PDA

View Full Version : carb /single plane vs stock TB and intake



zooguy
12-09-2016, 02:01 PM
so i have converted my 350 lt1 to a SBC intake and holley 650 double pumper with a weiand team g intake

i was wondering ... with that alone ... when it comes to flow i am sure it will do better but i am not sure how much... i am also a nitrous guy and the car will be on a bigger shot. i know form experience that the stock intake will start to pool the nitrous at about a 225ish shot ... i am going to be spraying more than that i hope ... but i was wondering if the restriction was in the intake or the heads intake port size.

maybe NightTrain66 could shed some light on this

NightTrain66
12-12-2016, 08:04 AM
I think the biggest problem with the LT1 intake and wet shot of nitrous is that the inlet is in the front and then you have runners entering the plenum from the front to the rear so the cylinder to cylinder distribution can be the problem.

If you check the plugs on some N/A set ups, they will steadily burn lean/rich from front/back.

Adding the nitrous makes this worse and less forgiving so in order to keep a few cylindrs from getting lean, you have to run enough fuel ending up making some others rich.

Obviously a fogger will get the right amount of nitrous and fuel in each cylinder but if the intake design already has some cylinders burning leaner than others when N/A, they will be lean on the nitrous also unless you take the time to fine tune and adjust the nitrous fuel jets for each cylinder to get them all burbing the same.,

The single plane gets the inlet in the center and has a better chance at getting all cylinders the same ratio of nitrous and fuel on a plate/wet system.

Lloyd

agenthol302
12-12-2016, 10:04 AM
iv always heard the issue was in the intake, I currently have AFR Heads and TPiS Mini ram, I run a 250 with no issues

zooguy
12-12-2016, 05:48 PM
I think the biggest problem with the LT1 intake and wet shot of nitrous is that the inlet is in the front and then you have runners entering the plenum from the front to the rear so the cylinder to cylinder distribution can be the problem.

If you check the plugs on some N/A set ups, they will steadily burn lean/rich from front/back.

Adding the nitrous makes this worse and less forgiving so in order to keep a few cylindrs from getting lean, you have to run enough fuel ending up making some others rich.

Obviously a fogger will get the right amount of nitrous and fuel in each cylinder but if the intake design already has some cylinders burning leaner than others when N/A, they will be lean on the nitrous also unless you take the time to fine tune and adjust the nitrous fuel jets for each cylinder to get them all burbing the same.,

The single plane gets the inlet in the center and has a better chance at getting all cylinders the same ratio of nitrous and fuel on a plate/wet system.

Lloyd

is this something you take into account when your porting heads? like putting bigger ports in the rear of the heads.

also ... how much nitrous do you feel the stock size ports are able to take in?

... i have my rings gapped at .033 top ring and .035 second ring. so i should be good to spray to about a 300 shot without any fear of rings butting up and lifting a ring land like my stock rings did

firebird_1995
12-12-2016, 07:39 PM
... i have my rings gapped at .033 top ring and .035 second ring.

Good God Gerti what a gash. Why so much gap?

Sent from my SM-G900V using Tapatalk

zooguy
12-12-2016, 08:46 PM
Good God Gerti what a gash. Why so much gap?

Sent from my SM-G900V using Tapatalk

File fit high performance application:
Formula: bore x ring end gap factor = minimum ring end gap.

FUEL APPLICATION RING END GAP FACTOR:

Street Normally Aspirated .0065"
---------------------------------
Drag Fuel and Alcohol .0075"
---------------------------------
Street Nitrous, Supercharged .0080"
Street Towing; Circle Track .0080"
Unrestricted & Alcohol; Marine .0080"


just wanted to be on the safe side ... pistons are the weak point and probe said they are good to a 250shot ... so ill prolly wind up close to a 300 shot cause i am sure there is some wiggle room there ... and if they let go then its 355 time and heavy nitrous pistons and prolly more juice