LH Performance
A how-to guide on making your LH faster for around 60 bucks.
In the world of aftermarket performance world the Concorde/Intrepid/Vision platform is comparable to Guam. There is about nothing for the LH series. So if you want performance, you'll have to have it custom done.
The cheapest ways to get performance on the LH cars with the 3.5L is to increase air flow and free up exhaust. Ill list the steps by price, starting with the best price free.
Remove Air Restrictor: Chrysler installed a funnel type device between the air box and the engine. Its used to reduce engine noise, but it also decreases power output. Its very easy to remove, it takes no specific tool. First you pop the hood and locate the air box on the passenger side of the car near the wheel well. Undo the bindings that hold the hose in place and pull it off the air-box. Do the same for the other end of the hose. Look into the end that was attached to the air-box and you'll see a plastic funnel. That is the restrictor. Position something on the center of the funnel (like a piece of pipe, a flashlight, anything that can push it out) and then for the tube down until you hear a pop or a crack. Pull out the restrictor and make sure there aren't any pieces of it left in the tube. Put the tubing back onto the air-box and intake ducting and make sure its secure. And that's it.
Cost: Free
Increase the filter's exposure to outside air: K&N is famous for their performance intake products. They offer replacement filters for any car (including the Concorde/Intrepid/Vision platform), and they also produce several high performance intake systems for various cars, but not for the LHs. So home-brew inventions to pick up where the aftermarket left off. A K&N cone filter from a different can work on the LH platform, but I don't know which one, so don't ask. I chose a less expensive way to go. If you expose the filter to more air, you get the same effect. So I cut off the bottom of my air box. The process is as follows. Take out the air-box by unscrewing the supporting bolts below it and taking it off the intake tubing. Take it apart so you have the top and the bottom sections. Now use a drimmel/jigsaw or anything that will cut plastic to cut off the bottom the box. Cut around the supports so it mounts in there better. An alternative to this is to grab a drill and Swiss cheese the bottom of the air box. Put everything back together like you found it and your done.
Cost: Free
Free up some exhaust flow my removing one of the mufflers: Just like there is no performance intake system for the LHs, there are also no performance exhaust systems for them either. The stock exhaust system consists of three catalytic converters, a muffler then a secondary muffler call the resonator. The muffler is the same one used on the 3.3L engine, but the 3.3L doesn't have the "resonator." This resonator is actually a low restriction turbo style muffler. So instead of using the real muffler and cutting off the resonator to free up some HP, you can cut off the muffler and use the "resonator" as the primary muffler. The resonator is louder without the muffler, but it sounds no louder than an aftermarket performance muffler (just deeper sound). An exhaust shop can cut off the muffler and put a 2.5" pipe in its place.
Cost: About $30
Improve air flow better by installing a K&N panel filter: As stated above, K&N makes replacement filters for all makes and models. These are not a complete intake system, they just go in place of your factory air filter. They are made of a special material designed to improve the flow through the filter. It works a lot better than the traditional paper or foam filter. With the other mods above, this helps with high RPM power around 4000. The installation is very simple. Take of the top of your air filter, take out your old filter and put in the new one. The K&N has a million mile warranty and needs to be cleaned about every 30,000 miles for normal use. A cone filter can be used, but you'll have to purchase one with a mounting bracket.
Cost: Around $40
And now for the more expensive performance parts.
Tires: Tires will improve your ride greatly depending on which kind you get. Performance tires will give you better take offs, more grip, better cornering and better high speed stability. The best consumer tires to get are Z rated tires. These are stable up to about 130 mph. Normal tires can go up to around 100 mph, but they tend to shake a vibrate a lot, which can put you into a scary situation. Several companies offer performance tires that fit the LH's 16" rims. The stock specs are 225/60 16". Keep the same specs unless you go to a wider and/or larger radius tire. The max tire width on these cars is about 245. If you upgrade the rims to a larger diameter try to keep the same overall diameter to keep the speedo correct. The tires I have now are Nitto NT450 Z -rated tired, they do a good job of holding on. I've had success with the Dunlop Sport 5000s (but they tend to wear faster than normal tires) and I've heard Michelin Pilots work pretty good on these cars. They usually cost over $100 a tire.
Wheels: Despite what everyone thinks, wheels aren't just for looks and can actually make a performance difference on your car. Especially when it comes to these cars. The stock rims are alright, but these huge cast aluminum wheels are just dead weight. I switched to a set of 17" Enkei aluminum alloy racing rims. They weight about 20 lbs each and I can tell a difference in acceleration. The car gets moving a lot quicker. I paid about $1200 total with new tires and installation.
Suspension: Lower cars provide a lower center of gravity and less body roll. To achieve this the best way is to install performance lowering springs. I haven't purchased these, nor do I know anyone who has them, so ask around before you buy 'em. They cost around $500. Also a thicker anti-sway bar will help reduce body roll. But this will run you a pretty penny, since it will mainly be a custom job.
Computer Chip: Superchips is the only company to my knowledge that offers a performance computer for the LHs. They take your old chip and "burn" in a new program so get better shifts, higher power and they remove the rev and speed limiters. It costs about $300 and is only offered for '93 and'94 computers.
Suggestions From Other LH Owners
Cooter Covell writes: I ran into a friend of mine whom I haven't seen in a long time working at the local shop, and yesterday, we tore out the entire system in my car from the 3rd cat-back... one on each of the headers and one at the beginning of the straight pipe?) anyway, he cut out the entire muffler system, now theres only regular 2.5" piping to a 40 series flowmaster out the back. he did all the cutting, bending, and welding (for liability reasons). the sound is awesome. has a more pronounced low hum at idle, more teeth in regular drive, and sounds like a short block Chevy when opened up. the muffler I picked up for 70 bucks, and my friend did all the installation for 110 bucks (w/ heavy discount, he took off like 150 bucks he told me). havent been able to go to the track yet to get some numbers, its been raining...my best run before was 16.35 @ 91, we'll see if that number goes down a bit!!
If you have any performance mods you'd like to share, mail them to me at brun064@hotmail.com