bonylad78

I have and continue to read conflicting sources on whether or not you can run low boost (4-5 psi) on a standard carb.

Ive heard:

"Yes you can and have been for years assuming low boost"

"Yes you can but its a matter of time before the floats collapse"

"Yes you can but tunings a bitch"

"No you cant"

"Yes you can but you need to mod the carb to work"


Im really looking for a proper size turbo on a 3.8 psi wg spring. Perhaps on the small side for quick spool up. I picked up a Dynojet Wideband Commander (IIRC thats the name) to help facilitate tuning.

My setup would be:

1991 Camaro RS
EFI being removed and swapped for a 283 SBC (65 rebuilt - Powerpac heads -weiand IM, etc.....a breathed on rebuild, nothing drastic)
Stock T5
Upgraded rear diff.....BW 9 Bolt 3.27 Posi

Any help would be appreciated. Thank you.

Matt Cramer

At the very least, it's going to need tuning. My own effort at running a carbed turbo buildup didn't turn out too well, but that was partially because the carb had been modified by someone who had a milling machine but no clue about how to set up a Holley for anything (on or off boost). I decided I either needed a brand new carb or EFI, and went EFI.

bonylad78

Thank you. The carb in question is this one.

Edelbrock 1406 Edelbrock Performer Carburetors - Free Shipping on All Orders @ JEGS

I realize tuning is going to be an issue, one I look forward to tackling with a wideband and some experience in doing so.....with EFI anyhow lol.

My issue is with the amount of boost I am going to run.

procharger.com says the following

"All carburetor’s will require removal of the choke assembly and choke horn, replacement of the floats with the solid nitrophyl floats and jetted to suit your motor."

Simple enough but FWIK all their kits are like 10 psi or more?

A 3.8 spring spiking to what 4 or so psi? No problem?

Matt Cramer

You'd have to ask Edelbrock what the floats are made of. Some carbs already come with solid floats. And some hollow floats could take 4 psi without collapsing.

And I'd dispute whether removing the choke is always necessary, particularly if the carb is in a box instead of using a hat type adapter.

guhman2002

I ran max 3psi (turbo) to a Mopar 360 small block for a year or so.. 650cfm square holley... All i did was put solid floats in it after some time (ran factory floats for a month with no issues though)... between 1.5 and 2 psi of boost was a VERY impressive and VERY noticable difference.

If you stay with a 4bbl and HEI you will no issues tuning either (carbs are ear and nose friendly, no laptop needed). I had the old school mopar ignition with the brain box and the ballast resistor and the empty distributor... I switched to a DAVIS UNIFIED IGNITION which is virtually a GM HEI set-up for a mopar

busa4

since your original engine was fi your better off just picking up a used tpi unit. boosting a carbd vehicle is such a pain in the ***....