Vortec 350 in need of more HP

[DaveH350]

I have a 96 Suburban with the 350 Vortec. I am working on getting more power and MPGs out of my engine on a budget (a tight budget). So far, I have done the basic tune ups like fresh air filter and spark plugs, and install better flowing cat system.

Here is what I am looking to do:

Reprogram the computer. Either buy a chip, or have my computer sent in to have it tuned.

Install a performance intake manifold. I really dont know much about this part...

Basically I want to know what is the best way to go about upgrading my engine. Im kinda new when it comes to wrenching on engines, so any help would be good.

[todd1969]

I've bought a cold air system from these people out of Canada before on a previous 1995 GMC Sierra X-cab with the 5.7 engine. www.ramairbox.com I am seriously considering buying another for the my 2nd 1995 GMC Sierra X-cab. The kit was well made, everything there, great directions, and I was very pleased. Even shipped quickly coming form Canada.

I bought the #F14x4@110kit
Full kit including delivery is $273.45

This includes:
-Ram Air Box part # 14x4@110
-Paper Air filter part# AIS AF4
-Aluminium base pan part # 14AL/FBase
-Brushed aluminium cover # 14AL/CCover
-2x aluminium 4" flexi tubes
-4x stainless 4" hose clamps
-2x 4" intake adapters, part # 4FLC
-stud, wing nut & jam nut
-Instruction pack

Tru-duals with or without cats , I'd say 2.5" or even 3" pipes with a huge choice of loud or quiet mufflers. I suggest keeping/ upgrading your cats, seeing that 96 was the year OBD II started for our trucks, so your computer is more emissions sensitive than older OBD I models like my 1995 and further back.

I can comment very little on an intake for your 1996 sine my 1995 TBI has very few choices for a simple to bolt up aftermarket intake. I know GM Performance parts makes an intake for your year, but I am positive Edelbrock does too. With GM Performance parts, dig deep in your pockets, but it should be well made. Edelbrock is very good too, but may save you a few dollars as well.

You can always upgrade your ignition and bump up your timing a touch, even 2 degrees will help, but 4 would be more noticeable. I'd not advance it more than that.

[DaveH350]

Thanks for your info.

I looked into changing the ignition timing. However, I don't have a distributor cap because its all electronic. So I have to find a way to reprogram the ecu. Anyone recommend any particular chips or companies?

[DaveH350]

Oh, wait, I'm an idiot. I do have a distributor cap. Just the timing is controlled by the PCM...

[oldred93]

longtube headers and a good flowing exhaust system, a tune, and non-over-sized tires would be a good start on top of a tune-up like you mentioned. Don't waste your money on tb spacer or cold air intake.

[94_c/1500]

Mpg is mostly a weight and aero game. You have a Suburban, which is not very light or very aero. So, the easiest to do is cut back as much weight as possible. You can make it more aero, but there isn't much you can do easily. Use skinny tires, light rims, disc brakes all around, and what's your gear ratio? A good exhaust, long tube headers and a good muffler is a good idea. Check out spintech. And a tune is a good idea, Black Bear is pretty common.

[Big2500Red]

95 and 96 engines are completely different, and cold air intakes don't do anyting either. Full length headers with full exhaust and a custom tune, alot of people here like black bear. You can also look into porting and polishing heads/manifold.

[GarrettCobb]

CAI
Full exhaust
Tune
Thats 30-40 hp
Intake manifold is another 5-10hp

[GarrettCobb]

Or just leave it and put a 3:90 or 4.10 gears in it and itll haul ass
An your city mileage will jump up but highway will suffer with a 4.10 by about 3mpg

[94_c/1500]

CAI
Full exhaust
Tune
Thats 30-40 hp
Intake manifold is another 5-10hp

GM trucks, along with many others have have had cold air induction longer than I've been alive. Even carb trucks had it from the factory. So suggesting a CAI is absolutely pointless.
The exhaust won't do much, the factory y pipe and the muffler is a restriction, along with the manifolds. Since he's on a budget I wouldn't change the entire exhaust.

A tune is a good idea. But with the mods you listed, that's not a 40 hp gain. Maybe 20.

[oldred93]

I think it's gunna be tough to get a huge gain in hp and mpg without spending the $$$.

[GarrettCobb]

Yeah money wise its a struggle
On an ls3 a catback exhaust and a CAI its a 30 hp gain
So headers, manifold, exhaust and a tune on a sb350 should pick up around 30-40
Alone, your right, a cold air doesnt do much but a CAI, manifold, and exhaust all work together to make it breathe better, and then a tune will top it off
But like i said, the best way to notice a difference in get up would be to change the gears bud.

[GarrettCobb]

These are conservative
CAI- 6-8hp
Full Exhaust- 12-16hp
Manifold- 8-10hp
And a tune by itself would only be maybe 10hp but with all of this contributing to getting the air in, and out as quick and efficiently as possible the tune will probabley be somewhere around 15hp
All of the numbers i listed were listed in a catalog boasting about 5 hp more on all of the parts, so really the numbers id listed are quite conservative
But if your goal is to save money then i dont suggest any of this haha

[94_c/1500]

Aftermarket CAI- 1-3 hp if you're lucky.
Full exhaust - maybe 8 hp. Really just changing the y pipe and maybe the muffler will do just as good
I'm not even sure what you're calling a manifold. Intake?
Headers will be good, long tubes. Probably 5-10 hp
Tune, who knows. But it'll help in pretty much every aspect. So that should for sure be on your list of parts.

What the tires and gear ratio?

[GarrettCobb]

Yes intake manifold
And when i say full exhaust i meant headers
Aftermaket intakes are dyno proven more than that on smaller engines
Change the final drive ratio