chevy inline 250 -T3 - CARB QUESTION ????
#1
chevy inline 250 -T3 - CARB QUESTION ????
Hello
I am in the process of building my first boosted engine. I have a good inline 250 chevy. I modded a Holley 2300 350cfm 2 bbl with .078 drilled pvcr's , jetted to 70 and running a 6.5PV, .110 needle / seat and completed all of the necessary Hanger18 mods. Also a modded Holley FPR for 1:1 referenced boost.
I will be running a GN T3 turbo from the original manifold and boosting through a carb hat.
***My question?? When boosting a modded carb, is it a two step process of tuning it right with out the turbo boost and then again when I have boost to the carb? It seems that when forced air is applied ( boost ) the adjustments will change when compared to a normally aspirated carb setup.
Also, do all of my vacuum ports need to be closed? two on carb and one on intake manifold?
Thanks, the board has been a huge help already
Shad in Nashville
I am in the process of building my first boosted engine. I have a good inline 250 chevy. I modded a Holley 2300 350cfm 2 bbl with .078 drilled pvcr's , jetted to 70 and running a 6.5PV, .110 needle / seat and completed all of the necessary Hanger18 mods. Also a modded Holley FPR for 1:1 referenced boost.
I will be running a GN T3 turbo from the original manifold and boosting through a carb hat.
***My question?? When boosting a modded carb, is it a two step process of tuning it right with out the turbo boost and then again when I have boost to the carb? It seems that when forced air is applied ( boost ) the adjustments will change when compared to a normally aspirated carb setup.
Also, do all of my vacuum ports need to be closed? two on carb and one on intake manifold?
Thanks, the board has been a huge help already
Shad in Nashville
#2
Doesn't look like anyone else is going to answer and I'm a newbie here.
But here's my answers.
Tune as you increase the boost. Start off low and slowly work your way up. Using a wideband.
Vacuum ports need to be plugged on your carb.
How are you running your PCV valve? You may want to run it to your intake with a check valve.
Post some pics please.
Lee
But here's my answers.
Tune as you increase the boost. Start off low and slowly work your way up. Using a wideband.
Vacuum ports need to be plugged on your carb.
How are you running your PCV valve? You may want to run it to your intake with a check valve.
Post some pics please.
Lee
Last edited by a1953mdl; 04-04-2010 at 10:33 PM.
Thread
Thread Starter
Forum
Replies
Last Post
boucher racing
Forced Induction
1
03-03-2010 03:49 PM
Wank.a.lot
General Discussion
13
10-24-2008 11:45 AM