johnsoex

Took my 2008 Tahoe to the track this weekend to make some passes. All runs were consistent, but best was a 13.22. Looking to get in the mid-high 12's. Seems dooable because I see guys in here with mods similar to mine and they are in the 12's, and even high 11's. Perhaps its because they are in SC or EC trucks that are a little lighter than mine? I dunno. But I could use some input on where to go from here to meet my goals....

Existing mods are:

stock 5.3 (heads never been off)
Magnacharger TVS 1900 2.8 pulley 11# of boost
AEM Meth injection
4L80E swap
Tru cool 40
Circle D 2600 stall
Auburn differential
4.56 gears
285 45 22 street tires

Edit: Also have pacesetter long tubes, Y pipe, no cats....

Running lean at 10 - 10.5 AFR. Timing is 22. Should I do a cam, lifters, and head studs next? Think that will get me in the 12's? Any other suggestions are welcome.

00silvylq4

That 10-10.5 afr is actually rich. 10-10.5 air to 1 fuel ratio. Aim for 11-11.5, maybe even 12:1 if knock would allow with that timing. The guys running 12's do they have the 4l60e? And yes a suitable cam for your setup would really wake it up.

nonnieselman

iTrader: (10)

https://www.performancetrucks.net/fo...7/#post4921675

1994Vmax

iTrader: (4)

You answered it yourself. You would need other similar weight trucks for an accurate comparison as the weight of a Tahoe is killing your times. And yes your AFR is very rich.

03sierraslt

iTrader: (22)

Oh boy, now I dont know what thread to respond to.... If you change the meth to water ratio it will throw off the air fuel ratio. You must tune when you do this. The biggest killer I see is your wheels.

03sierraslt

iTrader: (22)

12 afr is too lean, I would suggest no leaner then 11.5 at that boost and with meth. Methanol actually has a even lower stoich value and on top of that basically all gas has at least 10% ethanol in it now.