What exactly does tuning internals consist of ?

[Joey_112]

I bought a 2003 Jetta GLI almost a year ago and now want more power. It's completely stock. Before I just start adding performance parts I wanted to make the motor be able to handle the power instead of eating away at the motor and transmission. My best friend races a Honda hatch and that motor has been blown 3 times. I want to prevent that from happening. What is the best way to tune a motor from the inside out to handle high red lines and really pushing the car?

[GoFaster]

First what's needed, is a basic understanding of what the weak points are in the particular engine under discussion, for the application in question, and what would be beneficial to change (even if it's not a "weak point" as such).

What would be a weak point in one set of circumstances might not be the weak point in another set of circumstances, you have to consider the application. If someone doesn't want massive revs but does want massive boost pressure, they're going to run into a different set of issues than someone who wants to rev the engine to the moon.

If the weak point is the rods, you use stronger rods. If the weak point is the head gasket, you O-ring it. If rapid acceleration is called for, you lighten moving parts. If high revs are called for, you balance everything to reduce vibration.

This is not a simple business, because frequently what's done as a countermeasure for one issue creates other problems that have to be dealt with in turn.

[emkaytree]

I bought a 2003 Jetta GLI almost a year ago and now want more power. It's completely stock. Before I just start adding performance parts I wanted to make the motor be able to handle the power instead of eating away at the motor and transmission. My best friend races a Honda hatch and that motor has been blown 3 times. I want to prevent that from happening. What is the best way to tune a motor from the inside out to handle high red lines and really pushing the car?

For a track car on 2.0, turbo is your only option. Stock 2.0's can handle allot. They like small quick spooling turbos with high PSI, that would be equal to a big turbo low PSI. There are also kits out there for them, look up the kits made by kenetics. Stage 1 kenetics needs nothing. I think 2 and 3 with better parts/intercooler need built internals, but that is all, no balancing parts, stock head etc.

Your 2.0 already has a metal head gasket and 20% differential factory, which is a good thing going for you. The motor won't blow like his A: it's quality, iron block that is more durable with boost B: your trans is good. The trans will however need to be removed for 1: clutch upgrade, rear main seal 2: differential bolt kit. The stock rivets can fly out under a modded car and cause some nasty damage. The gears in the trans and the rest of it is strong, Dan J Reed has a GREAT page on modding the trans with bolts, making it high hp ready.

Before adding boost, if over 150k miles, I would rebuild it with an oem kit if you are planning stage 1 or small turbo. It's not expensive to rebuild these cars, it's just some thin metal parts rings etc, and cleaning. Forged parts will be more expensive. You will have to do researching to see what is going down.

If you only want straight line, a properly installed, introduced, and used no2 (lol nos) system, with WOT switch, would serve you well, and you could keep the on road reliability when not using it.

[HavokRuels]

Gli meaning 2.0 Wolfsburg or 1.8t???

If its a 2.0, no offense, don't bother spending money on it

1.8t, I would suggest "go big or go home" overkill on everything. Arp bolts and studs everywhere internally, upgraded rods, cams, manual tensioner timing belt assembly, etc etc