What LSX to get 78 or 90?
Thread Starter
TECH Fanatic
iTrader: (2)
Joined: Dec 2002
Posts: 1,107
Likes: 0
From: Orange county n.y.
What LSX to get 78 or 90? just wondering what you think. Not sure if i should go with a 78mm or 90mm. Mods are in my sig and i will be going with a set of AFR or ls6 ported stage 2 heads. Staying with stock cubes but if i ever have problems the biggest i would probably go is 383 or so. Thanks for any help!
TECH Enthusiast
Joined: Aug 2002
Posts: 521
Likes: 0
From: Los Angeles
Most people say that the 78mm is for stock cubes. One thing to take into consideration is that if you do get the 90mm intake you will also need another throttle body, MAF, and Lid to match the intake.
Originally Posted by SSDude
Most people say that the 78mm is for stock cubes. One thing to take into consideration is that if you do get the 90mm intake you will also need another throttle body, MAF, and Lid to match the intake.
TECH Fanatic
Joined: Dec 2001
Posts: 1,060
Likes: 0
From: MI
Jay at Absolute Speed did a flow check on the 90mm and said the flow was great ( he wrote a post on it) and when I talked to him about it he said it would be a great set up with my stage 2 heads and cam so I went with the 90mm intake.
Thread Starter
TECH Fanatic
iTrader: (2)
Joined: Dec 2002
Posts: 1,107
Likes: 0
From: Orange county n.y.
do you think there will be a power differance with a stock cube motor between the 2 manifolds and has anyone dyno'ed the 78 & 90 back to back on a 346 H/C car?
According to my book, the air velocity at WOT should be less than 300 ft/sec, which is for example 800cfm through a 3.5in/88mm body (includes shaft Dia. and turbulence). about 700BHP (I'm guessing)
An oversized throttle body will compromise slow speed driving, it will have difficulty metering low flows.
An oversized throttle body will compromise slow speed driving, it will have difficulty metering low flows.
