Need more passing power

pattersin86 · July 18, 2003

My truck needs help! I just got a 2003 1500 LS Z71 with a 4.8. I have come to learn that it just doesn't have any power when trying to pass people, or straight acceleration. Anyone have any good ideas ( such as new headers, exhaust, carb...)? Please help!

SilveradoWV · July 18, 2003

Carb?????

I actually dont have a prob with mine, pretty much the fastest truck I have ever had! Even out runs a FI 350. Most mods people start out with are either a K&N drop in or the FIPK, neither one add alot of HP though.

Wingnut · July 18, 2003

FIPK, and cat-back are the most used mods...And for good reason, they are the cheapest.

Best bang for the buck is going to be a supercharger....$3000 for a cheap one.

You could do pretty well just having your heads polished, adding some headers and exhaust, and a chip. But once you do all that (and do it right, mind you) you are approaching the cost of a cheap (or used) supercharger.

Just depends on how much you want to spend making a 5000lb+ truck into a hot rod.

Oh, and you don't have a carb.

SilveradoWV · July 18, 2003

Maybe he's thinkin about addin a Carb?

99-2door · July 18, 2003

IMO the 4.8L is too small for 4x4 trucks. I was really disappointed when they started letting Z-71s be equipped with it. On the old body style the 5.7L was a requirement for the Z-71 option, no 5.0Ls. It should have been the same for the 99-ups, only the 5.3L. But what can ya do? I wouldn't spend big bucks on the 4.8L, you will never get your investment back when it comes time to sell.

SilveradoWV · July 19, 2003

IMO the 4.8L is too small for 4x4 trucks. I was really disappointed when they started letting Z-71s be equipped with it. On the old body style the 5.7L was a requirement for the Z-71 option, no 5.0Ls. It should have been the same for the 99-ups, only the 5.3L. But what can ya do? I wouldn't spend big bucks on the 4.8L, you will never get your investment back when it comes time to sell.

I dont see how you can say this, they are actually putting 4.3s in 4x4 trucks!!! And the 4.8 will absolutely kill a non vortec FI 350. Plus I dont see the Z71 relavance, there is nothing on a Z71 that would indicate the need for a 5.3. IMHO that is too much power for "some" off road situations, its not really an OFF ROAD capable vehicle stock, no more than a 4x4 can be. I know I will probably get bashed for that but honestly a S-Series ZR2 with the 4.3 is WAY more off road capable than the Z71. My 4.8 can tow 3500lbs+ up about 5 miles of 7% grade with the AC on, and be doing 75-80 mph all the way, no other vehicle I have had including the 350 can do this.

Tex2kZR2 · July 19, 2003

I know I will probably get bashed for that but honestly a S-Series ZR2 with the 4.3 is WAY more off road capable than the Z71.

Depends on the situation but for the most part I would have to agree. Not that I am biased or anything.

Frank S · July 19, 2003

IMO the 4.8L is too small for 4x4 trucks. I was really disappointed when they started letting Z-71s be equipped with it. On the old body style the 5.7L was a requirement for the Z-71 option, no 5.0Ls. It should have been the same for the 99-ups, only the 5.3L. But what can ya do? I wouldn't spend big bucks on the 4.8L, you will never get your investment back when it comes time to sell.

Not exactly.

Up until at least '95,the Z71 was available with a 305 and a 5 speed.

How do I know this?Because I almost bought a mint green 1995 Z71 Sport Side with a 305 and 5speed manual tranny.

Wingnut · July 19, 2003

On the old body style the 5.7L was a requirement for the Z-71 option, no 5.0Ls. It should have been the same for the 99-ups, only the 5.3L. But what can ya do? I wouldn't spend big bucks on the 4.8L, you will never get your investment back when it comes time to sell.

Nope, I had a buddy that bought a 94 Z71 SB reg cab, with a 5 speed, and the 4.3 V-6. It pulled his jet-skis without a complaint well past 100k miles, and (while not a jeep) was quite capable off road.

Just my .02

99-2door · July 19, 2003

The Z71 option is available on LS or LT models only (Silverado for old body style). What does that have to do with offroading? Nothing! The point is the Z-71 is Chevy's flagship 4x4, and as such is only available in the nicer models. To you guys that say you have seen a 4.3L or 5.0L Z-71, I think you have been the victim of Truck rice. Do I really have to tell you how many Z-71s have been made at the dealership or in the driveway with a couple of decals? Check the RPO code next time you see one. It won't be there unless someone wrote it in Manual transmission is a non-issue. I myself owned a 95 K1500 that had a 5-speed and 5.7L it was a Silverado and a Z-71. I agree a 4.3L S-10 may be more offroad capable, not really the issue here though.

Frank S · July 19, 2003

No truck rice.

It was at a dealership,brand new and just put out on the lot that day with skids,Bilstein shocks and everything.Back then,you had to order the Z71 option to get those additions and the RPO code matched the truck.I didn't believe it until I opened the glove box but it was there.

Also,the guy that lived across the street from my parents ordered a fully loaded extended cab Sport Side Silverado with a V6 and a 5 speed.They aren't very common but they are out there.

WEFs99 · July 19, 2003

My truck needs help! I just got a 2003 1500 LS Z71 with a 4.8. I have come to learn that it just doesn't have any power when trying to pass people, or straight acceleration. Anyone have any good ideas ( such as new headers, exhaust, carb...)? Please help!

The original post talks about PASSING other vehicles, not necessarily racing them. My 5.3 with 3.73's will hold it's own off a stoplight with most any other truck but at highway speeds and 1700 rpm it PO's me so bad that it is going to get replaced. It has to downshift to get to a usable rpm range for even slight acceleration. In hilly areas or heavy traffic where speeds go up and down I leave it in D3. Our 2500HD 6.0 with 4.10 is a pleasure to drive and it weighs almost 1000 lbs. more. A 5.3 with 4.10 might be tolerable but IMHO a 4.8 with any gear should only be in a little truck.

SilveradoWV · July 19, 2003

IMHO a 4.8 with any gear should only be in a little truck.

To refresh what I said above, my 4.8L is better than a non vortec FI 350. Therefore you are saying that the 88-95 (not sure when vortec started), the 350 was way underpowered for the full size trucks???

MCourson · July 19, 2003

IMHO a 4.8 with any gear should only be in a little truck.

To refresh what I said above, my 4.8L is better than a non vortec FI 350. Therefore you are saying that the 88-95 (not sure when vortec started), the 350 was way underpowered for the full size trucks???

Im not an expert on this but I do know that my '94 5.0L TBI would pull our trailer a whole lot better than our old 01 4.8 Sierra.