7 Best Low Cost C5 Corvette Mods and DIYs
Think you know which zero dollar modification adds 10-15 HP to your C5? Click here to check your knowledge. One you'll want to try, a few you might, and a total reject.
1. Zip Tie Mod
So these are cheap mods, got that? A C6 Intake isn't cheap and neither is a good dyno tune, but you know what is cheap? Zip ties. A bag of 100 good, contractor-grade ones might set you back 20 bucks, but even that's still not too bad considering the hp-per-dollar-spent ratio. Forum members report increases of 10-15 hp from this mod. That's similar to the numbers you'd expect form a low-buck cold air intake/filter set up (which mount in the exact same spot). So what is the Zip Tie Mod? You simply remove the stock airbox cover, with its small, restrictive orifice, and use zip ties to fasten the filter to what's left of the airbox. That's it. It results in a sizeable increase in airflow, and more air means more power. There is concern over moisture finding its way into the intake more easily, that is if you ever take your car out in the rain, and that's why we recommend using an aftermarket the washable type air filter, used in concert with a hood seal (mod #5).
2. Flip Tie Mod
This mod is the same principle as the Zip Tie Mod, and in fact it also includes the use of zip ties. We suggest the wide black variety because they match the appearance of the stock plastic better, and because they are stronger. To perform this mod, cut a hole in the stock radiator shroud, remove the stock airbox cover—as in the Zip Tie Mod, flip the airbox over, and mount it facing the hole you just made in the shroud. Users report similar horsepower gains to those achieved from the Zip Tie Mod, but a cleaner more factory look.
3. Plasti Dip your Panels
Preparation is key. That's what everyone who's done this modification says. Pinstriping tape, or even electrical tape, is recommended for precisely mask areas off. Narrower tape is better for navigating tricky curves, and make sure you mask thoroughly to protect everything else from stray spray. Aerosol paint has a way of landing in places where you didn't mean for it to land, and that's true even when there's no wind. It's important to peel the tape away while the Plasti Dip is still fairly wet—it creates a sharper, smoother edge. The pluses of Plasti Dip are well know these days: 1. it's not expensive, and 2. it's easily reversible. Our favorite comment about this mod is, “It helps take away some of the fat butt look.”
4. Lower on Stock Bolts
Your Corvette is going to handle (and look) better if you lower the center of gravity. The best way to make that happen, as long as you don't want too dramatic a drop, is to lower it on the stock bolts. Forum members have had good results by lowering the suspension until just a couple of threads are showing on the bolt, once secured. The proper procedure for making ride height adjustments is to do it with all of the weight of the car still on the wheels (or jack stands under the suspension as if it were on the wheels). There are a lot of rubber bushings that get tightened in place and don't move easily, contributing to the spring rate. If you do jack up the car, adjust the ride height, and then lower it, don't expect the ride height to change completely right off the bat. It will take a few miles, users suggest around 50, for the bushings to allow your Vette to fully drop.
5. Hood Seal
No one likes a dirty engine. Maybe, as forum members have commented, GM "forgot" to seal the hood on our C5s, or maybe they were saving weight, but most of us would prefer to keep dirt and moisture on the outside of our engine room, so this mod is a no-brainer. Even worse than a dirty engine is moisture in your airbox. Engines like to breathe air and fuel, not water (boosted engines with water injection aside, but that's another kettle of fish), so this is a must-do if you perform the Zip Tie or Flip Tie mods. Luckily it's one of the cheaper changes you can make—weatherstrip isn't going to break the bank. You can usually find something at the hardware store that will do the trick.
6. Hood Liner
This is a popular place to mod, with several options. You can spring for a fancy aftermarket insulating hood liner, paint on (or add a decal to) your stock liner, or remove it entirely. The stock hood liner is there to quiet things down, but some feel the heat retention penalty isn't worth the noise reduction benefit so they chuck it. We like the idea of cleaning it up and painting it. Quiet, safe, nearly free, and not too bling-y.
7. Throttle Body Coolant Bypass
Probably don't do this one. The theory is that the coolant running through your throttle body warms your intake charge up excessively and robs valuable horsepower. Some aftermarket manufacturers claim a 5% hp increase from bypassing your throttle body. Nope. The difference in power, by all reports, is negligible, and the downside risk is great. Some have suggested that the plastic junction tubing is cheap enough, so why not try it? Slightly more expensive aluminum unions are more durable, but there's still no measurable advantage. It's best to leave well enough alone. Messing with the factory cooling system design is not a good idea if you drive in hot climates, or use the car hard. Removing the intake warming, that people smarter than you engineered, is a bad idea, especially if you drive your Corvette in cold weather, because ice can form on the throttle plate. If you need a project to keep you busy, just look up from that throttle body and you'll see a hood liner that could use some decoration.
For help with service of your car, check out the how to section of CorvetteForum.com