View Full Version : exhaust headers to improve mileage?


semvhu
06-26-2003, 02:51 PM
I need to get more details in my sig soon so I won't have to type everything every time. :tongue: Anyway, in my recently-purchased '93 Z71, I've noticed it seems to lack on low-end torque. I notice a significant difference below 2000 RPM; I'd say it probably has only half the torque at 1000 that it does 2000, but that's just a guess and not a dynoed result. :crazy: In my '94 Corvette, I don't notice much difference between 1000 to 3000 RPM, but then again it's a 'Vette, not a '93 Chevy truck.

Whether or not the engine runs perfectly or not is a bit moot. I'd like to improve the low end torque to pull hills better in high gear and possibly improve gas mileage as well. I estimated my mileage on my first fill-up at 12 mpg. I say estimate because I had to guess a bit and add up in my mind the mileage I had since the first fill-up. I'm keeping tabs on it in an Excel spreadsheet this time and will have a much better number on next-week's fillup.

Anyway, I've read some about exhaust headers. The truck appears to have the original exhaust manifold on-board. If I could get a set of headers for a decent price and improve the mileage and low end torque, I'd be a happy man. The exhaust is a Flowmaster exhaust of some sort, I haven't bothered to try to find exact numbers on it yet. After the engine, it is a single pipe into a Flowmaster muffler that splits into a dual exhaust at the rear.

Any suggestions for a set of exhaust headers for the improvements I'm looking for? 12 mpg is pretty low, but I might could squeak another 1 mpg by easing up more on the foot; it hasn't been too heavy of a foot, but it could still be a little lighter. :D If I could get 15 mpg out of the truck by spending one or two c-notes, I'll be a happy camper. :crazy:

kry226
06-26-2003, 10:39 PM
A complete tune-up should be first in the list of priorities. Then you can establish a stock performance baseline. Then start with the improvements.:D

semvhu
06-27-2003, 03:13 PM
Thanks, but it's already had a tuneup. :D Not long before I bought the truck, the former owner replaced the spark plugs, wires, distributor cap and rotor button, and fuel filter. I'm sure I might be missing something that some people consider as part of a tuneup; if so, please let me know what else could be done. However, the truck seems to run just fine; it idles great, runs just fine over the full range of the motor, and accelerates well for a truck above 2000 RPM. I'm just concerned a bit about the seeming lack of torque on the low end, but it may just be normal for that year and engine.

Otherwise, I've got to do something about that 12 mpg. :crazy:

2k on Dubs
06-27-2003, 06:09 PM
Hey, I put some Gibson Headers on my truck and I did notice a bit of an improvement on gas mileage...but not so much on torque. Also, I dont think your going to find some headers for a bill or 2. Unless you get some kragen flow tech headers or something. Brand names such as Gibson, JBA, and Edelbrock are gonna run you into the 3 or 4 bill range.

kry226
06-27-2003, 10:33 PM
Long tube headers for more torque. Lot of guys on here run either Arizona Speed and Marine or The Other Guys.

91_bowtie
06-28-2003, 12:13 AM
:word: I have Hooker long tubes on mine, and they :rocking: They were $320 from Summit when I bought them 2 years ago.

semvhu
06-28-2003, 12:58 AM
Hmmm, looks like a set of these (http://store.summitracing.com/partdetail.asp?part=HOK%2D2462%2D1) would work nicely. :rocking: Now then if they'll just bolt right in without any serious modification, I'll be just fine. Any comments on how easily they would install?

Thanks for the help!!!!

91_bowtie
06-28-2003, 01:57 AM
Originally posted by semvhu
Hmmm, looks like a set of these (http://store.summitracing.com/partdetail.asp?part=HOK%2D2462%2D1) would work nicely. :rocking: Now then if they'll just bolt right in without any serious modification, I'll be just fine. Any comments on how easily they would install?

Thanks for the help!!!!

The install was easy. Change yours plugs when you install these. Numbers 1 and 3 are a bit(h to get to. These headers will not bolt up to the stock exhaust system. To do the install, you will need a set of 2.5" to 2.25" collector reducers, (2) 2.5" collector gaskets, and a set of header gaskets. You will also need to have a shop build you a new y-pipe, which will probably cost you about $100.