Whats the most boost you can get from stock turbo?

subarufan · Post by **subarufan** » Tue Apr 01, 2003 12:10 am

I was wondering, how much boost can you get from the stock turbo? Also, at what point does an intercooler become nessesary? How do you go about increasing your boost? Thanks.

kelley · Post by **kelley** » Tue Apr 01, 2003 1:03 am

I ran 15 psi with my stock vf 10 and no intercooler. but with stand alone engine management.
you increase boost with some type of a boost controller.
but be careful that is how people blow up there engine's.

IggDawg · Post by **IggDawg** » Tue Apr 01, 2003 4:35 pm

I think the general consensus is that around 10-11 lbs is about all your should run without an intercooler. wiht stock engine management, I've had it up to 12, but only when it's bitter cold outside so the intake charge is still nice n chilly.

ciper · Post by **ciper** » Tue Apr 01, 2003 10:29 pm

I think 10 is high even with an intercooler. The amount of air needed to flow at that pressure is well above the turbos efficiency range. All you are doing is adding tons of heat.

subarufan · Post by **subarufan** » Tue Apr 01, 2003 11:05 pm

what type of boost do they run stock?

Jarvis · Post by **Jarvis** » Tue Apr 01, 2003 11:26 pm

8.7 lbs/sq inch IIRC.

Jim

LegacyT · Post by **LegacyT** » Tue Apr 01, 2003 11:31 pm

Whoa, people seem to be very conservative in this thread

These cars run 8.7 pounds stock. So practically 9 psi from the factory without an intercooler. When you add an intercooler 14-15 psi is fine (with a FCD). After that your just adding heat.

Mind you Nico Turbine is/was?? running 20 psi, WITH a massive truck Front mount intercooler in his Legacy. Last thing I heard his stock turbo (RHB5) hadn't let him down yet, but that was a while back

Mark,

ciper · Post by **ciper** » Tue Apr 01, 2003 11:40 pm

Anybody have the graph for the turbo showing its operating ranges? I always thought it was near the limit to begin with.

LegacyT · Post by **LegacyT** » Tue Apr 01, 2003 11:56 pm

The RHB5 is practically identical to a WRX TD04 which runs stock at 14.5 psi and is good till about 16 psi. The reason the Legacy turbo only runs 9 pounds is because SOA/SOC didn't bother adding an intercooler.

Mark,

boostjunkie · Post by **boostjunkie** » Wed Apr 02, 2003 2:21 pm

Mind you, 15psi on a 2L motor is different than a 2.2L motor. I'm not sure if these calculations are exact, but considering a 2.2L motor is 10% larger in volume that you'd have to fill than a 2L motor your expected max psi accomplished by a turbo is roughly 10%. that puts a turbo at around 13.5psi efficiency. Sure, the turbo can push this much air, but again, the wrx is intercooled.

I remember reading about that guy running 20psi non-intercooled. His engine let go about a month or so later. Melted a piston. I remember the pictures.

IggDawg · Post by **IggDawg** » Wed Apr 02, 2003 4:46 pm

I remember that guy. his boost controller would spike to 20 PSI a little too frequently. one time he got a really hard detonation and blew a hole right through the block. you could see into the crankcase from teh outside. very ugly.

entirelyturbo · Post by **entirelyturbo** » Wed Apr 02, 2003 7:46 pm

Not that I know a whole bunch about turbos and stuff, but would the longevity of the engine be compromised by upping boost even a little bit?

Igg, you use of the word "teh" was very funny considering the goings-on on NASIOC yesterday

morgie · Post by **morgie** » Thu Apr 03, 2003 2:56 am

"teh" 20psi pike hole :

Post by **Legacy777** » Thu Apr 03, 2003 2:57 am

wonder if the knock sensor picked that one up.....hahaha

IggDawg · Post by **IggDawg** » Thu Apr 03, 2003 3:19 am

subyluvr2212 wrote: Igg, you use of the word "teh" was very funny considering the goings-on on NASIOC yesterday

Yeah, nick was having a little fun with everyone for april fool's day

. last time he did something like that was when I convinced him to swap the word "wrx" with the word "n00b" to spite all those with WRX in their username

. got interesting. but theat one only lasted 10 minutes.

yeah. teh 20 PSI spike was a bad thing. I think with intercooling and proper management, 20 P{SI would be easily feasible. "teh junkie" isn't too far away from that now.

boostjunkie · Post by **boostjunkie** » Thu Apr 03, 2003 6:15 pm

Hehe. Yeah, I'm close . . . but I won't go anywhere near 20psi sustained without some injectors.

The closest I've gone (for about a 10 second run), was 18psi. Injectors were maxed and A/F was still showing rich, although closer to stoich, and it was about 10degrees outside. Needless to say, I lowered my boost controller after that . . .

Kelly should probably be able to make more than 20psi with his Autronic ecu and 800cc injectors that he should be getting soon, if he hasn't already gotten them.

-the junkie

rsstiboy · Post by **rsstiboy** » Sun Apr 20, 2003 4:01 am

i ran 20psi in mine for a few short bursts and it only began to lean out past 18psi. tons of fun too! but then again i run 16-17psi all day every day and no problems here. hey boostjunkie I visited your site and noticed you opted for a top mount cooler, why? with the standard bonnet vent you get no where near enough airflow to even make a top mounted air/air cooler work efficiently you would have been far better off going for a genuine water air cooler.

boostjunkie · Post by **boostjunkie** » Mon Apr 21, 2003 1:58 pm

Heh, it came with the car. I could go with a front mount or an a/w intercooler, but for now, the a/a top mount is sufficient for my needs. I'll use that money for injectors instead;)

-K- · Post by **-K-** » Sat Apr 26, 2003 1:39 am

As you can see the IC is not that important to this engine. It runs well with no IC stock. I just wish I could adjust the timing to get more out of my IC. It must pull a lot of timing to run 12 psi with no IC.

NICO · Post by **NICO** » Sat May 10, 2003 2:14 am

LEGACY T whats up
I LOVE IT LEGACY LOVERS F&%K THOSE WRX STI JUNK. WE GOT THE BEST TURBO MOTOR & NO RISTRICTIONS & SLEEPER STYLES HAHAHA.

By the way my car is still alive & yes u can get that baby turbo up two 24half psi but i run 20psi cuz i ant crazy. on the other hand the weak link in this car is the tranny. how many times has my dad rebuild mine - this will be my fitfh time. i owned it five years and every year four or five years i blow a gear.

if u guys out a down pipe the good ones thats all u need mad HP out of that. our up pipes R the best in the world we dont got a cat in the pipe so i wasted more money on this dame hks one, o well. but the best thing u can do to a legacy turbo is the down pipe. WOW! lets put it this way; SVT stang vs. me and two people, half a tank of 94octane. 1st same 2nd all most there 3rd BYE 4ft & then slam on the little rotors cuz u dont whant to get killed at the light cuz its red! svt guy said "what the fuck how the fuck and is there a v8 in there?!" hahahah

any ways GOOD 2 C LEGACY FANS! belive me, best motor subaru has evermade & i work at the dealer ship i drove all kinds & no wrx OR sti come close. But talons, those guys r hard i hate those cars but what can u do. i no rip ur car cut ur car & take everything out ahahahah
well i got to go BEAUTIFUL WEB PAGE
CIAO

(edited for a bit more clarity by Jason)

Post by **Legacy777** » Sat May 10, 2003 4:42 pm

Nico,

watch the language

LegacyT · Post by **LegacyT** » Sat May 10, 2003 5:40 pm

heh

NICO · Post by **NICO** » Sat May 10, 2003 8:52 pm

sorry about the language i get excited some times

Post by **Legacy777** » Sun May 11, 2003 2:21 am

no worries

know1 · Post by **know1** » Thu Feb 08, 2007 12:33 pm

Diving in the archives of legacy central I bumped into this. Man nico is a funny guy, but he says a lot in his crazy rantings. For instance, I had no idea we didn't have cats in our uppipes, I thought all turbos did

that makes me happy

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

Whats the most boost you can get from stock turbo?

Whats the most boost you can get from stock turbo?