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View Full Version : TBI experts,need advice



xxclaro
05-18-2012, 09:10 PM
I have a 95 k1500 with a 5.7 that could use a little more power. I'm not looking to make it a rocket,just maximize what I have. I've read some threads here that mention TBI mods but I;m not sure what exactly they're talking about.Could anyone enlighten me on what to do? The truck has 436000km, as far as I know he engine is original,but I can't be sure. I'm considering rebuilding it next january,as I'm back in school for auto tech at that time so all machine work would be free. For now, I'd like to see if I could make it pull a little bit better. It's got pretty tall gears in it so acceleration and pulling are not it's strong suits. If you could guide me through maximizing the efficiency of my TBI,that would be great. Thanks!

1.721afr
05-18-2012, 10:33 PM
http://lmgtfy.com/?q=tbi+mods

Doober
05-19-2012, 09:41 AM
You can advance timing a few degrees from 0 to get a little better throttle response, and the 'ultimate TBI mods', basically smoothing the transition into the venturies of the throttle body and getting rid of the ridges around them. It also wouldn't hurt to get rid of the breather "collar" between the air cleaner and the throttle body, but you'll need either a push-in breather or a hose to go from the original breather location to the hose connection the bottom of many universal air cleaners have. Next step would be the y-pipe and exhaust (desparately needed on stock trucks), headers too. That's about it outside tune-up stuff without opening up the engine. Past that I would balance the rotating assembly and port the heads, then a cam if you plan to go that far with a stock TBI long block. Once you've done all these changes you'll need more fuel, requiring more fuel pressure, larger injectors, or both. After allllll this is done you still need to tune it.

That's my $0.02

1.721afr
05-19-2012, 11:30 AM
Tnx Doob, 'calro, get the basic mods doober mentioned done, don't forget to make your regulator adjustable.

You may get away with a little more timing you may not, the ESC and engine operating condition will determine that.

Now is the time to start your EFI education.

http://www.moates.net/

http://www.tunerpro.net/

http://www.aldlcable.com/

94_c/1500
05-23-2012, 05:42 AM
I've done alot of little things to my truck. The best so far was adding 4 degrees of timing. Second was porting the throttle body. Third was probably changing the exhaust. I've gotten rid of the air silencer and replaced it with a tube. My truck is a V6, so I put a V8 air cleaner on it. Used to have a K&N filter, went back to paper. The bottom of the air cleaner has dynamat. It has the hot air valve and hose removed. It has a hypertech powercharger base, also covered in dynamat. The air cleaner was cut to match the base. It has a ported throttle body, pod spacer, and throttle body spacer. It has the timing advanced 4 degrees. It did have MSD wires and coil, all removed now. And it has dual exhaust with Thunderbolt cats and Flowmaster 40s. When the mufflers go bad, it's getting Spintechs. I've got headers for it, but haven't put them on yet. It's getting ram air soon. And a Yank converter is the next major modification I'm saving up for.

xxclaro
05-23-2012, 05:33 PM
Thanks for that information, it will prove helpful.I took a look at my throttle body and I believe I understand what your refering to as far as porting it. I'll give it a go and see how it turns out. I'm going to do a compresion test before I get carried away,as I don't know if this is the original engine. If it is, I imagine it will be a little tired at almost 450 000km,and it might not be worth trying too many things on it.

94_c/1500
05-23-2012, 07:38 PM
Me and best friend ported the throttle body. Took a grinder with a grinding wheel and removed most of the ridges. Then took a Dremel with a thick and round wheel to get the rest. Finished it off with a catridge roll and softened the radius a little. It took 1-2 hours taking our time. That includes removing, cleaning, and reinstalling too. My truck is just a V6 and it helped, it'll for sure help a V8.

UnderCover W/T
05-31-2012, 04:20 PM
Did you end up porting the throttle body yet? Im interested in doing the same. I know my timing needs some adjustment.