Ok, last year I had set my best time and 60ft (12.74 @ 106.58 and 1.83 second 60 foot). Today I went to the track with my stage 4 stiegemeier port and 28" slicks. I ran .2 faster than my stock time. I was stuck in the 13.4x at 103.x. 6 runs, all with cool down of about 20 minutes between runs. Launching at 1800-1900rpm and WOT from the line, no tire spin, temps for mst runs 80-83 degrees with humitidy around 70%, 560 ish feet above sea level. Best 60 foot was a 1.99 on slicks (I ran my 1.83 on street treads with a 1200 rpms launch and rolled into the throttle). I have not run this slow since I have modded (unless I had a bad launch and spun like mad). Also, the truck is so slow out of the hole, but then about 4k rpms it just comes right into it and pulls like a freight train. I want to blame the port since its the only thng that has changed since last year. This is not a reclocked stage 4, its one of the originals.

And its not my tune, I am running 12.0+:1 a/f will 3500, then drops to 11.5-11.7 the rest of the way, no tq reduction, and 16* timing. Tuned by Sal.

so what should i do. I lost peak and low end torque with the port (dyno'd -17ftlbs peak) but gained hp and tq above 3800. Boost builds slow (im guessing this is the reason I have less tq). should i try a reclock or just say screw it and get another stock eaton? at this point i think a stock eaton with a #5 (instead of my #4) and meth injection seems like the way to go.

 

I think its time for BFH TUNE

 

lol, i dont know about that.

 

I got my stock stuff for sale on ebay if you want to take a look

 

on your best run last year??

I ran 12.40's last fall. Last week on the SAME COMBO, 90 degrees, ran 12.90's. That's a half second just because of heat.

I would say between the heat, and the time you left on the table with the crappy 60ft, you could be off almost a whole second.

Not sold on the whole ported blower thing. Dyno numbers and real world performance never added up for me.

 

You don't have anything to worry! The weather was horrible today, shoot I think my hat had a gallon of sweat in it. The humidity was in the 90's all day, that's what killed your et. Was this at 131?

 

sounds like you need to add a 2.8 upper to add some of the low end back into the equation. Might also need better tune in it to gain some low end back.

 

I was Stanton running the Motorplex (track I like to call home, but its still a bit of a drive, 1hr 20min). I hope it was just the weather.

And my sixty foots were as good as they were going to get wednesday. I was launching as hard as I could without moving. I have never launched that hard before. weather was worse. warmer and more humid.

I talked to Sal today. Why tune is as good as its gonna get for a street tune ((16* a/f 12.3 @ 3500, 11.9 @ 4100, 11.7 @ 4400, 11.7-11.5 till 5500). I did leave that part out, I run on my street tune. Lead in race gas is not so O2 sensor friendly.

I am going to wait till fall and get back into some good air before I start ripping things apart or replacing blowers. I want to give the set up a good chance. I am just frustrated on the performance when I really thought I it was impossible to run slower than 12s on this setup. (yep, I am still green on weather and its effects on our trucks).

Chris

 

Rule of thumb........65 degrees and higher, with any humidity, easy drop from 2-5 tenths over your best time in say 50 degrees with low humidity.

These trucks don't like it hot and humid, as many engines don't . Even with the intercooler.

I completely understand your disappointment. Read my post about giving up racing. It was fun for a while, but you have to know when to say when before you get beyond where you want to be. I'm sure your combo will be good for 12.4-12.5

 

Take a look at Steig's posting from about a month ago. He explains the results and where the gains are found from porting which is only at higher rpms.

That's the nature of porting. Take a look at Steig's dyno sheets. You loose torque until 4K and really only gain above 4.5K. To make this work you have to achieve higher RPM's sooner to benefit from the porting.

Adding a bigger pulley only masks the problem and increase the risk of blowing your motor.(that's called pushing the envelope)

 

why are you launching at such a high rpm ?

Are you certain that you arent spinning ?

 

i guess my question is why not launch at as high of an rpm as you can? Is that the idea behind a stall, get to your power quicker?

 

4.10's

 

20 minute cool down? A gasoline engine gets it's hottest an hour after shut down.

Justin

 

say what?? usually with the hood up at the track my truck will drop about 35-40+ degrees in an hour, depending on weather. i run my efan for 5 min or less.