Again I would like to say thanks to everyone on this form. Here's the deal I just got back from the track with my new set up and am a little disappointed. I was looking to brake into the 12's but it didn't happen. 13.365 @ 100 with a 1.87 60 foot. My old time of 14.08@ 97 with a 2.3 60 foot (spining down the track on 20's) with the radix, there tune, catback, k&n intake and eation pois.

My new additions due to the failure of the 4l60 are:
4l80 with transgo
hughes 3000 stall
10lb pulley
nelson tune
ET street slicks

I’m running 373 gears and am wondering if its just the gearing of the 4l80 that’s killing my top end. Maybe I need some 4:10's.... Or I did notice that the power really seemed to level out at 5400 rpm in second gear. And it pulled better now in 3rd but it wasn’t great. Cam? Headers? Do I just need to get this thing to breathe better. I have very little room left on the credit cards but I really want to see 12's. And I get a little pissed when I see head and cammed 5.3's running 12.8. Make’s me rethink the radix.

I know I pulled about 7 tenths off my time but shouldn't it be just a little bit quicker. And what's up with only 3mph faster over all. Please help!

Thanks

 

man i do know that it takes a lot more power to turn a 4l80 then it does a 60. and the gearing is different also. that might be the problem.

 

What were the weather conditions on both runs?

 

I'd like to see What the iat's where on these runs ?
That isn't possible due to the intercooler design right ?
How much timing are you seeing during the run ?

 

That sounds about right actually. If you put a cam and headers on there, that would defiantly halp out.

 

The 4L80E has a taller first and second gear,your gearing is about the same as a 4L60E with 3.08 gears in first and second gears.The 4.10s will give a good compromise for overall performance,as it would take a 4.56 rearend ratio to give equal gearing in first to your 3.73/4L60E setup.Remember also that the 4L80E has a shorter fourth .75 as compaired to the 4L60E's .70,so a 4.56 rear gear might not be what you want.The best part of the 4L80E gearing is that the ratios are more closely spaced,so you don't have the huge drop on the second to third shift.The 3MPH increase in trap speed represents the horsepower increase you gained with the new pulley the rest is due to the change in converters and slicks.My Radix setup with headers in a much heavier Tahoe with longtube headers can turn over 102mph representing a big increase in horsepower attributed to the freeier flowing exhaust,with the headers you will also show about a pound less boost,do to the lessened restriction to the exhaust ports.

 

It was about 10 degrees warmer last night with a little less humidity. I know this played a factor but wasn't sure how much.

 

I don't have any scanning software. But I do believe it is possible to read iat's.

 

Does it sound right? I wasn't sure. I couldn't find anyones truck to compare it to. Which do you think would help more a cam or headers? Because I don't have the money(or credit I mean) for both.

 

To find out for sure, you have to calculate the density altitude.

With my truck, it seems like +10 degrees = -15 flywheel hp.