305 buildup for a daily driver
#1
Member
Thread Starter
Join Date: Jun 2003
Location: South Jersey
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
Car: '86 IROC-Z
Engine: LG4 305-4BBL
Transmission: T5
305 buildup for a daily driver
I've searched and read many posts about building up a 305 LG4 4bbl with the "peanut" cam. Most are for racing or getting as much power as possible without regards to economy.
What kinds of changes to you recommend to gain some more power / economy for a car I will just use as a daily driver on nice days with the T-Tops in the trunk. The car is an 86 with 39k original miles. I don't think there has been any mods. All parts including exhaust look stock.
So far I'm planning on upgrading to the dual-snorkel air cleaner with possibly a catback system as the exhaust pipe is starting to leak. I have already changed belts / hoses, and cleaned the carb. the plugs / wires were changed 5000 miles ago. Do things like intake, headers, and cam really make a difference for a daily driver that will never see a track? I read of 350's getting in the 20's for MPG. i'm getting 17/18 MPG.
Anything else you can think of? Since this is a daily driver should I just give it a good tune up and leave it alone?
What kinds of changes to you recommend to gain some more power / economy for a car I will just use as a daily driver on nice days with the T-Tops in the trunk. The car is an 86 with 39k original miles. I don't think there has been any mods. All parts including exhaust look stock.
So far I'm planning on upgrading to the dual-snorkel air cleaner with possibly a catback system as the exhaust pipe is starting to leak. I have already changed belts / hoses, and cleaned the carb. the plugs / wires were changed 5000 miles ago. Do things like intake, headers, and cam really make a difference for a daily driver that will never see a track? I read of 350's getting in the 20's for MPG. i'm getting 17/18 MPG.
Anything else you can think of? Since this is a daily driver should I just give it a good tune up and leave it alone?
#3
Supreme Member
Join Date: Jul 1999
Location: out of my mind; be back in 5 minutes....
Posts: 1,593
Likes: 0
Received 3 Likes
on
2 Posts
Car: 1989 Firebird Formula
Engine: Internal Combustion
Transmission: Completed
Axle/Gears: ones that turn.
If you're just looking for a little more 'oomph' when you hit the pedal, I'd recommend a set of headers, y-pipe and a good catback. This will help to get the air out of your LG4, as the stock manifolds and exhaust are very restrictive on this engine. Get a cat-back intended for a 305/350 TPI car, not an LG4. Same for headers.
Your stock intake and carb are plenty sufficient - no need to change those. You may need to tune in the secondary metering rods to keep up with the additional airflow. The dual-snorkel aircleaner is a good step. If you have a mechanical cooling fan, swap it out for an electric one.
If you are really ambitious, maybe swap in a bit larger cam, something with maybe a .420/.442 inch lift (intake/exhaust).
Your stock intake and carb are plenty sufficient - no need to change those. You may need to tune in the secondary metering rods to keep up with the additional airflow. The dual-snorkel aircleaner is a good step. If you have a mechanical cooling fan, swap it out for an electric one.
If you are really ambitious, maybe swap in a bit larger cam, something with maybe a .420/.442 inch lift (intake/exhaust).
#4
TGO Supporter
Join Date: Jul 2003
Location: Grand Rapids, MI
Posts: 4,803
Likes: 0
Received 0 Likes
on
0 Posts
Car: Z28
Engine: Sb2.2 406
Transmission: Jerico 4 speed
Axle/Gears: Ford 9" 3.60
I have the Xe256 in my LG4, granted its a Caprice, but still. It's a good cam. Fits under factory specs. Good idle, plenty of vacuum.
#5
Moderator
iTrader: (14)
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 36 Likes
on
34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Not only do you have to let the gases out, you have to let them in.
Do the exhaust as recommended above, but the dual snorkel is also essential.
Cam - Optional, but the XE and Compucam grinds are highly superior to the factory's peanut cam. Mine still idles at 500 RPMs in drive.
Do the exhaust as recommended above, but the dual snorkel is also essential.
Cam - Optional, but the XE and Compucam grinds are highly superior to the factory's peanut cam. Mine still idles at 500 RPMs in drive.
#6
Member
Thread Starter
Join Date: Jun 2003
Location: South Jersey
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
Car: '86 IROC-Z
Engine: LG4 305-4BBL
Transmission: T5
Thanks for the advice. I briefly looked online at summit and jegs. Not that I have the cash right now, but what brands / models do you guys recommend for a header-back and cat-back? If I am eventually going to replace the entire exhaust should I do it all at once or do you think I do a cat-back first than header and cat?
#7
TGO Supporter
Join Date: Jul 2003
Location: Grand Rapids, MI
Posts: 4,803
Likes: 0
Received 0 Likes
on
0 Posts
Car: Z28
Engine: Sb2.2 406
Transmission: Jerico 4 speed
Axle/Gears: Ford 9" 3.60
Do it all at once and all for a 305/350 TPI car, that way you get a larger Y-pipe (when it comes to that part). Do you have emissions? That determines header and cat choice.
Hooker makes a great cat back setup. So does Spintech, although, Spintech is a bit more pricey. It's about $120 for their Split Case direct replacement piece i beleive.
Hooker makes a great cat back setup. So does Spintech, although, Spintech is a bit more pricey. It's about $120 for their Split Case direct replacement piece i beleive.
Trending Topics
#8
Supreme Member
Join Date: Jan 2002
Location: Valley of the Sun
Posts: 3,852
Likes: 0
Received 0 Likes
on
0 Posts
Car: 82 Z28
Engine: Al LT1 headed LG4 305
Transmission: TH350
Axle/Gears: 3.73 posi with spacer
Hedman Shortie headers and y-pipe $200 for the set.
They aren't the best but they are cheap.
They aren't the best but they are cheap.
#9
Member
Join Date: Apr 2004
Location: Upsate NY
Posts: 199
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Z28 camaro HO Gun metal Gray
Engine: 305,L69 H.O. rebuilt
Transmission: 700R4
where?
Me Leigh, where can u get those headersand Y for that price and do they come with A.I.R.
Thread
Thread Starter
Forum
Replies
Last Post
colton_carlson
Firebirds for Sale
7
03-08-2019 12:21 PM