tuning the beast

[Mr. Rustypwnz]

Alright, I put the new head gasket on and got it tuned pretty well, I thought. Lately when I put her on down to the floor it gets to full boost and feels like it stops accelerating. I got it set on 16 pounds of boost at the moment and Ive had it to 25 also and same thing. I have the timing about as advanced as it will run (i dont know what it is set at though, pretty high). And have the fuel pressure set at 50 pounds unplugged. So what do ya guys think?

 

[Stinger]

I think you need to check where your timing actually is. I don't know how "tuned pretty well" and "timing as advanced as it will run.....as high as 25psi" go together.

Set your timing to 10º btdc with the spout unplugged.

What mods do you have to make you run 50psi fuel pressure? That is ALOT of base pressure...you shouldn't need that unless you are at ~300 rear wheel hp.

 

[65ShelbyClone]

Yeah, seriously. We don't even know what kind of turbo engine this is.

If the timing is "about as advanced as it will run", then you're probably getting pinging that is setting off the knock sensor and a bunch of timing is getting pulled by the computer.

 

[Mr. Rustypwnz]

Sorry for not specifying: 84 svo, knock sensor unplugged, no pinging. I need to set the fuel pres. lower, I set it here to be safe. It is not very modified, I did major porting on the ic just for the heck of it, minor porting on the intake and a gillis valve and a k&n on the vam and an adjustable fuel pressure reg. The thing is though, when I bought it and put the gillis valve on there at 18psi, it felt the same way. Im new to these cars, but ive rode in alot of turbo cars, GN's ,powerstrokes, and when the boost hits, hold the crap on (in the GN). Mine only feels strong at 5-10 psi, anything more and it just stops pulling. Im really confused with this car. Im going to put a timing light on it this week and set it to 10btc and go from there.

Thanks, josh

 

[65ShelbyClone]

Alright, now we're getting somewhere.

Is the boost solenoid and its control box disconnected? They should be if you're using a seperate boost controller. Alot of SVO heads would tell you not to disconnect the knock sensor unless you have a good ear for pinging.

18psi is probably the maximum efficient boost that the stock T3 can supply. After that, it just heats the air and falls out of the efficiency island. You should really feel the power come on by the time the boost passes 4psi. Mine is running through the stock solenoid and it kicks hard by 10psi. If I have the premium switch on, there is still a big surge of power between 10psi and 14psi. I don't know why yours would fall flat with more boost. The only things that come to mind are that maybe it needs a "Motorcraft" tuneup and/or the TPS/VAM checked. Sometimes the VAM can wear and get a dead spot.

 

[Stinger]

Actually, the T3 runs out of steam at about 24psi...but you lose 1-2psi through the IC.

Anyways, with 50psi fuel pressure, you are absolutely flooding out under boost. That's probably where alot of the power is going. Get the timing set, then turn the fuel pressure back down to 38-40psi. Don't run more than 15-16psi until you get it running right or you'll be doing another head gasket.

Also, more than 18psi or so could be asking for trouble with the stock fuel pump...only way to know is to monitor fuel pressure under boost though. If it's dropping, the pump isn't keeping up.

 

[Mr. Rustypwnz]

alright, I set the pressure to 40psi unhooked and took it out for a ride, man this sucker is faster off the line and on the top end and all between. I totally forgot that the fuel pressure builds for every pound of boost. I got 1 or 2 pings on the top end at 18psi, so I shall set the timing a little back and drive it again. You guys know what you are talking about, I cant wait for a header, t3 t4, big IC, and a little shot of nos. Man this sucker is going to be fast!

Thanks, josh

 

[Stinger]

Good to hear it's running better now...

 

[t3-svo]

i was just wondering... if you want to retard the timing can you just turn the distributor and if thats what you can do which way do you turn it??

 

[65ShelbyClone]

The distributor is the only way to retard the ignition timing without buying or modifying anything. To retard/reduce advance, turn the distributor the same direction that the rotor spins. You don't need to know which direction because you can see what it's doing with a timing light.......and you shouldn't play with the timing without a light.

 

[Mr. Rustypwnz]

Turn the dist. counter-clockwise to advance, and clockwise to retard the timing. Only move it a couple of degrees at a time, and if you move it when the car is running, remember to unplug the spout connector, if not dont worry about it.
Hope this helps.

 

[Mr. Rustypwnz]

oh yeah, this came to mind, I have a auto-meter a/f gauge hooked up and it don't work, it will light up about 3-4 red (lean) lights and never move from there. It is a narrow-band one, but ive seen video of one working on a 2.3t motor. I have it on the signal wire on the o2 harness and have a good ground and power and everything but it won't move into stoich or rich. Any suggestions?

Thanks, josh

 

[65ShelbyClone]

First, is your O2 still any good?

Second, double check all the wiring. Thats all I can think of.

 

[Mr. Rustypwnz]

The tfi is new and the o2 seems to be in good shape, I probably need to go over my wiring to see if I did it right.

 

[Stinger]

Either your wiring is wrong or your sensor is junk...