MPX/E85 Dyno Results.

[David Neibert]

Originally Posted by qc89SC

you are on the stock injector? wish ill get similar numbers with my mpx clone!!! will have almost the same mods that you have on a freshly rebuilt engine

He has 80# injectors.

http://www.sccoa.com/forums/showpost...6&postcount=21

David

[Mike8675309]

Originally Posted by Tedor

Sweet, what duty cycle did you get with the 80lb injectors and 255lph pump? Maybe planning on running mine on E85 too

It is more a relation to the engine, and tune. I can tell you that on my motor, the 255lph high pressure pump and stock fuel lines are not enough for 80lb/hr injectors and E85. (I was at over 120% duty cycle due to lack of fuel pressure) Others may not see such an issue.

[90blkbrd]

Originally Posted by Mike8675309

It is more a relation to the engine, and tune. I can tell you that on my motor, the 255lph high pressure pump and stock fuel lines are not enough for 80lb/hr injectors and E85. (I was at over 120% duty cycle due to lack of fuel pressure) Others may not see such an issue.

I forget what is that with or without methanol?

[Tedor]

Originally Posted by Mike8675309

It is more a relation to the engine, and tune. I can tell you that on my motor, the 255lph high pressure pump and stock fuel lines are not enough for 80lb/hr injectors and E85. (I was at over 120% duty cycle due to lack of fuel pressure) Others may not see such an issue.

Yes I know, but you have more rwhp than him, just wonder what duty cycle he had on his setup and power.

[92bird]

I can tell you that on my motor, the 255lph high pressure pump and stock fuel lines are not enough for 80lb/hr injectors and E85. (I was at over 120% duty cycle due to lack of fuel pressure) Others may not see such an issue.

Are you sure it was the lines and not the pump?

I wonder how you would have faired with an Aeromotive 340lph pump and stock lines? I know a proper tune on E85 is fuel hungry. My experience is not with SC's yet, but with GM 3.8L supercharged motors (GTP, Regal GS, etc). It requires about 30-35% more fuel at the same AFR as gas. But to make the best power, you need to be around .78 lambda (low 11's on a gasoline calibrated wideband), which eats up even more fuel. On a low boost or well intercooled setup you can go leaner, but on a high boost or non/under-intercooled setup, you gotta run it fat to see the biggest gains. Either way it won't knock, due to the octane, but leaner isn't necesssarily more power like gasoline. After all, the fuel is acting as your intercooler. I'm going to experiment with E100 on my GTP this year. Should be fun!

Jeramie

[Mike8675309]

Originally Posted by 92bird

Are you sure it was the lines and not the pump?

When running on 92 octane pump gas, I only had done street tuning and didn't log fuel pressure or do a dyno run. But, I know that my wide band and data logging did not indicate an issue with high rpm, high boost runs with injectors duty or o2 levels. When I switched to E85, and tuned on the dyno, I found these issues.

Neither the pump nor the fuel lines were sufficient. I data log fuel pressure and with logged 12 v to the fuel pump (directly powered by the battery through a relay) , 19psi of manifold pressure at 5300 rpm (nearly 1000 rpm below my comfortable rpm point). In theory, that should give me 39+19 psi or 58psi at the rail for fuel pressure. What I actually saw was more like 36psi of fuel pressure at the rail. I verified the fuel pressure regulator was operating properly. (AFR got as high as 13.1"gas" though target was 11.2)

I will be cutting my old lines open when I replace them to look for any signs of problems that might explain the issues I had. Though in general I believe for my application, i need larger fuel lines. Work for the spring.

[Super Duper Cou]

Originally Posted by Tedor

Sweet, what duty cycle did you get with the 80lb injectors and 255lph pump? Maybe planning on running mine on E85 too

I'm not sure what duty cycle the injectors are running at. I was wondering that too and forgot to ask him! My car is getting a little belt slip with the scp pulleys but I'm going to buy the 10rib magnum powers pulley set here real soon when I get my tax money back.

The track opens up here in the next couple of weeks. I can't wait to see what this thing can do.

[92bird]

Keep us updated bro. Excited to see your results.

That thing must be a tire fryer on the street!

Jeramie

[Super Duper Cou]

Originally Posted by 92bird

Keep us updated bro. Excited to see your results.

That thing must be a tire fryer on the street!

Jeramie

Thanks man, will do.

It burns the tires all the way through first gear and halfway through second on the street with 225 street tires! lol

[fturner]

By my calculations, running at 30% OD on the MPX, it is going to fall on its face at around 4200 rpm and become a huge heat pump and not move anymore air, and thats on a motor that can actually breath.

The rpm you saw the fall off at is to be expected because of the blower inlet plenum and the amount of back pressure the blower itself will be seeing right at the top, which would be in the neighbour hood of around 25psi or more with temperatures of 400+F, simply because the motor itself can't take the air the blower is putting out.

I don't think your car would do very well at the track because of traction issues with that much power down low, and the car falling over on its face because of heat etc.

Nice numbers though .

Fraser

[Super Duper Cou]

Originally Posted by fturner

By my calculations, running at 30% OD on the MPX, it is going to fall on its face at around 4200 rpm and become a huge heat pump and not move anymore air, and thats on a motor that can actually breath.

The rpm you saw the fall off at is to be expected because of the blower inlet plenum and the amount of back pressure the blower itself will be seeing right at the top, which would be in the neighbour hood of around 25psi or more with temperatures of 400+F, simply because the motor itself can't take the air the blower is putting out.

I don't think your car would do very well at the track because of traction issues with that much power down low, and the car falling over on its face because of heat etc.

Nice numbers though .

Fraser

Haha thanks man. We'll just have to wait and see I guess...

[JT's03]

Good numbers for an unopened engine. Have you had it back to the track yet?

[Super Duper Cou]

Originally Posted by JT's03

Good numbers for an unopened engine. Have you had it back to the track yet?

I haven't had it at the track yet. I want to get some 10rib pulleys on my car before I take it back to the track because it's getting some belt slip with the pulleys i have on now. I'll be sure to post my track results on here when the time comes which is hopefully soon!