ok first off no 4.8 bashing. I know alotta people bash on the engine. whatever I got one nothin I can do about it now other then sellin her or doin a swap.

basically what my GOAL FOR NOW is to have the 4.8L with a bigger pair of *****. basically right now I want it to feel like a 5.3L should be possible.

now my problem now is the shift points. I don't know much about it but what I do know is the only time it gives me actual power is if I'm going exactly 30MPH if I'm going any other speed it simply won't down shift.

I'm talkin from racing to try to pass a car and shift lanes real quick.
short story I raced my brothers car from 0MPH and held my own.. then I raced him from a 30roll and I took the lead then he started holding his own. BUT THEN as experiment we raced AGAIN from a 35roll.. and he absolutly raped me. the truck when from 2K rpm and I nailed it and the rpm's just climbed real slow.

that's bullshit. is this just changing the shift points? is there a way I can program the truck to act like a silverado ss?






ALSO! one of my buddies was talking to me about putting a zo6 cam in the truck and reprogramming the timing for it. what ya'll think about that?

 

Its hard to understand what your trying to say , but if you want more power just put a 125 wet shot on it!

 

A smal cam and some tuning will definately help the 4.8l. Go for it!

 

sorry bud but this is about one of the most unreadable posts i have ever seen... and we hava had some bad ones....

i have a 4.8 too.... oh well... its a good revving motor.... but clear up what you actually wnt.... cut out the confusing mixed stories.. and just tell us what your looking for

 

IDK litreddevil's posts are pretty damn hard to read for me

and dont forget about 02silveradoz71

seroiusly though man get a nelson tune and that will help alot then ge the normal boltons - headers exhaust intake gears stall efans UD pulleys, then get you a cam and you'll be runnin pretty good

or just swap in a 6.0

 

haha sorry bout that. I'm no sober.

ok..

basically what I want (for now) is for the truck to have some ***** to it. I want the shift points to be more like when I want power I get power. cause most of the time when I step on it, the rpm's just come up real slow and I can't do any high speed passes.

the story with my brother and the race was just that I beat him going at 30MPH roll but at 35 I got raped.


no matter how much power you got if you don't get a good downshift what good is it? your already so far behind.

 

you NEED a tune ( i suggest nelson performance) and a stall converter would probabaly help

someone who knows what the stall would do to his shift points/shift extensions please post up

 

basically what night runner is saying is you need money.... something i am lacking.... i need money so my little 4.8 can run a little better

 

I understand what you are saying. Your truck is not downshifting into 1st gear at 35mph, but it will at 30MPH. So when you try to race from a 35MPH it stays in second gear. The stock transmission file will only allow you to go from 2-1 below 31MPH. If you have your tow/haul button turned on (Perf Shift MPH) the 2-1 gets bumped up to 35mph. Now this information is based of my stock 04 tune. I can put my truck into first gear around 35MPH by pulling the shifter into first. Sometimes it works and sometimes it doesn't. It all depends on MPH. Just make sure when you pull it down and it kicks down to 1st you pull it back up so it will shift into 2nd. This has worked well for me when racing manual trans cars from a roll and you dont have to wait for the downshift when you punch it. Now whether or not your transmission will like it is up for debate. I have been pulling mine down into gear for awhile on my stock trans racing from a roll and have had no problems. Now on the other hand a good tune and stall will help you out the most so when you shift from 1st to 2nd your rpm drop will not be as bad and will allow you to get into your powerband sooner. Just my 2 cents!

 

GMCHammer is right, the 2-1 downshift in the pcm won't allow you to downshift once you are above the designated mph. Easily adjusted with a tune, Also, another big one is the 65 mph, once above that it won't shift down to 2nd, it will downshift to 3rd, and then you are as slow as *****. I have mine set to 72 or 73, cause my truck in second carries me to about 90. Of course, this might be why i broke my 60E with ALL TM removed