I was curious about if anyone has or has considered using a carbureted Edelbrock performer RPM airgap as an EFI intake instead of a single plane for street only apps. I know the single plane conversions work well, I have one on my '94... these intakes are smaller, but for their size and streetability seem to work very well up to around 6500 compared to a single plane, enough to consider it for a street only 350 anyway.

I figured one might work well on a low/midrange street LT1 without as big of a hit on mileage and some more torque where I can use it to boot. Was thinking of using one with a 1" spacer on an elbow with a factory 58mm TB on a 350 with a GM847. Might consider comparing it to my single plane for street use. Any opinions?

 

Like alot of things before i rebuild my Engine, i am considering it. I thinking of getting the LT4 version though, and if i wish for it later, just port it out some more. Ive heard good and bad things, some of whoch say its not enough hp gains for the money spent. And some say its a good fresh start. So its probably most likely based on what type of budget you have.

 

Um, who recommended that setup to you? There are many threads in this forum about the intake and how no one has seen noticeable gains from it.

The spacer on the elbow is a waste of money. There is no factory 58mm TB. Finally, the GM847 is not a very good cam selection. It is old tech and you should be looking at something different. You'd be better off staying with your cc305 or at least get an XE236/242 if you want to rev higher.

I see you have a couple Lt1's already, so have you seen different results with those mods? Do you have hard numbers/times? With all those cars it seems like you would know more about what works and what doesn't.

 

I don't know why everyone is so quick to change the LT1 intake. A lot of engine builders have proven that with porting, the stock intake can support high horsepower numbers without negatively affecting performance.

 

I agree. Only way I would really consider getting a new intake would be if someone made a composite one like the LSx intakes.

 

imo a 847 cam is far superior to the cc306, now thats an old cam.

 

You're right. I double checked and I was mistaken. I still think the 847 is a lazy cam and you should look at something with faster, more aggressive ramp design. For a stock ci motor, check out the cc503 or the lunati voodoo cams. I've seen the xfi cams do well, but more so in larger displacement motors.

 

its not a bad cam at all. your not going to see much of an increase with a 847

 

Didn't mean to start a cam debate. Feel free to get back on topic...

 

I'm looking at doing this on my 77 Trans Am project car. I'm taking my old LE1 engine and dropping it in, but am thinking about running a carb intake and 4 hole TB on top so I can keep the shaker and a somewhat ordinary apperance. My other option is to use the std intake/TB and then do something like the SS airbox and mount the shaker to that. If a single plane matches your application, like a retrofit, I don't see anything wrong with it, but don't go reinventing the wheel when it's not needed.

 

thats ok, they are both old and outdated. i vote custom cam either way.

 

Whoops. I should have been more specific. I meant the carbureted RPM airgap. Supposedly it lends itself to good low and midrange torque and you dont loose that much up top compared to a single plane, contrary to the belief in the design. Kind of want to see if for myself. I was considering one of those with a 1" spacer (for plenum volume and to blend in a better entry angle) and comparing it to my accel proram (unported) and seeing which would be better. I was thinking it might be a good idea for a street only motor and might pull some more mpg's and torque as well on a 350 or 383.

 

Lol, well you might want to start a new thread then. They make an air gap for the LT1 now so it was a bit confusing.