Hi I have been lurking here forever and decided to finally speak up. I have a 2005 Silverado and I recently completed the stage 1 exhaust mod. Not only does the bike sound great, My gas milage has skyrocketed. I used to get to between 110 and 130 miles before the low fuel light came on. Now I am between 190 and 200 miles before it comes on. I expected an increase but this is huge. Is this normal?

Hi Travis...

Welcome! I hear that is expected when you free up the exhaust. Apparently the roadstars come from the factory running kind of rich. Freeing up the exhaust helps it get out of the bike faster. If you're experiencing backfiring since doing the Stage 1, you might want to think about removing the AIS.

I'm drilling my stock pipes soon. Can't wait for that increase in mpg!!

Again...welcome and look forward to talking to you.

....greeny

WELCOME!

Glad to hear you like the stage one However, that seems a radical improvemnent in gas mileage...are you sure you didn't flip it to reserve and forget to turn it back If you did you may want to correct that like NOW

Regards, Ted

welcome Travis

I'm getting around another 50 to 55 miles before I hit reserve (Way past the light coming on) since I switched pipes and I thought I was kicking butt. Are you sure of those numbers?. <br><br>Post edited by: Musky, at: 2006/06/07 13:10

Hi,
Also been a lurker and getting great info.

But now, a little stumped regarding low MPG.

Bike Specs - At 2,500ft MSL -Density Alt averages about 4,000ft

2001 Midnight - Silverado windscreen and Bucks lowers - Silverado bags - Rider 195lbs

AIS removed
Stage 3 on Stock Pipes
FAT BAK Mod with K&amp;N filter and 5 - 1/2 inch holes drilled in forward side of stock air box.

Rejetted with Barons main 170
Barons jet needle with clip at 4th slot down.
(followed forum direction to not replace lowest washer on jet needle...under plastic spacer)

PMS started at 3 1/2 turns out.....much decel backfire.....out to 4 1/4....moderate backfire on moderate decel - Major Backfire on HARD decel.
No Carb cough
Checked for Exhaust or intake leaks...none noted

MPG = 33 to 34 @ speeds of 60mph AND 70 MPH...(no difference)

Had been getting about 38 prior to K/N filter and jet change. Bike seems to run strong through out throttle range...with an overall slight &quot;seat of the pants&quot; improvement. Needs choke on start, but less than before changes.

Travis,

I'm more surprised by your earlier mpg than I am by your current one. I have a 2005 Silverado and stock I was getting around 50 mpg which appears to be what you're achieving now. I changed my exhaust to Vance and Hines Powershots and it really didn't affect the mileage. I later added a BAK with suggested jetting for the 2005 Silverado and noticed a pretty good drop in my mileage. Also noticed my plugs were getting fouled pretty quickly. Dropped the jetting to 3.5 on the needle and about 2 on the PMS. I didn't change the main jet which is 172.5 even though I think most of the gurus, like Odo, are recommending 167.5. My mileage is back up to 50 and bike is running strong. Saturday, for example, I rode 305 miles and used almost exactly 6 gallons (this included a fair amount of riding at 80 mph on highway 78 in North Alabama).

I've determined that on my bike the low fuel light comes up when I have a little more than half gallon of gas remaining before I have to go to the reserve. The reserve has about .8 gallons so I would still have 1.3 to 1.4 gallons remaining when the low fuel light comes on.

I've purposely tried to jet with an eye toward good gas mileage. My simple logic is that if the bike is burning the gas efficiently it shouldn't be building up deposits in the cylinder head. Running this way I still have ample performance and don't have any trouble keeping up with my buds on their Road Kings, etc.

Thanks for all the replies. I know it sounds unreal. The numbers are correct though, I have run 3 tanks through it since the mod and had the same milage with each. It has been a mix of Highway 65-75 MPH and City stop and go.

I checked to see if I had turned it to reserve on accident but it is set for regular riding.

The low milage I was getting before I drilled the exhaust was really disappointing, I have read several threads on here and just accepted the fact that I was going to get poor milage since the engine is so big.

The Mechanic at my local dealer also told me that it was normal. When I went and told him about the difference he actually went on a long ride with me just to see if it was true.

Once again, thanks for the replies and for the great advice on this board. My next step will be to take the AIS off.

Travis

Welcome to the Clinic goflyslow2.

It's best to start a new discussion when you want to change the topic, especially if you're seeking help. It's easier to respond to you.

Not sure but if you're at 2,500 ft then your bike is running too rich with your current setup which seems to be confirmed by your low gas mileage.

I'd go with Mikuni 165 (stock jet for the 01), leave the needle at 4 and turn the PMS to 3.

Doc

goflyslow2 wrote:
Hi,
Also been a lurker and getting great info.....
AIS removed
Stage 3 on Stock Pipes
FAT BAK Mod with K&amp;N filter and 5 - 1/2 inch holes drilled in forward side of stock air box.

Did you run the stock air filter for some time before you got the K&amp;N? I am wondering if you jetted the carb after the &quot;FAT BAK&quot; with the stock air filter. Thanks Brother...

I have an 05 R* Silverado too and was wondering if anyone has done a stage 1 exhaust-only modification to stock mufflers and got good results for MPG. How is your low-end torque as compared to before the stage 1 was done? Did you only do the exhaust mod without rejetting? I was thinking of doing an exhaust-only mod without rejetting too, but some say the engine will run too lean and lose low-end torque without the backpressure. I did remove the AIS (Canadian model with minimal tubing) last night and really love the improved exhaust tone and not hearing that crappy chirping sound from the AIS at idle and low speed touring.
The mileage increase you ae experiencing only makes sense to me, if the engine has to work less hard to fight backpressure then the more mileage you'll get with the added efficiency. Anyone else got any thoughts on this?