How much Boost on Stock Internals?

abhattan · 01-26-2007, 12:28 AM

Hello guys, thanks for the help with the "Not Holding Boost". It turned out it was bad ignition wires. Got hot, and got bad. Anyway, I have an open air filter and a 3" exhaust from my downpipe back. I also have an NPR intercooler. I am about to put in a boost controller and was wondering what is the highest amount of boos I can push on that set up? Also, I will be installing a 2mm MHG soon after. What about then?

Supra2NR · 01-26-2007, 01:32 AM

Probly a decent 12-14psi
But be sure the engine is running healthy
Beyond any doubt b4 boosting the car

A new fuel pump, and an afc to control it should be your next mods in the list

abhattan · 01-26-2007, 10:02 PM

What's an AFC? I was thinking about putting in a VPC and GCC with a set of 580cc injectors, but not for another few months.

kwnate · 01-26-2007, 10:37 PM

Quote:

Originally Posted by Supra2NR

Probly a decent 12-14psi
But be sure the engine is running healthy
Beyond any doubt b4 boosting the car

A new fuel pump, and an afc to control it should be your next mods in the list

Have you heard of fuel cut?

abhattan · 01-26-2007, 10:39 PM

Yea, I was also gioing to get a fuel cut defenser from HKS. Is that good?

supraman121 · 01-27-2007, 01:38 AM

fuel cutoff is like 10-14 psi

http://www.suprastore.com/19turspec.html

Horsepower 230

Torque 245

Weight 3400-3500

Engine 7M-GTE 2954cc

Transmission R154

Boost 6.8psi

Turbo Toyota CT-26

Spark Plugs NGK BCPR6EP-N8

Injector Size 440cc

Compression 8.4:1

Cylinder Pressure 142

Fuel Pressure 33-40psi

Fuel Shutoff 11.4-13.7psi

Intercooler Efficiency 3psi drop@6.8psi

Wheels 16x7 / 225-50-16

abhattan · 01-27-2007, 02:22 AM

So that means that between 10-14 psi, the fuel will cut out? Why at that point? Is it some kind of protection?

IHateHacks · 01-27-2007, 03:11 AM

Fuel cut is when the fuel pump can no longer flow enough fuel to supply what the injectors are demanding. Fuel pressure rises about 1 psi for every psi of boost. As fuel pressure rises, flow falls. Yes, I know that doesn't make sense but it is a proven fact. That 10-14psi range is just the general range that a stock fuel pumps' flow falls off. Now when that happens the air/fuel ratio becomes dangerously high and detonation is emminent. Thats when the ECU cuts the fuel entirely to prevent damage. You can raise the fuel cut boost range with mods like a walbro fuel pump, 550cc injectors and a lexus MAF but fuel cut will always be there. It's your engine's way of telling you you need more fuel.

abhattan · 01-27-2007, 03:26 AM

okay..So do I have to use the Lexus AFM, or will the VPC be good enough? I will be using it in conjunction with a GCC anyway.

Supra2NR · 01-27-2007, 07:02 AM

Quote:

Have you heard of fuel cut?

i was boostin a steady 12 without hitting any fuel cut

but then my bov broke, and the car was overboostin nut still
i was boostin a steady 10 until my bov got worst
never hit fuel cut

Quote:

okay..So do I have to use the Lexus AFM, or will the VPC be good enough? I will be using it in conjunction with a GCC anyway.

get an afc, a new pump, you can still stretch out the injectors

01-26-2007, 12:28 AM	#1
abhattan 3" Exhaust Join Date: Oct 2006 Location: Brentwood, New York Posts: 162	How much Boost on Stock Internals? Hello guys, thanks for the help with the "Not Holding Boost". It turned out it was bad ignition wires. Got hot, and got bad. Anyway, I have an open air filter and a 3" exhaust from my downpipe back. I also have an NPR intercooler. I am about to put in a boost controller and was wondering what is the highest amount of boos I can push on that set up? Also, I will be installing a 2mm MHG soon after. What about then?

01-26-2007, 01:32 AM	#2
Supra2NR 1000whp postwhore Join Date: Apr 2006 Location: Chi-Town Posts: 1,643	Probly a decent 12-14psi But be sure the engine is running healthy Beyond any doubt b4 boosting the car A new fuel pump, and an afc to control it should be your next mods in the list __________________ http://www.myspace.com/supra_2nr Into Bikes now,, apparently the supra couldnt kill me, so my zx6 might lol

01-27-2007, 01:38 AM	#6
supraman121 12psi boost Join Date: Aug 2006 Location: North Carolina Posts: 361	fuel cutoff is like 10-14 psi http://www.suprastore.com/19turspec.html Horsepower 230 Torque 245 Weight 3400-3500 Engine 7M-GTE 2954cc Transmission R154 Boost 6.8psi Turbo Toyota CT-26 Spark Plugs NGK BCPR6EP-N8 Injector Size 440cc Compression 8.4:1 Cylinder Pressure 142 Fuel Pressure 33-40psi Fuel Shutoff 11.4-13.7psi Intercooler Efficiency 3psi drop@6.8psi Wheels 16x7 / 225-50-16 __________________ Upgrades- 225/50/R16's Kumho ECSTA AST (KU25) 273 bucks with shipping Magnaflow exhaust NO KAT K&N Air Filter www.myspace.com/coreyjstevens http://vids.myspace.com/index.cfm?fu...oid=1536317037 <------ this one should work check out the accident one aswell ya i might be a "fat kid" but i sure can move fast!~

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01-26-2007, 10:02 PM	#3
abhattan 3" Exhaust Join Date: Oct 2006 Location: Brentwood, New York Posts: 162	What's an AFC? I was thinking about putting in a VPC and GCC with a set of 580cc injectors, but not for another few months.

01-26-2007, 10:39 PM	#5
abhattan 3" Exhaust Join Date: Oct 2006 Location: Brentwood, New York Posts: 162	Yea, I was also gioing to get a fuel cut defenser from HKS. Is that good?

01-27-2007, 02:22 AM	#7
abhattan 3" Exhaust Join Date: Oct 2006 Location: Brentwood, New York Posts: 162	So that means that between 10-14 psi, the fuel will cut out? Why at that point? Is it some kind of protection?

01-27-2007, 03:11 AM	#8
IHateHacks 20psi boost Join Date: May 2006 Location: New Haven/Hamden Posts: 793	Fuel cut is when the fuel pump can no longer flow enough fuel to supply what the injectors are demanding. Fuel pressure rises about 1 psi for every psi of boost. As fuel pressure rises, flow falls. Yes, I know that doesn't make sense but it is a proven fact. That 10-14psi range is just the general range that a stock fuel pumps' flow falls off. Now when that happens the air/fuel ratio becomes dangerously high and detonation is emminent. Thats when the ECU cuts the fuel entirely to prevent damage. You can raise the fuel cut boost range with mods like a walbro fuel pump, 550cc injectors and a lexus MAF but fuel cut will always be there. It's your engine's way of telling you you need more fuel.

01-27-2007, 03:26 AM	#9
abhattan 3" Exhaust Join Date: Oct 2006 Location: Brentwood, New York Posts: 162	okay..So do I have to use the Lexus AFM, or will the VPC be good enough? I will be using it in conjunction with a GCC anyway.