I've been putting this mod off for quite some time but now I'm ready to do it. Hopefully the install won't be too bad. Anyway, what's the best AFPR out right now? I saw an expensive one in the Summit catalog in the 'LT1/TPI' section for $140. I'm looking to get the AFPR and a guage for about that much. Thanks in advance.

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1993 Z28 M6
116K, MAC Headers, Y-Pipe, Off-Road Pipe, K&N FIPK, Dynomax Ultra Flow Welded Muffler, 3" Cut-Out, TB Bypass, Taylor Wires, Bosch Platinum Plugs, Homemade Air Scoop, K&N Oil Breather, !Silencer, !EGR, !AIR

 

I believe that I got the G-2 AFPR. I guess the mech. had abitch of a time installing it. He claimed that it wouldn't fit so he had to machine part of it down. The factory claims that it would have fit. So whatya going to do?

Anyway, mine had to be used in conjunction with the stock one. I think it would be better if you could get the whole damn thing without having to use part of your stock Regulator.

Since the shrader valve is tucked up under the cowl, I'd suggest getting a 90 Deg. connector so you don't have to bend the hell out of the gauge hose to get it on the shrader valve.

Also, I bought a couple of those rachet thingys that are round and you turn them with your hand. I use one for loosening up the AFPR and the other to turn the little nut which adjusts the FP. Other wise its a bit to do the adjustments.JMHO

 

They are a waste of money. The computer will compensate for any adjusting you do.

 

Yeah, don't waste your money...you have no use for it.

I have WWAAAYYYY more mods than you (heads, cam, nitrous, all the bolt-on's, etc.) and still run a stock FPR.

By raising your fuel pressure, your PCM will compensate by opening the fuel injectors for a shorter time. This might be useful if say you were at the limit of the fuel injectors you are running, and want to lower their duty cycle by increasing the fuel pressure.

Also, high fuel pressures are harder on the fuel pump. This is exactly the reason why guys running FMU's or dry nitrous kits have to add an inline fuel pump (or bigger intank)....basically, need more pumping power due to the increased fuel pressure.

Hell, my roomate's head, cam, supercharged SS has a FPR on it....and he set it to the stock fuel pressure, lol.

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94 Firebird Formula Ram-Air, M6, T-tops, N2O, 12-Bolt, Bolt-Ons; was running 11's internally stock.432.8 RWHP / 588.4 RWTQ
No new times or dyno numbers with new top end (CC306, 1.6RR's, ported heads, etc.)

 

Yes, I remember changing my FP and gaining 17 RWHP, but as was mentioned, at least with the OBD11, the pcm will compensate back to factodry settings by adjusting the injectors.

On the other hand, a AFPR is just a FPR that happens to be adjustable. And I think its kind of handy to be able to adjust the FP myself.

But I wouldn't pay anyone to install it again.JMHO

 

Hey,
What if you had the pcm tuned for various mods and still used to afpr to get even more power out of the combo? Is that a reality?

Tim

 

My guess is that the tuner will tune your pcm based on stock FP. The basis for tuning the PCM is to reprogram the AF ratio, etc. in order to get a better burn.

So tuning should max your gains. Running a leaner than stock FP would screw up the tuning as well as compromise the ability for the injectors to get the right spray, since, as I understand it, the pressure should be at a minimum of around 43.5 to get the right spray. I'm no expert. JMHO.

 

If your tuning was crap to begin with, then yes there's a chance the AFPR could improve things. Seems like the wrong place to make the fix, though...

Dave

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1997 LPE 383/n2o Camaro Z28 Convertible
12.39@112.2, 1.76 60' (na) 11.27@124.6, 1.76 60' (n2o)
LT1 Diagnostics, New to Nitrous? Northern California Racing Club

 

The question "will the pcm return the FP back to stock after you set it" has been discussed thousands of times. This is true in all years EXCEPT the 93. The 93's PCM won't change the FP once you set it. My friend added an AFPR to his 93 TA and he got 12 RWHP. His FP has stayed the same ever since he set it (alomost a year ago). He made his own AFPR using a link located on one of Brent's technical installation pages. I don't want to make mine, I would rather buy one. My question ISN'T "should I get an AFPR", it's "WHICH one should I get"? Thanks for the replies guys.

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1993 Z28 M6
116K, MAC Headers, Y-Pipe, Off-Road Pipe, K&N FIPK, Dynomax Ultra Flow Welded Muffler, 3" Cut-Out, TB Bypass, Taylor Wires, Bosch Platinum Plugs, Homemade Air Scoop, K&N Oil Breather, !Silencer, !EGR, !AIR

 

I have a '93 and I was wondering the same thing. Does the computer ever compensate after you make the change?

 

I would recommend getting an AFPR on a 93 since it is Speed Density as oppose to Mass Air. You computer will not recommensate when changing the FP. I picked up 10 rwhp and 17 rwtq with a basically stock car so yes it works great on 93's. As far as brands goes I would recommend going with an Accel or a Hypertech. I would not waste your money buying a Aeromotive or LG Motorsports.

 

That's is what I thought. Thank you for your help.

I have an Ed Wright chip, and I am running very rich right now, so I think that will help a great deal.

 

Now that we're back on the true subject, which is the most popular brand that people have had the best results with.

 

Doesn't seem like anybody's been on this subject in about 5 months.

So sorry to have hijacked your thread.

 

I'm having good luck with the Hypertech AFPR. I've yet to get a dyno so as to get the best results but no problems or leaks.