carbed fuel system mods SUMMARY
07-26-07, 06:38 PM
#1
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carbed fuel system mods SUMMARY
I have been reading all the recent posts relating to upgrades for the fuel system on carbed first gens. The following is a summary of what appears to be the recommended system upgrades.
FUEL PUMP
The preferred fuel pump appears to be the Carter available from Summit (and others)
CRT-P4070 with 6PSI internal regulator or CRT-4594 with 8 PSI internal regulator.
The 6 PSI would be adequate for the Nikki or other carb that needs around 2.5 PSI at the carb. The 8 PSI may be a better choice if you might switch to a Holley or other carb that needs 6 PSI at the carb. Cost is $71.95 currently.
FUEL PRESSURE REGULATOR
A pressure regulator near the carb is needed for stable pressures. The Holley HLY-12-804 is the low pressure unit for 1-4 PSI (for Nikki or other low pressure carbs needing 2.5 PSI) or HLY-12-803 for 4.5-9 PSI would be correct for a Holley or other carb needing approx 6 PSI. Cost is $27.95 for either. Summit shows a QFT-30-803 regulator at $19.95 but it may only work for the 6 PSI applications (4.5-9PSI range)
FUEL PRESSURE GAGE
The Summit fuel pressure gage SUM-800115 with a range of 1 to 15 PSI and a cost of $16.95
FUEL LINES
High HP setups may also benefit from new fuel feed line. 3/8" should be adequate to around 250 HP. Banzai /turbo setups may need 1/2".
Please post any alternates or other preferences along with part numbers, source and price as well as the benefit of the alternate suggested.
FUEL PUMP
The preferred fuel pump appears to be the Carter available from Summit (and others)
CRT-P4070 with 6PSI internal regulator or CRT-4594 with 8 PSI internal regulator.
The 6 PSI would be adequate for the Nikki or other carb that needs around 2.5 PSI at the carb. The 8 PSI may be a better choice if you might switch to a Holley or other carb that needs 6 PSI at the carb. Cost is $71.95 currently.
FUEL PRESSURE REGULATOR
A pressure regulator near the carb is needed for stable pressures. The Holley HLY-12-804 is the low pressure unit for 1-4 PSI (for Nikki or other low pressure carbs needing 2.5 PSI) or HLY-12-803 for 4.5-9 PSI would be correct for a Holley or other carb needing approx 6 PSI. Cost is $27.95 for either. Summit shows a QFT-30-803 regulator at $19.95 but it may only work for the 6 PSI applications (4.5-9PSI range)
FUEL PRESSURE GAGE
The Summit fuel pressure gage SUM-800115 with a range of 1 to 15 PSI and a cost of $16.95
FUEL LINES
High HP setups may also benefit from new fuel feed line. 3/8" should be adequate to around 250 HP. Banzai /turbo setups may need 1/2".
Please post any alternates or other preferences along with part numbers, source and price as well as the benefit of the alternate suggested.
07-27-07, 01:13 AM
#3
Lives on the Forum
Here's my detailed writeup on the installation of the Carter pump and Holley FPR, followed by much discussion on different mounting options. Hope this helps...
https://www.rx7club.com//showthread.php?t=529605
https://www.rx7club.com//showthread.php?t=529605
07-27-07, 12:01 PM
#5
The Mallory Comp 70 or Mallory Comp 110 fuel pumps are nice little units. Much quieter than the carter or holley fuel pumps, and they flow just as much (more in the case of the 110).
I'm running one and I love it, also using the Holley 1-4psi regulator.
For pressure gauges, don't get a regular 1-15psi automotive pressure gauge. Read why here:
http://www.yawpower.com/fueldel.html
Get the one from respeed:
http://www.mrcmfg.com/respeed/catalo...2c14c094c95ff9
They also have a quick-disconnect "dry break" kit that works very well, and allows you to remove the gauge from the engine bay when not in use so that it does not get affected by vibrations.
Jon
I'm running one and I love it, also using the Holley 1-4psi regulator.
For pressure gauges, don't get a regular 1-15psi automotive pressure gauge. Read why here:
http://www.yawpower.com/fueldel.html
Get the one from respeed:
http://www.mrcmfg.com/respeed/catalo...2c14c094c95ff9
They also have a quick-disconnect "dry break" kit that works very well, and allows you to remove the gauge from the engine bay when not in use so that it does not get affected by vibrations.
Jon
07-27-07, 12:17 PM
#6
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That ding dong Paul Yaw talks about his carbs all the time but they are no longer for sale unless you have him build or buy a motor from him! 
I emailed that guy in the past like 10 times w/ no replies! lol. (sorry just venting)
