How to modify your car - Stage 2
1. Performance suspension kits:
With the additional power that your engine is churning out by now, increased grip levels are a must. There are plentiful branded options available for performance struts, coils, coil-over springs, dampers (shock-absorbers) and camber kits (Polyurethane bush kits).
2. Head Porting & polishing:
Cylinder head porting and polishing refers to enlarging and smoothening of the ports on the intake and exhaust. This results in better quality and quantity of gas flow-rates. Power gains are very noticeable from a high-quality porting and polishing job. Remember that the intake ports need to be finished rough while the exhaust ports should have a mirror finish.
3. Removing the revv-limiter:
A fairly simple modification which any ECU specialist can implement in a very short time. Your cars manufacturer-set rpm limits will be raised but you also need to check if your engine internals can take the additional stress. It wont lead to a power increase with all engines; yet can be a useful tool in improving lap times (holding a gear longer) and acceleration (one less up shift for 0 - 100).
4. Nitrous oxide systems:
NOS, as they are popularly called, are cheap power shots and a favorite with drag racers. Due to the inherent nature of the gas, it is a very risky installation. Don’t go overboard with the dose else your engine will end up blown. Also make sure that you back the timing off by a few degrees. Take a look at this guide on setting your car up with nitrous.
5. Performance camshafts:
Performance cams are a superb modification and can add upto 10% - 20% more power, with options available for low, mid and high-rpm gains. An increase in compression ratio is highly recommended. Also insist on a cam adjuster (variable cam pulley for adjusting cam timing) to realise the full gains of the cam. It is important to avoid over-cam'ing while the more extreme profiles will surely require head work. High lift cams cost a packet and are not recommended for daily-driven cars since the low-end response is compromised, fuel-efficiency takes a beating and you will need to fiddle with idle settings to get it right.
6. Map sensor signal modifiers:
These can improve part throttle performance, but will result only in marginal performance gains.
7. Valve angling:
A multi-angle valve job can lead to noticeable street performance gains by improving the head flow. Note that this is a highly precision-oriented task.
8. Over-boring / Stroker kits:
Over-boring is increasing the CC (cubic capacity) by changing the piston size and stroke of the engine. Pistons, connecting rods and the crankshaft will need to be replaced. Simply put, bigger engine size = more power. For e.g. a 1.3 liter can be overboard to 1.5 liters in capacity.
9. Piggy-back ECU's:
Piggybacks are additional engine control units that work along with the standard ECU. They enhance engine performance and leave the non-engine electronic work to the standard ECU. A piggyback modifies some signals (sent back to the ECU) and plays around with the performance parameters only (fuel injection, timing etc.). Fuel controllers adjust the fuel mapping and allow the engine to increase its power output. An example of a fuel computer is the ApexI S-AFC. They offer a multitude of adjustments whereby you can run rich or lean, depending on the driving conditions. It is imperative for the piggy-back to be compatible with your ECU. Remember that the AFR signal adjustment is to be done only in tandem with a wide band AFR kit. Leave the tuning part to an expert.
10. Engine remaps:
An ECU flash will give you higher power gains than a piggyback, by changing the entire characteristics and settings of the factory software. There are ready performance remaps available for a wide range of Indian cars and the installation procedure is fairly simple. If you plan on going further to stage three modifications, do the remap at the very end. Any reputable company is going to account for your full mod list in order to give you the best remap. Do the remap last, unless you want to do it twice.