please post what kind of MPG you get with your supercharger (and what kind of set up u have). also how many miles per tank do u get?

i just had a vortech supercharger installed with a lingenfelter supperram set up (on a 350) and on the first two tanks of gas (since the install) im averaging only 8.5 mpg !!! i get around 100-110 miles per tank...the motor is a 350, rebuilt, new plugs and wires, running mobil 1 synthetic oil...im not even 'heavy footed' this is just basic driving...need help !!!!!! anyone who can lend advice speak up!! ive heard that new motors need break in time and this can cuase bad mpg but 8.5 mpg is rediculous !!! i only run 93 octane too..

 

so go get a better tune done....? when you're out of boost it shouldn't be that bad.

 

only roots blowers are supposed to give bad mpg all the time..

btw, i get 8.5 mpg N/A...

 

I don't know where you heard that....... if you drive a roots with a light foot it will get better gas milage than without !

 

I agree with xpndbl3, if you truely are driving with a light foot ( hard to do with new power ) and getting poor milage I would look at your tune.

 

thanks shawn, i agree with you too And you're mr. blower from all those pics, so I'd believe you 100%

 

Huh...I was getting 22.6 avg MPG (25 hiway MPG) with my blown 350 and 4.10 gears. It was a Weiand 142 with an Accel 4 barrel TBI (with 4, 86# injectors) and Rbobs EBL.

 

Its something other than the supercharger. My mileage hasnt changed unless I'm racing... in which case the mileage is awful. But there's a lot more power

 

i get about 5....N/A...cant wait till the blower is on...wohhhooo

 

I know what you need to do!!!!!!
Take the SUPERCHARGER OFF GIVE IT TO ME,YEA!!!!!
THAT will make the gas mileage better!!!!!!!
lol

 

i know its running rich...as my mechanic told me it is. would leaning it out a bit help? also, can some explain to me exactly what is involved with tuning a supercharged vehicle? what is tested/checked/changed? and how exactly is it done?>...i would like to know as im new to having a supercharged car.

 

i stand corrected..

 

boosted cars aren't something for a novice to tune. Go take it to a dyno shop that specializes in them and pay to have it wideband tuned on a dyno, only way you'll get it right. N/A motors are more DIY'er but one lean spot on boost and you're done.

 

I don't know if this will help you but.. It might be in the F.M.U. Thats the fuel managment unit. Got to see if its working right under boost applications. I think your fuel pressure should be around 35-40psi driving around without boost. Under boost it will spike up a little more depending on fuel demand (where dyno tuning comes in.) My car would spike fuel pressure to around 80psi under hard boost (12psi). But still got around 190-200 miles a tank with a 383. Good luck

 

True, people don't seem to realize that Roots blowers utilize a valve to vent boost when not needed (idling, low RPMs), lower parasitic hp loss and increases mileage. In town, roots blowers can actually INCREASE mileage. Contrary to popular belief, they have evolved since the style of design was patented in 1860 (by Philander and Francis Roots of course).

Back on topic, a good dyno tune is probably just what you need

 

Actually only the newer Eaton's have the bypass valves. The Wieand's and B&Ms don't bypass them. They supposedly increase MPG because they're more efficient at stuffing air into the engine.

All this talk is making me jealous that my 144 is just supercharging my work bench.



So far with the mods in my sig I'm only able to get 15mpgs, but I didn't build it to baby it.

 

Weiand says they use the bypass valve on their blowers, you sure they don't?

 

100%, took mine apart, but mine's the smaller 142/144 variety, not sure about the big boys, but dunno why those would. They told you that on the phone?

 

No, it was in their supercharger catalog. The catalog has a good sized section where they go over supercharger details and info. I suppose that doesn't at all make it true, but I didn't think they'd fib on that

 

Weird, maybe its an addon?

 

You need to put a Wide Band O2 on the car. With out that your driving blind.

Tuning off the narrow band just won't cut it anymore. I use the AEM Widband on my stock ECM Cars.

Tuner pro will be able to edit your factory ECM. If your using a FMU... Ditch it. They are not going to give you the right AFR for all driving that a street car does.
If your not willing to learn how Tuner pro works and alot of stuff about hacking the factory ECM then go Aftermarket. FAST... or DFI. It's much more user friendly.
There's no reason why your getting the MPG you do except for a very Poor Tune.
~Scott.

 

i do have the FMU installed from vortech...(ur50slow) can u expalin why the fmu cant handle the needs of everyday driving? (this is not a strip car but as much of a daily driver as possible...but as powerful it can be as a DD with decent gas milage). i spoke with my engine builder, he told me he did a very basic tune on the car just to help break it in as the engine was rebuilt in addtion to the vortech supercharger and lingenfelter top end. i told him about my terrible gas milage and he said we could address that once its good and broken in (were agreed around march--giving it plenty of break it and daily use over that time period), he did mention getting it on the dyno at that time and doing a proper tune, as of now it hasnt been on the dyno yet.

can ui explain to the difference between 'wide band' and 'narrow band' ? im not familiar with the difference...thanxx

 

The FMU is nothing real fancy.
Your normal Fuel Pressure Regulator increases fuel pressure 1-1 with boost.
So every 1 psi of boost you get 1 more Psi of fuel pressure.

Your FMU however is setup depending on a diaphram inside to double/triple or more your fuel pressure depending on boost. So... Your boost go's up 1 psi and your fuel pressure go's up 2 or 3 or more depending on the disk inside.

Now.. with that being said... your ECM knows nothing of of this FMU. It's got the factory programing inside and it will account for some rich/lean in the Intergrator/BLM's (block learn) numbers but it can only adjust so much.
A FMU will never get you a proper fuel curve pushing extra fuel through stock or bigger injectors with the Barro/humidity/temp changes.
And it's not easy on fuel system parts having so much pressure on them when in boost.
If you decide to edit your ECM and install the proper Fuel Injectors for your HP level you'll end up with a longer living fuel system and a custom program that is able to adjust it's self on a daily basis and it's not going to fail as easily. With a system like Tuner Pro you can adjust your spark curves, fuel curves... Cold running/open loop/Idle ect It's limitless realy. But it's going to take some time to learn it.
Now... A Narrow band O2 reads in Mv. (Millivolts) You can tune with one but it's designed to read 14.7-1 Anything above or below it's not as accurate.
(Also called a one wire O2/ or can have 4 if it's heated)
A Wideband allows you to read actual AFR (Air Fuel Ratio) It's accurate over a wider range of your air/fuel that your car experiences.
It's much easier and more accurate to tune with one once you know what AFR to tune for.
Boosted cars like 11.7-11.3AFR at WOT and you can narrow the AFR's down to 14.7-15.3 (Or leaner) when crusing/light load. That takes more experience with tuning and timing to get right.
Being Pig rich isn't always a good thing either. If it's 6mpg and the afr's are 10's all the time you'll end up with fuel in your oil and it's not going to be a good thing.
A Dyno in my openion is a waste of money and time. Your much better off to tune in "real world" conditions with the wind and actual road load on the car. You could tune WOT on a dyno and get some "Numbers" for you to look at but it's not going to dial your car in for every day driving.
There's so much more to tuning than I can explain in a few paragraphs but this is a basic start behind what it takes to program for daily driving with factory ECM's.
The Wide band go's in a 2 1/16th pod on your pillar. 2 wire hook up. (Positive/neg.) and the other lead go's to the 7wire O2.
Be glad to help anytime,
~Scott