timing retard at high speeds

[oddiesGN]

My 87 gn runs off e85 has 60# injectors, ta 49 turbo, 18# of boost, walbro 340 fuel pump with hot wire kit, everything else is pretty much stock. I can take off and go threw all the gears without any timing retard until I'm in overdrive and when I'm around 100 mph I'll start getting timing retard on my scanmaster. Its pretty high at 4.5 and thats the only time I get it. I don't know what my fuel pressure is at under boost, but while idling the gauge on my fuel rail reads 36#. The temp outside was only 68 wasn't too hot if that helps.

 

[278cikiller]

fuel

With the line off the fpr. it should read 43psi,your lucky you did'nt spit a h/g out our hurt the bottom end.

 

[oddiesGN]

With the line off it reads 42# of fuel pressure.

 

[278cikiller]

fuel

With the line off it reads 42# of fuel pressure.

What kind of chips in the car?

 

[oddiesGN]

turbo tweak chip made for what I have.

 

[SHADOWII]

You may .....

want to check out the rail fuel gauge. they are known to go bad from the vibration when mounted directly to the fuel rail. Many have removed them to the fender w/a 3' extention to isolate them from the vibrations. In this way it can be moved and taped to the windshield/cowl to be read while driving.
Add a little more fuel to see if the knock goes away.

 

[CGASTON]

With E85 your injectors are to small. You need to have 80 lb injectors and your chip maker will burn your injectors to 60lbs. Reason for bigger injectors is that your car running S85 requires more fuel.

 

[we4Mateo]

With E85 your injectors are to small. You need to have 80 lb injectors and your chip maker will burn your injectors to 60lbs. Reason for bigger injectors is that your car running S85 requires more fuel.

Instead of tricking the car, why not just get the bigger injectors and have Eric burn them for an E85 tune? I think he does that now...

 

[CGASTON]

That is what I am saying... But the chip has to make ecm think different

 

[hiboom]

e 85

was wondering have you tried mixing e85 and 91 octane say 50/50. I run e 85 when I'm out of Alk.Mix it 50/50 with 91 run 25lbs of boost with 22 degrees of timing with 60 lb injectors no knock I have run straight e 85 at the same boost level but the car ran flat on the top end with out bumping up timing but no knock.So at your boost levels I think you need to verify fuel pressure with boost levels but I don't think the 60's is causing the knock 80's would be better.

 

[Eric Stage I]

My 87 gn runs off e85 has 60# injectors, ta 49 turbo, 18# of boost, walbro 340 fuel pump with hot wire kit, everything else is pretty much stock. I can take off and go threw all the gears without any timing retard until I'm in overdrive and when I'm around 100 mph I'll start getting timing retard on my scanmaster. Its pretty high at 4.5 and thats the only time I get it. I don't know what my fuel pressure is at under boost, but while idling the gauge on my fuel rail reads 36#. The temp outside was only 68 wasn't too hot if that helps.

Start with O2's. What do they look like at full boost in 3rd gear?

Is the chip an E85 chip?

Regards,
Eric

 

[oddiesGN]

I got the 60# injectors from Eric with the chip for e85. He told me that these injectors were big enough for what I have. If the injectors are too small, wouldn't it be doing this in first and second gear when the car is under more of a load taking off and needing more fuel. I only get this in over drive right around 100 to 105 mph.

 

[Eric Stage I]

I generally stay away from full throttle runs in overdrive due to the excessive load.

Check O2's. The injectors are plenty big enough for your setup. But you need to make sure the fuel system is keeping up.

 

[oddiesGN]

Start with O2's. What do they look like at full boost in 3rd gear?

Is the chip an E85 chip?

Regards,
Eric

My o2 is reading around 742ish at full boost. I think thats what it was may have to do it again just don't want to ruin stuff. Chip is e85.

 

[oddiesGN]

Can't I just adjust the scanmaster for full throttle fuel and timing in 4th gear? If I can do you think that this will help. I will check my fuel pressure at full boost to see if my fuel rail gauge is bad.