7.3 IDI NA boost opinions?

[bblaweless]

Hey fellas. (And ladies if there are any)

I've got my 92 7.3 turboed with a factory setup from a 93.
Right now it's at the factory setting pushing 8lbs max.

I DO have a boost gauge and I DO have a pyrometer.

The truck is running a 3" downpipe and 3" straight pipe from there to a side exit. I eventually plan to go to a 4" from the downpipe.

Fuel is turned up a bit, not too much though and I seem to be running happy egts across the board.

My question is- what is the SAFE maximum amount of boost I want to run with this NA engine? I don't want to eat head gaskets, but I would also like to see a little more than 8lbs when im hauling up the malahat on the island here.

Thanks for any input!
Cheers
Benny

 

[Rossroams]

Well it depends, you've got stock headbolts I assume. I would say 12psi is my conservative max on that, others will say up to 15-16psi. I've just finished my H1C build and I haven't yet got a boost guage to see. Even with head studs I don't plan on boosting my engine over 15 psi.

 

[bblaweless]

Well it depends, you've got stock headbolts I assume. I would say 12psi is my conservative max on that, others will say up to 15-16psi. I've just finished my H1C build and I haven't yet got a boost guage to see. Even with head studs I don't plan on boosting my engine over 15 psi.

Do you plan on modifying the boost guage rod? Or are you using a manual boost controller?

 

[Thewespaul]

A 7.3 with head studs can run more boost than a maxed out stock pump will ever be able to feed. With stock head bolts you will be fine with 10 psi, 15 psi is pushing luck and I feel more than that is a time bomb, which is fine to do if you plan on pulling the heads to head stud it anyways.

 

[pelky350]

@Macrobb would be able to explain this better I think he explained it to me before but 15 psi with less fuel and not advanced timing will have less cylinder pressure which is the head gasket killer. Example meaning if you are running a stock pump with fuel just enough to hit 15 psi and running 6-7' timing with not much black smoke is easier on the engine then running a large pump with 15 psi and huge clouds of smoke trailing and the timing at 9-10', the cylinder pressure would be really high and stressing the engine. Same amount of boost but cylinder pressure much higher

 

[FORDF250HDXLT]

@Macrobb would be able to explain this better I think he explained it to me before but 15 psi with less fuel and not advanced timing will have less cylinder pressure which is the head gasket killer. Example meaning if you are running a stock pump with fuel just enough to hit 15 psi and running 6-7' timing with not much black smoke is easier on the engine then running a large pump with 15 psi and huge clouds of smoke trailing and the timing at 9-10', the cylinder pressure would be really high and stressing the engine. Same amount of boost but cylinder pressure much higher

You explained it correctly.

My trucks (both 7.3l na blocks) boost 13 lbs. 7* BTDC.

 

[bblaweless]

Have you guys used the factory wastegate to increase the boost or a manual boost controller?

 

[Thewespaul]

Either will work. I personally prefer a manual controller

 

[Rossroams]

Well mine is a non wastegate H1C and I'm currently at about neutral with my timing and I haven't turned up the pump yet. The turbo whistles, yet isn't pushing since the NA level of fuel. Can't even make over 1 psi on the gauge.

 

[Rossroams]

So on controlling the boost it's up to how much I turn the pump.

 

[Thewespaul]

Boost is controlled by the wastegate and fuel as well. If you are at static timing you need to change that first

 

[Rossroams]

I haven't gotten it timed accurately yet, it burns clean and smokes slightly, but black upon hard throttle. If anything it's a an alignment mark past neutral alignment. How much do you recommend turning up a stock pump?

 

[Rossroams]

I'm thinking two flats should give me some boost to start with. Your thoughts?

Boost is controlled by the wastegate and fuel as well. If you are at static timing you need to change that first

 

[Thewespaul]

Go a flat at a time until your egts get to high or you reach your boost goal. Timing will make more of a difference than more fuel imo. Going a dimes width from the static mark will get you close but getting a good timing meter on it is the only reliable way to set it properly.

 

[Rossroams]

Go a flat at a time until your egts get to high or you reach your boost goal. Timing will make more of a difference than more fuel imo. Going a dimes width from the static mark will get you close but getting a good timing meter on it is the only reliable way to set it properly.

Alright, I'll try to have it advanced by my local shop. Thanks for the advice man!