Data Log Readers-Some insights please

[stkjock]

Gent

Attached are the logs of two dyno pulls made with the Shelby. Things look good to me in my very amateur review, any insights are appreciated as to how they look.

 

[lito]

Looks good,

- return fuel sys right? drop is unusually big for me but I am not used to those levels of flow, it should be expected tough.
- Do you have the AFR? with gas stoich reference you maybe running in the high 10s I guess (if my guessing still works).

Jon is going to beat you with a hammer if you keep asking around about his work, lol.

 

[stkjock]

Thanks Manuel

Yes return style, Fore triple pump system - what drop are you referring too?

The a/f was not logged on the SCT, it was on the dyno and it was a solid 11.2-11.4 on a gas scale from 3000-6700

not questioning the tune, I have 100% confidence in it, but how the motor is using it, I put it on the dyno just to check all out since it's been a year since I got it back and I turned it up some since I did. better safe then sorry IMO

 

[lito]

Just kidding with you.

Drop is normal in a return system, it is somehow proportional to flow so it is expected to be higher than what I am used to see. See in the log the read fuel pressure, while you are idling it is around 46delta, at the end of the run is close to 36-37, that is what I was talking about. As long as table are set right (and I am absolutely sure they are) and enough injectors at that deltaP (as shown with DC and AFR) you are good.

AFR was measured in the tail, right?

 

[stkjock]

Just kidding with you.

OK, Cool,

Drop is normal in a return system, it is somehow proportional to flow so it is expected to be higher than what I am used to see. See in the log the read fuel pressure, while you are idling it is around 46delta, at the end of the run is close to 36-37, that is what I was talking about. As long as table are set right (and I am absolutely sure they are) and enough injectors at that deltaP (as shown with DC and AFR) you are good.

gotcha, thanks for the explanation

AFR was measured in the tail, right?

yes tail pipe sniffer

 

[dysan]

How the heck are your IAT's that damn low!!!! 74 degrees at the end of the pulls is just crazy. I know you're running E85 but I thought that wouldn't show up in the IAT's since it's injected right into the heads and not picked up by the IAT sensor.

 

[lito]

James, look at downstream data, GT500 has to air temp sensors, the one in 74 is in the MAF, the ACT2 is the downstream.

 

[stkjock]

How the heck are your IAT's that damn low!!!! 74 degrees at the end of the pulls is just crazy. I know you're running E85 but I thought that wouldn't show up in the IAT's since it's injected right into the heads and not picked up by the IAT sensor.

James, look at downstream data, GT500 has to air temp sensors, the one in 74 is in the MAF, the ACT2 is the downstream.

/\ this

if you look at the downstream it never rises above 116*

 

[dysan]

That's still amazing.

Sorry to clutter up your thread.

/END-HIJACK/

 

[BruceH]

Gent

Attached are the logs of two dyno pulls made with the Shelby. Things look good to me in my very amateur review, any insights are appreciated as to how they look.

I'm not exactly an expert or anything but I noticed your fuel trims are off. The ecu is adding fuel in closed loop. Could be the maf xfer and it could be the blend of your local e85. Have you tested it lately and do you know what stoich the tune uses?

That's still amazing.

Sorry to clutter up your thread.

/END-HIJACK/

Whipples are usually in the 11x range at wot. At least mine was and so is anyone I've asked who monitored it.

 

[lito]

I'm not exactly an expert or anything but I noticed your fuel trims are off. The ecu is adding fuel in closed loop. Could be the maf xfer and it could be the blend of your local e85. Have you tested it lately and do you know what stoich the tune uses?

Apart from an unknown stoich value of current fuel used there are also differences induced with the cams and a disbalanced generated by bypass working.

 

[BruceH]

Apart from an unknown stoich value of current fuel used there are also differences induced with the cams and a disbalanced generated by bypass working.

Just thought of another one that happened to me recently while on the dyno. A cooling fan was blowing some of it's air on the air filter with some of that air reaching the maf, causing the trims to get a little screwy.

 

[dysan]

I've often wondered if my cervinis ram air hood ever causes any small issues like that. It's ducted right on top of the cone air filter so I'm sure something is happening at high speeds. Maybe one of these days I'll take the ducting piece out and just let it blow the air across the top of the engine and maybe that will help cool the blower's casing off a little.

 

[stkjock]

That's still amazing.

Sorry to clutter up your thread.
All good James
/END-HIJACK/

I'm not exactly an expert or anything but I noticed your fuel trims are off. The ecu is adding fuel in closed loop. Could be the maf xfer and it could be the blend of your local e85. Have you tested it lately and do you know what stoich the tune uses?t.

Last 2x I checked it was 85-87% area

IDK the sotich, I'd guess the E85 of 9.76 as it was tuned on 85

Just thought of another one that happened to me recently while on the dyno. A cooling fan was blowing some of it's air on the air filter with some of that air reaching the maf, causing the trims to get a little screwy.

There were two fans blowing on the car.

 

[stkjock]

Ok, so the stoich used in the tune is 9.85 as that is standard for pump E85. +/- 3% and it's fine. if the fuel were to test above 92% Ethanol then the tune would need adjustment. (paraphrased from Mr. Lund)