05duramax

Hello everyone, I recently just purchased 2010 cobalt SS. The person I bought it from said it was tuned for E47, just simply mix 91-E85 equal parts and all is good. My question is there is a station that sells E50 at the pump. Could I use this instead of mixing?

2nd question, If using the E50 is okay, could I use E55?

ECaulk

iTrader: (6)

You probably would be ok with e50, and e55 wouldn't be the end of the world. Your fuel trims would be off but not horrible, just stick with either mixing e85 and pump or run e50. The best idea is to get hptuners and log the car on e47 and then on e50 to compare.

05duramax

he said it was tune by trifecta, could changes be made with HPtuners or would the ECM be locked by trifecta

63 Nova SS

iTrader: (3)

You can use use hp tuners if the previous owner still has the factory tune, that can be reloaded on your computer. If not, you will have to contact trifecta and try and get your factory tune that you can reload because they lock the ecu. Mine was originally tuned on trifecta and I went to hp tuners, but I kept my original tune and was able to reload it. Car runs much better on hp tuners than it did on trifecta, or gms1.

ECaulk

iTrader: (6)

You can still log the car with hptuners, you just wont be able to make any adjustments to the tune file. You would need to get a trifecta cable and get a hold of the stock file from trifecta (which I recommend no matter what your plans for the car are)

T-Man

iTrader: (3)

Difference between E47 and E50 would be next to nothing.

Do yourself a favor and find someone reputable to tune your car with HPT and get away from Trifecta

63 Nova SS

iTrader: (3)

What matters more than anything, depending on how much timing and such that the trifecta tune has, Is E content in the e85 that you are mixing. I test it every time I get fuel.
If you are counting on it being1/2 e-85 and 1/2 premium, to give you 97octane gas, and the e-85 is actually e-75, then you can get knock due to lower octane.

double clutch

iTrader: (1)

I got lazy with that. It always tested as E85, so i havent tested it since spring. Probably should.

T-Man

iTrader: (3)

Knowing Trifecta, I'd guarantee that car doesn't have more than 20* of timing. Can easily get away with that on E30 if you wanted (assuming stock turbo)

I'd say the only issue with his situation is the fact that he's running a Trifecta tune.

T-Man

iTrader: (3)

Would be a good idea. Here in AZ, our "E85" is now called Flex Fuel and can have as little as 51% content.

I'm in-between two stations and one consistently tests at 60% and the other is closer to 55%

Kind of shitty really. Makes me want to invest in an ethanol content sensor

ECaulk

iTrader: (6)

I didn't have any KR running e85 and regular at 22* there is a point on these engines where the ethanol content really doesn't matter just helps with cylinder cooling. I agree the biggest issue is trifecta

63 Nova SS

iTrader: (3)

I have tested e-85 here and in between 85% tests I have seen it drop to 75% in the middle of summer. Must have been a winter mix truck that delivered (old fuel). You go from e47 to e42 with 85% mix to 75%. May not be a huge deal but I always try and keep it at 47, which may mean I actually mix 6gallons of e to 4.5 gas to keep 47% ratio on the e75.
Would love to have straight e so that I can use all 93 to mix with it.

05duramax

around here where they sell E85, they all have labels stating the E content is anywhere from 50%-85%

63 Nova SS

iTrader: (3)

Same here, that's why I test it.

mongorat427

iTrader: (82)

I have a couple cables even though I dont use Trifecta anymore. 412 915 3183 If you have a cable download Trifecta EZ Flash. It should see your tune and you should be able to flash it back to stock

05duramax

he gave me the cable with the car. how do I go about getting the stock tune? Also he had done some mods to the car which includes..

at 42,000 miles the motor got rebuilt which included-
-headgasket
-ARP headstuds
-shift cables
-135# opel injectors
-chain tensioner
-upgraded valve seals
-rods and bearings
-pistons and rings
-turbo oil and water lines

-zzp intercooler
-zzp charge pipes
-aftermarket FORGED diverter
-3inch downpipe
-3inch straight pipe with resonator
-k&n typhoon cold air intake system
-trifecta E47
-GM stage 1 Bosch sensors
-zzp billet motor and trans mount
-5speed short throw shifter, weighted shift knob
-stage 1 clutch
-brembo brakes, drilled and slotted rotors
-zzp pillar with RPD and glowshift boost gauge

b9k

You are going to have to get a trifecta cable and the trifecta software and then update ecu with the stock tune file.
Or you can buy a new ecu with a tune supporting your mods from zzp and replace the old one.

05duramax

well, I'm going to be getting my car dyno tune on Wednesday by ZZP. Anything I should before I go in? I've already changed the oil and put a new O2 sensor in.

63 Nova SS

iTrader: (3)

Make sure the plugs are good.