I was thinking about something that booger mentioned in this thread about the boost pressure difference before and after the Intercooler when his gauge was incorrectly installed. What would a good pressure drop across an Intercooler be? He mention that the pressure at the SC outlet was 11 PSI but the normal Vortech boost is 8 PSI measured after the IC. A 3 PSI drop seems like the IC itself is a major air restriction or is this a function of the temp drop? Would there be any benefit in a better IC with a lower pressure drop?

 

lower air temp should yeild subsequent denser air (ie more power)???


i have heard of boost creep resulting from a larger intercooler, but it's not a big amount at all...

boost creep... there's a topic us s/c guys havent discussed much (as well as wastegating!!)

perhaps all three of these are related?? why no wastegates for blowers, and run smaller pulleys anyway??? hmmmmmm....

hey teh... did your 312 yeild 9 pounds??? i verified mine several times this weekend, and managed 9lbs in 2nd and 3rd gear each time (first is over too violently to see, and 4th is gonna land me in the grayvbar motel, so i only tried the 2 and 3 gear)


-eS

 

Boost creep and wastegates are in the turbo domain so they wouldn't be applicable to a SC. Es..I am still at 8 PSI.

 

I would think that if you ran an IC with less restriction ...it may not have as good cooling effect . If my blower is weak as I suspect it is .You may have more lb's on the blower side of the IC than I have

 

All intercoolers have a pressure drop. The smaller the IC, the smaller the drop. Some factory FI cars that didn't run much boost didn't include ICs because they would loose so much of what the turbo just made. The 80s 300ZX turbos did not have ICs because they only made 5 psi and losing 2 of that would be a waste because the intercooler wouldn't make enough positive effect. Less pressure drop makes more power. However, a larger IC (usually with more PD) has more heat capacity. That leads to the air charge staying cooler under harder driving conditions. Realistically, the FI systems of the Z could use much smaller (not as pretty) FMICs. However, the systems would start to be heat-soaked just by sitting in traffic or full throttle runs.

 

THanks for the reply....


but why doesnt the same apply (the s/c is similar to the Turbo, but driven by an external belt rather than exhaust gasses)..

can you explain why to me??

((still green here))

-eS

 

The exhaust flow through the turbine wheel of the turbo is regulated by the opening of the wastegate. The wastegate opens at a certain boost level and lets exhaust gas bypass the turbine without providing force on it. This would be analogous to the supercharger changing pulley sizes or belt force on the fly (which can't happen with the vortech or ATI). This is one of the drawbacks to centrifugal superchargers.

 

10-4

but, maybe, we could wastegate downstream of the impeller/compressor (prior to the MAS)

??

-eS

 

ummm... I don't think you understand what a wastegate does. A wastegaste would be totally useless in a SC application.