I have a '99 auto. 4.2L F-150, and I got to say that this engine is gutless. I have put on many performance mods. on my 4.2L, and it's way faster than it use to be, but it is still slow off the line. Has anyone put on any mods. that gave their 4.2L a lot better acceleration off the line? I've done a lot to mine and I have it producing around 260HP, but it takes a long time for my truck to start producing all of that power when accelerating. I've raced a few stock 4.6L F-150's, and every time they beat me off the line but after about 200 meters I blow by them like they are parked. Does anyone have a 4.2L that can suggest something to add a lot quicker acceleration? I have one fast truck for a V-6, but I have to admit that these trucks suck off the line. Thanks.

 

I know that a supercharger, or many other large modifications can be done to add more power and acceleration. But I'm looking for something cheap, the 4.2 isn't worth a $2000 modification. What is everyone's opinion of the 4.2L? I got to say that this engine is gutless, especially stock. I mean 205 HP with a 4,700lb truck, come on

 

[updated:LAST EDITED ON 17-May-02 AT 04:08 AM (EST)]You don't list your mods

For more power:
-Open intake
-Free flowing exhaust
-Superchip
-3.73 or 4.11 Gears
-Underdrive Pully
-Electric Fan
-TransGo Shift Kit

Each one of these mods are very affordable and worthwhile. The Most noticable improvements, off the line, will be with the gears but, everything listed above will help.

 

Sorry:
-Volant high flow intake
-Poweraid TB spacer
-Gibson performance exhaust
-Diablosport 4 bank cust. burn chip
-Taylor high performance spark plug wires

 

I was thinking about changing the gears, but how should I go about doing this? Where did you take your truck to get it done? Or did you just do it yourself? Also how much did it cost? Thanks.

 

[updated:LAST EDITED ON 18-May-02 AT 05:16 AM (EST)]I haven't changed the gears on my truck. I still have 3.08's and average 18-20 MPG. Although I'd like a faster truck, I'm not interested in racing anyone and the 3.08's are fine once I get going.

You can't really change them yourself because very precise measurments are required or you'll shread the gears. You can have them changed at a transmission/rear end shop or an off-road shop. I wouldn't trust a chain store mechanic with something this complicated though.

The gears available are 3.08, 3.55, 3.73, 4.11, 4.30, 4.56, 4.88, 5.13. They cost about $135.00-$150.00 plus around $300.00 for the installation.

You can check your RPM's with different ratios here:http://4x4cyberstore.com/website/rpmchart.html

If you get 4.56 gears, you'll be very fast off the line but probably wouldn't want to spend too much time on the highway. The higher RPM's also mean that, at least in theory, your engine is not going to last as long because the crankshaft is turning more frequently than with a lower gear ratio traveling the same distance. Not really a big deal though.

If your prime interest is performance but still want to drive 70+ MPH, the 4.11 gears are a good choice. A low gear ratio really is a lot of fun.

 

Hey Thanks a lot, that is what I thought would happen if I was to change the gears. I think I'll keep it as it is, sure it's slow off the line but you are right once you get going I blow by people. My truck goes well over 100mph with all the mods., the chip did the most for that because it lifted the rev limiter. I think the gears are fine because I expect to get beaten off the line by almost any car. But if they dare come next to me and try to race when I'm already going at least 40mph, I have one heck of a chance in blowing them away. Once I got my custom burn 4 bank Diablo chip in there I noticed how fast I could get to 80 or 90 when cruising at around 40 or 50. I guess I'll just live with the fact that the 4.2 can't accelerate off the line very well, there isn't much I can do with a small budget. But hey, on the freeway or when traveling at high speeds I'm very satisfied with the power in my 4.2, I mean I can hit 100mph and still have a lot of throttle left to give. I say that isn't too bad for a V-6. Thanks again.

'99 auto. 4.2L f-150
-volant intake
-Poweraid TB spacer
-Taylor high performance spark plug wires
-Diablosport cust. burn 4 bank chip
-Gibson exhaust

 

I agree, off the line my truck is horrible, my friends trail blazer beat me (not cool), but once im going like 40 i'll take him apart, hell i can even beat my friends BMW , of coarse it is a POS one, but whatever... Anyways i was wondering if the underdrive pulluy are worth the money and if you changed your ger ratio by just the next one or two(ratios in the line above) if that would affect your top speed that much.:-X11


MODS:
diablo superchip
airforce one intake
flowmaster exhaust, dual
lights & etc.


Oh ya, what about the TB Spacers, are they worth it.

 

Hey trackguy yours an automatic? Which one do you have, Diablo or Superchip? Yeah the 4.2 is horrible off the line with its stock gears, and a pulley won't do much of anything. I've been told they only add about 5-8Hp, and that is nothing with the weight of our truck. I've raced a few stock 4.6L f150's and every time they woop me off the line, but after about 2-300 meters I blow by them like they are parked. I guess I'll just leave my gears stock, after all I can go well over 100mph with a V-6.


'99 auto. 4.2L F-150
-Volant intake
-Poweraid TB spacer
-Taylor high performance spark plug wires
-Diablosport cust. burn 4 bank chip
-Gibson exhaust

 

thats wut i like to hear. But i still want to know if the TB spacers do anything... I have heard mixed oponions

 

They aren't bad for the price, you won't really notice a HP increase but you will notice some torque. Also it will give you about a 1-2 mpg increase. So I would say that it is worth it. Just remember that it WHISTLES so if you don't want that don't get it. Do you have a performance intake system? If you do the spacer will make the incoming charge of air whistle even louder.

 

really? damn. cause ya i have an airforc one intake, so how bad is the whistling.

 

Not too bad, I mean its noticeable but not all that bad. I have mine installed along with a Volant intake system, I actually kind of like the sound. People notice it when they are next to me, some idiots even ask when they race me if it is a supercharger. But it is really more of a whistling sound than a whine. You also only really hear it off the line or in the mid RPM range, so it doesn't whistle all the time when your foot's on the gas.

 

260 horsepower?! I think the reason you are slow off the line is cause you are no where near 260! I have pretty much every bolton you can get and i was just on a dyno 253@4400 rpm it was a big shock to me but you cant just add up the hp claims that they say on the box horsepower is an art form and it takes the right combination! I can lay rubber for 20 feet but istill cant take my buddies honda off the line! but i can take the guys in my truck club who drive the 4.6 or the 5.4 even if they have the mods! because the weight to power ratio is there! remember every 100 pounds you get rid of gets you 1 tenth of a second faster
1999 4.2
MAC intake
high flow cats
Borla duals
S.P.E 1 inch throttle body spacer
A.S.P underdrive
variable I.A.T sensor
Diablo chip
9mm wires
Denso Iridium plugs
J.B.A headers
dual electric fans

 

No, I bet I'm not to far off. You haven't done much more than I have with exception to the headers and fans. You have to remember I had my chip cust. burned, is yours? Also I think you may have made your exhaust too high flowing. Especially with the duals on the 4.2L, along with everything being high flow, eventally you reach a point where it is too high flowing. When this happens you lose the exhaust velocity, causing you too lose power. I did estimate, so I'm not saying it's exact, but I bet I'm not too far off. My sister has a 5.4L which as you know has 260hp, and with that I have something to measure my truck up too, even though they are geared different. But hey, 253 that isn't bad at all.