best 'boost is wasted airflow' and I go rounds with a buddy that higher boost value is a bad thing (shows how inefficient your engine is at moving air)...
so (assuming everything is the same) is 10psi worth of air flow from a ST the same as 10 psi worth of air flow from a TT?
I would think depending on the turbo quality and design, the single would have better flow. Over 2 smaller twins of the same quality/design
But the twins could just be more efficient and produce more flow than a single being they are working together.
But I always thought single had a better output just more lag which is why top dragsters run big singles over twins for huge numbers. I'd like to hear someone else elaborate on the twins vs single my self. Might be something interesting.
I would think depending on the turbo quality and design, the single would have better flow. Over 2 smaller twins of the same quality/design
But the twins could just be more efficient and produce more flow than a single being they are working together.
But I always thought single had a better output just more lag which is why top dragsters run big singles over twins for huge numbers. I'd like to hear someone else elaborate on the twins vs single my self. Might be something interesting.
I'm not missing anything on why a ST creates less torque than a TT - as it relates to the OP's 364ft*lbs output? Like there's no hard & fast rule that TT03Z is saying?
(Its my understanding) a larger single has more airflow potential versus two smaller twins ... and spool time/lag/compressing air within the intake track is irrelevant bc they can gas/rev the engine prior to the tree-lights...
sorry for hi-jacking the thread... also interested in what others have to say
It's not singles vs twins it's all about CFM's. As long as you set it up correctly and get the correct sized turbos you can flow the same CFM's from twins as you do from a single. The twins should spool quicker resulting in more bottom end torque.
It doesn't matter how much force (psi) you put into a engine it's about how much air you can put into it (CFM)
Conway - you're a smart guy, been through a lot, have some good experience ... all things being equal ... do twin produce ~80ft*lbs more(roughly 20%) torque, at 4300rpm(+/-peak torque) compared to a single - as TT03z suggests?? or by 4300rpms are both the twins versus the single moving the same amount of air (ie producing the same torque output)?
I'd assume the tq would be exactly the same assuming air volume and psi matched.
As far as the motor sees x amount of air is x amount of air. Only thing that would happen is you would spool faster. Being they are smaller. But on paper it should be exactly the same.
If all things are equal (healthy engine) and your twins are producing 10psi at 40 cfms and your single is also producing 10psi at 40 cfms you will make exact the same power.
If your making ~40 ft/lbs of tq difference then one of two things is happening your tune sucks or your engine is not healthy.
hence why you can pick an A/R for your turbo and why they offer twin scrolls.
TT are usually smaller and are meant for a great mid range and decent top end. A ST can be sized to have a similar curve or be sized to have a huge top ends. Twins can also be sized to give a great low end (think 335i) and run out of breath on the top end. Or two large twins and have a massive top end.
The more cfm you can flow at a lower RPM...below 5250, the more TQ you will make relative to another RPM. So the quicker spooling TT setup will make good tq but then drop off in the top end which will lower the HP relative to a different setup but give you hp/tq that are almost even, albeit at different RPM.
A large single will make TQ but the Top end HP will rocket up once past 5250 which will give you a spread in your HP/TQ values.
Hence why the HR and VHR guys are making so much HP on their kits (no matter TT or ST)...their TQ is low. Theyll make like high 5xx hp and mid 4xx tq.
Its all in your turbo sizing/setup and goals.
Remember..the air that is forced into the engine must also come out the exhaust housing of the turbo.
Since being tuned I've put on about 700 miles with no issues....until today. I lifted my car up to just check everything out underneath the turbo and exhaust are and noticed that the Comp Turbo oil-less zerk fitting is no longer there. Please keep in mind that this is the second turbo that was sent to me from Comp under warranty. At this time I am unsure on how bad this is. Without the zerk fitting being there I am assuming that the oil has been leaking out of the hole....how much and how long I do not know but I assume its not a good thing. The zerk fitting hole does not appear to be a threaded piece since no threads are visible on the zerk port. I will be sending Comp a email here shortly to see what they think happened but was hoping members with the boosted performance oil-less turbo kit can chime in or Sasha himself.
Here's a pic before installation when it was new.
Last edited by knuckles899; 03-31-2018 at 08:47 PM.
Wait is this the water line? Or the grease port? It looks like the grease port but your bottom pic highlights the vibrant water line 90 fitting.
Sorry, disregard the red line, it was a older pic I used for something else but I attached this pic to show where the zerk fitting used to be, but yes I am speaking about the grease fitting.
*I have changed the photo without the highlight red line.*
*This thread is also posted on The370z.com forum
Last edited by knuckles899; 04-01-2018 at 08:09 AM.
01-11-2018, 08:33 PM
