[JP374]

Hey guys, I just received my P1X kit setup for 7psi (3.9" pulley) and am looking for some insight as to being able to run full pump e85 (75% locally). I have the lt4 stuff along with a DSX aux pump. I have been told my setup will be good to around 640 wheel with the 7psi pulley before running out of fuel? I've also been told I might want to consider a 4.13" pulley to go with 5psi to be able to run full e85? I'm not so much about chasing the numbers as I am to being able to run e85. PC techs have told me I will be fine with my 7psi setup on e85. I am sure there are plenty of guys on here with results. I haven't installed the PC on the car yet just trying to make sure I have everything sorted out. The current mods I have now are Flex fuel, MSD IM, 103 tb,2" ARH system. I also have the baro breakout harness too.

Thanks guys!!

[Trochoidal]

This thread is such a good read. There’s so much to learn from cjperformance’s experience.

https://www.camaro6.com/forums/showthread.php?t=597270

[LT1ornothing]

Originally Posted by JP374

Hey guys, I just received my P1X kit setup for 7psi (3.9" pulley) and am looking for some insight as to being able to run full pump e85 (75% locally). I have the lt4 stuff along with a DSX aux pump. I have been told my setup will be good to around 640 wheel with the 7psi pulley before running out of fuel? I've also been told I might want to consider a 4.13" pulley to go with 5psi to be able to run full e85? I'm not so much about chasing the numbers as I am to being able to run e85. PC techs have told me I will be fine with my 7psi setup on e85. I am sure there are plenty of guys on here with results. I haven't installed the PC on the car yet just trying to make sure I have everything sorted out. The current mods I have now are Flex fuel, MSD IM, 103 tb,2" ARH system. Thanks guys!!

You can either run the bigger pulley 5lbs on e85 or you can blend e85 and 93 and run the smaller 3.9 pulley. It is your call.

[JP374]

Originally Posted by Trochoidal

This thread is such a good read. There’s so much to learn from cjperformance’s experience.

https://www.camaro6.com/forums/showthread.php?t=597270

Thank you, I’ve read through that a few times in the past month or so

[JP374]

Originally Posted by 1LEornothing

You can either run the bigger pulley 5lbs on e85 or you can blend e85 and 93 and run the smaller 3.9 pulley. It is your call.

Ok. So with the 7psi (3.9”) I won’t be able to run full e85? With 5psi (4.13”) I’d be able too? How much difference in power between the 2 options would it be? I guess it wouldn’t be much work if I couldn’t run e85 with 7psi to swap to the 5psi pulley. I was trying to avoid blending the fuel.

[LT1ornothing]

Originally Posted by JP374

Ok. So with the 7psi (3.9”) I won’t be able to run full e85? With 5psi (4.13”) I’d be able too? How much difference in power between the 2 options would it be? I guess it wouldn’t be much work if I couldn’t run e85 with 7psi to swap to the 5psi pulley. I was trying to avoid blending the fuel.

I'm not sure if your set up will be able to maintain and meet the fuel demands on straight e85 and the smaller pulley. Also, blending is fairly simple and causes less strain on the fuel system demands than just e85. Blended also provides most of the benefits of straight e85.

[JP374]

Thanks 1LE.

I understand there are probably too many variables. Sounds like worst case I can run 7psi and blend. Both tuners I’ve talked to seem to think I’ll be ok @ 7psi with full E. Just trying to get more input is all. Dave from DSX said about the 640 whp mark is where I’m gonna start dropping fuel psi.

[cjperformance]

I would recommend starting by blending and scanning. Watch low side and high side psi, and inj PW. My limit with LT4 high side and dsx aux is around 50 to 60% eth. With trans tune (increased shift rpm and consequently the max boost), and pushing 9.5 psi in cool weather, its around 5.5 to 5.9 ms inj pw.

My guess based on what I've observed with engine airflow lbs/min you'll see 100 hp difference at the engine between 5 psi and 7 psi.

Im close to ideal timing with 50% blend, no need for 85%.

[JP374]

Originally Posted by cjperformance

I would recommend starting by blending and scanning. Watch low side and high side psi, and inj PW. My limit with LT4 high side and dsx aux is around 50 to 60% eth. With trans tune (increased shift rpm and consequently the max boost), and pushing 9.5 psi in cool weather, its around 5.5 to 5.9 ms inj pw.

My guess based on what I've observed with engine airflow lbs/min you'll see 100 hp difference at the engine between 5 psi and 7 psi.

Im close to ideal timing with 50% blend, no need for 85%.

Ok thanks for the info!! Very informative post you started on your findings. I do have the tcm tuned. So your findings are with you running 9.5psi? I have the 3.9” pulley on mine, spec’d for 7psi at 6500 rpm from PC. Rick Clarke is who tuned it FBO, he said once the PC is on it will be close to e70 blend and may have to trim shift points back etc. I’m not opposed to dropping psi down to 5psi either. Was told by dropping psi we can add more timing etc and be able to handle pump e85. I’m just trying to learn as much as I can about it. I’m not stuck on a number but just want to utilize e85, maybe I’m looking at it all wrong idk ??

Thanks again for the help guys!

[KingLT1]

No reason to run full E85 for other then being able to fill up without mixing. Anything over E40 provides substantial gains. E50-E60 is the sweet spot. Anything above that really just puts more load on the fuel system for little gains until your making enough power to need the added octane which likely will never happen.

However to answer you question you can run E80 on this setup:

LT4 Injectors
LPE DI pump
LT4 low side/ JMS booster

With just the LT4 system you could likely run the same amount of E on 5-6psi. I would probably just run 7psi and mix the E content back to E50-60.

I was able to run whatever the E came out of the pump(normally E78-80 at my pumps) with this fuel setup on 8psi with standard rotofab, ported 95mm throttle body, cat delete pipes. Car made right around 600whp with this setup in 5th gear. Car trapped right around 131-132 in the 1/4mi with this setup.

Now I am mixing down to E40-E50(depending on outside temps) with 103mm tb, rotofab big gulp, 10psi pulley, cat deletes/ borla x pipe(deletes AFM/Crush section), same fuel system. Car trapped 136 with this setup.

When temps drop down to 50 in the fall I see 11psi and have to drop back to E38. I plan on adding XDI +30 injectors to give me a more fuel headroom back. Ideally would like to run at least E50 during cooler months when less octane is needed, and E60 in the summer.

make sure to monitor fueling in the coolest weather you plan on driving the car.

[JP374]

Thx King!

Looks like I have been overthinking this.

I’m gonna stick with the 7psi setup and see how it plays out. I’m sure at 600 whp it will be a whole new animal! The pump content by me is 74-80% so sounds like I’ll be good. I daily drive the car in the summer that’s part of the reason I was trying to keep it simple with full e85. I do know I don’t want to run any meth inj etc.

I’m in Mi so if I can get my kit installed soon then I can monitor the data while it’s still cold out and that should help the tuner to be able to get the fuel/timing data dialed in better.

I have the DSX aux kit will that help with anything vs the jms booster?

Thanks

[SHE'Z 18]

Originally Posted by JP374

Thx King!

Looks like I have been overthinking this.

I’m gonna stick with the 7psi setup and see how it plays out. I’m sure at 600 whp it will be a whole new animal! The pump content by me is 74-80% so sounds like I’ll be good. I daily drive the car in the summer that’s part of the reason I was trying to keep it simple with full e85. I do know I don’t want to run any meth inj etc.

I’m in Mi so if I can get my kit installed soon then I can monitor the data while it’s still cold out and that should help the tuner to be able to get the fuel/timing data dialed in better.

I have the DSX aux kit will that help with anything vs the jms booster?

Thanks

Generally speaking, is it better to have your car tuned in the "colder" weather versus the middle of summer? Just curious if there's any difference whatsoever? Thanks..

[cjperformance]

Not clear on the pulley size to psi ratio. Im 99% sure i have the 4.13 inch. At least thats what the parts list says. And i am getting 9.5 psi at 6800 rpm. Pretty sure i checked the actual part too. So not sure what the 3.9 = 7 psi and 4.13 = 5 psi is about. Ive always gotten 6 to 7 psi with the 4.13 inch prior to trans tune and 8 to 9.5 after.

[cjperformance]

Originally Posted by SHE'Z 18

Generally speaking, is it better to have your car tuned in the "colder" weather versus the middle of summer? Just curious if there's any difference whatsoever? Thanks..

Yes, it makes a difference. You have to tune for both. Theres different concerns. Colder weather requires more fuel, hotter weather you have to keep an eye on predetonation and timing.