'Beefing-up' 2G internals (for turbo)

[JoeWagon]

Maybe one of you experts could share some info on what to have done by a shop, to prepare the internals on a 2G TSI for a bigger turbo.

My goal is to add overall hp, like everyone -- so if it comes down to a bigger turbo and reworking the engine.. what do i have done?

[Talon007]

Goals and plans, got any? Mild, wild, 300-400 HP, 600+? What turbo are you putting on? Have any supporting mods? Need those before internals.

[kjewer1]

Talon007 covered it. We need to know your plans. But I'll lay out the typical thought process. Up to 450-500 whp, stock 6 bolt. 500-600 whp, eagle rods, ross pistons. Over 600 whp, bigger rods (pauter, etc). There are other things to consider but most of it is personal preference for the buyer or the builder. Like compression ratio, cylinder finish grit, etc.

[turbo2nr]

lets not forget the head can be ported and polished, new cam shafts,valve springs, rockers.. ect. the bottom end is pretty good and so is the top but by modifying them you can oly make them better..

1

[kjewer1]

Originally posted by turbo2nr
lets not forget the head can be ported and polished, new cam shafts,valve springs, rockers.. ect.

The onl ything there I agree with is the cams. They help substantially. But ther rest of the stuff can be left aloe until you hit low 11s or high 10s. You can do it, but until you get pretty fast that money (and its a lot) can be better spent elsewhere (to get down to that level) IMO

[JoeWagon]

I want to go for mild, maybe very mild if i can't use the factory 2g (7 bolt) motor to go high in power. If i could get 350, 400hp out of it i would be happy. with the basics at a machine shop on my 7 bolt, and a bigger turbo, what can i be expecting on the dyno?

i don't know what turbo yet.. it depends on what you guys think the engine can handle, if you have any suggestions as to the right turbo for 300-400hp.. let me know that too! appreciate it.

[RockinWRX]

Anybody know much about Arias (spelling?) pistons? I know Easy Street uses them in their WRX , but I'm wondering about a DSM application.
Supposedly , they don't get the piston slap and expansion problems that Wiseco and JE and some others do.

[RockinWRX]

Originally posted by JoeWagon
I want to go for mild, maybe very mild if i can't use the factory 2g (7 bolt) motor to go high in power. If i could get 350, 400hp out of it i would be happy. with the basics at a machine shop on my 7 bolt, and a bigger turbo, what can i be expecting on the dyno?

i don't know what turbo yet.. it depends on what you guys think the engine can handle, if you have any suggestions as to the right turbo for 300-400hp.. let me know that too! appreciate it.

A stock 7-bolt can supposedly handle 400 Hp with no internal mods. We just had this discussion on my local DSM club list. A stock 1G 6-bolt can top 450-500 Hp with no internal mods. A 16G should be good for what you want the 2G motor to do. And it really depends on your application. Track or street/drag. Street/drag , I'd go 16G. Same with auto-cross. The 16G is a good all-around turbo. If you want BIG power , maybe a 20G , or an Big-28 , again , depends what you want out of the car. You can get 400 Hp any way you go , but track tuning demands different things. You can throw away some drivability at the drag strip , but auto-cross demands it. If you just wanna blow away people on the street , and run 12's at the strip , I'd go 16G.

[JoeWagon]

So then my last question (hopefully) is, does "no internal modification" mean JUST buy a turbo that will put me in my power goal, or are there other things that go with the 200 to 400hp jump?

[RockinWRX]

Originally posted by JoeWagon
So then my last question (hopefully) is, does "no internal modification" mean JUST buy a turbo that will put me in my power goal, or are there other things that go with the 200 to 400hp jump?

No , theres lotsa other stuff to go with a turbo. Fuel mods , for one. Pump , injectors , DSM link , etc ...... I'm not a 2G guy , somebody can help you set that up better than me. 95 GSXracer is good for that.......

[kjewer1]

Rockin pretty much covered it. I think what may be getting overlooked is that doinf internal mods have very little effect on power. The major exception is compression ratio change. Airflow is power. And you need to match airflow with enough fuel flow. So making more power is all about moving air and matching it with fuel. HANDLING the power is all about the internal mods, drivetrain mods, etc. They arent power producers, but they eventually become neccessary.

If all you want is 400 hp, stick with the 7 bolt. For 400 whp I would feel more comfortable with a 6 bolt, which is good up to 500 whp. Rockins turbo suggestions for turbo sizing make sense. If you want to make this kind of power and run mid 12s or better on PUMP gas however, you'll need a 20g or equivelent. Either turbo is a lot of fun.

[RockinWRX]

Yeah , I forgot to mention that the 16G (small) is good for about 375 - 385 Hp. Its the useability/streetability of this turbo that makes it a popular choice for DSM'ers. A 20G can be quite streetable also , but its important to remember that what goes in must come out. Meaning , to run a 20G and have it spool at a reasonable RPM , you'll need a 3" turbo-back exhaust system with no cat. A couple of DSM'ers in the local club have done some "street" testing of 20G's with full 3" exhausts and have reported reasonable (3 - 5 psi) boost as low as 2200 rpm and full boost by 4000. I think the 20G is a bit bigger than you might need , its capable of 450+ HP. If you are concerned about your engine internals , I'd get a smaller turbo than a 20G. Being a street-racer , I now how tempting it is to turn up the boost when you come across a more powerful car. A 16G is a good way to make sure that your engine will be nowhere near its internal limits should that happen.

[kjewer1]

I find that bushur (tdo5 clipped) 20Gs get 20+ psi by ~3500, and my tDO6H 20g had it by ~3800. Full 272s pushed it up to 3800-4000. I forgot what my point was already, but just another datapoint.