Fuel System upgrade for 9 sec (non E85) ?

[murphster]

Look at the screenshot from Paul..... At 3700lbs you need 733 rwhp and 76# inj at 80% to go 136mph. Fuel pump needed would be 76 x .8 x 1.25 = 76gph with the 25% margin. If you can do that at 25psi boost the 430 pump is enough. But any more power or boost you are pushing it. One unintended boost spike and you are out of fuel....

 

[pacecarta]

or a late shift ..

 

[Scott89TTA]

I haven't weighed car but should be ~3600-3700 stock, I'm doing quite a bit of chrome moly chassis upgrades, k-member, front and rear control arms, coilover suspension, torque bar, etc. which all should lower the weight a little but also getting a 10-point chrome moly cage and subframe connectors so I'll probably gain back what I lost with the front end parts? I may go fiberglass hood so that will shed a few lbs as well. Motor is a fully built 0.040 over 109 with a 219/219 Comp roller, billet mains, Eagle crank, K1 rods, Ross pistons, internal balanced, TA cover Champion ported heads and intake, etc. Should be around 9:1 compression. I'll be running 28" tires currently have 295/55-15 MT's but may switch to 275/60-15's still 28", currently have 3.70 gears but will probably change that to 3.50's eventually when I swap in the Currie 9" later this year, probably next winter.

 

[ttypewhite]

Here is my story. Maybe you can gather another perspective from it. Originally when I got my motor from Dan at DLS I was running 95# injectors with a single Weldon A1000 external pump (quiet and reliable, great on the street). I was able to make 740whp at the dyno with it, but the injector duty cycle was at 92%. The next year rolled on and I changed my setup to my fuel system to keep everything in line and lower my injector duty cycle. The substituted my A1000 Weldon for a 2025A external pump and upped my injector size from 95# to 120#. That gave me enough room on the street to play with, but when I started running the boost close to 30psi and wound up being in that same area again with a high duty cycle. Not liking this, along with the sound of that Weldon pump in the back of the car, I was looking for a switch yet again. I was talking to my buddy Jack from Racetronix and he told me to come by and lets do a test on my Weldon setup compared to his double pumper. The double pumper out flowed my system considerably even though my car had more voltage then the test bed he tested the double pumper with. So, being convinced I decided right then and there, lets change this out. I used his line kit, double pumper setup and hotwire kit. Took about 4 hours to pull my setup out and his setup in. Fired up the car and not being able to hear that piece of shit behind the car whining was by far the most soothing feeling ever. I took it to the track, ran 9.20@150mph at 26 to 27psi with a 66% duty cycle. I don't see me ever needing to change this system again. I'm quite sure I could run low 8's to possibly high 7's on the fuel system and have the comforts of a stock Buick while I'm driving on the street. The pass in my signature is with the double pumper setup. Notice you can't hear the pumps.... lol

Here is a datalog from another pass with more boost.

 

[murphster]

Here's the same program with numbers from my 9.2 run. The HP matches up well to my 5.84 1/8th mile and the rest are in the ballpark. I ran a little less boost in the second 1/8th. Says I should be running 80% duty cylce on my 83# injectors. But lets say 20% of my fuel comes from alky, then I would only need 80% of that 80%, 0.8 x 0.8 = 64% duty cylce. In the background is my XFI log from the run. You can see that I ended the run at 26psi boost and..... 64% duty cylce.

 

[Scott89TTA]

You guys are making my head spin lol...lots of good info! So based on my combo am I in the ballpark power wise?

 

[Scott89TTA]

Any body running 120# injectors with a similar combo to mine and FAST XFI 24-28 psi street tune 93 pump w/dual Alky and 28-30 psi race tune on race gas (no E85)...if so what pump are you running and have you had any issues with the 120's? According to the calculations provided by Paul, Murph and a couple others the 120's are too big though ttypewhite said he is running 120's...so will this be a problem with the XFI controlling them or will there be driveability issues? Seems like if I have the correct pump, fuel lines and rails I'll be OK and probably only have a 60% or so DC with room to grow? If the 120's are going to cause me headaches I'll switch back to 80's. Several pump options from big single in-tank 430's, Racetronix double pumpers, DW double pumpers, Reds double pumpers, Nick Micale double pumpers, Areomotive A1000 or Eliminator installed either in-tank or inline with a sump installed in the bottom of the tank. Fuel lines & rails...I have Champion fuel rails installed and I'm leaning towards replacing the stock lines and going with -8 & -6 lines so I'm not worried about line restrictions or pressure issues from restrictive factory return. As I said before I haven't skimped on anything else so far I want to do the fuel system right too. I know of some similar combos to mine that have dynoed 600+ ~24 psi and have gone 10.0's at ~136 with less cam and older GTQ70 turbo compared to the PT7168HPQ billet wheel turbo I'll be running. I would assume I would be able to make a fair amount more power and hopefully break a 9.90 pass...maybe it's wishful thinking on my part you tell me.