boostedjd

i have a 1990 honda civic with a d16zc engine with forged internals and ported and polished exhaust side of the head. right now im running a 16g turbo on it and it spools around 3500 rpms and the most ive been able to get out of it is 10-11 psi. I want to get a turbo that runs more boost and i have a 14b laying around and last time i ran that it spooled at 2000 rpms and ive also heard a t25 would spool almost right off idle. I know i could get more psi out of the 14b or t25 but would either of those turbos be better to run to get more horsepower out of them or would they not be efficent at more than 10psi or should i just stick with my 16g

grumblemarc

iTrader: (4)

I'm confused. Are you looking to upgrade or downgrade?

boostedjd

obviously looking to upgrade...

grumblemarc

iTrader: (4)

Not with the POS turbos you listed you aren't.

boostedjd

First off their not pos I know their not the best turbos out there but I'm paying my own way thru college so I'm on a budget plus its I'm not looking to run a 1000hp car I'm jut looking to see it or he three I have available which would be better so if your gonna be a condescending about it you can just not respond I'd rather talk to someone who's going to be helpful rather than codescending

effin

iTrader: (1)

You should just stay with what you have for now *16g. Sounds like your looking for a turbo with more potential than the current unit you have?

TheShodan

iTrader: (14)

You're downgrading by going with the 14b and T25 Radius flanged turbos. You're going to be doing a lot of spending and work for a guy on a budget utilizing these turbos.

As one that works and repaired these turbos on a regular basis, you're really doing yourself a disservice by utilizing anything but the MHI 16G that you currently have. If you want to run more boost, then turn up the 16G to run more boost (after a tune of course). I think you're under the impression that the 14B and T25 are somehow more efficient than the 16G you have. You are incorrect. you'd be getting worse performance.

Not being condesending , not being mean, just telling the truth.

KevMiha

listen to him^^^

boostedjd

And that does answer my question. I have my boost controller turned all the way up and by he time I hit 6800 rpm about where it redlines the I was at 10psi so unless I do other engine work I think that's the most I'll be able to get out of that turbo. I guess my question was more if I was running that 14b since it spooled at 2k instead of 3500 rpms like the 16g and llast time I ran that 14b I I got 15-16 psi when it redlined would it be worth it to switch back to the 14b to get 5-6 more psi or since the I'm assuming the flow and other factors of that 14b aren't as good as the 16g would I still be getting more performance out of that 16g at 10 psi than the 14b at 15-16psi

grumblemarc

iTrader: (4)

OMG with this PSI nonsense! Different turbos! You cannot compare PSI on one to PSI on another! Turbo101!

boostedjd

So your telling me that if I run 14b at 15psi then a 16g at 10psi there's no way to compare how much horsepower j get out of each setup? I couldn't dyno it and see how much horsepower I get out of a 14b and then how much horsepower I get out of a 16g and see which one is more on my setup??

grumblemarc

iTrader: (4)

Dumb. You were already spoonfed that you were better off with what you have. Move on.

boostedjd

And that's all my question was which one was I better off with. Not for someone to tell me there's no way to compare the two

grumblemarc

iTrader: (4)

That's all you've been doing is comparing these based off of ***-backward thinking. If you run the smaller turbos at a higher PSI spooling at a lower RPM will it out-muscle the turbo you have at a lower PSI while spooling at a higher RPM? Dumb. How about just add more PSI with a new tune to the one you have and make more power? Dumb. You can compare anything. What's your point? The two turbos you are considering are a downgrade. Move on.

boostedjd

Thats the point with my setup (and it is tuned btw) I can't get more than 10psi before I redline.. sow how am I supposed to get more psi when my boost controller is turned all the way up my waste gate doesn't even open and when I redline its at 10psi

grumblemarc

iTrader: (4)

Maybe the question you SHOULD be asking is "Why can I only get 10PSI out of my 16g"? Like I said, ***-backward thinking. And it sounds like your setup is ***-backwards too.

TheShodan

iTrader: (14)

Something is going on with the wastegate actuator (boost leak comes to mind immediately) if you're limited to 10psi of boost on a 16G no matter what you turn the boost controller to. THAT is the bigger problem to resolve as opposed to switching turbos. Those 16Gs can easily reach over 25psi on the stock actuator. Something is amiss here.

14b AT 16PSI has a different flow rate than a 16G at 10psi. you can't just correlate more boost with more power unless you know what the two turbos are capable of. Maps of both are ALL OVER the web to show flow rate at different pressure ratios. Hell , even the 16G turbine wheel is larger than the 14B. you'd just be blowing hot air anyway.

It might be beneficial for you to learn a bit more about each particular turbo individually before making any comparisons, as it seems your experience is limited to "boost pressure" from your previous setup, and nothing more. Once you've understood these differences, I think you'll be better informed about why the questions you are asking are not the correct ones when diagnosing your issues or needs.

Good luck to you .

wantboost

iTrader: (2)

The 16g is a larger turbo than the other you mentioned and is your best bet.

As far as not being able to make more than 10-11psi... what map sensor are you using? Stock ones don't read above 10-11psi... that's their limit... and a 16g should be able to make twice that pressure without issue

The other question is about thr turbo itself. Is it a big or small 16g? Genuine MHI turbo and not a Chinese piece of ****?

And how are you controlling/attempting to raise the boost level? Are you adjusting the wastegate actuator arm? Manual boost controller, electric boost controller?

Also this could be as simple as a bad actuator or a boost leak somewhere... have you tested for boost leaks? Not just at the couplers but every part on the intake tract that has a gasket. Compressor housing not seated fully, pinholes on the intercooler causing leaks, leaking blow off valve or it sticks and doesn't close all the way or at all, etc

What engine management are you using?

boostedjd

I am using the stock map sensor but i have a boost gauge and when i was running the 14b when i cranked it all the way up it read up to 17psi. Yes i realize my map sensor wont read it but i have my boost gauge would read higher and i boost controller turned all the way up so my wastegate doesnt even open and it hits 11 psi max at 7k rpms on the boost gauge so irregaurdless of what my map sensor reads if it was going over 11 psi my boost guage would be able to read it.

It is the big 16g and im not positive i got it off a friend but i beleive it is genuine.

I have a turbo xs manual boost contorller i am using to control my boost.

I have went over everything just by eye and am planning on using a smoke machine soon to see if i have any leaks anywhere but i havent really thought of the leaky blow off valve ill have to check that next. my bov is a genuine greddy bov.

And im using neptue engine managment system.

I have the exhuast side of my head ported and polished to a gasket match but intake side is stock. 2.5 in charge piping.'
Think it could be caused by poor flow from a stock y8 intake and poor flow of the exhaust mani, not positive what type it is but its just the basic one with short runners and is a bottom mount style?

justYncredible

iTrader: (1)

bingo! i knew this was the issue. the stock map sensor can only do so much. you mentioned your tuned but where was your tune set for? you cant just keep adding more and more without it being tuned for it. get a new map sensor say an ominpower 3bar and get a retune with it installed at the tuners shop.

boostedjd

yes i plan on getting one this winter.
And yes i realzie my stock map can only read 11psi but even if i get a 3bar that map sensor isnt going to make my turbo spool any quicker or anything and right now its 10 psi at 7k rpms so even if i had a bigger map sensor its still not going to build any more boost since its maxed out at 7k rpms.

Or am i missing something and should it be spooling sooner than 3500 rpms or when it spools at 3500rpms should it spool up quicker and build boost faster?
From my thinking is that if that turbo is capable of hitting lets say 20psi shouldnt it hit the 10psi mark sooner than when i redline so that when i turn it up it has the extra 1-2k rpms to spool up that extra 10psi or am i just completley wrong because right now my manual boost controller is turned all the way up my wastegat isnt even opening so form my thinking is it should spool up to its max psi since its not regulated right now at all by a wastegate or anything else

grumblemarc

iTrader: (4)

You OBVIOUSLY are missing something. Basic turbo knowledge and simple comprehension skills.

Are you just wrong? Yes.

But since your're stuck on stupid with this spool and PSI nonsense, why don't you go ahead and downgrade that turbo so we can hear later how you don't have the power that you used to and how your turbo seems build peak power too soon and falls off right when you want it to really kick in.

justYncredible

iTrader: (1)

Ok grumble calm down a little lol

OP you need a different map sensor and there is something else going on with your setup. Maybe you can have your tuner look at it

TheShodan

iTrader: (14)

its very simple. because he is outside of the efficiency range of his 16G with 10psi, he doesn't understand that responsiveness will actually be better with the higher reading sensor, so that over 12-20psi of boost pressure, the turbo will be in its efficiency range and actually be a better application. He'll need to retune regardless, but I think at this point he's rather stuck on his own logic. But that's alright. I wish him well.

boostedjd

All I was saying on the turbo thing was maybe that 16g was too big for a 1.6 l and that's why I wasn't getting more than 10psi yes I realize it has more cfm capability and is capable of more HP and psi but a semi turbo is capable of more HP and has more cfm but I wouldn't even be able to spool a semi turbo so I wouldn't run it that's all I was saying maybe it was too big but I'm passed that and wondering why mine only get 10 psi and since it seems like everyone is saying its my map sensor instead of just saying I'm retarted explain to me why I'm retarted or at least point me in the right direction cuz everything I've read so far says all your map does is read how much psi your turbo is putting out it does in no way control how much psi itn is putting out so how would running a bigger map sensor automatically make my turbo be able to hit 20 psi rather than 10