1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

smart people come here and read this

Thread Tools
 
Search this Thread
 
Old Mar 8, 2006 | 01:31 PM
  #1  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
smart people come here and read this

I have a 12a stock port and all. I have a Weber 44 IDF I want to stick atop it and I'm trying to find a fuel pump that is kosher with it. The problem I'm into is this I have plans of going full blown turbo as soon as I rebuild, and was hoping I can get a 18psi or so pump running roughly 100 gph and just regulate pressure down, use a return line, and run said carburetor.

But I worried that it'll be to much with the little air I'll be flowing and flood the ****** out. Is it pointless to try and do this, should I just intended to buy two pumps to use for each of these set-ups?
Reply
Old Mar 8, 2006 | 01:43 PM
  #2  
Sudox_E's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2002
Posts: 432
Likes: 0
From: Chesapeake, Va
I'm running a turbo setup through a weber 45 dcoe, and i'm using a 20psi pump with plenty of flow. I just got an aeromotive rrfpr, and set the fuel pressure to about 4.5psi at idle. You should be able to to the same for your na car until you go turbo
Reply
Old Mar 8, 2006 | 01:46 PM
  #3  
84gsNC's Avatar
12a turbo by FBII
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 183
Likes: 0
From: Waxhaw, NC
I agree, you could get a bigger pump if you wanted to, the RRFPR should work fine N/A, then when you go turbo just hook up the vacuum port. I would suggest a pretty decent size return line as well.
Reply
Old Mar 8, 2006 | 01:58 PM
  #4  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
So the gph will make little to no difference? I mean a fpr will limit psi not gph, so no need to worry about flooding the carb?

Thanks for the input.
Reply
Old Mar 8, 2006 | 03:18 PM
  #5  
Rx7Kidd's Avatar
Sp33d D3m0n
Tenured Member 05 Years
 
Joined: Jul 2005
Posts: 400
Likes: 0
From: colorado
go with a holley blue fuel pump man, ive used one before and it seems to run fine, only turned it up to 8 psi though.
Reply
Old Mar 8, 2006 | 05:41 PM
  #6  
84gsNC's Avatar
12a turbo by FBII
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 183
Likes: 0
From: Waxhaw, NC
Holley blue wont work for a boosted app. A FPR will limit gph to the carb by retunring it to the tank. I run a MSD FI pump which is something close to what you want to use on my boost prepped Nikki which should only have a constant 3-5 psi
Reply
Old Mar 9, 2006 | 12:25 PM
  #7  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
I guess the only follow up question I have is, is it best to just have no restrictions before the in-line pump? And when I say this I don't mean a fuel filter but a pre-pump as it were? I noticed some people were running these, but I'm supposing that is to prevent starvation of the high pressure pump? And carb'ed applications require this less so than F.I systems?
Reply
Old Mar 9, 2006 | 12:56 PM
  #8  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
I think I've narrowed it down to three pumps.

Holley HP 150 GPH / 16 PSI / 3/8 in.

Aeromotive 150 GPH / 16 PSI / 3/8 in.

Carter Rotary 150 GPH / 16 PSI / 3/8 in.

Just wanted some feedback on these three, because I'm planning on ordering it before the week is up. Carter is the cheapest, Holley the pricest but I feel like I'd be getting what I paid. How noisy are these three? Who will outlast who?

And I since I was going turbo I was wondering if 100-150 GPH will support 10-12 PSI on a IC/street ported/motor? I looked at ther MSD FI pump and its pressure is in the mid-80's with only 45 GPH, because 84gsNC mentioned it. I'm assuming he is boosted and doesn't have problems with starvation so is 100-150 GPH necessary?

Thanks people.
Reply
Old Mar 9, 2006 | 01:45 PM
  #9  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
http://www.cnc-motorsports.com/techc...fuelsystem.asp

This is a link to a fuel pump out-put requirement calculator. You shove in a horsepower figure and it gives you an approximate GPH number.

Here are some results

100 HP = 8.33 GPH

200 HP = 16.66 GPH

300 HP = 25 GPH

And even though its a rough estimate, it makes most pumps seem a bit over kill. So what the hell, is it burned money if you spring for the 150.00 pump to puts out 150 GPH.

This makes the MSD F.I pump not a bad choice if this is true.

Feel free to chime in anyone?
Reply
Old Mar 9, 2006 | 01:47 PM
  #10  
FB II's Avatar
Banned. I got OWNED!!!
 
Joined: Dec 2002
Posts: 4,192
Likes: 0
From: wishing i was back in FL
the msd pump will work, but as you noticed it is only 45gph. a walbroh is around 65gph it supports 400rwhp. 100gph would be great, but not neccessary.

i suggest not using the holley brand pump due to it's ability to wear itself out. the Aeromotive is the prime choice!!!

just saw your fuel calculator results... you have to remember that isn't "boosted" numbers. that's with the thought of lean fuel mixtures n/a's require.

if you read alot of fuel pumps power ratings they will say (example) supports 400hp naturally aspirated; supports 270hp forced induction

better safe than sorry as you will need to run rich mixtures under boost that the calculator you used isnt accounting for.

Last edited by FB II; Mar 9, 2006 at 01:51 PM.
Reply
Old Mar 9, 2006 | 02:18 PM
  #11  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
Originally Posted by FB II
just saw your fuel calculator results... you have to remember that isn't "boosted" numbers. that's with the thought of lean fuel mixtures n/a's require.
Just read this somewhere else.

The mulitplier for naturally aspirated is .4-.5 per HP.
While the multiplier for forced induction is .6-.75 per HP

But this only gives lbs of gas per hour. But though the use of magic, math. I came up with a figure which sounds right.

Using 300 hp as the standard, the quantity of gas in gallons/hr is...

20.4 GPH for N/A

38.3 GPH for F/I

These numbers mesh sorta well with the 25 GPH previously stated for a 300 HP engine, considering the average of the two is 29.4 GPH. I think that link uses .5 as there figure for calculations.

I guess I'm just surprised how little is really needed for a higher powered engines. And 45 GPH pump may be encroaching on risky considering over time a pump losses some efficiency. But for such a large gap between 45 GPH to 100 GPH to exist between pumps, just seems like 80-85 would be plenty safe.
Reply
Old Mar 9, 2006 | 04:07 PM
  #12  
84gsNC's Avatar
12a turbo by FBII
Tenured Member 05 Years
 
Joined: Mar 2004
Posts: 183
Likes: 0
From: Waxhaw, NC
go for the walboro 255 or the Aeromotive, you can get a new walboro 255 off ebay for 90 bucks
Reply
Old Mar 9, 2006 | 04:10 PM
  #13  
Anthrax Mike's Avatar
Thread Starter
never posts...
Tenured Member 15 Years
 
Joined: Mar 2004
Posts: 198
Likes: 0
From: Pittsburgh, Pa
I think I'm going to rock the aeromotive w/ their RRFPR.

They are shiny.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
ZacMan
Build Threads
4
Sep 19, 2015 09:20 PM
doritoloco
New Member RX-7 Technical
7
Sep 5, 2015 12:41 PM
SakeBomb Garage
SakeBomb Garage
0
Sep 4, 2015 05:20 PM
SakeBomb Garage
Vendor Classifieds
0
Sep 4, 2015 05:19 PM




All times are GMT -5. The time now is 02:31 PM.