AFPR is it really worth it and what will it do
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Joined: Mar 2002
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From: Dallas, TX
AFPR is it really worth it and what will it do
what the hell is a adjustable fuel pressure regulator for? ive heard people talk about them but i have no clue what they do or how much i would gain from getting one. can someone help me out here?
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Joined: Jul 2001
Posts: 5,225
Likes: 70
From: Buffalo, NY
Car: 1988 IROC-Z
Engine: 427 SBC
Transmission: ProBuilt 700R4
Axle/Gears: Moser 12 Bolt / 3.73 TrueTrac
Q: What fuel pressure setting will give me the best performance?
A: The stock setting is 42 PSI. Much track testing has showed that any type of increase will greatly benefit both horse power and torque. Here's some dyno testing on a stock 350 motor which substantiates those claims:
42 PSI (stock) 46 PSI 50 PSI
RPM Torq HP Torq/diff HP/diff Torq/diff HP/diff
------------------------------------------------------------------------
2250 237.7 101.8 254.9/17.2 109.2/ 7.4 275.0/37.3 117.8/16.0
2500 241.7 115.1 262.1/20.4 124.8/ 9.7 283.3/41.6 134.9/19.8
2750 241.5 126.5 275.2/33.7 144.1/17.6 297.0/55.5 155.5/29.0
3000 237.1 135.4 278.2/41.1 158.9/23.5 305.5/68.4 174.5/39.1
3250 233.8 144.7 278.9/45.1 172.6/27.9 311.3/77.5 192.6/47.9
3500 241.0 160.6 278.2/37.2 185.4/24.8 309.5/68.5 206.3/45.7
3750 246.6 176.1 283.4/36.8 202.4/26.8 303.3/56.7 216.6/40.5
4000 250.4 190.7 278.3/27.9 212.0/21.3 298.0/47.6 227.0/36.3
4250 251.6 203.6 272.5/20.9 220.5/16.9 289.1/37.5 233.9/30.3
4500 253.5 217.2 257.3/ 4.2 220.5/ 3.3 277.0/23.5 237.3/20.1
4750 245.0 221.6 242.1/-2.9 219.0/-2.6 266.4/21.4 240.9/19.3
5000 227.6 216.7 225.0/-1.4 214.2/-2.5 237.8/10.2 226.4/ 9.7
It shows that by increasing the fuel pressure to 50 PSI, results in maximum torque increase of 58 ft-lbs (along with a much flatter torque curve) and a maximum horse power increase of 19 HP over stock. 46 PSI also provides a noticable increase which should work well for day-to-day street driving. An adjustable fuel pressure regulator (see Chap 5.2) is required to increase the fuel pressure.
-Tech Articles @Thirdgen.org
If thats too hard to read, go here https://www.thirdgen.org/newdesign/faq/thirdgen.shtml
A: The stock setting is 42 PSI. Much track testing has showed that any type of increase will greatly benefit both horse power and torque. Here's some dyno testing on a stock 350 motor which substantiates those claims:
42 PSI (stock) 46 PSI 50 PSI
RPM Torq HP Torq/diff HP/diff Torq/diff HP/diff
------------------------------------------------------------------------
2250 237.7 101.8 254.9/17.2 109.2/ 7.4 275.0/37.3 117.8/16.0
2500 241.7 115.1 262.1/20.4 124.8/ 9.7 283.3/41.6 134.9/19.8
2750 241.5 126.5 275.2/33.7 144.1/17.6 297.0/55.5 155.5/29.0
3000 237.1 135.4 278.2/41.1 158.9/23.5 305.5/68.4 174.5/39.1
3250 233.8 144.7 278.9/45.1 172.6/27.9 311.3/77.5 192.6/47.9
3500 241.0 160.6 278.2/37.2 185.4/24.8 309.5/68.5 206.3/45.7
3750 246.6 176.1 283.4/36.8 202.4/26.8 303.3/56.7 216.6/40.5
4000 250.4 190.7 278.3/27.9 212.0/21.3 298.0/47.6 227.0/36.3
4250 251.6 203.6 272.5/20.9 220.5/16.9 289.1/37.5 233.9/30.3
4500 253.5 217.2 257.3/ 4.2 220.5/ 3.3 277.0/23.5 237.3/20.1
4750 245.0 221.6 242.1/-2.9 219.0/-2.6 266.4/21.4 240.9/19.3
5000 227.6 216.7 225.0/-1.4 214.2/-2.5 237.8/10.2 226.4/ 9.7
It shows that by increasing the fuel pressure to 50 PSI, results in maximum torque increase of 58 ft-lbs (along with a much flatter torque curve) and a maximum horse power increase of 19 HP over stock. 46 PSI also provides a noticable increase which should work well for day-to-day street driving. An adjustable fuel pressure regulator (see Chap 5.2) is required to increase the fuel pressure.
-Tech Articles @Thirdgen.org
If thats too hard to read, go here https://www.thirdgen.org/newdesign/faq/thirdgen.shtml
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Joined: Dec 2000
Posts: 222
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From: Central Indiana
Car: 1984 Camaro Z28
Engine: Blueprint 383
Transmission: T-5
Axle/Gears: 3.73
He's running a carburetor which means he is only running about 6psi. I'd say an AFPR would not benefit you at all.
good luck,
Craig
good luck,
Craig
Moderator
Joined: Jul 2001
Posts: 5,225
Likes: 70
From: Buffalo, NY
Car: 1988 IROC-Z
Engine: 427 SBC
Transmission: ProBuilt 700R4
Axle/Gears: Moser 12 Bolt / 3.73 TrueTrac
Originally posted by Craig84Z
He's running a carburetor which means he is only running about 6psi. I'd say an AFPR would not benefit you at all.
good luck,
Craig
He's running a carburetor which means he is only running about 6psi. I'd say an AFPR would not benefit you at all.
good luck,
Craig
Whoops
Senior Member
Joined: Aug 1999
Posts: 618
Likes: 0
From: Central, NJ
Car: 1989 IROC-Z
Engine: 350 Vortech Supercharged ZZ4 TPI
Transmission: T56
Axle/Gears: 3.73
But for anyone who does have TPI and is reading this... that table provides false info. In theory it could produce a +56 tq but it really wont. I raised mine to 50psi and got slower in the 1/4. I mean think about it... the L98 is 345ft/lbs stock... u mean to tell me that nothing but a $75 AFPR is gonna yield 345+56= 401ft/lbs out of a bone stock motor? I am thinking no. Anyone else have thoughts/ideas/input on this?
In addition, 50psi can produce knock in the upper RPM's and make the ECM retard the timing.
In addition, 50psi can produce knock in the upper RPM's and make the ECM retard the timing.
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