Why is the fuel gauge off after injectors and E85? Is the fuel level based on calculated usage or something? No sending unit in the gas tank? Seems odd.

I can see the calculated mileage left being off. But the fuel level should be correct.


Or am I way off here? haha I'm concerned as I am about to install ID1300 injectors and run E85. lol

 

Like Sam says it's a known issue from the factory with our cars not sure if it's just for .1 's or also .2's but even a stock car with zero mods ,try run your gas to almost empty then put in 5 gallons of gas it won't even register on the fuel gauge ,you have to put in ar least 6 to 7 gallons for the needle to move off of empty .
Something to do with a fuel tank with a hump in it & the sending unit is in one side of the hump,so after it gets past the hump it's all a calculation guess .Ive ran out when the computer says I have 110 miles left to empty ,it's just amplified once you run E85 ,I've had all the updates .Dont don't let that stop you I've been running E85 hard for at least 7 yrs & 40,000 +miles with no issues,the pros out weight the cons by a long shot .

 

So the tank has a sending unit and it shows the fuel level no matter what? If so I'm good. I don't really look at the "mileage until empty" in cars anyways.


*edit* didn't see twturbo's post when mine went up. I just saw it now. Kind of crazy that they could be that far off with 100 miles showing till empty. I also have owned a few cars with the gas tanks on both sides of a trans hump. Most have not been that bad.

I won't let it deter me from using E85. I have been using E85 since early on in projects. I was familiar with methanol back in the late 90's. E85 was a nice option when it because more popular. So ya, I am an E85 junky. haha

 

I agree, don't let that hold you back. Just becomes a little nuisance when your changing out from E85 back to pump gas or vice versus. At the track I run 93 pump gas with splash of 100 octane mixed. Then once done with the track, run it back down just past quarter of a tank, then fill up with E85.

 

No, this is not a "known issue". These cars have a level sending unit that has a certain calibration and it can work until to a certain point / level of fuel. From that point on the remaining fuel is calculated based on the injector opening times and resulting fuel amount per time unit.

By changing the injectors one must take care for the different conditions and adjust the values for the injector - it's more than one.

I can say that the fuel level display in the dash can be calibrated to OEM standards independent of the injector size in use and 996 or 997 are only a little different. The type of fuel you run is irrelevant.

 

+1 The "fuel level estimation" can be fixed/adjusted even with upgraded injectors.

 

I was just perusing this thread again and I have to say this is one of the best technical threads we've had on here in quite some time. Lots of REALLY excellent discussion and data. Big thanks to M3, Sam, and the others in this thread that keep me coming back to read more.

 

By way of update I am running on the corn now and the car is an animal

I am now realizing what a RWD Porsche that wants to have the rear end come around the front end feels like

The AWD system is totally overloaded and next to useless at this power level

If I leave the traction control on the light is blinking in 2nd and 3rd gear a lot

If I turn traction control off the car goes crazy fast in a straight line but gets really a handful in a corner - will take some getting used to

Frankly - it is a very fast street car now

I think that I have some work to do with Sam to dial in the fuel dash reading as it is way off and a few other things but generally his tuning is really amazing - cautious and his customer service is world class

I am totally satisfied with my investment of funds into this project - it has transformed the car into a monster while keeping 99% of its stock like start up - idle - and driveability

Totally satisfied

I am hoping to send a recent data log to Mr. M3 to see if he can run a virtual dyno for me and see how much power we are at now - my butt dyno is saying 650 whp at 22 psi peak

 

Sam - I would not dispute you on the 700 whp estimate - however I always like to estimate on the low side until I have actual data in front of me

If anyone has a similar car I am drawing 540 grams of air through my maf at this point and we are not done with the tuning if that is any help

All I can say with 100% certainly is I have very fresh Pilot Super Sport tires and it is in the high 70's and 80's here and it takes a lot of power to bust those massive rear tires loose clean in 3rd gear going straight down the highway

The car is starting to act like a high powered Z06 with a cam and a tune - not like a AWD Porsche

To me this means we are making big power

I think some suspension mods are next in line as you have suggested

 

08957 I knew you would be pleasantly surprised

Looking forward to data crunching as always

 

@Sam this certainly isn't helping me stay content with my stock turbo's. This thread may of just cost me some money.

i have really enjoyed working on the car so far, but it maybe time for some surgery before our baby is due in September.

 

thanks to M3 Maestro for your guidance and support

Here is the dyno sheet for evaluation of the spool up and power gains

Keep in mind the tuning is not done yet and I am still running cats and 2.5" exhaust tips

 

No problem anytime. Remember to get me the tire model you are running, how much you weigh lol, and the ambient conditions for the next run as you guys dial it in. All these things affect the results. Also try your best to have a level road no incline.

Enjoy!

 

I am running 19" stock size Pilot Super Sport

80 degrees ambient temp

I am a bit on the heavy side 240 pounds with clothes and car has a full tank of E85 (don't want to run out of gas again or attract any water)

Thank you Sir

 

I guess my butt dyno is reading a bit low but the car is so smooth it is hard to feel any "spot" where the power is so strong it is like a giant wave of power that is smooth and steady to red line - very good tuning

The dyno sheet is very reflective of the way the car feels - smooth

I am surprised to see that it is making this kind of power but Mr. M3 assures me that my 60 - 100 mph numbers bear out the power reading

I am a responsible guy with a lot to loose and I live in a very congested area so I sadly can not do any of those 130 mph runs until I take it to the drag strip which will be soon after Sam is done with the tuning

It is interesting to note that Sam is not done tuning and he also feels that I am able to pick up another 30 - 50 whp by dropping the cats - 800 whp would be impressive on such small and fast spooling turbos

I am very pleased with the results

Best part is that until I get on the boost there is no way to know that the car has been modified - it starts up idles and drives just like stock - I will state that getting on the loud pedal will scare the **** out of 99% of females out there. I already had one tell me I was a f'ing lunatic and to never do that again - guess I need a new driving companion