Fuel pressure regulator

[1dollardog]

Will a fuel pressure regulator from an 86/87 work on the hotair?

 

[esinger]

Yes it will work, there's no difference

 

[1dollardog]

Yes it will work, there's no difference

Ok I have another one for you. If your fp regulator is adjustable and you adjust it for more fuel pressure won't your injectors still only fire at their prescribed rate? In other words if you have for example 38lb injectors will they not shoot at 38lbs no matter how much pressure is pushing them? Will the readjusted fp send a greater amount of fuel through the injectors?

 

[BRAD_PADGETT]

Ok I have another one for you. If your fp regulator is adjustable and you adjust it for more fuel pressure won't your injectors still only fire at their prescribed rate? In other words if you have for example 38lb injectors will they not shoot at 38lbs no matter how much pressure is pushing them? Will the readjusted fp send a greater amount of fuel through the injectors?

I will but in here. Adj the fuel pressure in order to get a tune is really pissing up a rope. Set it to 43psi and leave it alone. Been there done it and ended up wasting time and money. My advice-get an 87 ECM and a TTchip. If you really want to know how to tune it will probably cost you around $900. Post if you want more info. Merry Christmas- Brad

 

[Jerryl]

Ok I have another one for you. If your fp regulator is adjustable and you adjust it for more fuel pressure won't your injectors still only fire at their prescribed rate? In other words if you have for example 38lb injectors will they not shoot at 38lbs no matter how much pressure is pushing them? Will the readjusted fp send a greater amount of fuel through the injectors?

Yes and no.
Fuel injectors are rated at 45 psi.
So, at 45 psi differential pressure, it will flow 38lbs/hr
At higher pressure it will flow more than the rated 38 lbs/hr.

That being said, the ECM (with an open loop chip) will keep the injector pulse width constant, typical at idle with the newer TT chip.
So, at a constant PW, with higher pressure, you get more fuel, and your BLM starts to change accross the board.

Some injectors are also known to be “off” from the asdvertised rating as well.
So a 50lb rated injector, may only be good for 48lb/hr under actual testing.

There was an article written by John Estill (I think) explaining the difference in fuel pressure vs. delivery output.
All I remmeber; it wasn't that much.
There is also infoirmation stating that some injectors (I think the 50lb) will "lock" at a given pressure (I think 70psi).
Man I am thinking a lot .......

 

[1dollardog]

Thanks guys. This was just another random question that I had rolling around in my head, not an actual at the moment tune question. The "38psi" was just lifted out of mid air, I really didn't know how much a stock injector flowed. Thanks again and I'm sure I'll have more for you later. By the way what does "PW" and "BLM" stand for?

 

[Jerryl]

Thanks guys. This was just another random question that I had rolling around in my head, not an actual at the moment tune question. The "38psi" was just lifted out of mid air, I really didn't know how much a stock injector flowed. Thanks again and I'm sure I'll have more for you later. By the way what does "PW" and "BLM" stand for?

BLM - Block Learn Multiplier and Integrator
PW - Pulse Width

 

[1dollardog]

BLM - Block Learn Multiplier and Integrator
PW - Pulse Width

What don't you know about TR's?

 

[Jerryl]

What don't you know about TR's?

There is "a lot more that I really don't know" than "what I think I don't know".

 

[1dollardog]

Ok generally, what is a good psi injector to use with the 87 ecm upgrade and TT chip? Will the 86/87 injectors work here too?

 

[Jerryl]

Ok generally, what is a good psi injector to use with the 87 ecm upgrade and TT chip? Will the 86/87 injectors work here too?

Stock 87 injectors (28lbs) will work fine.
Make sure they are cleaned and flow tested.

Now, the sizing of your injectors depends on the fuel you intent to use and your HP goal.
Here is how it works (I used conservative numbers); Say 30 lb/hr injectors

6 cyl X 30 lb/hr = 180 lbs/hr
At 80% DC, that is 0.8 X 180 lbs/hr = 144 lbs/hr
At 0.6 BSFC (Brake Specific Fuel Consumption) = 144 / 0.6= 240 Crank HP
(I think I got it right .......... )

Here is more info;
Performance, Horsepower, Injector, Fuel, and Turbo Guide