Well I gotta talk to Vosko about this one. Just be warned you are probably gonna get banned by tomorrow sometime

 

you know........... i've always wondered that......... 10psi + 10psi = 20psi right

 

Yeah... But when they transition... they make 10 together.... I just can't figure out how if the primary can do 10 on it's own... why combined they can't do 20.



I do understand the manifold won't flow that, and that's HELLA heat... I just wanna know why 15 seems to fry turbos... Dosen't seem logical!

 

LOL...



SHIELDS ON!

 

I think that basically the primary turbo has a different trim wheel or different A/R then the secondary. Thats why the primary can do 10 psi. When you crank up the boost it does combine it proportionally between the primary and secondary. I have no idea though I'm just guessing about that.



The major killer is the heat and the RPM. They don't like 100,000+ rpm for extended periods.

 

so they're not high rev loving like hondas at a stop light?

 

I have a lot of experience in turbocharged cars. I'm fairly new to the rotary scene but the basic principals are the same. It is true that the exact same engine can make more or less power on the same 12psi of boost from different turbos. Like someone already said all turbos have a flow rate they are most efficient at and will make the biggest power gain in these areas. A small turbo straining to make 12psi will rob more power from an engine because it blocks exhaust flow and has to be spun super fast which takes energy. Of course the smaller turbo will spool faster.

 

How come Vosko made 459 RWHP at 15 psi? Can one of you show me a 459 RWHP dyno at ANY boost level for stock twins?

 

I hate to go against my own signature so I won't reply to any arguments with this statement. It all goes back to high school science. Having dropped out of 5th grade to pursue my career as a pimp(which still hasn't quite got going yet) I borrowed one of my friends books to get this logic. If a turbo is more efficent it can pack more oxygen molecules into 12psi of air than one that isn't. If this weren't true than there would be virtually no market for turbos and no need for intercoolers. After all 12 psi is 12 psi right? Who cares if its super heated super expanded air or nice cool dense air. Wrong. The cooler and more dense the compressed air is the more oxygen rich, the more hp you get. That after all is the point of a turbo in the first place isn't it? To shove a super compressed amount of oxygen down your cars throat to get hp from combustion. This is the logic I used when I first read about a car producing more HP on the same boost as another car with basicly the same set up minus the better turbo. Now the whole which is better at certain rpms thing is way beyond my limited knoledge of tubos and flow rates and all that happy horse ****. I don't claim to be a turbo expert but I do remember High School science. Not saying that anyone here dosen't . It's just that we can accumulate so much knoledge on a subject that we overthink it and won't let ourselves see the much simpler picture. Remember K.I.S.S. whenever possible. Thanks, and I'm spent.

P.S. If I screwed the spelling in this sorry. I live off Outlook spell check

 

Can someone give me a quick run down on how the seq turbos work? I've worked on volvos for a while, but never done any reading at all on tt cars. I always thought the first turbo ran low boost like 5lbs in the lower RPM's and then at around 3000rpms the second turbo kicked in w/ like 10-12psi and the primary one shuts off? now how wrong am i?