4.0 wonders...

[mach1460]

I have a 1993 'X' Limited. it has 130,000 miles on it and it runs like a champ. the only thing(s) that is wrong with it is a little bit of rust on the rear bumper (Which i am about to fix), the other thing that i want to do is add some power to the 4.0. I am about to order some hedman headers a gibson exhaust and a jet high performance chip all combined is about an extra 60 horse(ish) increase. I know the newer 4.0s have 210 horse compared to the 155 that i guess mine has. i was wondering if anyone knows if newer 4.0 Heads would fit on my 1993 and would it make a diff? i would also like to know of any other mods that can be done with little or no money (cheap tricks) and something other than a 300.00 air sensor and a 270.00 throttle body for 10 horsepower, any engine components or websites that have explorer stuff, thanks

 

[flyguy]

Aw man. hate to burst your bubble. But heres the low down. Ive pretty much completed all the mods you listed. And Got nowhere near 60 horse. My toal combined hp with all my mods listed was around 20hp. Maybe a little more. Yes you can put on the heads from a newer X. Usually reffered to as 98tm heads. Make sure its from a 4.0L Pushrod engine though. The newer heads in your X should increase your compression to 10:1 for a hp boost of <5hp. Now..if you get them ported and polished, you might come out a little better. Anyways...dont do the Jet chip. They suck. On the dyno, I actually LOST about 4hp using the chip. I run a superchip now... seems to be better.. less problems, however I cant say much as I have not had it on the dyno yet. Anyways. Enough babble for now. If you have any questions, feel free to respond here or pm me.

nick

 

[Alec]

I'd do air filter/intake, catback exhaust, chip (NOT JET), MAS, and TB.

Headers will result in a loss of low end torque for the gain of some highway ponies.

take a look here:
Dead Link Removed

 

[J. Kennedy]

cheap tricks

With 130k, you don't want to sink a lot of $$$ into it. I am all about the cheap tricks. TRY:

1) Swiss cheese your air box. My factory air box inlet was about the size of a quarter. 10 minutes of playing with the drill, it was like a new car.
2) Make sure your throttle cable is tight. Mine was stretched out, and a new one made all the difference.
3) I notice you live in SD. Try unbolting the fan for the winter, but keep an eye on the temp gage. That's 10 hp right there.
4) If you have AC, replace your serpentine belt with one for a non-AC engine. Even when it is not cycling on/of, it makes a significant drag.

Your rig will never be a dragster, but the above should make a noticeable difference.

 

[flyguy]

Really? I didnt lose any torque when I installed mine. It was dynoed by itself too I think. I didnt gain any hp really though either. I dont remember what it was, but it was less than 5hp. For that kinda cash it was dissapointing.

nick

 

[mach1460]

thanks for all the replys, im glad that i didnt order that jet chip, lol. my truck has 130k but it has a brand new transfer case that transmission was replaced (not rebuilt) with a new one at 100k. the previous owner was an old couple that took it on a lot of roadtrips. they bought it brand new. FOr those reason im not worried about any of the drivetrain what soever. It been properly maintained all through the years they had a oil change every 2500 miles and had proof of all recipts. Are Headers really that bad of an idea?? i mean on my mach1 headers increased my performance all through the rpms. Other than "swiss cheezn"my air box are there any companys that make alum. heads for 4.0's? Whats the average gas mileage that people are getting with there x's?

 

[flyguy]

If you do headers.. I would just save them for last. They give you the least amount of power for your money. Trust me. With all the money Ive spent on mods, I could of bought a supercharger and I would have the 60hp your looking for. Also, there are no aftermarket heads available. I would stick with your stock heads and get the ported and polished. Increasing the compression with the newer heads gave me more trouble than it was worth. If it was my money, and you dont want to get a supercharger. I would get the intake tube with open air cone filter, a larger throttle body, and a cat back system. I found that removing one of the cat's (if you have 2) helps a bit too. I dont have any experience with porting the heads, so I cant say if they are worth it or not... but having seen them, It appears to be a bottleneck.

nick

 

[SaleenEXP]

JET = Crap Big Time! They make the some of the crappiest products. A friends had one on his Tahoe and it not only did the truck run like crap, but he lossed power on the dyno, same thing happened to people using them on Mustangs.

Superchips, Diablo, and the Hypertec Programmer are your best bets. I would recomand the Programmer becasue that way if your gonna keep adding mods or changing things, you can reprogram the computer everytime for new additions, and it will also give you the stock settings if you go to a dealer. With a chip, you'd have to keep getting it reburned unless you buy all the other mods 1st then get a chip burned.

 

[ScottyM]

exhaust mods

I have a 1994 xlt and there are no emission laws where I live and what to replace the exhause with 2.5" pipe from the Y pipe back. What do you think?

 

[Alec]

First I think that's very irresponsible as a citizen of planet Earth. If you cat works, keep it. It is doing your truck no harm. I don't get on a soapbox often, but your cat isn't costing you anything, and isn't hurting all-around performance.

After the cat, if you want to run a straight pipe, go right ahead. It will sound and perform worse than having a good muffler and tailpipe combo.

 

[ScottyM]

I wanted to run a 2.5" pipe and flowmaster combo. Is this combo too big? Should I go with 2.25" pipe and muffler combo?

 

[Alec]

You can go with 2.5 for the intermediate pipes and muffler, but use a 2.25" tailpipe after the muffler.

 

[ScottyM]

Why should I use 2.25" pipe after the muffler and not keep it at 2.5" all the way to the end. Does the smaller pipe after the muffler help with torque? I just want a setup that will give me some more get up and go.

 

[Alec]

A smaller pipe after the muffler can help with torque but actually it just improves sound. The older 4.0 in mostly stock form doesn't need a 2.5" tailpipe. The gases cool and compress by the time they hit the tailpipe and a larger pipe would actually slow down flow and make the sound more tinny.

EDIT: basically I recommend a tailpipe that is .25" larger than stock, and yours should be 2" stock. If it is 2.25" stock then go with 2.5", but I doubt it.

 

[ScottyM]

Sorry, I should have said that my X has a K and N air filter, drilled air box, supership, and a helix throttle body spacer. Should I still go with the 2.25" pipe and muffler combo with the mods I currently have?

 

[Alec]

Go with whatever tailpipe is .25" larger than stock, and with a 2.5" muffler.

 

[aldive]

I would definately go with 2.5" pipe.

Good luck.....

 

[Alec]

Aldive, you don't have an early model OHV so you don't know what they can sound like if the exhaust is too open.

No offense, just saying......