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

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.

nonnieselman

iTrader: (10)

10.0-10.5 Is rich..
11.2-11.4 is a good target for safety. and 22* sounds like alot of timing for 11# unless your pouring in a ton of Meth!

A cam would help a good bit and run stock wheels/tires to save some weight over those 22s

johnsoex

Drr...I meant rich. We are pouring in a ton of meth. Has the biggest nozzle. I ran through almost half a gallon during 7 runs!

Thought about runing stockers, but I want to be in the 12's on my daily driver set up. Perhaps a cam, lifters and springs is the way to go....

I'll ask my tuner about the AFR and timing. Thanks.

nonnieselman

iTrader: (10)

you could turn the meth down till the AFR gets right, or lean out the tune and adjust the Meth to get it right?

I understand, i wanna go 12s on my all terrains but i dont see that happening.

lglowe

iTrader: (3)

Needs headers if you don't already have em. And a nice exhaust

Gadgetized

iTrader: (9)

The wheels and tires are hurting you. The 60' time lower would help a lot. When I did my fastest run I was spinning with a 1.97. My truck with stock suspension normally would run 1.85. The meth can be tricky, especially if you are using a lot. Most people mix it at 50/50, and just inject it thinking more is better because it is cooler. Well the problem is that the more you inject, the more water is entering, and it could be bogging the engine instead of adding power. (I am still learning to tune with it, and maybe that is wrong, but that is what seems to be working for me). You can lean it out a bit too, that AFR is pretty rich. Shoot for the 11.2-11.4 area. Some people are running much leaner than that.

nonnieselman

iTrader: (10)

i mainly used 11.2 for towing, not exactly the most powerful making AFR, but i know it was safe for long hauls, so quick 13 sec burst its plenty safe.

03sierraslt

iTrader: (22)

I didnt see much gain going any lower then 70/30 Meth,water. For me 70/30 seems to work the best. I think once you get past 50/50 its diluted so much it barely burns.

johnsoex

Thanks for all the input guys.

I forgot to mention I have long tube headers, no cats, y pipe, all thru Magnaflow resonator and then 2 borla pro xs in series. Nice and quiet.

Also, spoke to my tuner and we are at 11-11.5 AFR an 22 degrees if timing. I use snow boost juice which is a 50/50 mix.

Will going 70 meth 30 water screw up the AFR without a retune or you think that's safe to try?

Looks like the answer is adjust to more meth, less water and go with smaller shoes, cam, lifters, and springs.

Missing anything else?
My best 60' was 1.85. Need to figure out best launch RPM too. 2000 didn't spin 3000 spun like crazy down the track. Think it's in the 2400-2600 range.

nonnieselman

iTrader: (10)

https://www.performancetrucks.net/fo...faster-501828/