More Power! 4.3L

[smoothchev]

Hello all. I have a 2002 GMC Sonoma. It has the 4.3L and an automatic. I bought it with 40,000 miles on it, so it's still fairly new. This is pretty much the GMC equivilent of an S-10 Extreme. It's lower than stock, has bilstien shocks, big front and rear swaybars, and 16" x 8" Wheels stock. Now, this truck was VERY fast, for a truck at least, in stock trim. I have also added some perfomance parts to it to pick it up some. I had a Flowmaster 50 on it, but removed it and straight piped it. It was much to quiet. Had the Y pipe changed to a larger one at the local muffler shop. Installed cold air intake, TB spacer, K&N. I even rapped my cold air intake with insulation to keep the engine heat off of it. My mileage has increased about 4 mpg with all of these upgrades. I was at 19mpg, in town, and lead-footing it, of course. Now i'm up to about 23 in town. Now here's my problem. I recently raced an '03 S-10 in stock trim identical to mine, except for a diff. brand of tires. It was DEAD EVEN. I know there isn't any changes from '02 to '03, so why is my truck not faster than his?? My truck feels more powerfull than when I bought it, but that didn't matter much in a race. Now, I have beaten a 3000GT, non-turbo, of course. What gives?

[dmbrisket 51]

well was he in a stick? what kind of injection do you have, and what are the rear end gears, thats the big one, if hes geared better, you lose

[smoothchev]

My injection is CPI. He had an automatic. Our gears were the same. The only thing I can think of is I had a passenger, full tank of gas, and a big subwoofer box behind my seat. Maybe the extra weight slowed me down enough.

[OverBoardProject]

aim your sub backwards the extra base will help you excelerate! LOL

It could be the weight, or it could be that his might be in a little better tune.
Some people luck out and get a more powerfull motor right from the factory.
There are also some dogs that hit the streets.

I don't know about the auto industry but motorcycle companies like Honda actually pull aside their best motors (known as factory perfects) and they'll end up on their race bikes. This is so they have the strongest motors, and they still qualify as stock.
They send their next best motors out on the bikes that reporters test

[smokey041369]

have you had the computer unlocked yet? if not i would this will remove the top end kill point and release a few more HP

[smoothchev]

Haven't gotten a programmer, yet. The 4.3L doesn't seem to have much on the top end anyways, although with all of the upgrades, it certainly has improved.

[dmbrisket 51]

get a turbo, then youll have every other 4.3 l beat, the other question is did he have the baby lt 4.3l its a v-8 4.3 ive heard rumors about them but never accualy seen or worked on one

[Jerry80871852]

Originally Posted by smoothchev

Haven't gotten a programmer, yet. The 4.3L doesn't seem to have much on the top end anyways, although with all of the upgrades, it certainly has improved.

Years ago, had 2 friends, both had 67 Dodge Chargers 440 automatics, identical except for color, in a drag race they would run dead even, did it many times.

One night I was with one of them, he took his air breather off and we went looking for the other friend, he said I know I can beat him with the breather off.

Well we found him, he beat him over 4 car lengths, the other friend could not believe this, did it again with same results.

A few nightslater I was talking to the one who lost, we were talking about this and I finally told him about the air breather.

He took his off and we went looking, this time he beat the other friend more than 4 car lengths.

Many people say breather off does not help, but back in the 60's I can guarantee you it did, I feel sure they be tricks out there that people are using to get the edge, maybe this fellow has found one.

[rlith]

Originally Posted by smoothchev

My injection is CPI. He had an automatic. Our gears were the same. The only thing I can think of is I had a passenger, full tank of gas, and a big subwoofer box behind my seat. Maybe the extra weight slowed me down enough.

Actually you have CSFI not CPI... That said, you have the VIN X motor or the VIN W? Which one did he have? You sure he was geared the same? Do you granny shift? Tire sizes? lots of factors.

[dmbrisket 51]

^ just gunna add a few while im thinking, what was your engin temp compaired to his, is he on synthetic oil, running a different octain, or an octain booster, did he have a tunno cover and you dont, or his tail gate down and yours up, as you stated the extra weight in your vehical, how hard you normally drive your truck to how hard he drives his, just to name a few, you could go on for hours and hours with small differences like that... and im just woundern, but if all the trucks are csfi, what is the difference between vin x and w anymore, i know it use to be throttle body or cpi, but what is the difference now?

[smoothchev]

I have synthetic oil, he didn't. My temp was normal, about 200*, he didn't have any mods on his truck whatsoever. I was also running premium fuel. The only major difference besides the color, was he had a... flareside??... bed. A normal short bed. I have the stepside. I don't think that should have made a diff though. Tire sizes the same, but diff brands. He had cheapos and i have Goodyear Eagles. And what the hell is "Granny Shift???"

[crazycory1]

"I had a Flowmaster 50 on it, but removed it and straight piped it" = lack of back pressure. On smaller engine a little back pressure is better than none. Lowering your back pressure will change your torque curve. Put a high flow cat on it and a nice muffler and you'll beat his a** with no problem.

[crazycory1]

"I had a Flowmaster 50 on it, but removed it and straight piped it" = lack of back pressure. On smaller engine a little back pressure is better than none. Lowering your back pressure will change your torque curve. Put a high flow cat on it and a nice muffler and you'll beat his a** with no problem.

[smoothchev]

Yeah. I still have my cat. Actually my truck has two. Even with no muffler, the exhaust isn't very loud at all. As for the torque curve: mine is now much more even. I'm sure you may know how "torky" the 4.3L is. With the cold air intake and the exhaust done, my low end torque is a little less, but the engine pulls a lot better now in the higher RPMs. I think a power programmer would really open her up, but i don't have that kind of cash, right now al least.

[dmbrisket 51]

for one, our trucks dont need premium, its flat out a waist of money to put higher grade fuel into a s 10, they are set up to run on 87. and all i can really say is sorry, you got beat, it happens, no matter what you do, how many mods, or how much money youve put into your vehical, there is alwase someone faster, stronger, bigger then you, im not saying this in an angry tone more as a sorry, i dont know what else to tell you, like i had said b4, there are a million factors to play into every race, sometimes you win, sometimes you dont, either way, when its done its doen, and you move onto the next