# How much boost can stock engine take safely?



## alex12582 (Sep 30, 2003)

Considering that I have an engine with 15,000 miles and that fuel is not an option (it won't run lean at any boost level). What's the max I could go safely without NOS.


----------



## TheVodKA (Sep 19, 2002)

Too many factors. First of all, and most important, what engine!

2nd, search if u can, if you have nothing, then come back.


----------



## alex12582 (Sep 30, 2003)

Did a search, not much on the engine that I'm interested in. It's a 1983 Nissan 280zx Turbo.
It has about 10,000 miles, bored to nearly 3.0 liter, new T3/T4 ball bearing turbo, custom intercooler, 240sx trottle body, ported/polished head and intake manifold, 3 inch exhaust, BOV, fuel press regulator, dual fuel pumps, oil cooler, dual stage boost controlers, 380cc injectors, upgrated ignition system (no airflow meter), and a lot more. 
That's not even half of the modifications, but these are mostly boost related.
I know that these engines can take a lot of boost and pressure due to the older design, but how much is too much? Any experiences?
Here it is


----------



## javierb14 (Jul 9, 2002)

what engine management? what are the specs on the turbo? who's tuning it? those 380cc injectors will limit you from making a lot of power. you might want to consider upgrading to larger injectors, and you want to make a lot of power....like 400+whp


----------



## morepower2 (Apr 19, 2002)

alex12582 said:


> Did a search, not much on the engine that I'm interested in. It's a 1983 Nissan 280zx Turbo.
> It has about 10,000 miles, bored to nearly 3.0 liter, new T3/T4 ball bearing turbo, custom intercooler, 240sx trottle body, ported/polished head and intake manifold, 3 inch exhaust, BOV, fuel press regulator, dual fuel pumps, oil cooler, dual stage boost controlers, 380cc injectors, upgrated ignition system (no airflow meter), and a lot more.
> That's not even half of the modifications, but these are mostly boost related.
> I know that these engines can take a lot of boost and pressure due to the older design, but how much is too much? Any experiences?
> ]


Well with 380cc injectors, it will run lean pretty easily. Those are small injectors. More importanly is the octane of the fuel you intend to use, what sort of engine managment, how skillfuly it was tuned, the compression ratio, etc.

Just as a very rough guess, I think your injectors may top out at around 15-18 psi but there are so many factors, thats not really a safe guess. You need to learn more about your engine and engines in general before you try to push the limits or it will get expensive fast.

Mike


----------



## alex12582 (Sep 30, 2003)

for now, stock engine management with a few modifications/adjustments, high performance coil.... Now, I'm pushing 13 psi boost, and still no problems with fuel. Turbo is capable of twice that boost. I'm running dual fuel pumps, high performance fuel presure regulaor(adjustable), 380cc injectors. I'm using 91 octane gas. 
I will upgrade to TEC3 stand alone sometime this year, and bigger injectors with it. If I get bigger injectors now, stock ECU will probably make it run very rich at idle and low rpm.
Do you guys recommend that I just keep raising boost until it starts running lean?
I know a lot about engines and turbos but nissans are very new to me. 
For now, I am tuning the engine by myself.
Before messing with this engine, I had a Supra with some really high HP.

Thanks for your responses.


----------



## morepower2 (Apr 19, 2002)

alex12582 said:


> for now, stock engine management with a few modifications/adjustments, high performance coil.... Now, I'm pushing 13 psi boost, and still no problems with fuel. Turbo is capable of twice that boost. I'm running dual fuel pumps, high performance fuel presure regulaor(adjustable), 380cc injectors. I'm using 91 octane gas.
> I will upgrade to TEC3 stand alone sometime this year, and bigger injectors with it. If I get bigger injectors now, stock ECU will probably make it run very rich at idle and low rpm.
> Do you guys recommend that I just keep raising boost until it starts running lean?
> I know a lot about engines and turbos but nissans are very new to me.
> ...


How are you running a stock ECU with no MAF?

Mike


----------



## alex12582 (Sep 30, 2003)

I am running stock ECU with a modified MAF. The car originally had an Air Flow Meter which I kicked out and replaced with a modified MAF to fit. Some people wouldn't say there's a big difference between the two but anyways...


----------



## morepower2 (Apr 19, 2002)

alex12582 said:


> I am running stock ECU with a modified MAF. The car originally had an Air Flow Meter which I kicked out and replaced with a modified MAF to fit. Some people wouldn't say there's a big difference between the two but anyways...


I would say that you really need to find out more about your vehicle. I would use JWT's switch to a later digital ECU and hot wire maf kit with 50 lb injectors. They sell this as a kit. It woll perform much better and be a lot safer that what you are running.

At least you need to put your car on a broadband and see where its really running at before you blow it up.

Mike


----------

