V6 Mustang Modification Guide

This article is meant to give someone who is new to cars some info on where and what to get for their V6 Mustang to make it faster and more fun to drive. Check out RGR’s article in the V6 forum for more great info. If you have any questions, sign up on our V6 Mustang Forum and our members will be glad to help you.

Suggestion One
First decide if you really want to sink money into a V6 Mustang. We 6′ers have a lower potential horsepower platform than our v8 brethren. Basically meaning we get less gains for the mods we do.

Now this is of course not the case in non engine related matters. For example, adding 3.73 gears and a locking differential would greatly benefit both a v8 as well as a v6. Same goes for most suspension mods. Tuning the cars computer can greatly benefit both platforms, even more if you have an auto. The point is that a v6 is capable of making big horsepower…but only for a V6 Mustang. If you want to make 800 at the wheels then go buy a fox and play with that. The v6 is a reliable platform to build a 300-400 horsepower daily driver. Granted drastic improvements must be made to most of the suspension and drivetrain to get there, the stock block has been known to stand up to quite the beating.

Suggestion Two
Work from the inside out. From my experience, and I’m sure other would agree, the gains from basic bolt on upgrades to a v6 are slim to none. It makes much more sense from a financial outlook as well as a performance outlook to first build a good base to have fun with.

For the big spenders you can have your motor stroked to a 4.2 v6. This is done using the stock or forged, depending on application, crank out of a Ford 4.2 6cyl engine. You can buy stroker kits from Super Six Motorsports and Morano V6 Racing. You can also pull a 4.2 out of a donor car and just use that. A used 4.2 rotating assembly can be had for rather cheap and once checked and machined, serve as a junkyard stroker kit! (You will have to use the pistons from a 4.2 as well)

For the medium spenders, I guess that’s what you call em, there are Head/Cam/Intake packages available from the same three as above. They utilize your stock bottom end, the block, crank, pistons and rods, and improve performance at the same time. The heads are given a full port and polish, new valves/springs, 3 angle valve job, and can be fully machined ready to bolt on for you. I also believe that all 3 sites mentioned will give you a custom speced cam if you order from them. This meaning they will talk to you about your goals for your car, and match a cam to your own personal interests. There are a ton of good cams out there and new grinds are being thought up each day I’m sure. The cam will increase the flow of air coming into and out of your cylinders by keeping valves open longer and opening them faster in some high-ramp lobe cases. It will change the sound of your exhaust note a ton and wake the car up. Lastly the intakes that you’ll get will be also ported and polished. The porter will take imperfections out of the runner walls by smoothing them out. All three mods complement each other very nicely. A nice cam will be held back by stock heads, while a nice set of heads will not be nearly as effective as if they had had a cam custom speced for them.

Suggestion Three
Point is, its easier to do it all at once. You don’t want to have to take an engine apart twice. After you pick which of the above routes you’d like to go or perhaps combine them and almost be done, it’s time to work on some suspension/drivetrain stuff.

Drivetrain

The stock V6 Mustang drivetrain is a dog. Well, maybe that is a little too drastic. The 5 speed versions are a bit more fun, as are the newer 99-04 due to the
better gearing, but they could use some help. First step in Drivetrain mods should be some new rear end gears and a locking differential.

Ring Gear and Pinion Set
The general rule of thumb is 4.10′s for an auto, and 3.55/3.73 for 5 speeds. In case your gear illiterate, the higher the number the lower the gear. Meaning 4.10 would give more acceleration than a 3.73 gear. You may be thinking, “I’ll take all I can get!”. Just know this, lower gearing will lead to increased cruising RPMs on the highway. This will affect gas mileage slightly (meaning 1-3mpg) at highway speeds. It also puts extra load on your car which is something to consider if it’s your daily driver. Cars that have stock computers will need to have their speed limiters raised and 99-04′s will need the gearing in the computer changed as well. Or they can pick something up called the SpeedCal which changes it for you. 94-98 will need a specific speedo gear for their gearing.

Trac-Lok Differential
You should also consider upgrading to a Traction Lock Differential. This will give you increased traction for your new gearing and allow you to do a 2 wheel burnout. No more one tire fryer. There is more than one type of Trac Lok, but thats where things can get complicated. If you’d like to explore your options check out Musclecarclub.com – Library – Tech – Differential for a very informative and technical article on differentials.

Gears and a new Tlok are one of the most beneficial mods you can do to your car. Relatively inexpensive if you can find an honest shop to install them, gears can be had for under 200 and the Traction Lok for under 300. Avoid used gears and used traction locks as gears develop a wear pattern after installed and traction locks take a lot of abuse. Also if you plan on going Forced Induction, even if you are automatic, you should go with no higher than 3.73′s. The extra power will be enough to move the taller gear. If you were to use a 4.10 gear in a super/turbo charged car it would bring the car up through the revs too fast and you will basically top out.

Aluminum Driveshaft
Aluminum driveshafts are a nice “finish it up” mod. They are not worth the price in my opinion.They will give slightly quicker revs and a minimal increase, but I doubt you would feel much. Maybe .1-.2 in the 1320.

Automatic Transmissions
The v6 automatic comes with an AODE in 1994-1997 Mustangs and a 4r70w 3 speed with Overdrive transmission for 1998-2004 Mustangs. The stock transmission suffers from soggy shifts and been known to overheat with abuse. You should invest in 2 inexpensive mods to help it.

Transmission Cooler

Currently your transmission fluid is cooled along side your coolant in your radiator. Don’t worry they are kept separate! By investing in a separate cooler you isolate the fluids heat and give better cooling to your transmission. The cooler can be mounted in a variety of places, but its mostly up to you. People like to mount them in the lower grills. They can be had for a little over 50 bucks at almost all auto stores. B&M is a trusted name.

Shift Improver Kit
Do not get a cheap one that alters shifts electronically. They put extra pressure in the valve body and can be bad for the transmission. Look for the ones that modify the separator plates between the valve body and main control/fluid pan. B&M as well as Trans-go make a good shift kit. Another option for the Do It Yourselfer would be to go to http://www.tccoa.org”>TCCOA and look in their transmission tech articles for Jerry’s Mod.You may also be interested in one of the hand held tuners below will allow a tuner to firm the shift points up.

Torque Converter
The next logical step in automatic transmission modding would be to replace the Torque Converter. Most would recommend a 2800-3200 stall converter for a stock-modded 6′er. A new converter will help your launch nearly as much as the gears and T-lok. It’s been said to be like Gears part 2! Replacing the converter means removing the tranny and some don’t have the resources or the knowledge to do such a task.

Manual Transmissions
Well buds, theres some stuff that even you can do to improve performace. I have an auto so not much experience, but there are aftermarket shifters as well as clutches/flywheels for sale to beef your shit. Shifters will help you nail 3rd gear and give you shorter throws, while clutches/flywheels will give greater grip for launch and less rotational mass meaning quicker revs.

Aluminum Flywheel
Aluminum flywheels allow you to rev up faster while reducing drivetrain loss, resulting in more horsepower to your rear wheels, just by reducing the amount of rotating mass and force it takes to get the flywheel turning.

High-Performance Clutch Kit
Nothing sucks more than adding more horsepower to your Mustang and then getting to the track only to have your clutch fail after one or two passed. In order to prevent that you’ll need to get a high performance clutch. The most popular by far for Mustang owners is SPEC clutches. Check out the Stage 1 and Stage 2 to see which one you think is for you.

Short Shifters
The stock manual shifter leaves a lot to be desired. That’s why short throw shifters are all the crazy with Mustang enthusiasts. In fact, for some, it’s one of the first modifications they do to their Mustang. A short throw shifter is an excellent way to make driving your Mustang more enjoyable and comfortable. The Steeda Shifter below is one of the most popular shifters for the V6 Mustang.

Suspension
Suspension offers so much potential for almost any car is amazing. Almost anything can be turned into a corner carver with the right resources and knowledge. Our cars are great platforms for Auto cross racing. They benefit from better weight distribution and a lighter front end over a v8 model.

First step is usually springs, and do we remember Lesson 3? Do it all at once! So that means if your gonna do springs, do struts and shocks. You have to remove each to do the other.

Lowering Springs
Question what kind of drop your looking for. Ford C Springs are a nice choice for someone looking for a small drop(about .8 front 1.3 rear). Eibach springs are pricey, Ford C’s can be had for nearly $130 less than their Eibach or H&R cousins. Many recommend H&R if your looking for a bigger drop than 1.5″, although there are many satisfied Eibach customers out there. Just know that going over that 1.5″ mark will require Caster Camber Plates(“C/C Plates”) to correct your alignment.

C/C Plates
Highly recommended for anyone who has a lowered Mustang, Caster Camber Plates insures that your tires last as long as possible on your lowered Mustang.

Rear Sway Bar
Some lucky V6 Mustang owners have one from the factory. For those that weren’t fortunate enough to have one (go look!) this is a worthwhile investment as it greatly increases handling ability. No one likes the back end getting away from them in a tight turn.

Tubular Front Swaybar
Another great addition to suspension minded modders. Increase your V6 Mustang’s ability to maneuver through those turns by installing a Tubular Front Sway Bar. The Steeda below is top notch quality. 1994-1995 Mustang owners need to be sure to pick up end links while purchasing.

Shocks & Struts
Properly working shocks and struts are a must for a good launch at the drag strip or a good day on the auto cross track. They are also a must if you are lowering your car as your stock ones won’t last long with a decent drop. Think riding in the back seat of the Mustang sucks now? Just wait till your shocks and struts give out.

Other mods you can do to stiffen up your chassis are a Strut Tower Brace, Subframe connectors, jacking rails, and Matrix Braces (look for Kenny Brown). You can do Upper and Lower control Arms to give you better bite off launches and better handling through corners. You can pick up full replacement bushing kits and get rid of those tired worn out old ones and replace with stiffer performance ones. There are also lightweight K-Members, battery relocation Kits, Panhard Bars, coilover conversion kits and more!

Boltons
Ah finally the boltons! I’m going to go through from most beneficial to least on a STOCK engine. On engines with increased airflow due to a new top/bottom end my statements may not be true. I will clarify when I can.

The number one most beneficial bolt on? Why that’s a tuned computer.We talked about them briefly earlier but I can’t stress how important a good tune really is. It is what makes or breaks a well built car. Stock cars will benefit from increased timing, among better shift points, no speed limiter, higher revs, firmer shift points, and better cooling. You can re tune your computer using either a computer chip or a handheld tuner. Diablo, SCT, and HyperTech all make great products. I have a 4 position chip and I’m quite happy with it. I have a 93 octane tune, an 87 octane tune, an 87 gas mileage tune, and the stock program on mine. Tuners are the more expensive option, but you can download tunes through email and burn them to your car’s computer instead of having to send a chip back for a re-tune.

Underdrive Pulleys
Others may say otherwise but on my car it seemed like one of the more beneficial boltons Ive done. They will increase hp and tq throughout the RPM range, not just at the top like exhaust or a cold air. They also give better gas mileage. Kind of a counter to gears, they increase by about 1-3mpg. People say they have charging problems on high end systems due to their alternators not making a big enough charge. Theres a solution for you audiophiles. Alternator Overdrive pulleys!! They increase your charging! Or you could simply pick up a bigger alternator from jegs.com, cjponyparts.com, or ebay!

Exhaust System
This is a step 2 if you’ve already finished your engine. Don’t get shorty headers, if you have a 94-98 our headers flow very nicely stock, almost identical to aftermarket shorties. Longtubes are beneficial on both v6 generations, but require you to lift the engine some to install. Straight/H/X pipes are all a matter of personal preference to sound. We have an even firing engine so we don’t benefit from equalizing the pressure in two exhaust pipes with an x or h pipe. I wouldn’t go Offroad Midpipe, the v6 doesn’t sound to nice without cats. It gets whiny above 3000. You can have a shop cut your Y pipe behind the converters and weld 2 straight pipes to a set of GT take-offs or opt to have a fully made set delivered to your door. I own MAC exhaust and it sounds nice. Bassani sounds amazing on our cars. Borla is a tad pricey but you pay for the best. Once again foollow Lesson 3 and buy the whole system at once. It’s just easier that way.

Cold Air Intakes
They’re basically for show for V6 Mustangs. You will get a small gain from one, but nothing too noticeable. Look on eBay for cheap ones, about 100 bucks I got mine after shipping. They don’t suffer in quality at all. As long as you get once that is smooth inside instead of ridged like your stock airbox your accomplishing the basic concept. Look for one with minimal bends, I have been told one 90 degree bend is like adding 3 feet of straight pipe to your intake. There is no difference in the Blue Filters compared to K&N. The blues are made by Holley, same people that make Nos.

MAF and Throttlebodys
It may be different on v8′s, but make no mistake, these things you should wait until almost LAST on your list. A new MAF is not needed until you turbo or supercharge your car. 94-98′s can benefit from a new throttle body so long as it is matched to your upper intake when you have it ported. Never buy a MAF or throttle body until you have done some internal engine mods. They are an almost worthless ‘bolt on” and can actually hurt your performance.

After you’ve gotten to this point, and your not broke or happy yet there are still plenty of things to do. Like maybe changing that stock looking appearance you’ve been ignoring for so long. Or maybe opt for a Nitrous kit? How about a turbo/supercharger kit? All these extra steps come with extra precautions, so when in doubt call a mechanic or parts store and ask them what they think you should do.