Got two questions about fuel pressure.... what is the stock setting for the TTA's and on a basically stock car what kind of et gain can you expect if any from putting a afpr on? (Car has Erics Street Chip, CAI, 100# springs, and RJC plate, thats it)
Fuel Pressure ?????'s
- Thread starter DaJoker
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I think it's 38-39 at idle and then 50-52psi at WOT. Others may want to chime... I think that ideal fuel pressure is 61 psi for 20 psi of boost, so a adjustable reg is needed. Eric's chip probably does fuel enrichment for the amount of boost the chip was made for, if it's a street chip for 93 octane then maybe a adjustable fuel reg isn't needed. I found that any additional boost over stock 16.5 that more fuel and octane booster was needed to avoid knock. My $0.02 
Fuel pressure regulator is used to match the injectors to the chip by watchig the BLM numbers on your scan tool.
The TTA came with a 45lb regulator from factory. Your fuel pressure regulator rises 1 psi per 1 psi boost. So 20 PSI is 65 PSI fuel.
So is there a performance increase, No. Tuning.. yes.
HTH
The TTA came with a 45lb regulator from factory. Your fuel pressure regulator rises 1 psi per 1 psi boost. So 20 PSI is 65 PSI fuel.
So is there a performance increase, No. Tuning.. yes.
HTH
83ttypecooled
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Hi,
In the past, with our cars, I have used 38-42 psi as a starting point. Razor is right when he says that it is a variable issue. The pump must be up to the task, however.A hard installed gauge can tell you what's happening when you're on it.An adjustable regulator is a must.
In the past, with our cars, I have used 38-42 psi as a starting point. Razor is right when he says that it is a variable issue. The pump must be up to the task, however.A hard installed gauge can tell you what's happening when you're on it.An adjustable regulator is a must.
Reason I asked is I was talking to a friend with a T-Type and he said I may be starving the motor without having the afpr, guess he thought mine was set at 38psi like the Buicks. I was looking for a way to shave off a couple of more tenths to get to the 12's. I'm in the 13.3's now with no afpr and like I said thought I might be able to bump a few tenth's down. Putting the dr's on and got the boost gauge in although it shows a boost spike of 14 to 15#'S then holding steady around 12 to 13lb's, going make an adjustable wastegate rod if all else fails.
Oh yeah I have a Walbro in there thats about a yr old so that should be good. I'm thinking about ordering one of the gauges from Johns Performance that connects to the rail and then tape it to the windshield, don't really want a gauge mounted.
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As a practical matter (for a basically stock car) I see almost no value added by adding an AFPR.
Eric's chip is made for about 45 PSI and will allow tuning by virtue of its programability (fuel and timing).
My last TTA had stock block and heads, injectors, a Ta-49, walbrow 340, Alchy kit, Alchy chip and an AFPR set to 45 PSI. It all worked so well from the start, there was no reason to adjust fuel pressure again. Same experience with the TTA before that. I've used both Eric's and the Extender chips on these TTAs, they thrive with 45 PSI (stock TTA) fuel pressure.
With the modern chips, set it at 45 PSI and forget it. If you're runing into the 11's the AFPR might be helpful, but won't change fueling one fiftieth as much as the chip can.
Eric's chip is made for about 45 PSI and will allow tuning by virtue of its programability (fuel and timing).
My last TTA had stock block and heads, injectors, a Ta-49, walbrow 340, Alchy kit, Alchy chip and an AFPR set to 45 PSI. It all worked so well from the start, there was no reason to adjust fuel pressure again. Same experience with the TTA before that. I've used both Eric's and the Extender chips on these TTAs, they thrive with 45 PSI (stock TTA) fuel pressure.
With the modern chips, set it at 45 PSI and forget it. If you're runing into the 11's the AFPR might be helpful, but won't change fueling one fiftieth as much as the chip can.
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The fuel pressure gauge is mandatory for a TTa owner
Put a manual boost controller and an alchy kit on there and you'll be just fine into the 12's.
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