How much boost

[87-TURBO-T]

Thinking about converting one of my cars to E85 and was curious about how much boost you can run with it? thanks

 

[TurboBuick86]

all depends how much fueling your setup is capable of... keep in mind with ethanol you need to add 30% of more fuel. Ive ran my 109 block with te61 at 30psi with 2 pumps, and currently on my 72gtq at 23psi im tapped out of duty cycle and even need more pressure. my good friend has ran his 109 with a 71 billet at 45psi.

 

[GNWANTED]

I was around 26psi with a TE-60 & 60lb inj.

 

[northerngn]

23 lbs 1st and 2nd and then boost creeping to @ 25-26 out the back door TE45a and 85's

 

[slimtastic]

all depends how much fueling your setup is capable of... keep in mind with ethanol you need to add 30% of more fuel. Ive ran my 109 block with te61 at 30psi with 2 pumps, and currently on my 72gtq at 23psi im tapped out of duty cycle and even need more pressure. my good friend has ran his 109 with a 71 billet at 45psi.

how fast does the car at 45 psi go in the quarter?

 

[Rafs-T-Type]

Depends on the setup, but most will be safe at about 28, provided the fuel system is there. 45 seems like quite a lot. Did that car spray double alky too?

 

[northerngn]

how fast does the car at 45 psi go in the quarter?

Id like to know that too... I find it hard to believe that a 109 could have enough clamping force to keeps the heads on (not lifting) and sealed at that level....for me I try to draw a line in the sand at around 25... I feel that is max for a 109 unless you like doing h-gask job

-Dan

 

[TurboBuick86]

how fast does the car at 45 psi go in the quarter?

The car hasn't been at the 1/4 mile at 45 psi, so far it should be somewhere like 9.7's -9.8's . It currently ran 6.2's @112.5 with a crappy 60ft. in the 1/8th. at around 38-40psi

 

[its2qik]

I run 40psi in my Evo all day long with E85. Its amazing fuel.

 

[GNVYUS 1]

So there's a 109 block running 45psi with a PTE71? If this is true I've run across the 2nd GN Unicorn in only 1 months time.

 

[TurboBuRick]

So there's a 109 block running 45psi with a PTE71? If this is true I've run across the 2nd GN Unicorn in only 1 months time.

LOL!

 

[jasjamz]

I don't find that hard to believe. If you figure its normal compression and the car had the fuel system and the tune right I can see it possible. I completely pegged a 30# autometer gauge on several occasions with a hot air block, studs, and felpro gaskets. 6765 turbo too. Had the fuel thing covered too 110 and meth, just didn't have the guts to run it that way since I really didn't know how much boost it was making. Safe a/f, No knock, or obvious signs of detonation either. I will try for 40# before winter.

 

[TurboBuick86]

Car see's no knock and a/f ratios are pig rich right now, were getting the car dialed in. This fuel is the **** if you have the extra support

 

[bison]

The car hasn't been at the 1/4 mile at 45 psi, so far it should be somewhere like 9.7's -9.8's . It currently ran 6.2's @112.5 with a crappy 60ft. in the 1/8th. at around 38-40psi

Seems a little hard to believe that number. I've been 114+in the eighth with a 6680 and 25psi. At 40 psi I'd expect 122-123mph in the eighth on a crap tune.

 

[bison]

I don't find that hard to believe. If you figure its normal compression and the car had the fuel system and the tune right I can see it possible. I completely pegged a 30# autometer gauge on several occasions with a hot air block, studs, and felpro gaskets. 6765 turbo too. Had the fuel thing covered too 110 and meth, just didn't have the guts to run it that way since I really didn't know how much boost it was making. Safe a/f, No knock, or obvious signs of detonation either. I will try for 40# before winter.

I don't find 40psi hard to believe. I find it hard to believe the car was that slow with that much boost though.

 

[TurboBuick86]

I explained that the car hasn't seen the track at 45 psi, the fuel system is allowing for the car to run very rich. Let me see a 109 block with ECM tuning with power steering and a/c , along with a full interior and no fiberglass parts go that much faster???

 

[GNVYUS 1]

I'm just baffled at how some GN's can't hold mid 20's psi and some are running 40 to 45psi possibly over and over. Of course the tune is important but the cylinder pressure at 45psi with a PTE71 isn't even close to say a PTE60 at 30psi so someones doing a great job of holding down a lot more cylinder pressure, on the same parts, than the majority.

Any chance we can get some insight on what headgaskets, bolts/studs and torque these heads are using?

And these 40-45psi runs are E85 and not E98?

 

[TurboBuick86]

Arp head-studs , and felpro headgaskets which I believe Are about 17-20 dollars over the counter at local autozone and advance auto parts. Yea the cylinder pressures are high , motor is over .20 so it isnt too thinned out

 

[bison]

I explained that the car hasn't seen the track at 45 psi, the fuel system is allowing for the car to run very rich. Let me see a 109 block with ECM tuning with power steering and a/c , along with a full interior and no fiberglass parts go that much faster???

You explained that the car went 112.5Mph in the eighth @38-40psi. That does not add up at all. Maybe the engine had a dead cylinder? It should be over 120mph in the eighth at that pressure if it makes it down the eighth.

 

[bison]

I'm just baffled at how some GN's can't hold mid 20's psi and some are running 40 to 45psi possibly over and over. Of course the tune is important but the cylinder pressure at 45psi with a PTE71 isn't even close to say a PTE60 at 30psi so someones doing a great job of holding down a lot more cylinder pressure, on the same parts, than the majority.

Any chance we can get some insight on what headgaskets, bolts/studs and torque these heads are using?

And these 40-45psi runs are E85 and not E98?

Just to avoid any confusion to any newbies the turbo does not determine the cyl pressure. The engine with the smallest ci/fewest cylinders and highest torque has the highest effective cylinder pressure regardless of the turbo. A 71 turbo will move enough air to support 1000 hp with the correct combo. A 60 compressor will support over 600hp on a 231. Key word is can support. Not make.