GTI Jake
Autocross Champion
- Location
- Charlotte, NC
I realize everyone has their own opinions on mods, so don't take this as an attack or personal. I just feel like misleading marketing tactics are tricking several mk7 owners into believing certain products are required to see performance gains. While dyno charts can show before and after gains, they should also be taken lightly, since conditions and dyno calibration can drastically effect the results. They are simply used as a go/no go tool to test back to back set ups to make sure results net a gain in HP & TQ vs stock. With that said, any "performance" product sold without proof via dyno graph is not very likely to improve performance...otherwise they'd show off the results? Right? Right. So with that said, here's my non brand specific list of mods to avoid, or at least save for last on your mod list and considered "bling or dress up/cosmetics" even tho they're advertised as "performance". I know this will piss a lot of people off, so to them I ask this. Prove me wrong. Prove these products are worth the investment.
1. Turbo Muffler delete- So the outlet of our turbo is the same size as the turbo outlet pipe, which leads to the intercooler, throttle pipe, throttle body, intake manifold, then finally into the head. What little turbulence may or may not happen way back at the turbo muffler (or delete) has no measurable effect on the HP and TQ you feel from the drivers seat. It's purely deleting an acoustic device designed to tame the turbo noise for the masses...that's it.
2. Turbo inlet pipe- That little 90* bend at the inlet of the turbo connecting it to your intake, is it a restriction? Well, no. It's not. The inside diameter of the turbo compressor housing isn't getting any bigger just because you slightly increased the piping just before it. You could do dyno pulls with an open turbo, no inlet pipe or intake at all and the results would be nearly identical. The turbo is not restricted by the stock inlet pipe.
3. Turbo outlet pipe & throttle pipe- Yes, the stock units are plastic and not perfectly round tubing. So is our intake manifold. Guess what? Several cars are making over 400-500whp with all of that ugly plastic in place, because for our turbocharged 2.0 they flow just fine.
4. Cold air intake- The stock intake is well designed, and can very cost effectively be improved with a drop in filter. Dyno results prove that no intake no matter what brand or price point has ever improved power by more than roughly 10whp. Now consider that many intakes cost the same or more than a piggy back power module or real tune (which can add 30-80whp) where is your money better spent? 10<80...there no shame in going the drop in route or even a hated open intake. Both with get you that minimal hp gain, but without the $500 price tag the extravagant carbon fiber units carry (with the same gains)
5. Cat back exhaust- Dual tips, quad tips, ten tips! It doesn't matter, the stock catback is not a restriction even at 450+whp. Proven by the current 1/4 world record holders both gti & R are running stock cat backs. If you've met your power goals and want more aggressive tone go for it, but stock or not you're paying $500-2000 for sound, not HP & TQ. Our cars benefit greatly from a 3" down pipe (esp when tuned to match) and added bonus this also wakes up the exhaust note with most down pipes (excluding those with cat & res options to keep noise to a minimum). Look again at hp gained per dollar spent. How much is 20-30whp worth?
6. Catch cans- Direct injection allows boost and timing otherwise impossible to run safely on pump gas. It also has one drawback that comes to mind, carbon build up on valves. While any modern direct injected turbo charged engine will circulate some oil film/foam thru it's recirculated PCV system ours does a pretty good job of minimizing it. Regardless of installing a catch can tho, between the inevitable oil blow by (damn turbo) and carbon deposits left from direct injection, you WILL need to clean the intake valves. If emptying a can of soupy oil broth helps you sleep at night spend the money on a can, but either way you or your mechanic will be cleaning those valves someday. Nature of the beast.
7. Aftermarket DV, BOV & spacers- The stock DV or diverter valve cuts boost pressure then dumps it back into the inlet of the turbo. This being completely controlled by the ecu and working with our electronically controlled waste gate can adjust boost in fractions of a second to match the engines demands virtually instantaneously. After market DV use old school methods such as dumping boost atmospherically and or by vacuum actuation (simple spring and piston held open or closed depending on boost/vacuum in the charge pipes). Some even modified the stock valve to "ensure reliability" but at the end of the day there's no fault with your stock DV! No point in spending money on a part proven to support 500+ hp reliably.
8. RS7 coil packs- not proven to improve anything, and there’s nothing wrong with the standard coil packs on our cars unless they’re worn due to high mileage
Fire away, bring on the arguments. But if this helps a few members spend their mod money more wisely in the name of performance I've done my job. Bling mod advocates don't forget to bring your dyno graphs to back up you're explanation of why I'm wrong! Go!
1. Turbo Muffler delete- So the outlet of our turbo is the same size as the turbo outlet pipe, which leads to the intercooler, throttle pipe, throttle body, intake manifold, then finally into the head. What little turbulence may or may not happen way back at the turbo muffler (or delete) has no measurable effect on the HP and TQ you feel from the drivers seat. It's purely deleting an acoustic device designed to tame the turbo noise for the masses...that's it.
2. Turbo inlet pipe- That little 90* bend at the inlet of the turbo connecting it to your intake, is it a restriction? Well, no. It's not. The inside diameter of the turbo compressor housing isn't getting any bigger just because you slightly increased the piping just before it. You could do dyno pulls with an open turbo, no inlet pipe or intake at all and the results would be nearly identical. The turbo is not restricted by the stock inlet pipe.
3. Turbo outlet pipe & throttle pipe- Yes, the stock units are plastic and not perfectly round tubing. So is our intake manifold. Guess what? Several cars are making over 400-500whp with all of that ugly plastic in place, because for our turbocharged 2.0 they flow just fine.
4. Cold air intake- The stock intake is well designed, and can very cost effectively be improved with a drop in filter. Dyno results prove that no intake no matter what brand or price point has ever improved power by more than roughly 10whp. Now consider that many intakes cost the same or more than a piggy back power module or real tune (which can add 30-80whp) where is your money better spent? 10<80...there no shame in going the drop in route or even a hated open intake. Both with get you that minimal hp gain, but without the $500 price tag the extravagant carbon fiber units carry (with the same gains)
5. Cat back exhaust- Dual tips, quad tips, ten tips! It doesn't matter, the stock catback is not a restriction even at 450+whp. Proven by the current 1/4 world record holders both gti & R are running stock cat backs. If you've met your power goals and want more aggressive tone go for it, but stock or not you're paying $500-2000 for sound, not HP & TQ. Our cars benefit greatly from a 3" down pipe (esp when tuned to match) and added bonus this also wakes up the exhaust note with most down pipes (excluding those with cat & res options to keep noise to a minimum). Look again at hp gained per dollar spent. How much is 20-30whp worth?
6. Catch cans- Direct injection allows boost and timing otherwise impossible to run safely on pump gas. It also has one drawback that comes to mind, carbon build up on valves. While any modern direct injected turbo charged engine will circulate some oil film/foam thru it's recirculated PCV system ours does a pretty good job of minimizing it. Regardless of installing a catch can tho, between the inevitable oil blow by (damn turbo) and carbon deposits left from direct injection, you WILL need to clean the intake valves. If emptying a can of soupy oil broth helps you sleep at night spend the money on a can, but either way you or your mechanic will be cleaning those valves someday. Nature of the beast.
7. Aftermarket DV, BOV & spacers- The stock DV or diverter valve cuts boost pressure then dumps it back into the inlet of the turbo. This being completely controlled by the ecu and working with our electronically controlled waste gate can adjust boost in fractions of a second to match the engines demands virtually instantaneously. After market DV use old school methods such as dumping boost atmospherically and or by vacuum actuation (simple spring and piston held open or closed depending on boost/vacuum in the charge pipes). Some even modified the stock valve to "ensure reliability" but at the end of the day there's no fault with your stock DV! No point in spending money on a part proven to support 500+ hp reliably.
8. RS7 coil packs- not proven to improve anything, and there’s nothing wrong with the standard coil packs on our cars unless they’re worn due to high mileage
Fire away, bring on the arguments. But if this helps a few members spend their mod money more wisely in the name of performance I've done my job. Bling mod advocates don't forget to bring your dyno graphs to back up you're explanation of why I'm wrong! Go!
Last edited: