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quick walbro 255 question
- Thread startersleepyvr4
- Start date
Even without the rewire the 255HP is TONS of fuel. If its not too much trouble I would put the wiring back to stock, it will be somewhat better.
Quote:
^^ Are those compatible w/ the stock rail?
No, but I made an adapter. /ubbthreads/images/graemlins/wink.gif I just need someone to test it that has a known overrun issue and runs 43psi base fuel pressure.
Quote:
^^ Are those compatible w/ the stock rail?
No, but I made an adapter. /ubbthreads/images/graemlins/wink.gif I just need someone to test it that has a known overrun issue and runs 43psi base fuel pressure.
16g 1/4mile record holder:
CLICK HERE - see #2
for all you nay-sayers about tuning w/ stock fpr + lines take a quick look at 100% stock tank to filter to fuel rail to fpr to return line (edit - filter to rail line installed after 10.3 run). 10.3@131 with e86 and buschur cosmo pump.
CLICK HERE - see #2
for all you nay-sayers about tuning w/ stock fpr + lines take a quick look at 100% stock tank to filter to fuel rail to fpr to return line (edit - filter to rail line installed after 10.3 run). 10.3@131 with e86 and buschur cosmo pump.
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Barnes
Well-known member
Uhg. I don't think anyone here is saying you can't run fast. It is true it negatively effects driveablity. It only makes logical sense that if you can't regulate your fuel pressure, you can have some really weird issues at varying driving conditions. I've know several DSMers that put AFPRs on their cars and it made a huge difference in driveability.
turbowop
Well-known member
Quoting sleepyvr4:
16g 1/4mile record holder:
CLICK HERE - see #2
for all you nay-sayers about tuning w/ stock fpr + lines take a quick look at 100% stock tank to filter to fuel rail to fpr to return line (edit - filter to rail line installed after 10.3 run). 10.3@131 with e86 and buschur cosmo pump.
Nobody is naysaying. Please see quote below:
Quoting turbowop:
Werd. Overall WHP and driveability are two different things. The stock FPR doesn't limit horsepower, it limits tuning at lower fuel pressures.
16g 1/4mile record holder:
CLICK HERE - see #2
for all you nay-sayers about tuning w/ stock fpr + lines take a quick look at 100% stock tank to filter to fuel rail to fpr to return line (edit - filter to rail line installed after 10.3 run). 10.3@131 with e86 and buschur cosmo pump.
Nobody is naysaying. Please see quote below:
Quoting turbowop:
Werd. Overall WHP and driveability are two different things. The stock FPR doesn't limit horsepower, it limits tuning at lower fuel pressures.
Well - good thing I personally never asked or cared about driveability - that record holding 16g car was driven regularly with no ill effects. I've seen others with less have luck as well.
I just wanted to know how far off the base fuel pressure would be - not what parts I supposedly need to buy or if my car would be difficult to tune or have shitty driveability.
My last Galant had an aero afpr - and it's driveability/consistency/power wasn't perfect.
Ultimately there's such a different concoction that goes into every one of these cars it's all up in the air, and this one is no exception. I'm not losing sleep over it, and will NEVER expect it to be perfect...
So anyone else "know" the bfp of 4g63 on stock fpr with a 255hp at 14v?? 11-12v??
Thanks!
Colin
I just wanted to know how far off the base fuel pressure would be - not what parts I supposedly need to buy or if my car would be difficult to tune or have shitty driveability.
My last Galant had an aero afpr - and it's driveability/consistency/power wasn't perfect.
Ultimately there's such a different concoction that goes into every one of these cars it's all up in the air, and this one is no exception. I'm not losing sleep over it, and will NEVER expect it to be perfect...
So anyone else "know" the bfp of 4g63 on stock fpr with a 255hp at 14v?? 11-12v??
Thanks!
Colin
turbowop
Well-known member
If it's that important to you and you're willing to accept the fact that every car is different, go throw a fuel pressure gauge on top of the filter with a tee fitting and measure the BFP with the 255 pump at different voltages.
belize1334
Well-known member
Quoting sleepyvr4:
Well - good thing I personally never asked or cared about driveability - that record holding 16g car was driven regularly with no ill effects. I've seen others with less have luck as well.
I just wanted to know how far off the base fuel pressure would be - not what parts I supposedly need to buy or if my car would be difficult to tune or have shitty driveability.
My last Galant had an aero afpr - and it's driveability/consistency/power wasn't perfect.
Ultimately there's such a different concoction that goes into every one of these cars it's all up in the air, and this one is no exception. I'm not losing sleep over it, and will NEVER expect it to be perfect...
So anyone else "know" the bfp of 4g63 on stock fpr with a 255hp at 14v?? 11-12v??
Thanks!
Colin
If all you care about is "on boost" performance, then why would you want to know the pressure at idle? If you knew the value and you reprogrammed your chip to compensate for that fuel pressure you'd end up with a nasty lean issue under boost. What's gonna matter is the pressure when you're up at like 10psi and above which is gonna be when the over-run issue goes away. At that point the pressure will be 37psi + boost.
Well - good thing I personally never asked or cared about driveability - that record holding 16g car was driven regularly with no ill effects. I've seen others with less have luck as well.
I just wanted to know how far off the base fuel pressure would be - not what parts I supposedly need to buy or if my car would be difficult to tune or have shitty driveability.
My last Galant had an aero afpr - and it's driveability/consistency/power wasn't perfect.
Ultimately there's such a different concoction that goes into every one of these cars it's all up in the air, and this one is no exception. I'm not losing sleep over it, and will NEVER expect it to be perfect...
So anyone else "know" the bfp of 4g63 on stock fpr with a 255hp at 14v?? 11-12v??
Thanks!
Colin
If all you care about is "on boost" performance, then why would you want to know the pressure at idle? If you knew the value and you reprogrammed your chip to compensate for that fuel pressure you'd end up with a nasty lean issue under boost. What's gonna matter is the pressure when you're up at like 10psi and above which is gonna be when the over-run issue goes away. At that point the pressure will be 37psi + boost.
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turbowop
Well-known member
Well, technically, his fuel pressure will be at 37psi when he hits zero vacuum, but I'm guessing that's what you meant, Roger. /ubbthreads/images/graemlins/smile.gif
The problem with raising fuel pressure to meet the overrun at idle and even if you set up the eprom chip to compensate for higher fuel pressure, if you ever wanna run 30+ psi of boost, it really works the pump to put out 70+psi of fuel pressure. This will become a bigger issue if trying to pump E85 at its needed extra volume. Just sayin...
Then again, I don't own a stripped out drag car with a stock FPR that puts down 11,0000 horsepowerz to the ground, so wtf do I know? /ubbthreads/images/graemlins/hsdunno.gif
The problem with raising fuel pressure to meet the overrun at idle and even if you set up the eprom chip to compensate for higher fuel pressure, if you ever wanna run 30+ psi of boost, it really works the pump to put out 70+psi of fuel pressure. This will become a bigger issue if trying to pump E85 at its needed extra volume. Just sayin...
Then again, I don't own a stripped out drag car with a stock FPR that puts down 11,0000 horsepowerz to the ground, so wtf do I know? /ubbthreads/images/graemlins/hsdunno.gif
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donniekak
Well-known member
You don't compensate for over run by changing the global injector size by itself. You change the deadtime settings also. A deadtime adjustment has much more effect on fueling at lower ipw's, right where over run occurs. I have had 1050's,a hotwired 255, and a stock n/t regulator on a car, it idled and drove fine. Fuel trims all near 100.
Got the car running (again) today. Torquey with the 2g head and intake manifold - however it falls on its face at 5500. Boost comes on very quickly - no boost leaks after check today. 255hp rewired and keydiver chip set to run 11.0 and with a splash of race gas. 20-25psi on 14b is a pretty good start - wideband says its at 11.8 through 3rd/4th. Tomorrow new lifters and 264's go back in - evo8 valvetrain also if it arrives tonight.
