Tuned and Converted to Flex Fuel (2015 Silverado 5.3L)

[Rawyzf]

I'm interested to know why you needed the extra parts to run e85? I thought the 14+ trucks were ready to run that right from the factory.

14s have it, 15s it was an option.

 

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[TrueBlueSilverAdo]

14s have it, 15s it was an option.

 

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oh! thanks for clearing that up.

[Rawyzf]

oh! thanks for clearing that up.

I thought the same as you, didn't even pay attention to that when I got my truck.

 

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[Carl T]

14s have it, 15s it was an option.

 

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This is correct, we have been looking into ways to "best" convert them over. With the OP's truck we installed factory lines from the tank to the engine. The problem is that there are at least 4 different line sets and they can be a nightmare to find the proper part numbers (they are different for crew, xtended, and RC trucks. What we have been doing is installing a fuel comp sensor about 10" further back than the o.e. sensor would be installed. It does require cutting the line and running a jumper harness from the stock harness to the sensor. I will post a few pics when I get a chance. It is a very clean and simple way to do it since it works on all trucks.

Edited November 24, 2015 by Carl T

[Carl T]

 

Have you tuned a L86 on e85 yet? Really curious to see some results of someone converting their new 6.2 to E85. I would love to convert over someday.

 

Yes I have but not a stock one, I am doing a bone stock '15 on Monday and can post results. I will do it stock, tuned and E60ish. Our winter blend fuel is around 65-70% ethanol. It is staring to get cold so it is time to shift away from fast car stuff and start working on trucks!

[El_Diablo_John]

Roughly how much did the e85 parts run? Was it a plug and play or did the ECU still not recognize e85 and throw a code until the new tune was loaded?

[Rawyzf]

Roughly how much did the e85 parts run? Was it a plug and play or did the ECU still not recognize e85 and throw a code until the new tune was loaded?

Right around $200 for parts.

 

I'll let Carl speak to the tune stuff.

 

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[Gmcant33]

200$Not bad I expects to be more

[benjaminforeal]

 

Yes I have but not a stock one, I am doing a bone stock '15 on Monday and can post results. I will do it stock, tuned and E60ish. Our winter blend fuel is around 65-70% ethanol. It is staring to get cold so it is time to shift away from fast car stuff and start working on trucks!

 

Awesome, that would be great. What kind of mods done to the one you have tuned? I'm wanting to do full bolt-on's eventually. Might was well do E-85 conversion/tune at the same time with bolt ons. Would have to get a tune for 91 as well since E-85 isn't available conveniently close to me where I'm at. Would just run E-85 at the track probably.

 

The E-85 in my area over this last summer was measuring around 70. I can't imagine what the winter blend is testing out.

Edited November 24, 2015 by benjaminforeal

[Carl T]

Roughly how much did the e85 parts run? Was it a plug and play or did the ECU still not recognize e85 and throw a code until the new tune was loaded?

 

It is not plug and play, you can install the lines and sensor without setting a code and then have a custom tune done to optimize. Your second option is to load a factory flex fuel tune right from GM. If you have a knowledgeable dealer tech or independent shop they should be able to figure that out.

[Sooperdave]

 

Parasitic loss isn't as complicated as it seems to be - the more mechanical moving parts you have, and the larger they are & the larger the distances they need to rotate/travel, then the more loss you will have.

Corvette - 2 seater, short wheelbase, transaxle (distance from engine to where the axle mates is quite short), no torque converter manual tranny, = low parasitic loss, maybe 13-17%

 

Large RWD sedan w/ traditional torque converter style automatic tranny like a charger or chevy SS = driveshaft longer distance from engine to rear axle compared to vette, torque converter absorbing some of the engine's power, etc. = 18-22% loss

 

Boosted AWD car like a subie STi - turning all 4 wheels ALL the time w/ center diff but has manual tranny = 18-22% loss, if equipped w/ auto = 22-25% loss

 

Truck w/ long ass heavy ass beefy driveshaft, heavy beefy rear axle, 4WD components, beefier heavier duty clutch components in the tranny/converter = 25% loss

 

My Z06 vette only "lost" 11.1% of its HP on a relatively stingy mustang dyno in stock form - 360whp, rated @ 405....realistically that car probably made closer to something like 415-420hp in stock form which would put that figure more like 14-15% loss.

Sounds about right excluding pulls are generally not made in 4wd on 4x4 applications so you can't account for loss there. As I said before general rule of thumb for most shops is 20% for auto's and 15% for stick cars. It calculates out to be fairly close to factory ratings when doing the math. Excluding some that are underrated. And proven to be underrated based on track results. Such as many LS applications. You gave a good example with the LS6 in your Z06 as well as the 4thgen F-bods. They were pulling 280-300 stock in a stick car and were flywheel rated at 310hp. 15% loss puts them at numbers near the C5 LS1 ratings(15%). If the above truck was ran in 4th gear and lets say it made in the 285-90ish range as its base pull.. would it still be a 25% loss? Or will you be changing the percent based on where the flywheel number is? And I've seen a couple dyno pulls of stock 5.3 run in the 290 range and the 6.2's in the 340 range. Based on what the tuner said earlier which is typical, numbers are usually lower in 3rd gear pulls. A 20% loss on the 266 above number would be 332 fwhp. A lower than stock number. Sounds right to me. By any means am I trying to stir up anything in the other post or here and regardless how you calculate it, the above results are indeed impressive and I'm sure the truck runs damn good!! Simply, just stating my opinion from my past experience working at a late model gm performance shop from 2000-2008. Congrats to the owner!

[SMiller]

I always enjoy seeing the driveshaft fly out on the dyno when doing a 4th gear pull.

 

 

Does the software allow for corrected power when pulling in 3rd?

[Rawyzf]

Sensor installed, for those curious:

 

 

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[crushNchowda]

Sounds about right excluding pulls are generally not made in 4wd on 4x4 applications so you can't account for loss there. As I said before general rule of thumb for most shops is 20% for auto's and 15% for stick cars. It calculates out to be fairly close to factory ratings when doing the math. Excluding some that are underrated. And proven to be underrated based on track results. Such as many LS applications. You gave a good example with the LS6 in your Z06 as well as the 4thgen F-bods. They were pulling 280-300 stock in a stick car and were flywheel rated at 310hp. 15% loss puts them at numbers near the C5 LS1 ratings(15%). If the above truck was ran in 4th gear and lets say it made in the 285-90ish range as its base pull.. would it still be a 25% loss? Or will you be changing the percent based on where the flywheel number is? And I've seen a couple dyno pulls of stock 5.3 run in the 290 range and the 6.2's in the 340 range. Based on what the tuner said earlier which is typical, numbers are usually lower in 3rd gear pulls. A 20% loss on the 266 above number would be 332 fwhp. A lower than stock number. Sounds right to me. By any means am I trying to stir up anything in the other post or here and regardless how you calculate it, the above results are indeed impressive and I'm sure the truck runs damn good!! Simply, just stating my opinion from my past experience working at a late model gm performance shop from 2000-2008. Congrats to the owner!

4th gear pulls are typical on many 6 speed cars because it equates to 1:1 ratio and I guess is the best for tuning the vehicle properly, I don't think that holds true for ALL vehicles by any means, depends on transmission/final drive etc. I know that many tuners don't like putting big trucks on the dyno (mine included) for fear of throwing the shaft or the truck slipping off etc. - I don't have enough experience to say exactly what the problem is dynoing trucks vs. sports cars....but that may be some reason for wanting to dyno in 3rd??

 

And I do think you'd read about 5-10whp lower in 3rd than in 4th, I think its important to be consistent and use the same gear every retune/dyno run, but I'm also pretty damn positive you should be dynoing a 6L80E or T56 equipped GM vehicle in 4th - not 3rd.

 

NO CLUE what the rule of thumb is for the 8 speeds lol.

 

So that being said, I still think these trucks have more than 20% drivetrain loss based on what I have seen in the past.

[Carl T]

4th gear pulls are typical on many 6 speed cars because it equates to 1:1 ratio and I guess is the best for tuning the vehicle properly, I don't think that holds true for ALL vehicles by any means, depends on transmission/final drive etc. I know that many tuners don't like putting big trucks on the dyno (mine included) for fear of throwing the shaft or the truck slipping off etc. - I don't have enough experience to say exactly what the problem is dynoing trucks vs. sports cars....but that may be some reason for wanting to dyno in 3rd??

 

And I do think you'd read about 5-10whp lower in 3rd than in 4th, I think its important to be consistent and use the same gear every retune/dyno run, but I'm also pretty damn positive you should be dynoing a 6L80E or T56 equipped GM vehicle in 4th - not 3rd.

 

NO CLUE what the rule of thumb is for the 8 speeds lol.

 

So that being said, I still think these trucks have more than 20% drivetrain loss based on what I have seen in the past.

 

^^This is good^^

You always want to operate the transmission as a 1:1 ratio. For 4l60/80 and most other A4's that is third gear, That holds true with older TH350/400's as well, glides are done in 2nd/high gear.

 

6l80's you dyno in 4th gear (which is not a 1:1, it is 1.15:1). 8 speeds are a 1:1 gear ratio in 6th gear. We always want to dyno in a 1:1 gear ratio but high wheel and driveshaft speeds prevent that. Most dyno operators are dynoing big trucks with 6 and 8 speeds in 3rd and 4th gear.

 

The loss in power is moslty caused by parasitic loss in the gear reduction not a dyno calibration.