1G Proper 1g fuel pressure with these mods?

[davetheman81]

Im going to set my aero a1000 but first i wanted to know if any one had an idea on were it should be and also will it affect my tune? i have a 6 bolt with bc 272s jmf smim fic 1350cc injectors , walbro 255 on dsm link v3, the car was tuned but with the fuel pressure reg set to 32 psi during idle, i currently idle at 11 inches of vacuum, should i adjust the regulator and will it affect my tune, thanks!

 

[Bud92gsx]

A 1g awd 5 speed should be 38psi stock on 450's...

 

[white92talontsi]

Base fuel pressure should be 37 psi with no vacuum at the regulator.

 

[Bud92gsx]

37-38..Ahhhh..Not the same thing but..Almost..

 

[white92talontsi]

37-38..Ahhhh..Not the same thing but..Almost..

37-38 is generally OK.

 

[Bud92gsx]

If a mod wants to edit right now..I would also be ok with that..See official drunk thread if you don't get what I'm sayin.

 

[1990AWD]

I personally found it easy to set my base fuel pressure to 43.5 psi since that's what most injectors are flow tested at. I feel it would give the most accurate tuning.

 

[bastarddsm]

Yeah...None of this is really right. The correct fuel pressure depends on your boost level and your fuel pump, and your injectors. Check this out:
1.) injector flow changes with the square root of the pressure. So new flow = sqrt(bfp/43.5)*injector rating.

2.) Your fuel pressure raises 1:1 with boost. So if you have a 43.5bfp, and 30psi boost your fuel pressure is 73.5psi.

3.) fuel pumps have a high pressure limit, a pressure where the high pressure bypass opens. You'll want to stay under that.

So first of all you need to see what the flow rate of your pump is, and where the high pressure limit is.

So if you have a pump with a lower pressure output, and you want big boost you'll want to use a lower bfp. This will let you let you go farther on your pump, but your injectors will be "smaller"

If your injectors are on the small side, and your pump has pressure to spare you will want to run a higher bfp.

Personally I run 750's on a n/t regulator for 47psi bfp, to gain the most flow from my injectors.

Finally, the 1g turbo m/t runs 37psi, so you'll need to take this into account when setting your global fuel injector compensation.

Do it like this injcomp = sqrt(bfp/37)*injector size.

I'd probably set yours to stock 1g of 37psi, you have 1350's, and I'd assume a 255hp which has a bypass that opens at about 80psi.

 

[white92talontsi]

Yeah...None of this is really right. The correct fuel pressure depends on your boost level and your fuel pump, and your injectors. Check this out:
1.) injector flow changes with the square root of the pressure. So new flow = sqrt(bfp/43.5)*injector rating.

2.) Your fuel pressure raises 1:1 with boost. So if you have a 43.5bfp, and 30psi boost your fuel pressure is 73.5psi.

3.) fuel pumps have a high pressure limit, a pressure where the high pressure bypass opens. You'll want to stay under that.

So first of all you need to see what the flow rate of your pump is, and where the high pressure limit is.

So if you have a pump with a lower pressure output, and you want big boost you'll want to use a lower bfp. This will let you let you go farther on your pump, but your injectors will be "smaller"

If your injectors are on the small side, and your pump has pressure to spare you will want to run a higher bfp.

Personally I run 750's on a n/t regulator for 47psi bfp, to gain the most flow from my injectors.

Finally, the 1g turbo m/t runs 37psi, so you'll need to take this into account when setting your global fuel injector compensation.

Do it like this injcomp = sqrt(bfp/37)*injector size.

I'd probably set yours to stock 1g of 37psi, you have 1350's, and I'd assume a 255hp which has a bypass that opens at about 80psi.

You basically told him the same thing that had already been said.

The lower the base FP the better as the higher you run the FP the less flow you get from the pump.

 

[bastarddsm]

No. Thats not always true. If he were running 850's 47psi would be better as you can get more out of the injectors.

 

[wranglerunner22]

Research a little so you don't need to go by a few different peoples theories.



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