Page 1 of 1

Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 1:10 pm
by GT-B Spec R Pilot
More of a general question, with the higher mass flow rate of e85 compared to 98RON petrol, what increase in the injector duty cycle would you expect to see on an otherwise stock engine? Is there a basic rule of thumb that can be applied across modified as well as stock engines??

I am considering running pump e85 in my vehicle. Mod wise i have fitted a c.a.i, GFB b.o.v. (100% plum back) and 3" turbo back exhaust otherwise the engine is stock. A higher flow fuel pump and tune to suit are definite but I am not sure the stock injectors will flow enough with the mods I have already done if I change to e85. If my understanding is correct, then the c.a.i. with the stock turbo will pump more air than stock injectors can flow fuel for (and stay within safe air/fuel ratio range). If this is the case then a change to 850 or 1000cc injectors is also required.

Cheers

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 1:36 pm
by kiahatsiu
Sorry for the short reply, but you will need bigger injectors and a bigger pump. Rule of thumb is to scale up fueling by 30%. Run some id1000s and a 265lph pump and you will be fine on e85 with your mods.

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 2:04 pm
by GT-B Spec R Pilot
kiahatsiu wrote:Sorry for the short reply, but you will need bigger injectors and a bigger pump. Rule of thumb is to scale up fueling by 30%. Run some id1000s and a 265lph pump and you will be fine on e85 with your mods.


Thanks. I was actually looking at the ID 2000's to leave a bit of headroom in case i decide to go with the Blouch 380xt (or similar) turbo upgrade.

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 2:37 pm
by jacks-GTB
GT-B Spec R Pilot wrote:
kiahatsiu wrote:Sorry for the short reply, but you will need bigger injectors and a bigger pump. Rule of thumb is to scale up fueling by 30%. Run some id1000s and a 265lph pump and you will be fine on e85 with your mods.


Thanks. I was actually looking at the ID 2000's to leave a bit of headroom in case i decide to go with the Blouch 380xt (or similar) turbo upgrade.


i've seen 1.5xtr on e85 with id1000 and duty cycle at 92% IDC....i wouldn't go ID2000...i would go 1300's instead 2000's.....but stick with 1000's....they'll do fine... and the pump will be fine....I sell a 265lhp E85 compatible drop in pump....PM me if your interested :)

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 3:37 pm
by KiDo_Tuning
VF46 is possible on stock injectors. 11.6 AFR results in 91% IDC at 6400rpm holding 14.7psi.

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 4:23 pm
by GT-B Spec R Pilot
KiDo_Tuning wrote:VF46 is possible on stock injectors. 11.6 AFR results in 91% IDC at 6400rpm holding 14.7psi.


On 98 or e85? I pretty much anticipated an injector upgrade, i just didn't know how much larger i need to go and I didn't want to upgrade now only to find out I have to upgrade again if I decide to go down the turbo upgrade path later on...

Re: Pump e85 & injector duty cycle.

PostPosted: Mon Sep 09, 2013 8:48 pm
by KiDo_Tuning
GT-B Spec R Pilot wrote:
KiDo_Tuning wrote:VF46 is possible on stock injectors. 11.6 AFR results in 91% IDC at 6400rpm holding 14.7psi.


On 98 or e85? I pretty much anticipated an injector upgrade, i just didn't know how much larger i need to go and I didn't want to upgrade now only to find out I have to upgrade again if I decide to go down the turbo upgrade path later on...


E85 is 91%

Most tuned P98 VF46's are around 70% IDC at 13psi up top with 10.8:1 AFR's to reach around 170Kw@wheels

E85 requires around 30% more fuel so 70% x 1.30 which becomes 91% BUT your running more boost and leaner AFR's.

ID1000's are fine as an upgrade as they flow 82% more fuel than stock injectors :)