High altitude mods

[Rock2610d]

I have a 95 AWD talon tsi,everything is stock except the engine which I just rebuilt. I put in 9.1 pistons, arp head bolts, and eagle rods. Had to mill head and block a total of .029 so I put on a .080 thick HG.
I live at 7800 feet and work at 6000 feet. So my pressure up here is about 10.5 psi instead of 14.7 psi.
What additional mods do I need to consider to make the car run like it did 275,000 miles ago when I bought it brand new? And ran it at about 500 ft of elevation.

 

[LandSpeed-DSM]

If you are on the T25, running more boost to see that same indicated gauge pressure alone may not do it.

A turbo that moves as much or more air as you did when you were 500ft above sea level, but more efficiently at a higher pressure ratio. In your case, something like a 16G would be appropriate.

 

[Rock2610d]

Ouch, I just had the t25 rebuilt.....was hoping the 9:1 pistons would offset the elevation. Guess I will look for a new 16G!

 

[TopGun8818]

+1 of the 16g or bigger. Since you are running 9 to 1 compression you don't need an instant spool t25 aka blow dryer turbo. A big 16g (I recommend the evo 3 big 16g) typically spools a bit slower but that's not going to be an issue since you are running higher compression than the stock 8.5 to 1. What you'll notice is a nice power curve from 3k to redline unlike the t25 that starts loosing power at the higher rpms because of its efficiency. I went from a FP t-28 to a big 16g and noticed a big difference at the same psi setting (16). I can't imagine the difference you'll experience upgrading from a stock t(too small)25

 

[n0de]

Honestly i think a 14b would even suffice. Just throwing that out there.

 

[Bud92gsx]

Honestly i think a 14b would even suffice. Just throwing that out there.

This^


I ran a small 16g at 7200 feet..I actually hit fuel cut being that high, which was weird.I also had no tune or anything at the time..

The 14b is a great upgrade to you 2g guys.

 

[n0de]

I actually hit fuel cut being that high

Driving under the influence causes fuel cut?

 

[Bud92gsx]

I did not expect that....Good one

 

[LandSpeed-DSM]

Figure out how much DA changes day to day. When you are already at 7k feet, depending on the area, one particularly good day could be DA 5.5K.. or a really bad day could approach 10K+ where the 14B would be out of breath compared to the 16G as well.

A 14B is such a small increment above the T25, that for the effort and money you'd be better with the 16G.

 

[n0de]

Figure out how much DA changes day to day. When you are already at 7k feet, depending on the area, one particularly good day could be DA 5.5K.. or a really bad day could approach 10K+ where the 14B would be out of breath compared to the 16G as well.

A 14B is such a small increment above the T25, that for the effort and money you'd be better with the 16G.

What effort? Its not a 3000gt vr4 or a 300zx tt (that makes me shutter)

 

[Rock2610d]

Ok it reads like a evo 16g is what I will get. Considering the thin air is a fuel pump and injector upgrade needed?

 

[TopGun8818]

Ok it reads like a evo 16g is what I will get. Considering the thin air is a fuel pump and injector upgrade needed?

You don't need to upgrade the injectors but adding 190lph fuel pump wouldn't be a bad idea. I'm currently running my big 16g@16psi and have the 190lph with no tune. According to road race engineering - that's the limit with no upgraded injectors and tune. I wouldn't run more than 14psi on the stock fuel pump if you get the turbo first and the fuel pump later.

 

[WES_393]

With a legit Evo 3 16g you will need a larger pump and injectors to safely run anything over stock boost. Regardless of altitude. I was maxing out my stock fuel system at around 12psi with a legit Evo 3, and I'm a mile above sea level.

 

[TJCTalon]

I have a small 16g with stock injectors (have 255, AFPR, feed and return lines) And at 16 psi Im at 83% duty cycle. Im guessing im making decent power because im running damn close to my buddys 315WHP wrx.

Stock injectors have suprised me.

 

[Rock2610d]

Well given this in put I will probably scrap the Evo 16G plan and just get a "regular" 16G. I do not want to add a lot of non stock stuff. I will get a 190 fuel pump though as the car has lots of miles and I have never had to replace the one it came with.

 

[spydergstftw]

grab some evo 560s and an evo 8 pump and call it a day, cheap and good enough for a DD

 

[TopGun8818]

Both 16g's are non stock turbo's for our 2g's. It's a much better idea to get the evo 3 16g as it is a great turbo in every aspect to the previous 16g's. Whether you go with a 14b (stock from 1g) or a evo 3 16g - you will need a 2g install kit since the turbo has a different inlet angle. If you want to remain as stock looking as possible - the t-28 would be your best bet. Unfortunately, I don't think Forced Performance makes them anymore. Use the resources provided on this website to become more informed of these different setups before you buy anything

 

[Rock2610d]

OK, so I have been lucky and found some good turbos. I now have a 14B, a T25, and a couple of s16Gs.

All are in such good condition that I cannot detect any side to side or in and out. I am sure there is some, but I cannot detect it.

Now...I drive from home(7800 Ft.) to work(6200 ft) every day. My T-25 can have 7 psi of boost at about 1900 to 2100 rpm. and full 15 psi at 3000. I have removed the altered stock BOV and put on a steel EVO 9 BOV.

When T-25 boost gets above 7 or 8 psi it sounds like: Well a empty air tank being filled by a high pressure high volume pump.

My new engine has only 850 miles one it and I RARELY rev past 5000 rpm. BUT this car is not the car I bought new in 1995 (500 Ft elevation).

What turbo would compensate for the altitude best and bring car back to stock performance.

All 3 turbos came with everything I need to hook up to my 2G. So that is not a concern. I just want my stock 2G to run like it did when I was young

You know what is nice about getting older......having money for my toys