[MMsport335]

So I know all the details of details of Cobb vs Jb4 with all the goodies but there doesn't seem to be a very good direct comparison of stock cars with 91 octane gas in them. I've searched for Dyno results but I didn't find any apples to apples.


I'm thinking JB4 Map 1 (or map 5) vs Cobb Stage 1 Sport. I know what I would want if I was mixing 93 or Meth every day but here in CO day-to-day I will be just 91 octane with an intake.

Does anyone have experience with this?

[Johnny Boost]

Originally Posted by MMsport335

So I know all the details of details of Cobb vs Jb4 with all the goodies but there doesn't seem to be a very good direct comparison of stock cars with 91 octane gas in them. I've searched for Dyno results but I didn't find any apples to apples.


I'm thinking JB4 Map 1 (or map 5) vs Cobb Stage 1 Sport. I know what I would want if I was mixing 93 or Meth every day but here in CO day-to-day I will be just 91 octane with an intake.

Does anyone have experience with this?

Do you have access to ethanol?

[MMsport335]

Not really, at least not for every day driving. Plus I would need a DP at that point, wouldn't I?

[Johnny Boost]

No not necessarily. IMO map 1 and stage 1 sport will both be small increases in power but you can't go wrong either way. What are your plans for future mods?

[JBird..]

I can tell you from having both that the JB4 Map 1 gains are much stronger than that of the Cobb Sport Stage 1 Map.

[FriedPiston]

Cobb is definitely more conservative than JB4. You'd need at least an e-tune to keep up with a JB4 stage 2 on 50% e-85...

I'm at Sonoma raceway right now. Seems like best time for a Cobb Stage 2+ Aggressive on 50% 100 octane is around 12.9 second 1/4 mile

[MMsport335]

Thanks, guys. jczepf96, exactly what I was looking to hear!

Anything I put on will either benign or removable until my CPO is up. So jb4, intake, suspension and spacers, maybe fmic. When I have a tune I might add some meth every once in a while just to mess with my friends and his new Ghibli.

[Johnny Boost]

Originally Posted by narstune

Cobb is definitely more conservative than JB4. You'd need at least an e-tune to keep up with a JB4 stage 2 on 50% e-85...

I'm at Sonoma raceway right now. Seems like best time for a Cobb Stage 2+ Aggressive on 50% 100 octane is around 12.9 second 1/4 mile

He said he probably wont be running ethanol.

[MMsport335]

So I'm intrigued. I did some E85 research and I can get it all over town and dirt cheap. So with a Jb4 and flex fuel wires I can be running this with a mixture of 91 octane? That would allow me to run a more aggressive map or at least map5 and get all the bang for my buck?

Does anyone run this day after day?


Also, I've read that you can run more aggressive maps (like map2) with straight 91 octane at altitude as if it was 93. Is there any truth to that? The science/math is there but I have a suspicion that it doesn't work out that nice in the real world.

[JBird..]

I do not know about the altitude and 91, but it would seem to make sense. When the warmer weather is here in NY I run a 93 and E85 mix everyday and have not had one issue. I would however invest in a CP for you car because Map 1 you will run around 12-14psi but with E85 and Map 5 you could peak at almost 18. The stock chargepipe won't last long at that boost level.

[MMsport335]

Okay, looks like ISO JB4 for me then eventually a DP, charge pipe and e85. It seems that running E85 without the two is just asking for something to break.

One more thought, it seems these cars with JB4 and FBO with 50/50 pump/E85 are producing 425 ft lbs of torque (give or take) at the wheels meaning your pumping something in the range of 500 at the flywheel. To me that's an insane number, have other issues started to present themselves?