Big 16g max on 93 octane?

[4gfun]

Alrighty I am new here and I have searched through most of the 409 threads or so that pertained to this in some way or another.

This is my 2nd 91 TSI AWD that I have owned, and I would like to say that the information that I have seen here concering tuning is light year ahead of some of the DSM forums that I have seen elsewhere. I wish I knew about this forum yrs ago!!

With that said, the car has the following mods (I must be vague in some areas, because I have limited information from the previous owner):

Centerforce DF clutch, Fidanza Flywheel, Big 16G port matched to 2G manifold, ported and polished head, bigger cams, Galant VR4 1st Gear, K&N, Apexi SAFC, Apexi Exhst, Autometer Boost Gauge, EGT Gauge, Palm iiic with mmcd, SX AFPR w/ gauge, Walboro 255, MBC, JE Pistons and Eagle Rods, 2G Exhaust Manifold, SS Brake lines, ported O2 housing, JSPEC transfer case & tranny, modified fuel rail.

My question is this:

What is the max boost that can be run on 93 octane on a 16g if knock and A/F are in control?

I may not subjectively have whatever is required in place to support the highest possible boost, but I really want to see how far I can push it (while remaining reasonably efficient for a Big 16g) since it hardly gets run hard.

Most of the answers that I see for a Big 16g are from a few years back since there are other turbos/preferences nowadays.

Any thoughts?

Thank you for your time.

 

[kittay]

With E85, you will be using ~ 30% more fuel. I ran it this summer with 750 injectors.
The most boost I have ran on my evo3 16g is 28psi with no knock. However, I do not feel comfortable driving with it that high, so that only lasted a day.
At the track it's never seen more then 19psi. My best run with the 16g was 12.3 @112.

 

[thorlief4g63]

Best thing is to have it taken to a place with a dyno and have them tune it for you. Each car varies but roughly low 20's is what you can expect if everything is up to par. Peace

 

[4gfun]

I just wanted to let you know that I looked at the pump again this morning. (This just happened to be a local Sunoco gas station).

On the 93 pump it said may contain 10% less ethanol. To me that seems to be a positive thing not a negative thing. (Maybe it is a way of saying well we don't sell 94 octane at most places anymore)?

Ethanol gas (ie. Sunoco 94) bad? - Toyota Forums :: Toyota Nation

What do you think? I am getting excited .

 

[pitbull419]

What headgasket is in it? The stocker is reliable to 20psi.
The stock fuel system will support 16psi.

 

[4gfun]

What headgasket is in it? The stocker is reliable to 20psi.
The stock fuel system will support 16psi.

Mine? I have no idea at all. I won't be pushing it much further than 22 psi though.

 

[Black_Bullet]

What headgasket is in it? The stocker is reliable to 20psi.
The stock fuel system will support 16psi.

People have commonly taken there stock headgaskets with stock head studs up to 27-28psi. A bad tune with knock or too aggressive timing ran on top of that high boost is what lifts heads. Im still on stock head gasket with only ARP head stud upgrades and ive seen 25lbs a few times on race gas, and one of those times was with some pretty bad knock and I still have no issues. YMMV

 

[FonZ454]

Stock headgasket and studs here, hit 25psi once at the track, 22-23 psi daily in this cold weather, never on race gas, never had a problem.