[whodat]

First of all, Hi. My vehicle is a 1993 Jeep Grand Cherokee 5.2, mods sufficient to bring me to ~260hp 350ft/lbs tq, fulltime 4by. That is the standard by which I measure mods. My wife's car is a 94 Intrepid ES 3.5l, mostly stock but for an infinity gold stereo (out of my jeep) a remote starter system, and some Yokohama AVS dBs. Currently it handles OK, and accelerates well. The transmission seems sloppy to me, and under hard cornering it will lift a rear tire. I'm looking for information about honest modifications that affect horsepower, handling, acceleration. Not tint, blue light bulbs, or wings (what the hell does a wing on the back of a front wheel drive car do anyway?)

Does anyone actually have a performance chip, either Superchip or ACE/ If so, did it make any changes?

Has anyone found any real gains to be had from a K&N filter, either drop in or complete replacement?

What is the recommended exhaust system for performance/ Read that as no shiny chrome trash can resonator tip making it sound like a lawnmower or motorcycle. Hiflow cat (s), mandrel bent tubes, hiflow but somewhat quiet mufflers?

Is there any type of shift kit or modification to improve the transmission, specifically firming up shifts and speeding downshifts?

Does anyone have any actual experience with aftermarket antisway bars? Addco, hotchkis? Are any made for the intrepid?

How about shocks/struts, what is a good combo to replace the stockers (with ~100K miles)? Good ride with good performance-good ride being the more important of the two (two kids in carseats)

Aftermarket springs, while searching I found many recommendations for one or the other brand, but I wish to keep relatively stock ride height. The suspension is there for a reason, I want to keep it.

This might sound kinda harsh to some, but each specific question is something that I have actual experience with on my jeep, all mods were researched and purchased based on the experiences of others. I would rather spend money on a performance enhancing intake than my license plate bracket, and would rather be fast than look or sound fast.
whodat

 

[Dodge4life]

Amen to your words, to bad i got most of the crap u hate. AKA all flash little gas. But i would like to do what u say but i'm a poor high schooler w/ no money. HeHe. maybe someday i'll get enough money to do the real stuff. Anyways good luck on your quest, there are alot of members knowledgeable in the hardcore modify'n around here.

 

[whodat]

I don't hate them, I just can't afford them. I'd rather go without a type-r sticker for a while in order to save up for something that will make a real difference.
whodat

 

[jnutz]

(what the hell does a wing on the back of a front wheel drive car do anyway?) It slows you down

Does anyone actually have a performance chip, either Superchip or ACE/ If so, did it make any changes? Since you are pre-OBDII you have more selection than later models; however, I have not looked into them. Mine is OBDII and won't take a chip, but requies computer reprogram.

Has anyone found any real gains to be had from a K&N filter, either drop in or complete replacement? My personal feelings are that a drop in will work better, unless you set up a complete replacement that is segregated from the hot engine compartment.

What is the recommended exhaust system for performance/ Read that as no shiny chrome trash can resonator tip making it sound like a lawnmower or motorcycle. Hiflow cat (s), mandrel bent tubes, hiflow but somewhat quiet mufflers? No one makes a kit yet, but meny custom exhaut shops are out there and they will do anything for a price. If you go dual, I would stay around 1 7/8" or 2" especially if you go mandrel bent.

Is there any type of shift kit or modification to improve the transmission, specifically firming up shifts and speeding downshifts? People have talked about getting a Prowler shift kit and putting it in, but I have heard of no one that has done that yet.

Does anyone have any actual experience with aftermarket antisway bars? Addco, hotchkis? Are any made for the intrepid?
I have looked and have not found anything yet, but one guy here has "a prototype sway bar." Not sure what or where or anything.

How about shocks/struts, what is a good combo to replace the stockers (with ~100K miles)? Good ride with good performance-good ride being the more important of the two (two kids in carseats)? Still looking into that myself, sorry no help here.

Aftermarket springs, while searching I found many recommendations for one or the other brand, but I wish to keep relatively stock ride height. The suspension is there for a reason, I want to keep it. Again still looking into it.

This might sound kinda harsh to some, but each specific question is something that I have actual experience with on my jeep, all mods were researched and purchased based on the experiences of others. I would rather spend money on a performance enhancing intake than my license plate bracket, and would rather be fast than look or sound fast.
whodat

 

[Black94ES]

Re: Re: Real Performance Mods

(what the hell does a wing on the back of a front wheel drive car do anyway?) It slows you down

Umm... Not exactly, u need rear downforce at high speeds for stability, but we're talking over 80mph stability here. Besides, I've taken my car to top speed and it was pretty stable to me, a spoiler would have helped.

 

[whodat]

How many real honest to god sports cars have spoilers at all, much less large wings? In my admittedly short and woefully inadequate memory, only twice in the past couple of years has a wing been added to a car as a performance measure. Wanna guess what cars? The audi tt roadster and the VW bug. Both cars were designed very similarly (is that even a word?) and both had a problem of lifting the rear end off the ground at 100+mph speeds due to exceptionally clean aerodynamics. The wing does not so much provide downforce (on these two particular examples) as it breaks the laminar airflow over the rear of the vehicle, effectively acting like a spoiler on a wing disrupting the airflow. (can you tell my aviation background?) It was apparently decided that overall aerodynamics and a low coeffecient of friction was less important than the rear of the car lifting off the ground at high speeds.
Go to www.autospeed.com for a fairly interesting look at practical aerodynamics.
whodat

 

[IntrepidXJ]

Who puts on a wing for performance? It's only a cosmetic mod on consumer vehicles.

 

[79lilred]

I also seek answers to these long standing mysteries. The only thing I might input is about exhaust...mufflers specifically.

I did extensive research looking for unbiased evaluations of back pressure, real performace gains (1/4 mile ET) and NOISE. I want performance without drawing the attention of every cop or waking the neighbors.

I found a very good comparison that shows one of the best performing mufflers was also one of the quietest - the Walker Dynomax Super Turbo (less than $40 from Summit). And guess what....it showed the only reason for buying a Flowmaster was so you could experience that awful resonant drone at cruise speed.

Lets see if the article is still on-line.....HOT DANG! Found it!

Entire article is at:
http://www.jr333.com/pontiac/exhaust.htm

 

[whodat]

I found a very good comparison that shows one of the best performing mufflers was also one of the quietest - the Walker Dynomax Super Turbo (less than $40 from Summit). And guess what....it showed the only reason for buying a Flowmaster was so you could experience that awful resonant drone at cruise speed.

Cool, quantifiable verifiable numbers finally. You did make one mistake however. That drone is not the only reason to go with a flowmaster. I had a dynomax super-turbo cat-back on my jeep prior to my flowmaster/mike leach combo. I replaced the dynomax not only for performance reasons but because it showed serious surface rust and lots of rock dents and dings after only a year or two of use. The flowmaster (70 series SUV 3" I/O) is a much heavier duty unit. I don't have any drone, by the way, 3" from the hiflow carsound cat through the flowmaster through the mandrel bent leach tailpipe. Not directly applicable for the intrepid, but I figured I'd mention that flowmaster isn't all that bad. Looking at the exhaust on the intrepid however, I'm stumped as to how to design a good high flowing system. The actual muffler seems to be a side input, rear output flat rectangle, and the ones behind that seem to be just resonators. I'm loathe to bypass the stock real muffler and install a bypass pipe in it's place and rely on a universal fit in the resonator's place to provide all sound damping, but that may be my only option. The piping doesn't seem all that complicated, I may just buy the pipe and some mandrel bent corners and weld it up myself. Tube diameter becomes a question though. Stay stock size, go bigger (more airflow but moves the torque peak higher) or smaller (either moves the torque peak lower or keeps it the same due to better quality build and lower backpressure)? Another possibility is a variable restrictor in the exhaust, which keeps a certain amount of backpressure in the system at low rpm while opening fully for great flow at high rpm. Questions, questions. I don't suppose anyone has accurate diagrams and measurements of the stock '94 3.5l ES exhaust system, do they? I need a good representation so I can start cross-checking dimensions against the manufacturer's specs for mufflers and such.
whodat

 

[Djnrg]

I was going to try to build some sort of variable resistance valve for my exhaust system when I get it this summer, so I don't lose too much torque (who knows it might even add some like when the idiot at the repair garage stuffed a rag inside on of the two tips on my resonator, and forgot about it)

My question is, can you buy one of these units? How much are they, and how do they work?
Thanks.

 

[whodat]

Automatic Variable Exhaust Restrictor