My 1998 sierra z71 build thread

[98sierra4x4]

I don't believe in cold air intakes for anything other than they look good. Maybe they do, maybe they don't. I'm just not sold on them. I run a K&N drop in filter, mainly because when it's dirty, I can clean it and not have to run to the parts store and buy one every year. And I run a Dynomax cat back on my truck. Sounds decent, not loud at all, but has that little rumble when you get on it. I can't say for sure if I picked up any MPG.


Just my opinion and what I have done to mine. I'm sure one of these other guys will chime in with their findings.

Ok thank you for you opinion, doesn't the vortec kind of have a cold air intake?

 

[98sierra4x4]

I'll trade trucks in heart beat if that's Pewter! That's one of my favorite colors for these trucks. How you drive will make a big difference in gas mileage too. I know when I first got my 98 Silverado, I was getting maybe 18 with a tailwind going down hill... 15-16 was pretty common. Now that I've done a bunch of mods to my truck I'm pulling in anywhere from 11-16 mpg. Usually 13-15 on average.

But I was in New Mexico this summer and averaging anywhere from 19-23 mpg. Don't know what to tell ya..

Edit: MB TKO rims all the way!

Sent from my iPhone using Tapatalk

Thanks for the info, I like how you have your truck set up but you know what they say the fun is in the build lol

 

[98sierra4x4]

Just my $0.02 on cold air intakes:
I they think they work. I pulled an extra 1.0 mpg after installing the K&N unit. Also noticed a good boost in throttle response.
Like Montes said, make sure everything else is up to spec. New spark plugs, wires, cap rotor fuel filter etc, will help you gain back any mpg you may be losing due to worn out parts. You can also look into getting a custom tune for your truck, will wake it up and most people see a 1-2 MPG increase.
As far as exhaust systems increasing gas mileage? No truth to it on a stock truck, if anything you will probably lose some from pressing the skinny pedal to hear it

Thank you for your opinion, how many mpg do you get?

Haha that's true about the exhaust

 

[98sierra4x4]

Flowmaster 40 or 44 are good mufflers, nice and deep sounding, not to loud. Plenty of knockoff brands that sound nearly the same if you don't want to pay $80 for a muffler. My truck has no cats and a Full Boar single chamber which is like a Flowmaster Super 10, but would probably be a bit loud for your taste, but they are only like $30 a piece. The 2 chamber ones they sell (Nearly identical to the Flowmaster 40 or 44) are like $35-$40. I can send you some links to those mufflers if you'd like. I like the truck man, it looks sweet. Love those wheels with the pewter and black rockers!

Thanks man, could you send me those links?

 

[Torchred]

Thanks man, could you send me those links?

Here is the 2 chamber FM40 style muffler
http://www.ebay.com/itm/Full-Boar-D...Parts_Accessories&hash=item19d6a025f9&vxp=mtr

Here is the FM10 style Single Chamber I'm using
http://www.ebay.com/itm/Single-Cham...Parts_Accessories&vxp=mtr&hash=item2ed780bc88

This is a video of the muffler on my truck. Want to make a new video of it, but it needs a fuel pump. https://www.youtube.com/watch?v=fk-sdyU-UhU

 

[98MNChevy]

Thanks for the info, I like how you have your truck set up but you know what they say the fun is in the build lol

Exactly! It's been a fun ride for me! You're part way there with your truck; got a good start!

By the way. I'll try to get the pictures of the rack tomorrow for you. It's homecoming today and the parking lot is packed so I can't get any good pictures.


Sent from my iPhone using Tapatalk

 

[98sierra4x4]

Exactly! It's been a fun ride for me! You're part way there with your truck; got a good start!

By the way. I'll try to get the pictures of the rack tomorrow for you. It's homecoming today and the parking lot is packed so I can't get any good pictures.


Sent from my iPhone using Tapatalk

Ok thanks man

 

[twomanymontes]

Ok thank you for you opinion, doesn't the vortec kind of have a cold air intake?

Sort of, they do go to the passenger side fender and draw air from the vent behind the front grill. If you have the Vortec motor, there is a mod to seal off the silencer and that is supposed to help performance.

 

[SwampHound]

Thank you for your opinion, how many mpg do you get?

Haha that's true about the exhaust

I used to get 12.5-13.3 give or take a bit. Then I got straight pipes and I'm down to 11.8-12.1 lol

 

[98MNChevy]

Ok thanks man

Well....totally forgot to get pictures before I went to the concert last night, and now the truck is in the shop for some front end work. Not sure when I'll get it back, but when I do, I'll get those pictures.


Sent from my iPhone using Tapatalk