After a few years of on and off weekend work I finally got my truck through the first stage of the build. Yesterday I went to the dyno and got the results and frankly I was a bit surprised by the low numbers based on lots of posts I've read here over the past few years.

2007 NNBS (standard cab long bed - WT)
4.8 (stock longblock)
212/212/112 Isky cam, 165a springs, NGK BR7EF plugs
72mm Magnum turbo @ 15psi, 40mm w/g, 3" intercooler, 3" downpipe, badlanz custom cutout
88lb infinity injectors, walbro 450 in stock bucket (returnless)
AEM TruBoost contoller
4L80E swap, 5" custom driveshaft, 3.73 gears, 31.5" rubber
CircleD Triple Disk 258mm (stall speed B which seems to stall at 3000-3200 for me)

I'm running 12* timing, 13-15psi of boost (depending on the mood my truboost is in), and 10.8:1 AFR.

On the track a few weeks ago I ran consistent 12.6@110. My best was 12.4@110 but my 60' times were horrible at 1.9-2.1 ish. It was a hot day and IATs were off the map. My log shows them 130F at the line and 180F down at the trap.

Yesterday on a SuperFlow SF-840 dyno, I put down 517/551 rwhp/rwtq on 100 octane. I only used the extra octane to be safe but 93 doesn't behave much differently in terms of knock for my setup. IATs were more like 95F at the start of the pull to 130F at the end. Not great, but not horrible either. I dont pull any timing in the tune until 140F anyway.

Am I crazy or with 15psi on this engine, should I be seeing in the 600 range? Its not that I'm unhappy with the dyno numbers, but I just expected more from the build. I'm curious to hear from others with a similar setup and what they are seeing for numbers. I have HP Tuners logs from the dyno runs (.hpl files) if anyone cares to see them let me know.

 

Well a big congrats on getting it running! Nice build with lots of potential. I would just keep working on it because yes we both know its capable of much much more and you will see it. As far as ideas probably just the tune and 60' will get you there as long as you can keep it cool. Hoping your cooler is enough. I'm guessing you don't use meth is the reason your tune seems conservative but I'm no tuner.

As far as the 60' those tires are way the hell too big for your gear and stall. Try a short tire. To get the 1.69 60' on 20x32" tires on my old sts truck I had 4.10's 3.06 1st gear with a 3k converter that I held until 4400 off the foot brake with ~ 8lbs boost. It bucked and jerked all over the lane or it likely would've been 1.60's with straps or other aids. Lots more in your build. The fun is in the journey my friend

 

For that level of timing on pump fuel I dont think those are unexpected results. With a better fuel you could increase timing by as much as 5* and it would make a world of difference.

 

I'm fairly certain my cooler is not big enough. its 3" core and is 31 inches long. Mounted in front of the radiator. I'd really like to tuck a 4" in there. its also a cheap cooler, nothing fancy.

Meth kit going in this weekend. Trying to do it nice and clean so its taking a bit of time to fabricate brackets for pump and tank. Yes, I am running fairly conservative timing but mainly because it knocks like hell if I get near or over 13*.

My bad, I run around town on 31.5" tires, but at the track I run M/T 295/65r15 (30.1" I believe). Still a big tire, but without lowering the truck, going much smaller looks silly IMHO.

 

If your Dyno pull isn't as long as your time slip at the track;
your air temps can be lower.
methanol injection will help keep your temps down.

 

Numbers seem right to me.

 

did you play with AFR or timing on the dyno to see if it gained? i'm no tuner but it seems rich and very conservative on timing with 100 octane.

 

I did not touch the AFR or timing between pulls. The shop owner does not allow tuning for the 30 min dyno sessions so I was only able to log. If I kicked up an extra $100 for the full hour then you can tune. I just wanted to get a baseline but maybe next time I should do some true "dyno tuning" and not just blind pulls.

 

Are you going through the traps in 2nd gear or short shifting it?

 

Tires are too big. Need more rear gear.