julianmwallace

Hi, new here, and I need some help. I have a 1996 Cheverolet C1500 with quite a few mods, but I feel like its not as powerful as it should be. I have no dyno near, and not to many other performance trucks/cars around. It has a Whipple SC kit with I assume 6-7psi, but my boost gauge isn't installed yet. The 5.7 Vortec engine has been rebuilt with forged dished pistons (+.040), Comp Cams camshaft, and stainless steel valve springs. It also has some bolt-on mods: Long-tube 2.5" headers (1 5/8" primaries), high-output fuel pump, Jacobs distributer, jacobs Ceramic 8.5mm plug & coil wires, Hypertech reprogramming, and a B&M Shift+ kit. The truck came with a 3.42, auto-locking rear end. The fuel injectors, throttle body, MAF sensor, and intake tubing are all still stock (I know, pitiful). What range of HP/torque should this truck be puttting out? What should I change first to take full advantage of the Whipple? (I have no experience w/ forced induction motors) How much psi can the Whipple put out that my forged, dished pistons can handle? I was thinking 8-9psi, but thats just a guess. Should a set-up like this be a lot faster than a stock 380hp Lightning?, cause it's not much of a difference. Sorry for so many questions. Please help me out.

hog

The small 19 pph injector in your truck will limit forced induction power to around 350 hp or 400 hp naturally aspirated.

Sounds like you need to get yourself a Marine Intake like myself and James B has.

http://www.sfatek.com/images/efi.jpg

All the info is here
http://www.pacificp.com/forum/viewtopic.php?t=317

I am using 24 pph injectors which flow 28.4 pph at 4 BAR of fuel pressure.

The marine intake flows much better than the stock L31 truck intake.

peace
Hog

julianmwallace

Thanks, I was starting to think no one else on here had a 96-99 chevy on here, just all 99+. Whats the best place to get this manifold, and what size injectors do you think a truck like mine would need?

James B.

iTrader: (1)

The smallest pulley you can install on that supercharger (1.6L Lysholm) is 2.5" without bad belt slippage. This is the pulley I am running. On a 355CID engine that should get you to about 9psi boost.
Depending on what the static compression is at with those pistons, it might be necessary to inject water or a water/methanol mix at to support 9psi without detonation.
The auxiliary whipple injection will support the smaller pulley and the extra boost but you will need to swap out one of the 42lbs/hr whipple injectors for a 65lbs/hr unit.
The Marine Manifold is a fairly intense project, you would need a lot of time and patience. You can get anough out of your current fuel system to beat a Lightning by a full second.
You mentioned you have Hypertech programming. Unless you have their SC Module with that handheld tuner, uninstall it. The only thing you can use that programmer for is changing the gear ratio and speed limit. You can't even use it to bump up the shiftpoints because the extra power will make it bump the rev limiter. The Hypertech tuning (without the S/C module) is incompatible with the Whipple.

julianmwallace

I have the S/C module, but since this is also a daily driver, I put the Shift+ on (just a resistor really) so I can turn it off or on, and it shifts at about 5400rpm at full throttle.So this 2.5" pulley will yield 9ps1, cause your sig. says 6psi, just didn't know if it was out of date or not. Where can I get this 2.5" pulley? Thanks for the help.

Vortec350ss

iTrader: (20)

The reason he is only running 6 PSI with that pulley is because he now has a GM 383 engine. Basically a bigger air pump, and the whipple cant push enough aur to create 9 PSI on that size of an engine. With his old 350 set up he had 9 PSI rockin though.

-Rob Nap

julianmwallace

Whats with the water/ethenol injection idea? Is that just because the water can withstand higher pressure, but still release oxygen when in the combustion chamber? I am an 18 year old atv mechanic and racer, so some of these automotive performace ideas are a little foriegn to me, so thanks for the knowledge. Can I pick up the 2.5" pulley from Whipple, or do I have to go elsewhere?

James B.

iTrader: (1)

You can get the pulley from Whipple, yes.

Injecting water into the intake cools down the combustion chambers and prevents detonation. It's a form of gaseous intercooling and has been used since World War II, maybe even earlier.

97ChevyVortec

I know this thread is old but What water or water/meth injection kit is a good one to run on a daily driver Whipple 5.7 vortec ??