450z fuel ?'s
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MRJERRY300ZX
- Posts: 43
- Joined: Wed Jan 30, 2008 2:48 pm
- Car: 92' 300zx soon a "Z45"
450z fuel ?'s
will there be any problems of fuel starvation car is a 92 300zx swapped in a Vh45 and I'm only asking b/c I went from 3.0 to 4.5 I still have the stock fuel pump can you please point me in the right direction thanx
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Q45tech
- Moderator
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- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: 450z fuel ?'s (MRJERRY300ZX)
The twin turbo pump and Q45 pump are the same, the 300zx NA is about a third less capacity.
The 4.5 rail , regulator and pulse damper are designed to be feed from the Q45 pump with the 3 speed voltage control [FPCU].
The 4.5 rail , regulator and pulse damper are designed to be feed from the Q45 pump with the 3 speed voltage control [FPCU].
You going turbo with that VH or NA? You should be fine even if you go turbo up to about 8-10 PSI. I need to check my fuel pressure at full boost but my AFR's are good up to 8 psi, haven't tested much above that yet but I have ran at 9 psi for a short time with no obvious trouble.
If you are staying NA you are in great shape.
If you are staying NA you are in great shape.
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craigztoyz
- Posts: 727
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- Car: lots of unique hot rods, and customs, with modern engines, and a good truck to pull the trailer.
Re: 450z fuel ?'s (MRJERRY300ZX)
If your car was T then you are fine, if it was NA then you need to swap.MRJERRY300ZX wrote:will there be any problems of fuel starvation car is a 92 300zx swapped in a Vh45 and I'm only asking b/c I went from 3.0 to 4.5 I still have the stock fuel pump can you please point me in the right direction thanx
So you are in H town? Nick is over there in the Smog too. Ha Ha Ha
I'm in Austin, SO there are about to be 3 of us Z45 guys in the hill country, interesting............
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SSDwellah
- Posts: 306
- Joined: Tue Nov 12, 2002 9:45 pm
- Car: '90 Z32 Coupe w/ VH45DE + 5-speed (FOR SALE)
'06 Infiniti G35 Coupe 6MT
'08 Frontier 4x4 SE KC
Re: 450z fuel ?'s (craigztoyz)
My setup was originally a NA Z32 and I opted for the walbro 255, but I heard rumors that the Z32TT/VH45DE unit is the same as the walbro. I find that hard to believe because they didn't look the same, and I have seen benchmarks that the walbro 255 does not ultimately flow as well as the Z32TT pump in the high HP ranges but I can't find that thread again... I'll keep looking. In any event, the walbro was like $200-300 cheaper than what the stealership quotes for a brand new in box TT fuel pump, and about $200 cheaper than the cheapest sale you can get an honest to God Z32TT new pump for.
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Chrispy300
- Posts: 405
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- Car: 1993 J-Spec 300ZX 5 Speed Slicktop
- Location: Brisbane Australia
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Re: 450z fuel ?'s (SSDwellah)
Z32TT pump and 255 Walbro are definately different. I believe the standard Z pump is a Bosch unit.
The standard Z32TT pump is one of the higest flowing in tank pumps available.
The standard Z32TT pump is one of the higest flowing in tank pumps available.
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: 450z fuel ?'s (Chrispy300)
255 lph is 67 gallons per hour or 480 pounds per hour enough to create 900 HP.
The rub is how you regulate the pressure and what it is as the flow starts to decline when you exceed 43.4 psi.
Good engineering practice to assure 70k+ life that the pump capacity is 3 times larger than PEAK DEMAND..........thus a 300 HP engine is supplied with a 900 HP capable pump.
Same with the regulation system having the ability to divert 2/3 of the flow demand back to tank allows a lot of wear and tear to occur before the inlet flow decreases enough to stop ACCURATE REGULATION.
Use cheap pumps if you don't mind replacing them frequently.
The rub is how you regulate the pressure and what it is as the flow starts to decline when you exceed 43.4 psi.
Good engineering practice to assure 70k+ life that the pump capacity is 3 times larger than PEAK DEMAND..........thus a 300 HP engine is supplied with a 900 HP capable pump.
Same with the regulation system having the ability to divert 2/3 of the flow demand back to tank allows a lot of wear and tear to occur before the inlet flow decreases enough to stop ACCURATE REGULATION.
Use cheap pumps if you don't mind replacing them frequently.
Even this used one will outperform a new walbro in the long run.
http://cgi.ebay.com/ebaymotors...02951&
http://cgi.ebay.com/ebaymotors...02951&