hello my friends , i have a custom blazer xtreme, and i am looking to add more power of what i can to my 4.3 without building a motor for power. there has to be add ons for this ? right now i have done the throttle body part of taking the cup off the butterfly, it added some. then the cold air, then the plate that goes under the throttle body. what a waste..lol i added the msd coil and 5a box. my blazer is a five speed , not sure what gear in the rear but feels like a 3.73. i was just wondering if there is a good programmer that really works ? or is there any kits to bolt on? let me know what you all have done? thanks for your time, and take a look at my xtreme and tell me what you all think?

 

First off, what part of Florida are you in? If you need a hand and happen to be near the Tampa area I'd be more than happy to help on any future projects.

Sounds like so far you have a cold air intake, throttle body spacer, and an upgraded ignition system. Removing the butterfly doesn't really add power, it frees up throttle responsiveness. Your best bet for PCM programming is going to be a mail order tune, or depending on your area, a dyno tune. I'd suggest you look into upgrading your exhaust system. Headers don't really do much for these engines and for the same price tag you can buy a cam. More involved but much more bang for the same amount of buck. Moving past headers, hi-flow cat doesn't really add power per say, but it does change the exhaust tone nicely. From my experience anyways. Modern factory cats are much less restrictive than the older ones. Lastly upgrade the exhaust pipe diameter to say 2.5" or 3" with a better muffler. Look on youtube for "4.3 (insert muffler brand here) exhaust" and just pick what you think sounds the best. Theres going to be no noticable hp gain between one brand of muffler over the other.

You could also do an under drive crank and alt pulley. Again, this doesn't add power, but it does make your engine not have to work as hard to produce power, hence why people say it frees up hp. A colder thermostat is always a good cheap investment. I have a 180* thermostat and again, its not going to add hp, but a cooler engine = a more efficient engine. Also, you could do an electric radiator fan, which will take drag off the engine in the same sense that an under drive pulley does, thus also freeing up hp.

As for the rear end gearing, look in your door jamb and there will be RPO codes. GT4 is the RPO code for 3.73. Helpful thread with RPO codes.

https://blazerforum.com/forum/2nd-ge...po-codes-1989/

 

Phil has great tips there... except:

Not really true. This has been tried and tested over and over.. yes by tuners! Actually lose horsepower and dont gain economy either.*
Colder Thermostat Increase Power - Fact Or Fiction - Import Tuner Magazine
Do not confuse operating efficiency with cooling system efficiency.. two different things.

Like the K&N getting better gas mileage this is wisdom belonging in the Carburetor era, and wasnt always true even then.

* Let's remember.. at PARTIAL throttle - meaning cruise power levels - more HP at given airflow = more fuel economy.
And your given airflow is determined by the angle of the throttle plate. Given good fuel trim and optimum timing advance - determined, BTW, by knock sensor - the less heat absorption by the chamber, the more goes to powering the wheels.

EVEN at full throttle Dyno runs with very good coolant system,.. the coolant temps tend to run at about 190-200 so where's the gain?

 

Before I put on my 180 I would see my summer temps get up to 210-220. Now my coolant gauge never goes above 200. Definitely something I need to look into more, heck there might have been another problem besides the thermostat to cause those temps. Thinking about it, the gasket was probably trashed. But I'm running at a lower temp and that makes me happy as a 12 year old in a strip club lol.

 

hello, thanks for getting back with me on this. In did forget to put in there tyhat i do have my exhaust done on my blazer, i have the flowmaster set up on it. it has dual exhaust out the back, and the cat was removed. the o2 was done like what people say to do ion this form to extend it out some to get a good reading without setting the check engine. I am in Hernando fl. not to far from tampa. i was thinking on a custom tune . i was going to do the electric fan to replace the drag one on there. i have the worst gas mileage now . but the thing runs good.