StallionCorvette

Hi guys,
I don't know if i am in the right section, if not please moderators let me know and will gladly move along.

Yeah gas right... tell me about it! Let me start by:

*I had a System Charging issue on my Vette before the Meth kit. Causing the car to stall and run rich.

-Had my SC belts changed (TVS2300)
-Had the belt changed
-GM ignition wire set (NKG's causing misfire under load)
-Swapped GM alternator causing DIAG ELECTRICAL ISSUES for a MECHMAN high amp alternator 170v
-Last step was the ALKY kit
-Dyno tune (by a very reputable shop)

-MY SET UP
-LS2
-M6
-STOCK CLUTCH
-STOCK BOTTOM END
-STOCK TRANNY
-Cam (mild)
-Headers
-Xpipe
-CAI
-TVS2300 SC
-MSD FUEL BOOSTER

Having electrical issues with the Charging System was a PIA causing the car to run rich and that annoying beeping sound come on every 5 minutes it was just nerve wrecking. Took my car over to (reputable shop) and had it diagnosed and came out with the solution of swapping the GM alternator which i had just replaced along with the battery 5 months ago for a MECHMAN 170v....IT WORKED! No more beeping crap at the very least. After the alternator they moved along to replacing the supercharger belt since the old one had a rip on it (never slipped). Finally before the ALKY KIT they changed spark plugs and recommend e to change to OEM GM cables since the MSD ones that i had cause issues with misfire under load. Dyno Tune came along and even though i requested a before baseline run on the Dyno to see where i am standing before pulling the METH numbers it was never done, not sure why they choose not to even though they requested $100 extra for a baseline and agreeing on it.
A month went by (alternator was in back order) car was ready Picked up the car and drove it home (14 miles) and notice high coolant temp 225 at 45MPH and occasionally it would stall and also notice that on a FULL TANK i was ranging 174 miles with an Average consumption of 8.8 MPH!!!

Call them and let them know of such issues and that in my humble opinion it was a calibration tune related problem. Took it back the next day and they told me it was because a bad wire connected on the SC that was causing that and that there was no need to Dyno the car again. TODAY 8/17/18 Picked up the car again and the car was running much smoother even though it was very hot out there (92 FL) i was getting Coolant Temps of 205 A/C on stuck on traffic and it will drop to 199/200 as soon as started moving...BUT,,, once i started switching to the MPG I notice that on a FULL TANK i was ranging 174 miles with an Average consumption of 8.8 MPH!!! AGAIN!

My question to you guys is this normal? Should i see that much gas consumption with such mods? I was getting 28MPG before the Meth kit.

Attached are the pics of my dashboard were you can see the MPG and a FULL TANK picture @174mpg, ignore the Check Engine light since that turned on as soon as i took my car from the mechanic shop the first time right now it has been corrected. Also if you guys would like to chime in about the Dyno numbers for such mods it would be greatly appreciated.

THANK YOU!





8.8MPG


174 MILES FOR A FULL TANK


DYNO SHEET. WHAT DO YOU THINK OF SUCH #'s?

demon340

realcanuk

The calculation for MPG and range can be way off when injectors are changes. They probably didn't change it. Run a full tank of gas and see how many miles you really get from it.

StallionCorvette

Stock OEM, my mech changed the cables (NGK) for some OEM, said that it was misfiring under load... whatever that means..

StallionCorvette

Well the injectors were not changed when the ALKY kit was installed and i have the stock injectors that came on my Maggy TVS2300, i believe they are 80lbs. So far when i filled the tank up it gives me a range of 174/5 miles and i can guarantee you that i drove that car on traffic for 30min/14miles and it took 1/4 of a tank

schpenxel

Needs a log with a wideband on it for starters. The MPG calc usually is totally wrong after injectors are changed. It can be adjusted in the tune but not many people would bother

Was there a tune change when the meth was added?

Dano523

Start the car and let it idle, put a multi meter set to 20V DC positive probe of the meter on the alternator output terminal under the rubber boot on the back of it, the negative probe on the body of the alternator and check the voltage. If the voltage is less than 14.7 volts, the problem is the spark plugs and spark plugs wires your using has less resistance than the oem plugs and wires that act like RF noise suppressors, and this is causing RF noise back through the coils to the ECM.

The ECM controls the output of the alternator, and when it getting RF noise to it from the coils, ends up with the ECM controlling the alternator output at a lower voltage than 14.7 volts instead. As for how much lower, if the RF noise is bad enough, have see ECM's controlling the alternator output voltage way down in the low 13 volt range.

So for a spark plug for S/C, use the LS9 plugs, hence 41-104.
As for spark plug wires, just double check their Resistance and make sure it close to the same as the OEM wires. The oem spark plug wires have a resistance of about 360 Ω .