2876r questions
#41
Spoolup and transient reponse are two different things. The spoolup between a journal turbo and ball bearing starting at say 2000rpm ( assuming the same compressor and turbine ) will be identical. The thing about Ball bearings are in between shifts, on/off throttle at an autocross etc will be improved...thats your transient response. Say your turbo hits full boost at 3500 rpm.... one is ball bearing one is journal, if you are cruising at or above that rpm and stab the throttle the BB will respond faster. Im sure I did a terrible job of explaining it but you get the idea.
#42
Its possible that im wrong, but any dyno ive seen says otherwise. Some see a 500rpm peak boost difference. Especially on miatas. Garrett (prolly hype to sell turbos) says a possible 15% increase. I know a 2554r vs stock sr20 turbo has a really nice increase and they are dead *** the same size. And my buddy went from an sr20 turbo to a, bb 2860 i wanna say, and it also spooled slightly faster. But none of these take into account wear and tear. Bearings over time have to cause more friction and most dont test an old jb to an old bb, most are old jb and a new bb. Idk, tell me if im wrong and its all a placebo effect or something, im all ears
*edit: andy beat me to it.
#54
Well as i said my current turbo is a time bomb. Im short on cash because I pay out of pocket for tuition and bills. Its either get a reliable turbo that spools late, chance my turbo throwing blades through my motor like my mx6, or getting another cheap turbo. If a 2560 popped up for 375 id buy it, but they don't. The only other option i had was 20-25 year old sr20 '2554' turbos that are a hit and a miss on seals. It's just that this turbo will forsure last me a few months until i have some extra money. Then i can look into better turbos and selling this one. Damn part time work full time shcool drains the bank hard.
#56
Nah im done with churbos, my buddy's Integra blew his up in 3k miles, and another's galant smoked out of the box. Ill run this while i save some money, get a buyer lined up for this turbo on an sr20/volvo/Audi forum, sell it and order me a real turbo. Its just this way being a daily driver I can put miles on it, worry free miles that is.
#57
Nah im done with churbos, my buddy's Integra blew his up in 3k miles, and another's galant smoked out of the box. Ill run this while i save some money, get a buyer lined up for this turbo on an sr20/volvo/Audi forum, sell it and order me a real turbo. Its just this way being a daily driver I can put miles on it, worry free miles that is.
#60
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I used to have a Chinese 2871 Journal bearing. It didn't suck and spool did not suck. If anybody is trying to go wide open throttle below 4000 RPM they should have downshifted it anyway. I think the 76 will be fine.