Ive never heard that either. Mine is installed according to Whipples instructions. Being 2 years ago I dont remember where it even hooks up

 

I was told that the injector # rating is at a specific differential pressure (difference between the induction air pressure and the fuel pressure in the rail). The PCM takes this into account when mapping fuel. That is why the factory sensor has both an intake air and a fuel connection (otherwise it would just be vented).

In the "stock" ?! Whipple location all the fuel pressure sees is non-boosted intake pressures. It will see plenty of vacuum in the stock location, but it will see zero boost.

If you don't have a catch can, it will also fill up with oil using the stock hose routing.

 

Wrenchbender how do you have yours hooked up?

Mine is hooked up as per the Whipple instructions and gets plenty of fuel at full boost, a little more than needed it seems. I would think if I hooked up mine to see boost and it does actually increase the amount of fuel delivered it would be way to much.

Tim

 

I agree as I have thrown a few rich codes in the past month.

 

On my '05 the dashed lines (before) are the factory injectors, no boost-a-pump, FRP/Whipple tune w/fuel sensor teed into the brake booster line.

The solid lines (after) the fuel sensor is teed into the control line for the bypass valve. Running 39lb injectors and a boost-a-pump wired to run at max all the time and a custom tune.

I didn't spring for the injectors/boost-a-pump and the tune for the "extra horsepower", I did it for the fueling. I really don't know what I am looking at, but is easy for me to see on my truck it was running too rich, then leaning out at the big end, and the log showed the fuel pump was running wide open.

The solid fueling line is where people that know about this stuff tell me it needs to be, and the pump duty cycle was at 72% (instead of 99%).

From talking to the tuner before I ordered a supercharger kit pretty much knew where I was going to be going in, I showed up at the dyno with a set of injectors and the boost-a-pump. The tuner said he wanted to do a baseline run to confirm that my truck with the stock install/tune was going to need the mods before I did them.

If JDM's "canned" tune was done with the intake sense line re-routed from "stock" I can see where this could make a big difference in fueling. It isn't something to do just for the heck of it.

Edit: Almost forgot. The dashed (before) line is with the PCM speed limiter in the FRP/Whipple tune disabled. With with the speed limiter present on the stock install you can't get up to the leaning out point on the big end-and as mentioned above, you are probably running too rich.

 

Your A/F looks good to me on the revised tune and fuel updates. Mine was way to lean with stock injectors and is a little to rich sometimes with the 39's. I think I may just get the datalog plug for the Xcal save some runs and email them to JDM with some of my questions about the PSI sensor routing. Your dyno sheets look like its running good.

Tim

 

All I know is what people have told me-not pretending to have any experience beyond the last 9 months driving the truck after bolting on the parts and paying somebody to tune it.

The tuner explained to me how the canned tunes with the various kits tended to run (according to what he has seen on the dyno).

Since I went with the Whipple, he suggested that I show up with the extra parts just in case, but wanted to do a baseline pull or two to see where my truck was at. He said that the boost-a-pump was mainly there for insurance on the big end, and the increased voltage would significantly reduce the pump duty cycle.

If I remember right, he said that the acceptable tolerances for the injectors, all the sensors, the condition of the engine, etc. can all add up to there being quite a bit of variance from vehicle to vehicle with the same tune.

Have still got long-tubes and a modified 10psi kit on my wish list and need to split my IAT sensor off of the MAF vane. Supposed to be getting a high stall converter this spring, and will be able to raise the shift points also. Will need another tune after that so will try to do it all at once. Hoping to get the parts around to do an e-fan conversion also.

Been working too funky of a schedule to get much done-and being salaried sucks when it comes to making any extra truck $$$.

Was shooting for mid 14's by last fall, and made that. By end of next summer would like to be in the mid 13's...

 

Hey Wrenchbender you should easily see 13's with the 8psi kit. Unless you are in a very heavy truck. I was running 13.5 on my street tires with just the Whipple & stock exhaust except for the Magnaflow catback. Was also on 3.55 gears which aren't bad untill you put 20" wheels on with 32" tires. What stall are you going with?

 

Whatever Darrin decides to send me-I need to call him and remind him/check to see where it is...paid for it over the off-season.

Dunno my weight, is an XLT Screw w/cloth non-power seats & steelies. 3.73 & 30" (I think) stock tires.

Am trying to figure out what I can get for a tall street/drag radial and how to get it on the truck (wheels). Not to the point yet where I want to swap for slicks at the track/but am still thinking about that. Work for a tire company you would think I could get a deal...

My 60' times are consistant (and slow). Seems like I can launch decent, but then get serious hop when I roll on the pedal.

 

My best was a 14.5 with the 8psi kit and stock whipple tune. I couldnt get a 60 foot lower then 2.3, the tires would just spin. With all the stuff I've done now I have no idea what I would get, but from what I raced I would easily guess low 13s high 12s with a good 60 foot.