98 5.7 Vortec Performance Upgrade Questions

[drummer_boy51]

I have a bone stock 98 C1500 5.7L 350 Vortec. I have modded the exhaust a little bit, though still running the stock manifolds and exhaust piping. I will also be adding a cold air intake in the next few days. What are some performance mods that will give me a good amount of torque and hp for not alot of money? Headers are probably out of the question, though shorties might be a possibility. I'm looking for a cam, maybe roller rockers, and stuff like that. I'm new to all the technical stuff like that so I have no idea what I need or what all will be involved with it. The truck is my daily driver, and sees mostly street use, and I don't really do any towing, just want more power. Any advice would be greatly appreciated! Also, please include the links to the parts ya'll list, so I know where to find them and how much they'll be.

[96ImpSS]

In order of best bang for the buck
1. Custom tune. PCMforLess has a great mail order tune for your truck, developed on the dyno with mine when it had the stock cam.
2. A tight stall 9.5" or 10" converter
3. Gears. What do you have now? If 3.42 or less, go with at least 4.10's with your tire size. If you already have 3.73's, might want to leave them.
4. Headers, preferably longtubes. Shorties still better than nothing, and you can keep your stock cats/headpipes.

Cold air intake will net you nothing over the factory intake.
A cam would be a waste without headers.
Roller rockers are not a very good bang for buck mod on this engine.

Mine dyno'd 254 rwhp and ran 14.9's in good weather with only the pcmforless tune, longtube headers, Vig 3000 converter, and single 3" exhaust.
Edit: also had a Transgo kit in it.

[culookn]

i added a cam, longtubes & catback and could defiently tell the difference in the low end

[The Fiddle]

In order of best bang for the buck
1. Custom tune. PCMforLess has a great mail order tune for your truck, developed on the dyno with mine when it had the stock cam.
2. A tight stall 9.5" or 10" converter
3. Gears. What do you have now? If 3.42 or less, go with at least 4.10's with your tire size. If you already have 3.73's, might want to leave them.
4. Headers, preferably longtubes. Shorties still better than nothing, and you can keep your stock cats/headpipes.

Cold air intake will net you nothing over the factory intake.
A cam would be a waste without headers.
Roller rockers are not a very good bang for buck mod on this engine.

Mine dyno'd 254 rwhp and ran 14.9's in good weather with only the pcmforless tune, longtube headers, Vig 3000 converter, and single 3" exhaust.
Edit: also had a Transgo kit in it.

kee kee kee









...but true. :whyme:

[Ghostyman25]

kee kee kee









...but true. :whyme:

Im gonna gues you learned this the hard way?

[The Fiddle]

Im gonna gues you learned this the hard way?

Still am. :fail:


383 + stock exhaust manifolds = WTF.

[Ghostyman25]

Still am. :fail:


383 + stock exhaust manifolds = WTF.

At least say it doesnt have stock exhaust under it!

[Koots]

A set of long tube headers would end up being cheaper than shorties and way worth it, just requires some exhaust modification, but i would get an off road y-pipe (ORY) and then you replace all the bottlenecks in the system in one shot.

[r90camarors]

I think you'll be surprised by what a tune will do for you. Off the top of my head, I removed all of the brake tq management, removed the 4 second PE enable delay, turned off abuse mode, added 3* of timing across the board, and increased the 2-3 shift a hair. Made a HUGE difference in power. Still ran it on 87 octane. I am sure there was still more to be had, but the truck was stolen when I was down in Knoxville :(
The only mod to do to your air system is to block off the silencer (basically a free mod). Other than that, it is more than efficient for the crap factory intake manifold. Leave your air intake alone, do not mess with the throttle blade or MAF sensor. When the time comes (if not already), and you need to replace the spider fuel assembly, you will understand why modding the other portions of the air intake system is pointless.

[The Fiddle]

At least say it doesnt have stock exhaust under it!

Stock manifolds, stock headpipes, stock cats....glasspacks.



I'm keeping a hell of a leash on it right now. lol

[shealyn1]

I'm keeping a hell of a leash on it right now. lol

Understatement of the year award winner right there.

[drummer_boy51]

Awesome thanks for the help guys! I see a Blackbear tune in my future lol

[96ImpSS]

I think you'll be surprised by what a tune will do for you. Off the top of my head, I removed all of the brake tq management, removed the 4 second PE enable delay, turned off abuse mode, added 3* of timing across the board, and increased the 2-3 shift a hair. Made a HUGE difference in power. Still ran it on 87 octane. I am sure there was still more to be had, but the truck was stolen when I was down in Knoxville :(
The only mod to do to your air system is to block off the silencer (basically a free mod). Other than that, it is more than efficient for the crap factory intake manifold. Leave your air intake alone, do not mess with the throttle blade or MAF sensor. When the time comes (if not already), and you need to replace the spider fuel assembly, you will understand why modding the other portions of the air intake system is pointless.
This guy gets it ;)