minytrker

iTrader: (13)

Whats the most hp anyone has seen still off the stock fuel pump? I have around 450rwhp on motor and also have a Nitrous Outlet plate. I was running a 100 shot with no problems but now I want more. I just changed to a 150 shot but my goal is a 200. I dont have a fuel pressure gauge but I do have a WB in the car. Is it safe to just go by the WB and as long as its not getting lean Im good? I do plan on getting a new fuel pump, but I want to run this weekend on the bottle if I can. Also what fuel pumps are out there for C5 Z06's?

Robert56

iTrader: (2)

I did 480rwhp, but decided to upgrade. The Racetronics pump and hot wire is the kit to get. We recently ran a plate kit at 200 jetting (about 570rwhp), and were still getting a nasty lean spike upon activation, but then evened out and this was with a racetronics pump and hot wire. The real problem is the regulator at the tank, he is draing the rails and fuel system can't keep up. On my car I went Racetronics and a '97 style return and regulator at the rails, this has cured all lean spike issues. I have ran up to a 250rwhp shot and no lean spike none, nadda, zilch. Many run with this lean spike and some even claim it hurts nothing. Well, I have no desire in busting a ring land and have enough high n2o shot runs to prove the fuel upgrades are a good investment for the bigger shots. It's all your call though, and just giving my real world experiances.
Robert

minytrker

iTrader: (13)

What is involed in switching fuel rails? I have a complete 98 ls1 for parts.

Robert56

iTrader: (2)

As far as I remember, the f-bods never used the return and reg at the rails. They come only from a '97/'98 vette. Here's a link with all the info. I got mine from the vette site parts for sale, but you can buy all the parts from chevy.

http://forums.corvetteforum.com/showthread.php?t=739059
http://photos.strasser.us/gallery2/m...g2_itemId=7882
http://forums.corvetteforum.com/showthread.php?t=919394
Robert

terry s

iTrader: (5)

100 shot here on the stock fuel pump and no lean spike at all. When I watch the data logging as soon as the voltage comes up and activates the TPS the AFR immediatly starts to get richer.

The wide band is good but unless you data log the lean spike probably happens so fast you cannot see it on the guage. You need to data log to see if you have a lean spike or not.

smokin00ss

125 wet shot here. Iam making 466 rwhp and 525 rwtq and I have the lean spike too. I actually posted a thread asking how I should cure it. So should I try the racetronix pump and see if that cures it?? Or do I need to do the return style fuel rail setup. Iam looking into going with a bigger shot down the road anyways. At the track I went 12.4 @ 120. The 60 time sucked (2.1) The car fell on its face, it was due to the lean spike. Sorry if I hijacked the thread Iam just trying to find a answer to my problem.

Robert56

iTrader: (2)

On a smaller shot a pump upgrade will sometimes cure the problem, but if you plan on going big in the future you might just think about the whole upgrade. The way I looked at is, a safety thing to make sure I don't hurt my motor and that would be much more $$.

One more thing, the car above (the C5) when running a 150rwhp the lean spike was not present with just a Racetronics (or it was so small as not to really be a problem?). So, it seems there are variations on when/where/how the lean spike comes into play depending on car, hit size and upgrades.
Robert

minytrker

iTrader: (13)

What about upgrading to bigger fuel rails? Would that work vs doing the 98 fuel system mod?

Robert56

iTrader: (2)

Well, if ya go to the Racetronics site, they claim with the return/reg and/or a BAP and pump/hot wire kit with stock rails fuel system can handle like 700 plus hp. So it's not a rail size issue but rather supply. With the reg at the tank when you have a great demand for fuel it takes longer for the dropped pressure to reach reg and then to repressure and have supply back up, and thus a lean spike. Whereas, reg and return at rails you have big pressure right up to rails, so when demand is there the rails are kept full and pressurized. Hope this makes sense, I know I kind of jumped around.
Another fix for this issue is fuel accumulator, which we sell, it's NX brand. basically, it's just a reserve of fuel at pressure for instant use.
Robert

smokin00ss

Cool. Thank you Robert. It looks like I have my answer. Time to start saving. One more question. What about a small stand alone fuel system, just dedicated for the spray??

minytrker

iTrader: (13)

Thanks. It all makes sense, I just didnt think about enough, my first thought was the rails were being sucked dry. I just saw the accumlator in my catalogs last night, so Im going to look into it a little more.

Robert56

iTrader: (2)

Yes a stand alone will work also, but the $$ amount compared to the rails mod is more. Furthermore, imo, the stand alone is really only needed for the DP kits. Dave does sell a standalone for the C5.
Robert