Performance Upgrade Suggestions

[z71rhino]

Hey everyone, i own a 90 Sierra 1500 4wd. Ive lifted it 6 inches on 35 mud terrains, took out the bench seat and installed 2 buckets and a custom speaker box in between them with 2 alpine 3ways and a 12in kicker sub. Tool box in the bed as well. I did the cosmetic stuff i wanted to do so now i want to do some performance upgrades.

This is the first truck I have owned that isnt carberated. I didnt know what a throttle body was until I bought this thing. So anyways if any of you out there have any suggestions or advice I would love to hear it. I have 3 things lined up that I would like to do and if you can add to the list or give me some tips on what ive posted then I will be thankfull.

1. Replace throttle body with Holley GM performance throttle body 2bbl 670cfm, should give me around 20 more hp's and better mpg's

2. Install throttle body spacer, adds a little hp and mpg

3. Either split dual exhaust or true dual exhaust, again minor gain in hp and mpg (if i dont go to big on the tubing. Im thinking 2.5 main and 3" out)

4. Cold air intake, dont know wether to go with the disc shape or the cone

5. Possibly headers with the new exhaust

So thats what I was thinking. At the moment I dont have the time or money to do any major engine overhauling. So im looking at both cheaper and less wrench intensive ways to gain some power and precious fuel economy.

 

[Molson02536]

Hey everyone, i own a 90 Sierra 1500 4wd. Ive lifted it 6 inches on 35 mud terrains, took out the bench seat and installed 2 buckets and a custom speaker box in between them with 2 alpine 3ways and a 12in kicker sub. Tool box in the bed as well. I did the cosmetic stuff i wanted to do so now i want to do some performance upgrades.

This is the first truck I have owned that isnt carberated. I didnt know what a throttle body was until I bought this thing. So anyways if any of you out there have any suggestions or advice I would love to hear it. I have 3 things lined up that I would like to do and if you can add to the list or give me some tips on what ive posted then I will be thankfull.

1. Replace throttle body with Holley GM performance throttle body 2bbl 670cfm, should give me around 20 more hp's and better mpg's

2. Install throttle body spacer, adds a little hp and mpg

3. Either split dual exhaust or true dual exhaust, again minor gain in hp and mpg (if i dont go to big on the tubing. Im thinking 2.5 main and 3" out)

4. Cold air intake, dont know wether to go with the disc shape or the cone

5. Possibly headers with the new exhaust

So thats what I was thinking. At the moment I dont have the time or money to do any major engine overhauling. So im looking at both cheaper and less wrench intensive ways to gain some power and precious fuel economy.

Here is a link for your throttle body upgrades that should help you tune your TBI. http://www.cfm-tech.com/

As for your exhaust, stay a single and no larger then 3 inches. Your stack cam is not big enough to handle a larger lower restrictive exhaust and you will loose most of your lower end torque and HP.

Cold air intake is one of the most restrictive area's for your air flow. You can replace your stock air filter with a K&N or buy the cold air intake, doesn't really matter which type you buy. As long as your air intake is not coming from inside your engine compartment pulling in the hot air form the engine.

Would not replace the exhaust manifold unless your also replace the cam, the headers will help your stock cam to breather better but for the cost and time to replace it. It's just a wast of money if your looking for performance gain.

Long story short to gain more performance.

1 Start with the fuel pressure to ensure that your TBI is running at 13 PSI
1.a Add a throttle body spacer
1.b Replace your PCM chip with one that is tuned for better performance
1.c Replace the throttle body with a ported TBI

2. Replace the Catalytic converter with a high flow Cat and run a single exhaust no larger then 3 inches. Going from a single exhaust from the cats to a split exhaust is just a waist of money and time with more things to repair and replace after time.

Running true duel exhaust your going to have to run two Catalytic converters and run an extra O2 sensor of after the cats to keep them monitored which is optional if you want both cat's monitored.

3. Cold air, self explanatory.

4. Headers when you replace the cam, you can replace the stock exhaust manifold but will not notice performance gain other then a different exhaust tone.

5 Next thing for improvement would be to replace servos for better shift firmness and boost valve. The servo's can be replaced with out dropping the transmission pan and takes about 30 min to replace if your good with tools. The boost valve best will be 0.500" and don't forget to replace the TV elevated pressure spring since your transmission is open also.

Good luck and hope this helps.

 

[z71rhino]

Wow

Holy crapples Molson thank you so much. Thats one awsome morsel of information. Also thanks for going into detail and explaining why certain things are a bad idea and what effect they can have. That was rather quick too. Anyways thanks bro, i really appreciate your time and expertise. This should be a fun project