Will I go lean with a 383?
Thread Starter
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Will I go lean with a 383?
Hi...
I'm thinking of rebuilding me engine to a 383 will I go lean at idle If I don't change the injectors or prom?
I have stock injectors and a TPiS level 5 prom and if I change to a 383 I will have to buy a new prom from TpiS and not upgrade the old one.......
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
I'm thinking of rebuilding me engine to a 383 will I go lean at idle If I don't change the injectors or prom?
I have stock injectors and a TPiS level 5 prom and if I change to a 383 I will have to buy a new prom from TpiS and not upgrade the old one.......
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
GTA,
Given your current list of modifications, if you are still using the 19lb/hr injectors at moderate fuel pressure, you are probably a bit lean already. I would suspect the extra stroke of the 383 would beg for more fuel at the middle RPM ranges. It would be fairly easy to justify 24 lb/hr injctors on a 383.
------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0
Given your current list of modifications, if you are still using the 19lb/hr injectors at moderate fuel pressure, you are probably a bit lean already. I would suspect the extra stroke of the 383 would beg for more fuel at the middle RPM ranges. It would be fairly easy to justify 24 lb/hr injctors on a 383.
------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0
Thread Starter
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Vader,
So you think I dont need to upgrade the prom just adjust the fuel pressure?
what if I put on a 9psi Procharger? will I have to put on bigger then 24 lb/hr injectors?
One thought that has hit me is if I stroke it to a 383 wouldnt my heads be a big restiction?
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
So you think I dont need to upgrade the prom just adjust the fuel pressure?
what if I put on a 9psi Procharger? will I have to put on bigger then 24 lb/hr injectors?
One thought that has hit me is if I stroke it to a 383 wouldnt my heads be a big restiction?
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
Thread Starter
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
Then I have major work tuning it so It wont run rich at idle and get a new prom $$$$$
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
Thread Starter
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
I just talked to a hop www.musclecars.se they have build a 383 with trickflow heads and 1.6 RR anda 9 psi ATI and they have stock prom and stock injectors!!
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
Trending Topics
Thread Starter
Supreme Member

Joined: Aug 1999
Posts: 2,441
Likes: 1
From: sweden
Car: GTA -89
Engine: Blown 415"
Transmission: 4L80E
Axle/Gears: Strange 12-bolt
I know what you mean, I talked to the guys and they have increased the pressure to about 90 psi.
For the power, they dont have any dynoresults yet.
22 lb/hr arent they 19 lb/hr stock?????
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
For the power, they dont have any dynoresults yet.
22 lb/hr arent they 19 lb/hr stock?????
------------------
GTA -89:Free flow muffler,dual 3" HF cats, Edelbrock headers, Vette heads, 1.52 RR 7/16, ZZ-9 cam, Big Mouth, AS&M LTB, ported plenum, 52 TB, MSD 6AL, TPIS level V prom, Mod .MAF, Superior shift-kit and some minor mods. and more to come!
http://www.itv.se/tacs/members_cars/m279/m279.html (Swedish Trans Am Club)
Supreme Member
Joined: Sep 1999
Posts: 1,383
Likes: 0
From: Oakville, Ct
Car: 1991Firebird T/A
Engine: 350
Transmission: Modified Viper t-56
Axle/Gears: dana 44, 3.55
in my opinion, ur looking to start an engine fire runnin 90 psi.. get larger injectors, like at least 24's..... especially if ur gonna put a ati on it... the prom costs money, but you will get better power and idle if u get the custom chip just made up.. sure as hell aint worth burnin a hole in ur pistons over it!
Steve
Steve
Thread
Thread Starter
Forum
Replies
Last Post
LT1Formula
Engine/Drivetrain/Suspension Parts for Sale
7
Oct 8, 2015 08:34 PM







