Author Topic: e85 tune from trifecta (Read 26008 times)

Ames Performance Tuning · « **Reply #25 on:** May 11, 2011, 09:19:40 AM »

Let's see if the images work. If not, I went to Dyno and did see increase of 35 whp and approx. 60 ft lbs. on E85 across the power curve.

Kelu · « **Reply #26 on:** May 11, 2011, 09:24:37 AM »

Nice gains

I have some questions:
1) What happens above 6000rpm, seems like a big drop?
2) The AFR with E85 shouldn't be way lower than with gas?

snaponbob · « **Reply #27 on:** May 11, 2011, 11:10:30 AM »

Quote from: BrentnKC on May 11, 2011, 09:19:40 AM

Let's see if the images work. If not, I went to Dyno and did see increase of 35 whp and approx. 60 ft lbs. on E85 across the power curve.

Something is strange. The first MC Racing charts are from May 2010. The WinPep7 chart from MC shows over 100 wtq increase at 3000 rpm, 55-60 whp at 5500 rpm, and at least +50 wtq at 5500. In any event, that is BIG.

Ames Performance Tuning · « **Reply #28 on:** May 11, 2011, 10:50:30 PM »

You are right snaponbob, these Dyno runs are over year not the same day. I started with the GMMP tune, later on I purchased the Trifecta tune, and just recently the E85.

Kelu, I can't claim any E85 expertise but I think the A/F is should be the same but requires and advance of the fuel injection timing.
Anyway that is a guess.

SKY888 · « **Reply #29 on:** May 11, 2011, 11:17:03 PM »

damn nice numbers!!!! That TQ is phenomenal!

and due to the stock turbo size, they just die at the top rpms.........unlike bigger turbos...which comes alive at the higher rpms.

Kelu · « **Reply #30 on:** May 12, 2011, 03:18:11 AM »

AFAIK Stoich AFR for gas is 14.7:1 and for E85 is 9:1

GeeTeeOh! · « **Reply #31 on:** May 12, 2011, 05:13:10 AM »

All the E85 tunes and dyno runs I have seen has AFR closer to 10. 13 is lean even for 93.

snaponbob · « **Reply #32 on:** May 12, 2011, 08:02:57 AM »

The AFR may be a function oh HOW Vince manages the fuel delivery. If there is no knock retard, then all is okay. Another thing to consider is that DI usually operates leaner than port injection or other fuel systems. Clearly, it is working as those curves look a lot like what is seen on the Cobalt and HHR forums.

Brent, hope you are planning on a clutch !!!!!

Kelu · « **Reply #33 on:** May 12, 2011, 09:52:23 AM »

Quote from: snaponbob on May 12, 2011, 08:02:57 AM

The AFR may be a function oh HOW Vince manages the fuel delivery.

The AFR plot from dynos are not made by direct measurement from a probe sticked on the exhaust?
In this case ECU calibration has nothing to do with the plot.

Brazen17 · « **Reply #34 on:** May 12, 2011, 10:24:15 AM »

Quote from: BrentnKC on May 11, 2011, 10:50:30 PM

You are right snaponbob, these Dyno runs are over year not the same day. I started with the GMMP tune, later on I purchased the Trifecta tune, and just recently the E85.

Kelu, I can't claim any E85 expertise but I think the A/F is should be the same but requires and advance of the fuel injection timing.
Anyway that is a guess.

Are you still running the stock fuel pump?

Ames Performance Tuning · « **Reply #35 on:** May 12, 2011, 01:35:16 PM »

I am still running a stock fuel pump but I think I am borderline with it. I also installed a DDMWorks fuel filter. I was glad to see that it did not measurably affect fuel pressure. Some additional observations, in warm humid weather above 70 degrees, knock is minimal if not 0 under full throttle. Plus 80 to 90 degrees outside you can't make it knock. On the other hand, a cool 40 to 50 degree day with low humidity will produce more knock than I am comfortable. Car still runs great and I can't hear knock but the gauge makes me nervous.

Anyway, I have some more observations to make but worse case, I would recommend gas tune for Winter weather and E85 for Summer.

Ames Performance Tuning · « **Reply #36 on:** May 12, 2011, 01:36:27 PM »

Or maybe a upgraded fuel pump would cure this?

Kelu · « **Reply #37 on:** May 12, 2011, 01:52:08 PM »

Colder intake temps generate knock? That is weird, shouldn't this be the other way around?

As far as I know the limitation is HPFP and not the LPFP. There are no upgrades for HPFP yet, I presume Vince already increased your HPFP pressure.

Ames Performance Tuning · « **Reply #38 on:** May 12, 2011, 02:14:24 PM »

I am purely guessing from tuning my old Grand National, but the colder denser air probably requires additional fuel and I may be close to my fuel pressure max on my Solstice. Cool air vs warm air is like the cooling effect of Nitrous, creating more air density but on a lesser scale.

Anyway, I need to do some more testing before I can say anything for sure. Since this is my fun car, I put on about 30 miles a week at best so it is hard to get data very quickly.

SKY888 · « **Reply #39 on:** May 12, 2011, 02:21:40 PM »

new stage 3+ clutch will be needed soon...with that tq level.

I thought Vince, started bringing down the 2900psi HPFP.....to lower psi? Since brining the HPFP up to that level doesn't really cure the issue....and just stresses out the pump so much.

Ive read somewhere that he brought it down to 2500psi instead.

some cobalt owners have upgraded the LPFP (255lph walbro pump).....using the trifecta tune with E85.

Ames Performance Tuning · « **Reply #40 on:** May 12, 2011, 02:25:37 PM »

Thanks for the additional info!

Kelu · « **Reply #41 on:** May 12, 2011, 03:23:31 PM »

What plugs are you using? Did you checked them since using E85?

snaponbob · « **Reply #42 on:** May 12, 2011, 04:19:10 PM »

Quote from: Kelu on May 12, 2011, 09:52:23 AM

The AFR plot from dynos are not made by direct measurement from a probe sticked on the exhaust?
In this case ECU calibration has nothing to do with the plot.

Yes, the AFR is measured by an exhaust gas analyzer. But what comes out of the tailpipe IS 100% dictated by the ECM, as the ECM controls everything that is going on. If the AFR is too lean, the ECM can be programmed to correct it by commanding (among other things) more fuel.

Ames Performance Tuning · « **Reply #43 on:** May 13, 2011, 10:14:41 PM »

Kelu, The plugs are stock

2.0 tspeed · « **Reply #44 on:** May 14, 2011, 11:43:39 AM »

BrenTnkc what psi is your e85 tune at

Kelu · « **Reply #45 on:** May 14, 2011, 06:27:17 PM »

Sorry for my drift, did more reading and found a useful info:

Quote

You may have already read that E85 has a different stoichometric air fuel ratio than gasoline's 14.7. The stoich AFR for E85 (at 85% Ethanol) is 9.76. The stoich value represents an ideal perfect burn of the fuel usually used at part throttle conditions. Full throttle conditions require a richer mixture than stoich to prevent the dreaded detonation, or pinging.

However most AFR gauges you can purchase to display a numerical value of the AFR, are showing you values for gasoline. This is where it can get tricky, and it's important to understand how this ratio works on both gasoline and ethanol-based fuel.

All AFR's regardless of fuel type work off of a common number called Lambda. A value of 1.0 in Lambda represents the stoich for any fuel. Gasoline is Lambda 1.0 at stoich. E85 is Lambda 1.0 at stoich.

If you already have a standard gasoline AFR meter hooked to a wideband O2 sensor, you can still use the displayed gasoline AFRs in determining your engine's true AFR. For example, if your gasoline meter is showing 14.7, then we know this is Lamda of 1.0. The equivelent on the E85 side is around 9.7. Therefore you can conclude that the 14.7 you see on the gauge is a true AFR of 9.7. This allows you to effectively use existing gasoline AFR components or software to tune on E85 without buying special equipment. Simply use the same target AFRs on your gasoline gauge that you normally targeted for gasolline.

This explains that 12.5 AFR displayed by gauge/hpt/sniffer is actually 0.85 lambda which means 8.2 AFR in case of E85. Something was weird imho, now is clear.

2.0 tspeed · « **Reply #46 on:** May 19, 2011, 03:34:45 PM »

Going e85 today I'll let you guys know how it goes

Arabas · « **Reply #47 on:** May 19, 2011, 03:43:39 PM »

good luck!!! looking forward to seeing your results!!

2.0 tspeed · « **Reply #48 on:** May 20, 2011, 07:28:25 AM »

Finishing up the tune after work today

2.0 tspeed · « **Reply #49 on:** May 20, 2011, 06:13:29 PM »

tune is done boost is set at 23 psi now i just gotta fine a dyno or some cars to play with me :-D

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Author Topic: e85 tune from trifecta (Read 26008 times)