How much is enough fuel?

[Suddenly]

After having my IP timed I’ve decided to turn it up a bit and see if there’s a noticeable difference in power or boost numbers.

when should I stop turning it up? I did 3 flats and took it for a test drive, I gained 1 max psi as far as I can tell. From 7 to 8 psi max.

From a stop I launched to 140km/h I saw max ~750 egt and 8 psi. The truck is intercooled, 4:10 gearing 150000km on the engine and I think the IP is original. Turbo rebuilt a few years ago, and the wastegate was unplug for the tests. It smokes like a chimney if I floor it and it drops a gear, but if I’m wot cruising there’s no smoke.

Should I keep turning it up until it smokes on wot then turn it back down a flat? My understanding is black smoke=not enough air, is that when I stop and turn it back? Do I need to tow my trailer around so it has a load for testing?

Thanks, Dan

 

[chillman88]

My understanding, if you're intercooled on the factory IP just turn it all the way up, you'll probably be able to use more fuel than your pump can make now. I'd start saving for a slightly bigger pump from Wes if it was me.

After you turn it up all the way, hook up the trailer and give it a workout and see what you get for EGTS then.

Is your waste gate locked open or just unplugged?

 

[chillman88]

What turbo are you running?

 

[Suddenly]

My understanding, if you're intercooled on the factory IP just turn it all the way up, you'll probably be able to use more fuel than your pump can make now. I'd start saving for a slightly bigger pump from Wes if it was me.

After you turn it up all the way, hook up the trailer and give it a workout and see what you get for EGTS then.

Is your waste gate locked open or just unplugged?

The wastegate is just unplugged, I couldn’t find an example on how to lock it open. by turning it up all the way are you suggesting that there is a point where it won’t thread any more? It’s a 94 factory turbo.

 

[chillman88]

The wastegate is just unplugged, I couldn’t find an example on how to lock it open. by turning it up all the way are you suggesting that there is a point where it won’t thread any more?

I'm not certain because I've never done it myself. But from what I've heard, just unplugging it it can still limit boost. I can't give you a definite answer but the topic has been covered here before so a search should turn up something.

 

[Philip1]

There is only so much adjustment in the injector pump. When you reach that point and still need/want more fuel you will have to get a bigger pump. I would turn it up until the egts get out of hand then back it down if necessary to keep the egts in a comfortable spot. With the wastegate, even with the boost reference line removed, the drive pressure in the exhaust side can push the wastegate valve open. To prevent this you will need to lock the arm in place so it cannot move. An example would be using some wire (at least for now) and tie the wastegate into place.

 

[Suddenly]

There is only so much adjustment in the injector pump. When you reach that point and still need/want more fuel you will have to get a bigger pump. I would turn it up until the egts get out of hand then back it down if necessary to keep the egts in a comfortable spot. With the wastegate, even with the boost reference line removed, the drive pressure in the exhaust side can push the wastegate valve open. To prevent this you will need to lock the arm in place so it cannot move. An example would be using some wire (at least for now) and tie the wastegate into place.

So I’m just stopping it from being able to move? I’ve done some searching on this before but couldn’t find a picture or simple explanation

 

[Scotty4]

Should be an arm going to the wastegate or some sort of op rod depending on turbo style. I welded mine shut on my Subaru to use an external.

 

[Suddenly]

I’ll try wiring the wastegate shut tonight and test again. I guess my next step would be tracking down any potential boost leaks, and I’ve seen people mention oil in the intercooler, might see if anything comes out of it.

 

[Black dawg]

with that turbo and intercooled (what intercooler?) you should be able to crank the pump all the way.
You should have more boost than you do now though.....also, an NA calibrated pump on my truck turboed and intercooled will show more egt than what you are seeing. Where is the thermocouple for the pyro.

 

[Suddenly]

with that turbo and intercooled (what intercooler?) you should be able to crank the pump all the way.
You should have more boost than you do now though.....also, an NA calibrated pump on my truck turboed and intercooled will show more egt than what you are seeing. Where is the thermocouple for the pyro.

I’m not sure about the intercooler, I believe it was branded Garrett on it but haven’t looked too hard for any info on it. The thermocouple is on the side of the engine, looks like second cylinder? From the back on the drivers side. Sorry not familiar with the terminology.

 

[Black dawg]

Your egt sounds off to me then, I really think it should read higher than that.
Any pictures of the intercooler?

 

[Suddenly]

Before timing the engine I saw egts over 1200 while hauling, but never for extended periods. My cruising temps are around 550 at 110km/h now which seems really cool. It’s hard to find hills here that stress the engine at all without a load.

no pictures of the intercooler I will get some after work.

 

[Detroit80]

For whatever it's worth...I have a Banks Sidewinder on my truck, and a rodent chewed boost reference hose on the wastegate. So functionally, the equivalent to being unplugged, lol. If I try, I can get to spike to 14-15psi, but generally it's opening on it's own around 12psi anyways, and under most normal driving it's only going up to around 10psi. I'm maxing around 800EGT, if I really try I can get it to tickle 900, cruising flat ground at 65-70mph it's running 550-600.

 

[Suddenly]

For whatever it's worth...I have a Banks Sidewinder on my truck, and a rodent chewed boost reference hose on the wastegate. So functionally, the equivalent to being unplugged, lol. If I try, I can get to spike to 14-15psi, but generally it's opening on it's own around 12psi anyways, and under most normal driving it's only going up to around 10psi. I'm maxing around 800EGT, if I really try I can get it to tickle 900, cruising flat ground at 65-70mph it's running 550-600.

Seems like your egts are similar to mine. Maybe I just need a load to see more than 8psi. Thanks