What Performance Mods are good and gentle on the engine?
And what performance mods would boost hp but at the same time be harmful to the engine and thereby significantly reduce engine life time?

Headers, After-market Mufflers, Camshaft, Air Intake Systems, Thermostat, Fly-wheel, Trans-go... Ect.

Thanx in advance

 

Wheels, tires, brakes, pads, Zaino, paint, exhaust, intake.

As to headers, cams,... the stress level in the engine is primarily controlled by the driver via his right foot. I have seen seriously buit engines go 100,000+ miles with mature drivers; even used on road race tracks and still have long reliable lives. The key is driver restraint--but this does not mean the driver never uses the power, it means that the driver respects the power and the machine and does not drive the car to the breaking point.

 

Generally, bolt-ons (aside from super/turbo chargers) are gentle because they don't increase power by large amounts. The more power you add, the more stressed the engine will be. And different mods will affect certain components in a different way.

If you really want to feel the power without stressing the engine, add a lightweight flywheel, 4.10 rear end, and sticky tires. Of course then you're really stressing the drivetrain.

I think an intake, LT headers, an axle back system, and a mild tune is a great comprimise for good power gains and excellent durability. That's what I want to do with my car. Oh yea, and a 3.9 rear end for some extra kick.

 

[QUOTE=mlongo99If you really want to feel the power without stressing the engine, add a lightweight flywheel, 4.10 rear end, and sticky tires. Of course then you're really stressing the drivetrain.[/QUOTE]

The added rear gears take load off of the driveline, transmission, differential pinion; but add stress to the differential ring gear and half-shafts.

 

Gentle - Exhaust, headers, intake, ECM tuning (be careful here).

Less gentle, but still long-life potential- Limited use of forced induction (i.e. pre-engineered kit with 5-6 pouns of boot maximum), NO2 150HP shot, mild cams with matched valve-springs

Even less gentle - aggresive cams, raising redline above stock, aggressive forced induction or nitrous

Remember - your car is a system. You can add a decent cam and headers and stay within the operating parameters of the whole system, but you can easily overpower other parts. For example, the transmisson, differential, clutch, pistons/rods and wheels/tire are designed for 400Hp and 400 LB/FT, with some margin of safety (over-engineering). If you modify your car and start making 500HP, you eat into that margin. If you get traction, like drag radials, you can start breaking driveline components (clutch, diffs, trannys). If you get into 600HP N/A (naturally aspirated, meaning mods to heads, cams, other serious engine mods but no forced induction), with a stock short block, you will be revving your engine over 6500 RPM and will be seriously stressing the design parameters of the pistons, rods, and crank. Translation - broken engine.

My opinion for THIS car... if you're going NA, limit it to 500-550HP (about 440RWHP). If you want more than that, use forced induction like a blower or turbo.

SMM