Audi TT Forum banner
1 - 13 of 13 Posts

·
Registered
2008 TTS
Joined
·
1,525 Posts
Would definitely agree, it's a must do mod
Anyone else reading this thinking about exhuasts...
Downpipe over a cat-back should always be done!
much more noise increase and also performance increase for a similar price, you just don't get a nice new set of shiny tips :ROFLMAO:
 

·
Registered
2012 Stage2 TTS coupe
Joined
·
2,226 Posts
MarkTheShark said:
Ok i will. Is the cat part of the downpipe? That would complicate things.
A downpipe replaces your primary cat. Removal will likely throw an O2 sensor error unless it is mapped out (usually part of a Stage2 map). Sometimes you can get lucky by using a spacer but there is no guarantee.

A secondary cat is necessary to pass MOT / emission inspections and should be replaced with a high-flow sport cat. Going 'catless' is enviromentally unfriendly and provides zero performance gain. The only reason to go catless is to save money at the expense of others.
Bicycle part Gas Audio equipment Engineering Composite material


Automotive lighting Hood Automotive design Motor vehicle Automotive exhaust
 

·
Registered
Joined
·
752 Posts
Yep, stuff like intakes and "catbacks" are mostly meaningless when it comes to performance. Downpipe and tune, much more important and if you don't have an unlimited budget those are the things you should spend money on first (for performance) on a standard output 2.0T.

That's why I always thought the TT-S was the simplest of the bunch to add the most "OE+ daily driver" performance to, without having to keep spending.

To end up at similar performance across the three main 2.0Ts:

TT-S (EA113 HO):
-Downpipe
-HPFP (upgraded piston)
-Tune

TT 2.0T (EA113 standard output):
-Downpipe
-K04 turbo
-Upgrade injectors
-HPFP (upgrade piston)
-Tune
-Upgrade intercooler
-Larger brakes

TT 2.0T (EA888 standard output, or VL ed.):
-Downpipe
-K04 turbo
-Tune
-Upgrade intercooler
-Larger brakes

List is longest on the lower output EA113s since you need to upgrade the injectors but none need an intake or exhaust to do much of anything. Obviously one could go much further than this do a lot more, but this is pretty much the most basic list you need to do to get to that same OE+ level presuming you want to maximise driveability for a "daily", don't need to do any track work, and want to keep it simple.

One could arguably use a Frakenturbo or TTE or GTX, etc. instead of a K04 but the bigger turbo you use the more low-end you lose out on, the less of a daily driver it becomes, and the cost starts shooting up exponentially from there (building the engine, upgrading the transmission, for example). Also I wouldn't even bother upgrading the intercooler on the lower-output engines (I would just add w/m instead) but just listed to show the things the S already has by comparison.
 

·
Registered
2012 Stage2 TTS coupe
Joined
·
2,226 Posts
TT'sRevenge said:
That's why I always thought the TT-S was the simplest of the bunch to add the most "OE+ daily driver" performance to, without having to keep spending. ->snip

snip-> List is longest on the lower output EA113s since you need to upgrade the injectors but none need an intake or exhaust to do much of anything. Obviously one could go much further than this do a lot more, but this is pretty much the most basic list you need to do to get to that same OE+ level
The other point that should be considered when comparing motors is the EA113HO used in the TTS was purpose-built by Audi to handle the additional stress that comes with increased horsepower.
You can built up a standard EA113 / EA888 to TTS power levels but your underlining foundation (the bones) supporting your upgrade (the muscle) is weaker and therefore more prone to failure.
 
  • Like
Reactions: TT'sRevenge

·
Registered
TT 2.0 TFSI (FWD, EA888, CESA)
Joined
·
13 Posts
Yep, stuff like intakes and "catbacks" are mostly meaningless when it comes to performance. Downpipe and tune, much more important and if you don't have an unlimited budget those are the things you should spend money on first (for performance) on a standard output 2.0T.

That's why I always thought the TT-S was the simplest of the bunch to add the most "OE+ daily driver" performance to, without having to keep spending.

To end up at similar performance across the three main 2.0Ts:

TT-S (EA113 HO):
-Downpipe
-HPFP (upgraded piston)
-Tune

TT 2.0T (EA113 standard output):
-Downpipe
-K04 turbo
-Upgrade injectors
-HPFP (upgrade piston)
-Tune
-Upgrade intercooler
-Larger brakes

TT 2.0T (EA888 standard output, or VL ed.):
-Downpipe
-K04 turbo
-Tune
-Upgrade intercooler
-Larger brakes

List is longest on the lower output EA113s since you need to upgrade the injectors but none need an intake or exhaust to do much of anything. Obviously one could go much further than this do a lot more, but this is pretty much the most basic list you need to do to get to that same OE+ level presuming you want to maximise driveability for a "daily", don't need to do any track work, and want to keep it simple.

One could arguably use a Frakenturbo or TTE or GTX, etc. instead of a K04 but the bigger turbo you use the more low-end you lose out on, the less of a daily driver it becomes, and the cost starts shooting up exponentially from there (building the engine, upgrading the transmission, for example). Also I wouldn't even bother upgrading the intercooler on the lower-output engines (I would just add w/m instead) but just listed to show the things the S already has by comparison.
may i ask why upgraded HPFP and injectors aren't required for the EA888 engine?
also, i dont intend to upgrade the turbo, do i need to upgrade the intercooler?

currently induction kit, downpipe (decat), stage 1 superchips/bluefin remap with o2 delete (on its way), and forge blow off adapter cos i like the noise lol.
 

·
Registered
Joined
·
752 Posts
may i ask why upgraded HPFP and injectors aren't required for the EA888 engine?
Simply because they are already up to the job of fuel delivery for a K04 and a tune. The HPFP is a much better design to begin with (no stupid flat follower to replace periodically), and it also has the capability of flowing more in stock form. The stock HPFP for the EA113 is enough to carry a ~300hp tune on the K04 (both on the HO engines and the std. output) and it's actually okay at higher RPM for more output, but the real problem is in the mid-rev range it can't provide enough fuel so the engine can become dangerously fuel-starved, if not upgraded, on a typical "full" K04 tune. Various tuners do offer a "downgrade" tune if you haven't upgraded the HPFP on these engines, with free upgrading to the "full" tune, once you have.

This is IE's explanation, taken fro their site:
IE High Pressure Fuel Pump (HPFP) Upgrade Kit for VW & Audi 2.0T FSI & 4.2L FSI Engines
Integrated Engineering said:
As you can see on the dyno chart to the right, the factory fuel pump is out of fuel much earlier than the IE HPFP. Although it is capable of over 350hp at 7000rpm, it does not provide nearly that much in the lower rpm range where most quicker-spooling setups see peak power numbers.
As for the injectors, the standard output EA113s simply used lower-flow injectors that can't keep up so those must be replaced for anything more than the factory K03 turbo. On the HO versions (that already have a K04) they used better ones, which don't need upgrading until you get into big turbos. Remember the DI EA113s were first-gen turbo DI engines, where the costs of things were probably at their highest due to it being newer engine tech at the time. So why the EA888 doesn't suffer from that is likely due to economies of scale and injectors with a higher flow rate then becoming cheaper for Audi to use in even the "base" engine (we wouldn't see a HO version of the EA888 until Gen 3).

The EA888 does have the issue of some engines having "weaker valve springs", however. The early ones didn't have this problem but the later Gen 1s Audi used cheaper valve springs I guess. This creates a problem with the K04 in particular, where the valves can get held open by exhaust back pressure. The problem doesn't occur on larger turbos, nor obviously on the factory IHI turbo. The phenomena is explained here:

Note though that I actually have what APR identified as the "weaker" springs in the pictures in my A3, yet mine is fine (and has been for years) with a K04 on a Unitronic tune. Now that may be because of differences in tune between Uni and APR or it may be that I'm just lucky but thankfully I didn't have to replace my valve springs--that was a job I was not looking forward to!

also, i dont intend to upgrade the turbo, should i still upgrade the intercooler?
currently induction kit, downpipe (decat), stage 1 superchips remap with o2 delete (on its way), and forge blow off adapter cos i like the noise lol.
Everyone is going to have a different take on this and these are all just my opinions but I don't think you should bother...

There's two (actually three) upgrade paths you can take for the intercooler--one is to use the factory intercooler from the HO cars (TT-S/S3), or go with a full aftermarket one. The thing about the intercooler is I don't think any tune, even for a K04, is going to cause the engine to run dangerously should you not upgrade the charge cooler. The main reason for this is they always have to account for a full intake temperature range because even an upgraded intercooler can end up running just as hot as the stock one. I/Cs don't do anything if they have no airflow over them--so if you're idling, stuck in traffic, etc., it don't matter what I/C you have, the intake temp will end up rising to the same level. An air-to-air I/C is only effective when the car is constantly moving with enough velocity. You would certainly see lower temps comparing both I/Cs with the car moving, but not moving enough, is the story above.

The "third path" is to not upgrade the intercooler at all. In climates where it doesn't get that hot for that much of the year one may opt to forego it; though in summer it surely gets hot enough to benefit from an upgrade there, one might not think it worth it. Additionally, using water/meth injection is a better charge cooler than any air-to-air cooler could hope to be. So using the money towards adding that (and not bothering with the I/C upgrade) is arguably a better idea. In fact it's what I would do if I did it over again. Because w/m has the added benefit of keeping the intake valves clean, in addition to being a better intercooler than an upgraded [air-to-air] intercooler. Of course with w/m you do have to keep the alcohol filled, which is an added expense over already skyrocketing fuel prices.
 
  • Like
Reactions: EGZ

·
Registered
TT 2.0 TFSI (FWD, EA888, CESA)
Joined
·
13 Posts
Simply because they are already up to the job of fuel delivery for a K04 and a tune. The HPFP is a much better design to begin with (no stupid flat follower to replace periodically), and it also has the capability of flowing more in stock form. The stock HPFP for the EA113 is enough to carry a ~300hp tune on the K04 (both on the HO engines and the std. output) and it's actually okay at higher RPM for more output, but the real problem is in the mid-rev range it can't provide enough fuel so the engine can become dangerously fuel-starved, if not upgraded, on a typical "full" K04 tune. Various tuners do offer a "downgrade" tune if you haven't upgraded the HPFP on these engines, with free upgrading to the "full" tune, once you have.

This is IE's explanation, taken fro their site:
IE High Pressure Fuel Pump (HPFP) Upgrade Kit for VW & Audi 2.0T FSI & 4.2L FSI Engines


As for the injectors, the standard output EA113s simply used lower-flow injectors that can't keep up so those must be replaced for anything more than the factory K03 turbo. On the HO versions (that already have a K04) they used better ones, which don't need upgrading until you get into big turbos. Remember the DI EA113s were first-gen turbo DI engines, where the costs of things were probably at their highest due to it being newer engine tech at the time. So why the EA888 doesn't suffer from that is likely due to economies of scale and injectors with a higher flow rate then becoming cheaper for Audi to use in even the "base" engine (we wouldn't see a HO version of the EA888 until Gen 3).

The EA888 does have the issue of some engines having "weaker valve springs", however. The early ones didn't have this problem but the later Gen 1s Audi used cheaper valve springs I guess. This creates a problem with the K04 in particular, where the valves can get held open by exhaust back pressure. The problem doesn't occur on larger turbos, nor obviously on the factory IHI turbo. The phenomena is explained here:

Note though that I actually have what APR identified as the "weaker" springs in the pictures in my A3, yet mine is fine (and has been for years) with a K04 on a Unitronic tune. Now that may be because of differences in tune between Uni and APR or it may be that I'm just lucky but thankfully I didn't have to replace my valve springs--that was a job I was not looking forward to!


Everyone is going to have a different take on this and these are all just my opinions but I don't think you should bother...

There's two (actually three) upgrade paths you can take for the intercooler--one is to use the factory intercooler from the HO cars (TT-S/S3), or go with a full aftermarket one. The thing about the intercooler is I don't think any tune, even for a K04, is going to cause the engine to run dangerously should you not upgrade the charge cooler. The main reason for this is they always have to account for a full intake temperature range because even an upgraded intercooler can end up running just as hot as the stock one. I/Cs don't do anything if they have no airflow over them--so if you're idling, stuck in traffic, etc., it don't matter what I/C you have, the intake temp will end up rising to the same level. An air-to-air I/C is only effective when the car is constantly moving with enough velocity. You would certainly see lower temps comparing both I/Cs with the car moving, but not moving enough, is the story above.

The "third path" is to not upgrade the intercooler at all. In climates where it doesn't get that hot for that much of the year one may opt to forego it; though in summer it surely gets hot enough to benefit from an upgrade there, one might not think it worth it. Additionally, using water/meth injection is a better charge cooler than any air-to-air cooler could hope to be. So using the money towards adding that (and not bothering with the I/C upgrade) is arguably a better idea. In fact it's what I would do if I did it over again. Because w/m has the added benefit of keeping the intake valves clean, in addition to being a better intercooler than an upgraded [air-to-air] intercooler. Of course with w/m you do have to keep the alcohol filled, which is an added expense over already skyrocketing fuel prices.
excellent explanation, very detailed, thank you!

i'm going to avoid the intercooler upgrade now since im not modding the car for track days or speeding, just want that available performance once in a while, jumping off the lights kinda thing lol. never going to be racing or accelerating for prolonged periods of time. it's good to know my model variant comes with some decent quality parts on it! i intentionally chose the stage 1 remap over stage 2 purely to maintain the longevity of the car, to be honest i like the stock drive on it but i do want the throttle to be more aggressive hence the remap.

thanks for your time bud, aqppreciate it!
 

·
Registered
Joined
·
752 Posts
excellent explanation, very detailed, thank you!

i'm going to avoid the intercooler upgrade now since im not modding the car for track days or speeding, just want that available performance once in a while, jumping off the lights kinda thing lol. never going to be racing or accelerating for prolonged periods of time. it's good to know my model variant comes with some decent quality parts on it! i intentionally chose the stage 1 remap over stage 2 purely to maintain the longevity of the car, to be honest i like the stock drive on it but i do want the throttle to be more aggressive hence the remap.

thanks for your time bud, aqppreciate it!
No prob :)

Yeah the stock turbo has lots in it compared to what Audi limited it to, so not being tuned/remapped is basically just leaving performance out for no reason (particularly when no longer in warranty). Stock they limited boost pressure to 11.5psi IIRC, so a tune basically just lets the stock IHI turbo do what it can instead of being limited. Good for some 50-60hp and somewhere around 80lb*ft, with zero other things done**, so it's definitely worth it to do a Stage 1 remap.

**On the CESA the gains are less since it already has 11hp and 58lb*ft more than the CCTA, but you get the idea.

I would note going too much higher on the FWD car is not that desirable either and you'll end up having to do suspension upgrades, mount upgrades, in order to keep the power down, and still struggle to some degree...not to mention giving you more NVH. So you may be on the right path to just stay at Stage 1.

Power is of course, addictive, lol--some "always want more". Me, though I would like more, I think the cost of getting significantly higher, on these cars/engines, becomes much more than it's worth. The 350-ish hp level is obtained easily enough out of the 2.0Ts and provides a lot of fun and smiles. I do forsee a much higher power car in my future (like a twin-turbo V8 C7 S6 😁 ), but not going to try to do anything nuts on a 2.0T. That of course is a few years away esp. since have to wait for those used car values to come back to sane levels!
 
  • Like
Reactions: EGZ
1 - 13 of 13 Posts
Top