t25 max boost

Basic tech questions such as future setups, different turbo kits, car diagnosis, etc
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ViperGT
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t25 max boost

Post by ViperGT » Wed Feb 20, 2013 12:39 am

just wondering what kind of boost you guys are getting out of you t25's
mine is out of a dsm so slightly different, .48ar turbine housing i think or .53 w/ tubular log manifold, i see 12 psi at 3500 then a drop to about 9 psi at 6500 i also have a very small exhaust leak havent checked intake yet.
all input w/ turbine a/r is apreciated and type of manifold.
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

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Post by RosadoRacing » Wed Feb 20, 2013 6:52 am

The turbo on my sr20 broke at 15psi I do think dsm has a better t25 but I wouldn't push no more than 12

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Post by Freise » Wed Feb 20, 2013 7:16 pm

theoretically: you can run it as high as you can get it
Realistically: I think 14psi is its limit in terms of efficiency, past that you are doing nothing but pumping heat into your motor
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Post by emo_tactical9 » Wed Feb 20, 2013 7:25 pm

Freise wrote:theoretically: you can run it as high as you can get it
Realistically: I think 14psi is its limit in terms of efficiency, past that you are doing nothing but pumping heat into your motor
This. 12 to 14 is going to be max.
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Post by wannabethestig » Wed Feb 20, 2013 7:41 pm

Just me but wouldn't the dsm guys have this figured out??? Seems like most run around 15 but that turbo has problems maintaining pressure from 5500-6500 rpm... you also could use the compressor map and some math to figure out max boost while staying on the efficiency island.

For fun I did it for my t4 50 trim and it told me max is about 23psi and still have decent efficiency.
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Post by schmauster920 » Wed Feb 20, 2013 8:05 pm

I know you have an AEM EMS, do you have an intake temp sensor? This would give you a real good indication when you are hitting the end of its efficiency,

i realize you prob dont care, but running any journal bearing turbo towards the end of its efficency range will drop its life expectancy quickly.

Do it with an old out of balance turbo like mine and it will be fun for a week lol
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Post by ViperGT » Thu Feb 21, 2013 1:10 am

lol yeah it will make me fork out the dough for the gt30 or hx, and i guess im hitting max lol this sucks balls, i want more power lol, and i have an intake air temp sensor.... brand new in a box lol, i know i really need to instal it since im running map, and with all the wild weather these past few days my car had been running like crap with out it.
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

ViperGT
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Post by ViperGT » Thu Feb 21, 2013 1:11 am

and i do ussulay feel the intercooler after a hot run, the hot side is pretty warm, and the cold tank is ussualy quite cold to the touch.
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

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Post by mewantkouki » Sun Mar 03, 2013 7:57 pm

I've known a few people to run a t25 up to 17psi but it's completely inefficient and will greatly shorten the life of the turbo. I'd say 13psi is pushing the safe stock limit.

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Post by ViperGT » Mon Mar 04, 2013 12:28 am

lol well i fixed i couple pre turbo exhaust leaks and now it spools at like 2.5k, it will hit 18psi but it comes down to 12 at redline, it also leaks a little oil on the intake side lol but no shaft play or anything, i might just need to hook up water cooling lines.
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

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Post by boker240 » Tue Mar 05, 2013 2:14 pm

small turbo is gonna fall off on high boost at the top of ur rpms.they all do cuz their not made for high boost.with as built as ur motor and head are,,,,just buy a sufficient turbo to hold 20 lbs of boost.gt3076= best turbo for ka imo.
arias 8.8.1,615 tomie inj.,clevite bearings,arp 10mm hs,z32 maf,jwt ecu,intake butterflies removed,all emissions removed,cx rad. dif dual fan controller,altima dual fans,fidanza fw,stage 3 clutch,solid d shaft,j30 rearend,energy suspension bushings,kyb struts,155 lbs weight reduction.
currently n/a.
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He'll probably blow the motor, and then join the army of retards who hate on KA's for no good reason.

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Post by sdaigle240 » Tue Mar 05, 2013 2:26 pm

^yeah.... looking at a compressor map doesnt exactly tell the story, especially in this case where the exhaust housing is limiting what you can actually run.


actually peep a 3071, it spools faster than a 76 and will make just as much power at 20# on pump. i dont think either are really that much better than an hy35 though.
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Post by ViperGT » Tue Mar 05, 2013 4:14 pm

what can a gt30/71/76 do on race gas? i really want to push 25-29 psi thats why i really would like to get a gtx3076/71
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

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Post by sdaigle240 » Wed Mar 06, 2013 7:28 am

dunno but if your planning to run that much boost the 76 may be better. a 3071/6 will do low 4s on 22ish. whats importatnt is the area under the curve, that turbo will have a lot.
airman wrote:I'm all about spreadsheets. Bitches love spreadsheets.
schmauster920 wrote:I shall cast my own pistons in the sands of time, then forge them in the depths of hell.. as funds allow
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hy35 18psi Build Thread: viewtopic.php?t=38784
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Post by wannabethestig » Wed Mar 06, 2013 6:44 pm

ViperGT wrote:what can a gt30/71/76 do on race gas? i really want to push 25-29 psi thats why i really would like to get a gtx3076/71
What kind of efficiency are you getting at that kind of pressure? I am guessing that you are trying to achieve decent spool and 500-550 hp with something like that. Depending on the efficiency high pressure will drive up intake temps and you will see diminished returns the farther you move off of the efficiency island.

Did i say "efficiency" enough times?
My wife "haven't you spent enough time and money on that car yet?" my answer "no"

The build thread-> viewtopic.php?t=58421&highlight=

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Post by boker240 » Sun Mar 10, 2013 3:23 pm

ViperGT wrote:what can a gt30/71/76 do on race gas? i really want to push 25-29 psi thats why i really would like to get a gtx3076/71
either will do, and im sure ur not worried about efficiency @ 500+ whp.lol
hx or hy35 would do also.they are made to run 20-25 psi of boost normally.get a rebuilt or new one though.think a guy in kentuky or tenn rebuilds them for $300.
arias 8.8.1,615 tomie inj.,clevite bearings,arp 10mm hs,z32 maf,jwt ecu,intake butterflies removed,all emissions removed,cx rad. dif dual fan controller,altima dual fans,fidanza fw,stage 3 clutch,solid d shaft,j30 rearend,energy suspension bushings,kyb struts,155 lbs weight reduction.
currently n/a.
Image

He'll probably blow the motor, and then join the army of retards who hate on KA's for no good reason.

ViperGT
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Post by ViperGT » Wed Mar 13, 2013 12:20 am

Thanks guys and I'm not sure about the efficiency thing I'd probably go for the 30/76 since I was originally gonna go for the 35/82, I really want to get a set of stage 3 bc cams if I go with the gt35/82.
I've also been considering the hx and hy but I'd really love a nice brand new shiny GARRET on the compressor housing + ball bearing, hx and hy's aren't really made to spool they're designed to just spool once and then keep 20+psi going all the way up the hill with that fat ass toy hauler latched on, (or ka-t race car :D)
in a datsun 510:
arias 8.8 .020
eagle rods
clevite bearings
ferrea/exhaust supertech/intake stk
supertech springs and retainers
bc valve guides v2 cams currently crower 288/288 (no good)
port and polish
arp head, main, rod bolts
osk timing
current: custom log mani, TIAL mvr,
later: ati SD garret gtx3071 currently in my possession looking for gtx3576
custom downpipe
lol:
sdaigle240 wrote:beat that thing like it owes you money.

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