Jackass w/ LS9: original build and new Jackass 2.0 updates!

[will69camaro]

That's an excellent output for the track day. Got some decent logging done.

Oil/Water temp look great for the temp and track duty. What is your prediction on the falling fuel pressure?

[Stielow]

Originally Posted by will69camaro

That's an excellent output for the track day. Got some decent logging done.

Oil/Water temp look great for the temp and track duty. What is your prediction on the falling fuel pressure?

The car voltage is staying rock solid at 13.4 volts. I think I need to add another boost a pump or go to bigger fuel pumps. I will add two channels to my data logger to look at voltage at the pumps and make sure that is not the issue.

I also need to check the calibration of the sensor. I have chased data before to find out it is a sensor.

The learning curve on the fuel system on the E-85 has been a little rough but the results on track look very good so I’m sticking with it.

On the positive side the C&R cooling stack look like they work well and the bigger intercooler bricks are also keeping the inlet air temps down.

Mark

[Muadi]

I had the opportunity to watch the runs on Monday. What a great car to watch on the track.

[will69camaro]

Originally Posted by Stielow

The car voltage is staying rock solid at 13.4 volts. I think I need to add another boost a pump or go to bigger fuel pumps. I will add two channels to my data logger to look at voltage at the pumps and make sure that is not the issue.

I also need to check the calibration of the sensor. I have chased data before to find out it is a sensor.

The learning curve on the fuel system on the E-85 has been a little rough but the results on track look very good so I’m sticking with it.

On the positive side the C&R cooling stack look like they work well and the bigger intercooler bricks are also keeping the inlet air temps down.

Mark

I really am enjoying getting some knowledge dropped on me before I start my own journey with learning E-85 and the fueling requirements of a big power plant.

Hard to see from the logs on the screen. Was the pressure dropping the entire time during the pull or did it start to catch back up (possible issues of pump reaction being a dead head setup vs a return style fuel setup)?

You said you are using E-85 from the pump correct? Your system using a GM computer so have a flex fuel sensor installed to help the tune correct for variance in the ethanol content? (believe i've seen as low as 70% from other boards on the ethanol content).

William

[hersheys69z]

Is the next Stielow Camaro in the works yet?
Crossing my fingers for twin turbo awd on Z/28 struts since Mark likes to push the engineering envelope

[CarlC]

All of the calc's should be right for E85 but the pressure is still falling during high-power application. Mark has been steadily increasing the power going to the pumps and doing some diagnostics/datalogging to see where the weakness lies. This has definately been the most challenging project to get sorted. Big power = no Easy Button.

[mikels]

Originally Posted by will69camaro

Hard to see from the logs on the screen. Was the pressure dropping the entire time during the pull or did it start to catch back up (possible issues of pump reaction being a dead head setup vs a return style fuel setup)?

You said you are using E-85 from the pump correct? Your system using a GM computer so have a flex fuel sensor installed to help the tune correct for variance in the ethanol content? (believe i've seen as low as 70% from other boards on the ethanol content).

William

We've had no issues running returnless fuel systems - even with big power / high flow - when you stage secondary pump to come in early enough to maintain stable control as fuel flow rates rise.

In Brian Thomson's Corvette, we have basically the same engine as JA2.0, but are running dual TI 267 pumps with staged Vaporworx PWM controlled system. Same E85 - same flow rate requirements. So far, has performed perfectly with no pressure falloff - although we have not yet tracked the car (coming soon!).

On both cars I integrated the flex fuel sensor to allow seemless transition between pump premium, E85 and everywhere in between. Mark even has the ECM measured ethanol percentage displayed on his dash. Yes, there is variation in ethanol %, but system accommodates all levels without issue.

Like Carl says - big power & high flow rates mean no easy solution - but we will get there!

Carl has been great to work with as development continues on Jackass 2.0 and TA Corvette systems. Having a system that will meet WOT E85 fueling requirements while delivering stable flow rates on gas @ idle WITHOUT fuel heating issues is an incredible demand. All this would not be possible without his support.

Primary reason we went to E85 was not for power, but for cooling. Power gains are just side benefit (6-8% is what we measured).

I think we have reached a practical limit for the Thomson Automotive 7.0L SC package. We've passed point of diminished returns as far as lap time reduction (will still help in 1/4 mile and standing mile events). However, as Mark can also attest - being traction limited to ~80-100 MPH is something you'll never tire of!

Dave

[wiedemab]

Originally Posted by mikels

However, as Mark can also attest - being traction limited to ~80-100 MPH is something you'll never tire of!

Dave

I don't think I've ever owned anything that would spin the tires at 100mph with bald tires on the snow! Yeeehaw!

[will69camaro]

Originally Posted by mikels

We've had no issues running returnless fuel systems - even with big power / high flow - when you stage secondary pump to come in early enough to maintain stable control as fuel flow rates rise.

In Brian Thomson's Corvette, we have basically the same engine as JA2.0, but are running dual TI 267 pumps with staged Vaporworx PWM controlled system. Same E85 - same flow rate requirements. So far, has performed perfectly with no pressure falloff - although we have not yet tracked the car (coming soon!).

On both cars I integrated the flex fuel sensor to allow seemless transition between pump premium, E85 and everywhere in between. Mark even has the ECM measured ethanol percentage displayed on his dash. Yes, there is variation in ethanol %, but system accommodates all levels without issue.

Like Carl says - big power & high flow rates mean no easy solution - but we will get there!

Carl had been great to work with as development continues on Jackass 2.0 and TA Corvette systems. Having a system that will meet WOT E85 fueling requirements while delivering stable flow rates on gas @ idle WITHOUT fuel heating issues is an incredible demand. All this would not be possible without his support.

Primary reason went to E85 was not for power, but for cooling. Power gains are just side benefit (6-8% is what we measured).

I think we have reached a practical limit for the Thomson Automotive 7.0L SC package. We've passed point of diminished returns as far as lap time reduction (will still help in 1/4 mile and standing mile events). However, as Mark can also attest - being traction limited to ~80-100 MPH is something you'll never tire of!

Dave

Carl has been excellent in my dealings with him so far as well. We discussed two CTS-V versus three when I had ordered. As plans always seem to change and the project snowballed even further, I'm going to be pushing the two more than I had originally intended.

I am very aware of the benefits on the sensor, and sadly holley has not made a compatible sensor available yet on their standalone engine management systems, but I am told they are working on it. 6-8% when you're talking 1000+rwhp cars adds up however. I'm hoping to make north of 1000rwhp on pump 93, so the benefit of E-85 with cooling as well as the benefit of resistance to pre-detonation, I'm hoping we can add timing and see more than just the 6-8% gain. I'll find out more when I get to testing and maybe by then holley will have their system of ethanol content working by then!

Looking forward to traction at 100mph issues!

William

[mikels]

Originally Posted by will69camaro

I'm hoping we can add timing and see more than just the 6-8% gain.

We are adjusting timing based on ethanol % and 6-8% is typical. I've never seen E85 gain more than that without additional airflow (in this case would be boost).

Did find higher percentages of ethanol (up to 85%) to be very knock resistant - when trying to hook the spark curve on dyno, would reach point where additional timing made no more power - but still did not generate knock. On pump gas typically start running into knock issues simultaneously with power gains flattening out - if not before (this on high cylinder pressure engine).

You are correct though that while 6-8% may not sound like much, when added to numbers in the mid 900's, it's quite a bit!

All numbers I quote are engine dyno as well - 1000 RWHP is a staggering number - and nearly impossible to achieve while maintaining the driveability level we have with this package.

Dave