3rd Generation Specific Talk about 3rd gen RX-7's here.

How Much Boost Is Bad?

Thread Tools
 
Search this Thread
 
Old 05-03-2003, 10:59 PM
  #21  
Senior Member
 
93 R1's Avatar
 
Join Date: Sep 2002
Location: Maryland
Posts: 3,867
Default

Well I gotta talk to Vosko about this one. Just be warned you are probably gonna get banned by tomorrow sometime
93 R1 is offline  
Old 05-03-2003, 11:00 PM
  #22  
Senior Member
 
FikseRxSeven's Avatar
 
Join Date: Jan 2003
Location: union, new jersey
Posts: 8,079
Default

you know........... i've always wondered that......... 10psi + 10psi = 20psi right
FikseRxSeven is offline  
Old 05-03-2003, 11:02 PM
  #23  
Senior Member
 
9BASE3's Avatar
 
Join Date: Feb 2002
Location: Frederick MD
Posts: 6,331
Default

Originally Posted by cmartinp28' date='May 3 2003, 10:00 PM
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!



9BASE3 is offline  
Old 05-03-2003, 11:03 PM
  #24  
Senior Member
 
9BASE3's Avatar
 
Join Date: Feb 2002
Location: Frederick MD
Posts: 6,331
Default

Originally Posted by 93 R1' date='May 3 2003, 09:59 PM
Well I gotta talk to Vosko about this one. Just be warned you are probably gonna get banned by tomorrow sometime
LOL...



SHIELDS ON!
9BASE3 is offline  
Old 05-03-2003, 11:13 PM
  #25  
Senior Member
 
93 R1's Avatar
 
Join Date: Sep 2002
Location: Maryland
Posts: 3,867
Default

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.
93 R1 is offline  
Old 05-03-2003, 11:32 PM
  #26  
Senior Member
 
FikseRxSeven's Avatar
 
Join Date: Jan 2003
Location: union, new jersey
Posts: 8,079
Default

so they're not high rev loving like hondas at a stop light?
FikseRxSeven is offline  
Old 05-04-2003, 02:05 AM
  #27  
Senior Member
 
RX73rdgen's Avatar
 
Join Date: Dec 2002
Location: San Diego, CA
Posts: 205
Default

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.
RX73rdgen is offline  
Old 05-04-2003, 11:38 AM
  #28  
Senior Member
 
93 R1's Avatar
 
Join Date: Sep 2002
Location: Maryland
Posts: 3,867
Default

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?
93 R1 is offline  
Old 05-04-2003, 01:21 PM
  #29  
Senior Member
Thread Starter
 
jackdhammer's Avatar
 
Join Date: Jan 2003
Location: Oxnard, CA.
Posts: 283
Default

Originally Posted by rx7machine' date='May 3 2003, 12:25 AM
Humm.. 12psi.. so, is there any point to run a single turbo if you're going to stay at 12psi or under? (sorry that was off-subject)
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
jackdhammer is offline  
Old 05-04-2003, 02:12 PM
  #30  
Junior Member
 
NoCal's Avatar
 
Join Date: Apr 2003
Posts: 11
Default

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?
NoCal is offline  


Quick Reply: How Much Boost Is Bad?



All times are GMT -5. The time now is 02:44 PM.