Key Considerations when modifying your Car


Modifying Cars

We all have our passion for cars, and nothing makes a better statement about our passion for cars like our very own modified ride. Everyone has their own goals for their cars. Some focus on the exterior, going for a customized appearance that sync to their personality and passion. Let’s call these bunch of people ‘Showboats’. Then there are those who focus on what’s under the hood, trying to make a daily commuter car into a bat shit insane fire breathing powerhouse that can shame some exotic supercars. These people can be commonly referred to as ‘GearHeads’. Then there are those who focus on the In Car Entertainment, making their cars into a rolling audio visual powerhouse that can put some of the most exotic clubs to shame. These people are also called the ‘ICE Crew’. But what unites these vastly different groups of people is their simple undying passion for cars and modifying them to suit our lifestyles.

Most of you reading this article already have or one day will own a car that you put your hard work and sweat to modify. And after modifying it, you’d like to keep the car running in perfect condition for as long as you own it. So keeping that in mind here’s is the Car Guy’s mini Bible to building and maintaining a modified car. This will be a bit more focused towards the ‘GearHead’ crowd but the other two can get a few tips out of this as well.

“It’s STILL a commuter car underneath dummy!” – Part 1

Let’s face it, sports cars are called sports cars for a reason. They are built ground up for a single purpose, to be driven hard and withstand abuse. All the wear and tear components: mounts, brakes, rubber bushings, suspension, clutch etc. on the car are designed to take whatever abuse you as a driver can throw at them. The engine is designed so that it can withstand being driven at 8000rpm for long durations and gearbox will shifts every time at that engine RPM and the clutch bearing wont explode from repeated engagement.

The commuter cars we drive and love to modify and extract more performance out of ARE NOT DESIGNED for the same abuse. We keep modifying the engine’s power output, but generally tend to ignore the other components which often lead to catastrophic failures or make the car totally un-driveable daily. Even sports cars that are based on commuter cars such as the Mitsubishi Lancer Evolution, have 250-300 additional welds, braces, mounts etc. to be able to match the chassis performance of a proper ground up sports car like a Ferrari. So just because your Skoda Laura VRS looks like sports sedan, doesn’t mean it is designed to withstand the abuse of 24/7 sports car level of driving style without developing major rattles and wearing out bushings.

So when you do set out to modding your car, approach it in a holistic manner rather than just ‘MOOAR POWER’ and damn everything else way.

“Know Thy Car and Understand WTF you’re going to do to it!”

Before going out and spending your or your family’s hard earned money on a mod, do your research. Don’t just go blindly with what a garage or a friend tells you is best for the car. The internet is your best friend here. There are a gazillion forums (not the Indian ones) out there with a lot of useful information specific to your car and the modification you’re looking at doing. Go read these forums, sign up and become a member. Most of these are free to join, post and ask questions and there are several threads and posts already about the questions that you may be asking. Don’t be afraid to look like an idiot, and never feel shy to as the most obvious questions, as the answer to them may not be as obvious. You learn about your car by reading, questioning, verifying and reading again. Multiple forums may have different opinion about the same mod, so go thru them, ask your questions and form your own opinion. Chances are that 99.9% of the time, the mod your planning has already been done. Forums also offer a source of trouble shooting issues and some of the large aftermarket vendors have dedicated forum reps online. So go in there, state your issue, interact with these reps and they along with the whole community will work with you to find a solution to your issues.

“It’s STILL a commuter car underneath dummy!” – Part 2

Now that you have your goals set for your car, do a rough estimate on how much it’s going to cost. Go a visit a few tuning shops and garages in your city and speak to the owners, managers, staff to get a good idea of their capabilities and mind set and make sure it suits your own. Not every workshop manager can get along with all kinds of people although they try their best to! Same goes for you, so choose a workshop that can get along with your mind set.

Don’t blow your load

Keep a realistic power goal in mind. Most engine block are designed to take about 150% more stress than the OEM power levels. On some turbo charged cars that happen to share parts with their higher power output counter parts, the engines can take up to 300% power levels over OEM without any modifications to it. However at this power level you will need upgrades to the cooling and oiling system. So get a good idea of how much stress your OEM block can take. Choose your platform accordingly. No point taking a high compression engine like the Honda 3.5L v6 and adding forced induction to it. ‘Yes’ it will work, ‘No’ it won’t be cheap to build as your putting forced induction into an engine that is not designed for it, and ‘HELL NO’ it won’t be reliable because the engine block and engine systems as a whole is not designed for it.

Banging Gears

If you set out to extract 2x power out of your engine block, make sure the gearbox outfitted to that soon to be 2x power engine is capable of handling that power level. Most gearboxes can, but if you pick up a Maruti 800 and put 500NM thru its OEM gearbox, know that things are going to break sooner than later and it’s going to be an expensive fix.

Gearbox Good? Next make sure that the clutch your car comes with can handle the extra power that your car is expected to make. Please note that all clutch kits are rated to hold up to a certain level of Torque, not horsepower. So get a good idea of how much torque your build is going to make and select the clutch accordingly. Also most good clutches come as part of a 1, 2 or 3 piece kit. There is just uprated clutch kit (1 piece), uprated clutch disc and uprated pressure plate (2 piece) or uprated clutch disc + uprated pressure plate and a lightened flywheel (3 piece). Most kits are designed to reuse the OEM throw out bearing (ToB) but some 2 and 3 piece kits come with their own ToB that are matched to the new clutch disc cover.

Another thing that most commuter cars with hydraulically actuated clutch systems come with is a clutch delay valve. This valve adds a delay in the clutch engagement so as to smoothen the engagement in case of an improper gear change. These valves are usually located in a fitting on the clutch line or integrated into the clutch slave cylinder. This works wonders for new or casual drivers but in a race car it’s a pain in the arse! There are several solutions available for removal of this valve from simply using a drillbit to drill out the valve, to replacement of the valve fitting or the clutch slave cylinder with one that doesn’t have the valve. Hint: Most aftermarket clutch slave cylinders don’t come with the valve as it’s a complicated and expensive part to integrate into the cylinders.

‘Map or Box?’

Now that you’ve confirmed that your car’s engine and transmission are good for uprated power, and there are parts that help increase power on your engine available in the market, you need to decide how you are going to program your car’s ECU for that extra power. Two options exist: Re-Map or Tuning Box.

A remap is simple, it’s like a custom ROM/OS for your smartphone. A re-written version of the ECU programming, with parameters customised to account for all the mods you have on your car. These are usually the best options for modded cars, as they mostly keep all the OEM safety features in check and the ECU in the car knows what’s going on in the engine at all times. Remaps are available from several different tuners. Always go for a well-known tuner and keep the tuner informed about what all parts you have on your car before they remap it.

A tuning box is slightly complex. It’s essentially a device that fools the OEM ECU to thinking it’s not making its target power and then the ECU compensates by trying to reach its target power levels. The tuning box does this by sitting in between various sensors that the ECU uses to control the car, and modifies the signal going from these sensors to the ECU with different values. For example, if your factory ECU is tuned to generate 10psi boost and add fuel accordingly, the Tuning Box will tell the ECU its generating 8psi boost when it’s actually at 10psi. ECU will then change its parameters with its own limits asking the car to add 2 more psi of boost so that it can see the target 10psi. But in essence it’s actually asking the car to make 12psi. This is an over simplified example, but this is the way a tuning box works. Signal Intercept and Signal Modification. Now most modern tuning boxes have come a long way and some modern boxes can completely take over the ignition control, fuelling and boost control from the ECU and act as a semi-standalone ECU. Either way, a tuning box is a bad idea for larger powerful builds unless there are no remaps available for the factory ECU or the factory ECU does not have enough memory to support a larger map that you will need to run your build. Choose wisely.

‘I need to breathe!’

An engine is basically an air pump. Air goes in, magic happens, air goes out. Somewhere in between is a commuter car factory air intake designed to reduce intake noise instead of increasing air flow, a filter designed for longevity instead of free flow and a ‘noise free’ exhaust that is trying its best to reduce noise and emissions by restricting exhaust flow. All the above needs to be addressed and upgraded parts need to be installed accordingly if you’re going to make your target power levels. Easier air in, easier air out, and the magic in between amplifies! No an aftermarket muffler does NOT add power. Nor does an open intake filter sitting right next to your engine sucking in hot air from a closed engine bay.

‘Keep it Cool Bro!’

Congratulations, your car is now generating more than it’s supposed to! While it’s making more power, it’s also generating more heat, much more. Some turbo cars use the engine coolant to cool the turbo propeller shaft and engine oil to lubricate it. So increased boost leads to increased heat transfer to the coolant and the engine oil. Finally some turbo cars also have a liquid cooled intercooler that uses the engine coolant to cool the compressed charge air entering the engine like the GT TSI. Now if your coolant is already at 120 degree, and your air coming out of the turbo is at 150 degrees, imagine the air at the combined temperature of the two, going into you’re cylinder and mixing with fuel. Hello Knock!

And heat is the enemy of any engine. Excess heat leads to degradation of engine oil, higher cylinder temps, low power output, bad fuel economy, and overtime can lead to seals, gaskets and parts melting eventually leading to engine failure. Again most cooling systems in cars (radiators, coolant pump, thermostats etc.) are designed to handle variations in heat levels to a certain degree. But most likely any major build is going to put your cooling system outside its comfort zone. So either upgrade the components (larger radiator, better thermostat, stronger coolant pump) or say ‘bye bye’ to the longevity of your engine. Oh and while you’re at it, get a better coolant as well as they have a higher boiling point and can extract heat faster from the block and into the radiator

I’ve seen several engines blow due to the cooling system not being able to take the extra stress generated by heavy engine and power mods. So glance at the temperature gauge once in a while when you are out driving the nuts off the car. For cars that run on the track, it’s advisable to remove the rubber weather strip from under the hood before you get to a track day or when you are in a mood to drive the nuts off the car. The sole purpose of this strip is to keep rain water from getting into the engine bay. And in doing so, it’s also keeping heat from getting out. So removing it, allows heat to get out. In my car the under-hood temperatures dropped by about 40 degrees from removing the weather strip, and it finally stopped overheating on track as the hot air from the engine bay was able to escape. Yes it works! Also remember to put it back on after a track day or your car cleaning boy might just put water into the engine bay which is not a good idea at all.

For serious racers, it’s a good idea to invest in an upgraded aluminium radiator, better thermostat (if available) and some good high temp coolant. Also some hood vents won’t hurt either.

‘Do you even Brake Bro!’

 Now that your car is making 150%+ more power than its came from the factory with, you need to to stop 150%+ faster than you normally would. What this means is that the factory braking system of your commuter car will eventually call it quits and you will fly off a cliff in a blaze of glory. Unless you like that picture, I’d recommend you upgrade the braking power of your car in a similar fashion that you upgraded your engine. Fortunately due to regulations most car braking systems are horrendously over engineered to take a beating. But that beating comes at the cost of added wear and tear.

First mod for brakes is getting better brake pads that are designed to operate at much higher temperature than the OEM ones without fading. Next cheap mod is steel braided brake lines. The OEM rubber brake lines blow up like balloons when hot and are unable to transfer the full braking force to the brake callipers. The steel braided brake lines prevent this from happening, keeping the brake line structurally intact and ensure the full pedal pressure is transferred to the brake calliper.

Next mod are better brake discs. Slotted or drilled or both. These discs let the hot gases trapped between the pads and discs escape providing better cooling. They are usually made of better material than OEM discs so their resistance to overheating, warping is much more than the standard OEM discs.

The last mod is better brake fluid. Any super DOT4 or DOT5.1 brake fluid should be good enough. The good part is that most high performance racing brake fluids are also available via now. These fluids have much higher boiling point than the regular commuter car fluid and significantly reduce brake fade.

So go ahead and get some Motul RBF 600/660 or Castrol SRF brake fluids and bleed your brakes properly. Also keep a note that some car with hydraulic clutch controls use the brake fluid to actuate the clutch. So when you’re bleeding the brakes on these cars, also bleed out the clutch line as well to ensure no bad fluid is left in the system.

Most of the time you should be able to get away with a brake pad change. Brake line changes are an added bonus. Disc change is the last thing you should change out as these are expensive. General rule of thumb is that a power increase of up to 130-150% over stock, the OEM Braking system can take it. In the rare case you’re generating over 200% more power than the factory car, you will need to upgrade to a Bigger Brake setup. This can be either the brakes of a more powerful model of your commuter car, or a full on aftermarket setup with fixed callipers and larger discs from companies like Brembo, Tarox, D2, Alcon, Stoptech, Baer etc.

While changing your pads, don’t let the calliper hang and dangle away hanging by the brake line. This is an absolute nono. I’ve seen several shops do this and this weakens the line, stresses the seals and allows air into the system by stressing the seals and the result is a soft brake pedal or worse a leaking line at the calliper.

Also bleed the brakes properly. A good old fashioned manual bleed will work on non ABS cars, but cars with an electronic ABS controller will need a pressure bleeder, no questions asked. Also when pressurising your braking system for a bleeding via a power bleeder, make sure the pressure is not more than 15PSI. DON’T reuse old brake fluid or even new one that has come out of your braking system. And don’t forget to top off the master cylinder reservoir after your brakes are bled.

‘What’s all that Screeching Yo!?!’

No point of making a 1000hp if you are going to end up sitting at a stop line burning rubber while the Toyota corolla next to you makes you look stupid with its clean take off. Nor does it help to have a 200hp car understeer off the track while a 105hp car goes thru the corner hitting the apex. Power and control come hand in hand. Now that you have power, work on the way that power is put down to the ground. First step is increase the contact patch of the tire, also known as wider tires. Chances are that your commuter car came with cheap econo tires and a tire width designed for fuel economy and will give up at the first sign of real torque or the need for lateral grip. Wider and stickier quality rubber helps put the power down!

Chances are that the suspension of your commuter car is designed for comfort and safety and will dip, dive, squat and understeer at the first sign of aggressive driving. Upgrading your suspension can offer huge rewards as it significantly improves your car’s ability to put down the power in a straight line and in corners. Several options available here from simple uprated springs, shocks and anti-roll bars to full on coilover spring and damper kit. Lots of people take the cheaper option of just going for springs, and end up with blown dampers due to the extra load on them. So do your research on whether the OEM dampers can take the extra load due to the lowering spring.

Pick your poison based on the usage and road conditions around you as that lowered stiff car will still have to come home thru the brilliantly engineered roads of India.

‘Maintenance, cuz Bae ain’t cheap!’

Now that you have your #RaceCar #BuiltNotBought, time to maintain it properly. A modified car requires more maintenance than the factory econobox you bought. A modified car will break down engine oil faster, wear out coolant more, eat up brake pads and brake discs faster. Keep a check on the engine vitals, check your oil before you go out for a hoon ride. Keep extra engine oil and coolant in the car. Keep a check on the degradation of various rubber hoses in the engine bay.

Reduce your service intervals. If the service manual says 14000km, reduce it to max 8000km if you’re beating on your car daily or it’s seeing a lot of track duty. Ideally a 9000km service interval is recommended for any modified car that’s generating ~150% more power than it came with from the factory. More power and prolonged aggressive driving will also wear out the several rubber bushings on your engine mounts and suspension components. A normal bushing set of a commuter car is expected to last at least 40,000kms. In a modified car that is driven hard, you will be lucky to get 20,000kms out of them. So budget accordingly. No point throwing away good OEM mounts and bushings, but keep an eye on them and replace them with stiffer uprated ones as and when they show signs of fatigue and wear. Note that the uprated mounts and bushings will add more noise, vibration and harshness to the car. So pick your uprated mounts accordingly.

“It’s STILL a commuter car underneath dummy!” – Part 3

And don’t you forget it! At the end of the day your #RaceCar is still a commuter car underneath. So its chassis and other components that you may not have upgraded aren’t designed to take constant abuse like that of a sports car would. So drive it accordingly. If you need to use the car daily, back off a little, don’t go all our every time you get into the car. Do it once in a while and drive normally at times. Take care of the car and it will keep rewarding you. Drive it like you stole it every day and every night, and you’re going to be replacing parts every few months if not sooner or worse!